FIThydrowiki - User contributions [en]

Main Page

2023-03-27T15:08:57Z

Bendikhansen:

[[file:fithydrologo_large.png|thumb|300px]][[file:Flag_of_Europe.png|thumb|300px]]
=The FIThydro project=
FIThydro addresses the decision support in commissioning and operating hydropower plants (HPP) by use of existing and innovative technologies. It concentrates on mitigation measures and strategies to develop cost-efficient environmental solutions and on strategies to avoid individual fish damage and enhancing population developments. Therefore HPPs all over Europe are involved as test sites.

=Hydropower and fish: challenges=
Hydropower is a very site-specific technology developed where the topography and hydrology are favorable. All hydropower plants require construction of a dam or weir, generally obstructing fish movements. Habitat are altered by imposed changes in flow and/or sediment transport and the set of impacts can be inter-related. The magnitude of the changes in flow is to a large degree determined by the size of the reservoir, making it possible to store water from period of abundant resources to periods of lower inflow. Biology and composition of the fish population is, however, unique to each site. As such, the environmental problems and the related measures are also very specific to each location, posing challenges to presenting generic measures viable to all possible sites, and often the solution will be a combination of measures.

In general, hydropower [[:category:types of problems|impacts]] on fish are divided into five categories on this wiki. Each of these challenges are briefly described, and then a catalogue of potential mitigation measures are presented.

#[[Habitat]]
#[[Environmental flow]]
#[[Sediments]]
#[[Downstream fish migration]]
#[[Upstream fish migration]]

Habitat impacts can be caused directly by alterations in the river, such as flood banks or channeling, or indirectly through alterations in the flow/sediment regime. Environmental flow impacts are related to changes in the flow regime in the river, such as low flows, floods, and average flow. Changes here can directly impact migration patterns, as well as indirectly impact habitat conditions (e.g. sediment clogging, armoring). Sediment impacts can be caused by alterations to the sediment balance in the system, such as surplus or deficit of sediments (once again leading to clogging or armoring). Upstream and downstream migration are related to the physical barrier that fish encounter when a dam (and turbine) is built, which can be a challenge for migratory species.

=What is the FIThydro wiki and how do I use it?=
This wiki was created to help users implement the appropriate [[:category:solutions|solutions/mitigation measures]] for environmental challenges caused by hydropower production. The mitigation measures are classified according to various [[Classification table|parameters]], such as appropriate climatic regions, which species they are aimed at, which physical condition they address, etc. Each measure has a suggested procedure with recommended [[Methods,_tools,_and_devices|methods, tools, and devices]] for different stages of the implementation. A number of [[:category:test cases|test cases]] are also presented, with links to applied and relevant solutions, methods, tools and devices. Additionally, information about studies on [[Policy and public acceptance]] and estimates of [[Costs of solutions|the cost of implementing mitigation measures]] are presented. Lastly, a [[Decision_support_system|Decision Support System]] (DSS) for selecting appropriate mitigation measures has been developed. The DSS synergizes with this wiki.

[[file:wiki_overview.png|600px|center]]

=Categories of mitigation measures=

Click the image to go to the main article for each category. The mitigation measures for each category are listed in the drop-down menus, as well as in the main articles.

<gallery widths=250px heights=250px>
Habitat icon.png|link=[[Habitat]]|[[:file:Habitat icon.png|Photo]]: Ulrich Pulg<categorytree mode="pages" depth=0 namespaces="Main Category">Habitat measures</categorytree>
E-flow_square.png|link=[[Environmental flow]]|[[:file:E-flow_square.png|Photo]]: Atle Harby<categorytree mode="pages" depth=0 namespaces="Main Category">Environmental flow measures</categorytree>
sediments_icon.png||link=[[Sediments]]|[[:file:sediments_icon.png|Photo]]: NASA<categorytree mode="pages" depth=0 namespaces="Main Category">Sediment measures</categorytree>
downstream_icon.png|link=[[Downstream fish migration]]|[[:file:downstream_icon.png|Photo]]: Tore Wiers<categorytree mode="pages" depth=0 namespaces="Main Category">Downstream fish migration measures</categorytree>
upstream_icon.png|link=[[Upstream fish migration]]|[[:file:upstream_icon.png|Photo]]: Jerome Charaoui<categorytree mode="pages" depth=0 namespaces="Main Category">Upstream fish migration measures</categorytree>
</gallery>

Template:Fact box for Bannwil

2021-06-08T14:05:21Z

Bendikhansen:

{| class="wikitable" style="float:right;width:350px;"
! colspan="2" style="text-align: center;background-color:#2cb4da; color:#ffffff;" | Fact box: Bannwil
|-
| Country
| Switzerland
|-
| River
| Aare
|-
| Operator
| BKW Energie AG
|-
| Capacity
| 28.5 MW
|-
| Head
| 5.5 - 8.5 m
|-
| Inter-annual discharge
| 268 m3/s
|-
| Turbine(s)
| 3 Bulb turbines
|-
| Detailed report
|[[:file:Test case presentation Bannwil HPP.pdf|Click for pdf]]
|}

Template:Fact box for Bannwil

2021-06-08T14:04:27Z

Bendikhansen:

Bannwil test case

2021-06-08T14:03:55Z

Bendikhansen:

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (''Salmo salar'') rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

===Downstream migration===
There is no specific measures implemented at HPP Bannwil. Fish can pass through the turbines and/or over the weirs when they are in operation. Weir discharge occurs on average (1935-2015) for about 42 days per year.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

The results of the studies on downstream fish migration at HPP Bannwil indicate that no fish injury is expected during fish spillway passage since fish terminal velocity is higher than the weir velocity. However, due to back-roll in the stilling basin of spillway, fish might be exposed to increased predation or strike to baffle blocks. Numerical model results also indicate that hydraulic conditions at potential positions of a fish guidance structure in front of the turbines are unfavorable.

Analysis of the Biological Performance Assessment (BioPA) based on the CFD simulation of the turbines indicate that the average fish friendliness scores of the HPP Bannwil are 9.1 and 8.5 out of 10 at an acclimation depth of 5 m and 10 m, respectively. The former i.e. 5 m is more realistic for the HPP regarding the depth of the river. For an absolute fish survival rating, this factor plays an important role.

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2021-06-08T14:03:44Z

Bendikhansen:

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (''Salmo salar'') rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

===Downstream migration===
There is no specific measures implemented at HPP Bannwil. Fish can pass through the turbines and/or over the weirs when they are in operation. Weir discharge occurs on average (1935-2015) for about 42 days per year.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

The results of the studies on downstream fish migration at HPP Bannwil indicate that no fish injury is expected during fish spillway passage since fish terminal velocity is higher than the weir velocity. However, due to back-roll in the stilling basin of spillway, fish might be exposed to increased predation or strike to baffle blocks. Numerical model results also indicate that hydraulic conditions at potential positions of a fish guidance structure in front of the turbines are unfavorable.

Analysis of the Biological Performance Assessment (BioPA) based on the CFD simulation of the turbines indicate that the average fish friendliness scores of the HPP Bannwil are 9.1 and 8.5 out of 10 at an acclimation depth of 5 m and 10 m, respectively. The former i.e. 5 m is more realistic for the HPP regarding the depth of the river. For an absolute fish survival rating, this factor plays an important role.

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Agent based model

2021-06-08T12:20:09Z

Bendikhansen: /* Quick summary */

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:ABM_results_1.png|thumb|250px|Figure 1: Result of CASiMiR-Migration illustrating migration corridor suitability and predicted path for grayling]]
[[file:ABM_results_2.png|thumb|250px|Figure 2: Migration model results for barbel at 40 m³/s with additional flow releasen of 1 and 3 m³/s from the fish pass entrance: migration suitability barbel at dotation 1 m³/s (left top) and 3 m³/s (right top), migration path barbel at dotation 1 m³/s (left bottom), path barbel at dotation 3 m³/s (right bottom), fish pass entrance area marked with red and white rectangles]]

Date: Development of current version started in 2017.

Developed by: SJE Ecohydraulic Engineering GmbH

Type: [[:Category:Tools|Tool]]

=Introduction=
The agent-based model CASiMiR-Migration for attraction flow assessment is a module of the fish habitat simulation system [[CASiMiR]] (Noack et al. 2014, Schneider et al. 2016). The model is designed to mimic fish movements in the environment of upstream migration fish pass outlets. It is implemented as a combination of habitat suitability model and agent-based model. The tool uses knowledge on hydraulic preferences of fish in the period before entering a fish pass, on etho-hydraulic thresholds for flow velocities and on the searching behaviour of individual fish. It is the progression of a first model version based purely on flow velocity vectors (Kopecki et al. 2014, 2016).

The knowledge processed in this extended model version in terms of fuzzy-rule systems has been gained by field data (fish tracks), expert judgement and literature. The application of the model is aiming at the assessment of probability for fish being routed into the lower end of fishways. An outcome of this assessment is, that the fishway design can be adaptively improved focussing on the entrance position and geometry in conjunction with the amount and orientation of the prescribed attraction flow.
=Application=
The model can be used for the investigation of different locations and designs of fish pass outlets as well as for different release flows. Basis for the model application is a 2D or 3D hydrodynamic model providing information on the spatial distribution of water depth and flow velocity. Habitat suitability (migration corridor suitability) is calculated, and fish agents are placed in the model. Following behavioural rules that integrate habitat suitability, flow velocity magnitude and direction, swim direction and random behaviour the fish agents generate tracks that either lead them to the fish pass entrance or not. Depending on the percentage of agents finding the fish pass the attraction flow is rated. Running the model for different scenarios of the fish pass location and design as well as morphological and hydraulic variants the planning can be optimized, or the functionality of existing system can be assessed.

CASiMiR migration has been developed and applied in the FIThydro test case [[Altusried test case|Altusried]] at river Iller. Figure 2 shows the application of the model for two different release from the fish pass entrance area. First results seem to indicate that higher flow releases in the fishpass outlet area do not significantly improve attraction flow for barbel that approach from the downstream central part of the river. Another first impression the results give is that an increased flow in the river, i.e. a smaller relative flow release from the fish pass is not necessarily negative for the attraction. However, the number of scenarios modelled has to be increased and the evaluation of the database is ongoing.

=Relevant mitigation measures and test cases=
{{Suitable measures for Agent based model}}

=Other information=
The model is not yet available for third parties but is intended to be made accessible in a licensed version in future under http://www.casimir-software.de, where current demo versions of other CASiMiR-modules are available for download

=Relevant literature=
*Kopecki, I., Tuhtan, J., Schneider, M., Ortlepp, J., Thonhauser, S., Schletterer, M. (2014): Assessing Fishway Attraction Flows Using an Ethohyraulic Approach. 3rd IAHR Europe Congress, Porto, April 14-16.
*Kopecki, I., Schneider, M., Tuhtan, J., Ortlepp, J., Thonhauser, S., Schletterer, M. (2016): Attraction flow at upstream migration facilities: Assessment and optimization via etho-hydraulic modelling (in German). WasserWirtschaft, 2016/10, 37-42.
*Noack, M., Schneider, M. and Wieprecht, S. (2013): The Habitat Modelling System CASiMiR: A Multivariate Fuzzy Approach and its Applications; in Ecohydraulics: An Integrated Approach, Chapter 6 (75-93); Editors I. Maddock, A. Harby, P. Kemp, P. Wood, John Wiley & Sons Ltd
*Schneider, M., Kopecki, I., Tuhtan, J., Sauterleute, J., Zinke, P., Bakken, T., Zakowski, T., Merigoux, S. (2016): A Fuzzy Rule-based Model for the Assessment of Macrobenthic Habitats under Hydropeaking Impact. River Research and Applications, 1467-1535

=Contact information=
Information on CASiMiR software:

http://www.casimir-software.de

Developer and seller:

SJE Ecohydraulic Engineering GmbH, Viereichenweg 12, 70569 Stuttgart, Tel. +49 711 677-3435, mailbox@sjeweb.de, www.sjeweb.de

[[Category:Tools]] [[Category:developed in FIThydro]]

Agent based model

2021-06-08T12:19:48Z

Bendikhansen: /* Quick summary */

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:ABM_results_1.png|thumb|250px|Figure 1: Result of CASiMiR-Migration illustrating migration corridor suitability and predicted path for grayling]]
[[file:ABM_results_2.png|thumb|250px|Figure 2: Migration model results for barbel at 40 m³/s with additional flow releasen of 1 and 3 m³/s from the fish pass entrance: migration suitability barbel at dotation 1 m³/s (left top) and 3 m³/s (right top), migration path barbel at dotation 1 m³/s (left bottom), path barbel at dotation 3 m³/s (right bottom), fish pass entrance area marked with red and white rectangles]]

Date: Development of current version started in 2017.

Developed by: SJE Ecohydraulic Engineering GmbH

Type: [[:Category:Tools|Tool]]

{| class="wikitable" style="width:350px; float:right; clear:right; margin-left:10px"
! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant solutions !! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;"|Applied in test case?
|-
|[[Mitigating reduced annual flow and low flow measures]]||Yes
|-
|[[Mitigating reduced flood peaks, magnitudes, and frequency]]||Yes
|-
|[[Nature-like fishways]]||Yes
|-
|[[Placement of dead wood and debris]]||Yes
|-
|[[Placement of spawning gravel in the river]]||Yes
|-
|[[Placement of stones in the river]]||Yes
|-
! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant MTDs !! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;"|Applied in test case?
|-
|[[3D sensorless, ultrasound fish tracking]]||-
|-
|[[Acoustic Doppler current profiler (ADCP)]]||-
|-
|[[Acoustic Doppler velocimetry (ADV)]]||-
|-
|[[Acoustic telemetry]]||-
|-
|[[Agent based model]]||-
|-
|[[Barotrauma detection system]]||-
|-
|[[BASEMENT]]||-
|-
|[[CASiMiR]]||-
|-
|[[Current meter]]||-
|-
|[[Differential pressure sensor base artificial lateral line probe, iRon]]||-
|-
|[[Fish Protection System (induced drift application)]]||-
|-
|[[FLOW-3D]]||-
|-
|[[HEC-RAS]]||-
|-
|[[LiDAR]]||-
|-
|[[OpenFOAM]]||-
|-
|[[Particle image velocimetry (PIV)]]||-
|-
|[[Radio frequency identification with passive integrated transponder (PIT tagging)]]||-
|-
|[[Radio telemetry]]||-
|-
|[[River2D]]||-
|-
|[[Shelter measurements]]||-
|-
|[[Structure from motion (SfM)]]||-
|-
|[[TELEMAC]]||-
|}

=Introduction=
The agent-based model CASiMiR-Migration for attraction flow assessment is a module of the fish habitat simulation system [[CASiMiR]] (Noack et al. 2014, Schneider et al. 2016). The model is designed to mimic fish movements in the environment of upstream migration fish pass outlets. It is implemented as a combination of habitat suitability model and agent-based model. The tool uses knowledge on hydraulic preferences of fish in the period before entering a fish pass, on etho-hydraulic thresholds for flow velocities and on the searching behaviour of individual fish. It is the progression of a first model version based purely on flow velocity vectors (Kopecki et al. 2014, 2016).

The knowledge processed in this extended model version in terms of fuzzy-rule systems has been gained by field data (fish tracks), expert judgement and literature. The application of the model is aiming at the assessment of probability for fish being routed into the lower end of fishways. An outcome of this assessment is, that the fishway design can be adaptively improved focussing on the entrance position and geometry in conjunction with the amount and orientation of the prescribed attraction flow.
=Application=
The model can be used for the investigation of different locations and designs of fish pass outlets as well as for different release flows. Basis for the model application is a 2D or 3D hydrodynamic model providing information on the spatial distribution of water depth and flow velocity. Habitat suitability (migration corridor suitability) is calculated, and fish agents are placed in the model. Following behavioural rules that integrate habitat suitability, flow velocity magnitude and direction, swim direction and random behaviour the fish agents generate tracks that either lead them to the fish pass entrance or not. Depending on the percentage of agents finding the fish pass the attraction flow is rated. Running the model for different scenarios of the fish pass location and design as well as morphological and hydraulic variants the planning can be optimized, or the functionality of existing system can be assessed.

CASiMiR migration has been developed and applied in the FIThydro test case [[Altusried test case|Altusried]] at river Iller. Figure 2 shows the application of the model for two different release from the fish pass entrance area. First results seem to indicate that higher flow releases in the fishpass outlet area do not significantly improve attraction flow for barbel that approach from the downstream central part of the river. Another first impression the results give is that an increased flow in the river, i.e. a smaller relative flow release from the fish pass is not necessarily negative for the attraction. However, the number of scenarios modelled has to be increased and the evaluation of the database is ongoing.

=Relevant mitigation measures and test cases=
{{Suitable measures for Agent based model}}

=Other information=
The model is not yet available for third parties but is intended to be made accessible in a licensed version in future under http://www.casimir-software.de, where current demo versions of other CASiMiR-modules are available for download

=Relevant literature=
*Kopecki, I., Tuhtan, J., Schneider, M., Ortlepp, J., Thonhauser, S., Schletterer, M. (2014): Assessing Fishway Attraction Flows Using an Ethohyraulic Approach. 3rd IAHR Europe Congress, Porto, April 14-16.
*Kopecki, I., Schneider, M., Tuhtan, J., Ortlepp, J., Thonhauser, S., Schletterer, M. (2016): Attraction flow at upstream migration facilities: Assessment and optimization via etho-hydraulic modelling (in German). WasserWirtschaft, 2016/10, 37-42.
*Noack, M., Schneider, M. and Wieprecht, S. (2013): The Habitat Modelling System CASiMiR: A Multivariate Fuzzy Approach and its Applications; in Ecohydraulics: An Integrated Approach, Chapter 6 (75-93); Editors I. Maddock, A. Harby, P. Kemp, P. Wood, John Wiley & Sons Ltd
*Schneider, M., Kopecki, I., Tuhtan, J., Sauterleute, J., Zinke, P., Bakken, T., Zakowski, T., Merigoux, S. (2016): A Fuzzy Rule-based Model for the Assessment of Macrobenthic Habitats under Hydropeaking Impact. River Research and Applications, 1467-1535

=Contact information=
Information on CASiMiR software:

http://www.casimir-software.de

Developer and seller:

SJE Ecohydraulic Engineering GmbH, Viereichenweg 12, 70569 Stuttgart, Tel. +49 711 677-3435, mailbox@sjeweb.de, www.sjeweb.de

[[Category:Tools]] [[Category:developed in FIThydro]]

Agent based model

2021-06-08T12:19:20Z

Bendikhansen: /* Quick summary */

Agent based model

2021-06-08T12:18:55Z

Bendikhansen: /* Quick summary */

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:ABM_results_1.png|thumb|250px|Figure 1: Result of CASiMiR-Migration illustrating migration corridor suitability and predicted path for grayling]]
[[file:ABM_results_2.png|thumb|250px|Figure 2: Migration model results for barbel at 40 m³/s with additional flow releasen of 1 and 3 m³/s from the fish pass entrance: migration suitability barbel at dotation 1 m³/s (left top) and 3 m³/s (right top), migration path barbel at dotation 1 m³/s (left bottom), path barbel at dotation 3 m³/s (right bottom), fish pass entrance area marked with red and white rectangles]]

Date: Development of current version started in 2017.

Developed by: SJE Ecohydraulic Engineering GmbH

Type: [[:Category:Tools|Tool]]

{| class="wikitable" style="width:350px; float:right; clear:right; margin-left:10px"
! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant solutions !! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;"|Applied in test case?
|-
|[[Mitigating reduced annual flow and low flow measures]]||Yes
|-
|[[Mitigating reduced flood peaks, magnitudes, and frequency]]||Yes
|-
|[[Nature-like fishways]]||Yes
|-
|[[Placement of dead wood and debris]]||Yes
|-
|[[Placement of spawning gravel in the river]]||Yes
|-
|[[Placement of stones in the river]]||Yes
|-
! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant MTDs !! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;"|Applied in test case?
|-
|[[3D sensorless, ultrasound fish tracking]]||-
|-
|[[Acoustic Doppler current profiler (ADCP)]]||-
|-
|[[Acoustic Doppler velocimetry (ADV)]]||-
|-
|[[Acoustic telemetry]]||-
|-
|[[Agent based model]]||-
|-
|[[Barotrauma detection system]]||-
|-
|[[BASEMENT]]||-
|-
|[[CASiMiR]]||-
|-
|[[Current meter]]||-
|-
|[[Differential pressure sensor base artificial lateral line probe, iRon]]||-
|-
|[[Fish Protection System (induced drift application)]]||-
|-
|[[FLOW-3D]]||-
|-
|[[HEC-RAS]]||-
|-
|[[LiDAR]]||-
|-
|[[OpenFOAM]]||-
|-
|[[Particle image velocimetry (PIV)]]||-
|-
|[[Radio frequency identification with passive integrated transponder (PIT tagging)]]||-
|-
|[[Radio telemetry]]||-
|-
|[[River2D]]||-
|-
|[[Shelter measurements]]||-
|-
|[[Structure from motion (SfM)]]||-
|-
|[[TELEMAC]]||-
|}

=Introduction=
The agent-based model CASiMiR-Migration for attraction flow assessment is a module of the fish habitat simulation system [[CASiMiR]] (Noack et al. 2014, Schneider et al. 2016). The model is designed to mimic fish movements in the environment of upstream migration fish pass outlets. It is implemented as a combination of habitat suitability model and agent-based model. The tool uses knowledge on hydraulic preferences of fish in the period before entering a fish pass, on etho-hydraulic thresholds for flow velocities and on the searching behaviour of individual fish. It is the progression of a first model version based purely on flow velocity vectors (Kopecki et al. 2014, 2016).

The knowledge processed in this extended model version in terms of fuzzy-rule systems has been gained by field data (fish tracks), expert judgement and literature. The application of the model is aiming at the assessment of probability for fish being routed into the lower end of fishways. An outcome of this assessment is, that the fishway design can be adaptively improved focussing on the entrance position and geometry in conjunction with the amount and orientation of the prescribed attraction flow.
=Application=
The model can be used for the investigation of different locations and designs of fish pass outlets as well as for different release flows. Basis for the model application is a 2D or 3D hydrodynamic model providing information on the spatial distribution of water depth and flow velocity. Habitat suitability (migration corridor suitability) is calculated, and fish agents are placed in the model. Following behavioural rules that integrate habitat suitability, flow velocity magnitude and direction, swim direction and random behaviour the fish agents generate tracks that either lead them to the fish pass entrance or not. Depending on the percentage of agents finding the fish pass the attraction flow is rated. Running the model for different scenarios of the fish pass location and design as well as morphological and hydraulic variants the planning can be optimized, or the functionality of existing system can be assessed.

CASiMiR migration has been developed and applied in the FIThydro test case [[Altusried test case|Altusried]] at river Iller. Figure 2 shows the application of the model for two different release from the fish pass entrance area. First results seem to indicate that higher flow releases in the fishpass outlet area do not significantly improve attraction flow for barbel that approach from the downstream central part of the river. Another first impression the results give is that an increased flow in the river, i.e. a smaller relative flow release from the fish pass is not necessarily negative for the attraction. However, the number of scenarios modelled has to be increased and the evaluation of the database is ongoing.

=Relevant mitigation measures and test cases=
{{Suitable measures for Agent based model}}

=Other information=
The model is not yet available for third parties but is intended to be made accessible in a licensed version in future under http://www.casimir-software.de, where current demo versions of other CASiMiR-modules are available for download

=Relevant literature=
*Kopecki, I., Tuhtan, J., Schneider, M., Ortlepp, J., Thonhauser, S., Schletterer, M. (2014): Assessing Fishway Attraction Flows Using an Ethohyraulic Approach. 3rd IAHR Europe Congress, Porto, April 14-16.
*Kopecki, I., Schneider, M., Tuhtan, J., Ortlepp, J., Thonhauser, S., Schletterer, M. (2016): Attraction flow at upstream migration facilities: Assessment and optimization via etho-hydraulic modelling (in German). WasserWirtschaft, 2016/10, 37-42.
*Noack, M., Schneider, M. and Wieprecht, S. (2013): The Habitat Modelling System CASiMiR: A Multivariate Fuzzy Approach and its Applications; in Ecohydraulics: An Integrated Approach, Chapter 6 (75-93); Editors I. Maddock, A. Harby, P. Kemp, P. Wood, John Wiley & Sons Ltd
*Schneider, M., Kopecki, I., Tuhtan, J., Sauterleute, J., Zinke, P., Bakken, T., Zakowski, T., Merigoux, S. (2016): A Fuzzy Rule-based Model for the Assessment of Macrobenthic Habitats under Hydropeaking Impact. River Research and Applications, 1467-1535

=Contact information=
Information on CASiMiR software:

http://www.casimir-software.de

Developer and seller:

SJE Ecohydraulic Engineering GmbH, Viereichenweg 12, 70569 Stuttgart, Tel. +49 711 677-3435, mailbox@sjeweb.de, www.sjeweb.de

[[Category:Tools]] [[Category:developed in FIThydro]]

Solutions, methods, tools, and devices

2021-04-14T09:21:00Z

Bendikhansen:

Developing new and existing solutions, methods, tools and devices (SMTDs) to improve the environmental performance of hydropower is central in FIThydro, and they are frequently applied on formal documents from the project. FIThydro's understanding of these terms is:

<categorytree mode="pages" depth=0 namespaces="Main Category">Solutions</categorytree> – these are the overall concept for how to solve or mitigate a problem

<categorytree mode="pages" depth=0 namespaces="Main Category">Methods</categorytree> – these are typically descriptions in how to do something

<categorytree mode="pages" depth=0 namespaces="Main Category">Tools</categorytree> - these are methods embedded in for instance a computer program / a model

<categorytree mode="pages" depth=0 namespaces="Main Category">Devices</categorytree> – these are typically physical instruments or similar used to measure/control something



=The project stages of a mitigation project=
The first step before implementing a mitigation measure, is to investigate whether there is a reduction or impact on the fish population. If so, what is the pressure and problem that causes harm to the fish population. Further, suitable mitigation measures must be selected, planned, implemented and maintained. Methods, tools and devices (MTD) for each mitigation measure (solution) are described for three stages:
#Planning the measure
#Implementing the measure
#Maintaining and monitoring the measure
The roles of the MTDs might be different in the three stages of a mitigation project, but sometimes they are also similar. Some MTDs are used for several mitigation measures.

[[file:MTD_stages.png|600px|]]

Placement of spawning gravel in the river

2021-03-16T11:45:58Z

Bendikhansen: /* During planning */

[[file:icon_habitat.png|right|150px|link=[[Habitat]]]]
[[file:icon_sediment.png|right|150px|link=[[Sediments]]]]

Note that this measure is included in both the habitat and sediment categories.
=Introduction=
[[file:Eggs gravel.PNG|thumb|250px|Figure 1: Salmon eggs in gravel. The picture on the left shows high egg survival (transparent = alive) in placed spawning gravel. The picture on the right shows low survival rate in natural spawning gravel where sand has filled in much of the substrate]]
[[file:spawning_gravel_model.png|thumb|250px|Figure 2: Example of simulation results from a hydrodynamic model. Flow velocity map for ﬂow rate of 15.4 m3/s is shown at the top and for 100 m3/s at the bottom.]]
[[file:spawning_gravel_excavator.png|thumb|250px|Figure 3: Excavator placing spawning gravel in a river.]]

River regulations often change the natural flow regime and the sediment connectivity, introducing changes to the substrate composition both in the bypass section and downstream the outlet of the hydropower plant. This is often leading to a reduction in magnitude, frequency and duration of floods that impact the substrate composition, typically leading to fine materials clogging the substrate and possibly creating an armoured layer. An armoured layer will inhibit the spawning of fish species laying their eggs in the substrate, potentially reducing the number of eggs deposited in the substrate, increasing the predation and possibly also reducing the survival of eggs, e.g. due to low oxygen levels in the hyporheic zone. As such, the areas supporting spawning can be reduced due to regulation and hence represent a limiting factor ('bottleneck') for the fish population.
The grain size distribution of the spawning gravel to be placed in the river must be correct for the species of concern. The spawning fish should be able to dig and lay their egg in the added gravel. Fine sediments should not be able to clog the gravel. The shape of the stones should be similar to the natural conditions in the river, and sharp-edged stones from blasting, often available close to a hydropower projects, should only be used if considered appropriate for the species of concern. If the gravel is not sufficiently 'clean', it should be washed prior to deposition in the river to avoid particle pollution and possibly increased clogging downstream.
Before placement of spawning gravel in the river is made, the hydraulic conditions where the spawning gravel is placed must be investigated. The gravel must be located in a part of the river that does not dry out during low flow conditions, in areas with sufficient through-flow of fresh, oxygen-rich water to the eggs, and in areas that are not exposed to out-wash/flushing during high flow and flood events.
This measure has been implemented in several rivers in Norway (Pulg et al 2017). It is a fairly inexpensive measure to introduce, it stimulates the natural population and seems to achieve very good results in all rivers it has been used.

=[[Methods, tools, and devices]]=

==During planning==
A first step in considering placement of spawning gravel as a measure would be to assess if the total and distribution of spawning areas are limiting the development of fish population, i.e. diagnosis in the environmental design terminology. The spawning areas are often assessed by visual inspection of the river, i.e. by foot beside the river, by wading or from boat. Aerial photos can also in some cases assist this step. When the spawning areas are identified, they can be mapped in a GIS and the total area and their distribution assessed. For Atlantic salmon, spawning areas are considered being large if more than 10% of the total river has suitable spawning conditions, moderate if between 1-10% and small if less than 1% (Forseth and Harby 2013). The distribution/spread is considered large if more than 500 meters between identified spawning areas, medium if between 200-500 meters, and small if less than 200 meters. These threshold values are considered indicative for Atlantic salmon, but they may be different for other fish species.

<table style="height: 207px;" border="1" width="764">
<caption>Table 1: A system for an overall classification of spawning habitat for Atlantic salmon (Forseth and Harby 2013).</caption>
<tr style="height: 13px;">
<td style="height: 13px; width: 264px;"> </td>
<td style="height: 13px; width: 121px;"> </td>
<td style="height: 13px; width: 357px; text-align: center; vertical-align: middle;" colspan="3">
Extent of spawning habitat as a percentage of river area
</td>
</tr>
<tr style="height: 15px;">
<td style="height: 15px; width: 264px;"> </td>
<td style="height: 15px; width: 121px;"> </td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 103px;">
Small (<1%)
</td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 129px;">Moderate (1-10%)</td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 113px;">Large (>10%)</td>
</tr>
<tr style="height: 20px;">
<td style="height: 46px; width: 264px; text-align: center; vertical-align: middle;" rowspan="3">Distance between spawning habitats (across all segments)</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 121px;">
Large (>500m)
</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 103px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 129px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 113px;">Moderate</td>
</tr>
<tr style="height: 13px;">
<td style="text-align: center; vertical-align: middle; height: 13px; width: 121px;">Medium (200-500m)</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 103px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 129px;">Moderate</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 113px;">
Large
</td>
</tr>
<tr style="height: 13px;">
<td style="text-align: center; vertical-align: middle; height: 13px; width: 121px;">Small (<200m)</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 103px;">Moderate</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 129px;">Large</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 113px;">
Large
</td>
</tr>
</table>

Hydraulic analysis can support the identification of the best location to place the spawning gravel, in order to meet the preferences of the fish of concern. For typical gravel spawners, it is recommended to avoid locations with too slow-flowing water and areas exposed to flushing during high flow conditions.

A high number of hydro-dynamic and hydro-morphodynamic tools are available for such analysis with different functionality and data needs, ranging from more simplistic 1-dimensional (1D) hydraulic tools, to highly advanced 3-dimensional (3D) tools solving a range of partial differential equations (Navier-Stokes equations) in all directions. They all require detailed description of the bottom topography of the areas the gravel might be placed, and the flow regime the river will be subject to. As average flow velocities will not be sufficiently detailed to identify the best locations, 2D- or 3D models will be required. Examples of such models are [[River2D]], [[HEC-RAS|HEC-RAS 2D]], Flo-2D/[[FLOW-3D]], Mike21c, [[OpenFOAM]] and [[TELEMAC]] 2D and 3D.

==During implementation==
The implementation of the measure would require access to substrate of suitable grain size distribution, shape and of proper mineral composition, preferably similar to the substrate naturally present in spawning areas. In order to transport and place the new material at the right locations in the river, heavy machinery such as dumpers and tractors would be needed. In case where the site is difficult to access, use of helicopters can be the best option. The dumping of the substrate in the river would normally require supervision of a biologist, hydraulic engineer or another experienced person in order to secure the right positioning of the substrate, proper thickness of substrate layer and finish of the surface preparation. Hydro-morphodynamic models can also be used to guide the positioning.
The construction work will often require use of heavy machinery. Depending on the location of the river and how accessible it is and the costs, the transport of gravel will typically be made by dumper or by helicopter. If helicopter is used, the gravel can normally be dumped directly into the river, under the supervision of a biologist or another experienced person. If the new material is transported into the site by dumpers, an excavator will normally be needed at the site. This will also require the presence of an experienced person to ensure the correct placement and thickness of the gravel.

Habitat measures in regulated rivers must often be maintained unless the natural functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. How often the maintenance must be made will differ from river to river and can vary from for instance every 5 year to every 20 years. Rivers with intense growth of moss, algae and macrophytes would need more frequent maintenance than rivers with cold water and low nutrient concentrations (less growth).

==During operation==

Habitat measures in regulated rivers must often be maintained unless the natural functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. How often the maintenance must be made will differ from river to river and can vary from for instance every 5 years to every 20 years. Rivers with intense growth of moss, algae and macrophytes would need more frequent maintenance than rivers with cold water and low nutrient concentrations (less growth).

=Relevant MTDs and test cases=
{{Suitable MTDs for Placement of spawning gravel in the river}}

=Classification Table=
{{Placement of spawning gravel in the river}}

=Relevant Literature=
*Pulg, U., Barlaup, B.T., Skoglund, H., Velle, G., Gabrielsen, S.E., Stranzl, S.F., Espedal, E.O., Lehmann, G.B., Wiers, T., Skår, B., Normann, E., Fjeldstad, H-P. 2017. Tiltakshåndbok for bedre fysisk vannmiljø: God praksis ved miljøforbedrende tiltak i elver og bekker. Uni Research AS.
*Forseth, T., and Harby, A. 2014. Handbook for Environmental Design in Regulated Salmon Rivers. NINA Special Report 53. Trondheim: Norwegian Institute for Nature Research.

[[category:Habitat measures]][[category:Sediment measures]][[category:Solutions]]

Fish guidance structures with narrow bar spacing

2021-01-26T15:54:54Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|- style="font-weight:bold;"
! style="font-weight:normal;" |
! Vertically inclined bar rack (VIBR/VIPP)
! Angled vertical bar rack (AVBR)
! Angled vertical streamwise bar rack (AVSBR)
! Angled horizontal bar rack (HBR)
|-
| style="font-weight:bold;" | Fish species
| Tested on: smolt, European eel
| Tested on: smolt, European eel
| N/A
| All
|-
| style="font-weight:bold;" | Power losses
| Low head loss and symmetrical turbine admission flow
| High head loss and mild assymetric turbine admission flow
| Low head loss and symmetrical turbine admission flow
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold;" | Certainty of effect
| Very certain
| Very certain
| Moderately certain
| Very certain
|- style="text-align:center;"
| style="font-weight:bold; text-align:left;" | TRL
| 9
| 9
| 4
| 9
|}

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Fish guidance structures with wide bar spacing

2021-01-26T15:53:51Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:FGS_layouts.jpg|thumb|250px|Figure 1: Different FGS layouts (a) Louver, (b) Angled Bar Rack (ABR), (c) Modified angled Bar Rack (MBR) and Curved-Bar Racks (CBRs) with upstream tip angle of (d) 90° and (e) 45°]]
[[file:CBR_schematic.jpg|thumb|250px|Figure 1: Top view of a schematic CBR arrangement with indicated rack angle α, power canal and bypass. The fish are guided along the rack towards the bypass, where they pass downstream]]

The revised Swiss Waters Protection Act (WPA) of 2011 demands the restoration of water bodies and the elimination of negative impacts of hydropower plants (HPPs) regarding fish migration until 2030. Similar demands are stated by the European Water Framework Directive (WFD) of 2000.

To minimize fish injuries or mortality during turbine passage at Run-of-River (RoR) HPPs and thus to fulfill the demands of the WPA and WFD, mechanical behavioural Fish Guidance Structures (FGS) with wide bar spacing and vertical bars have been developed for using at RoR HPPs and water intakes with high design discharges. These are Louvers, Angled Bar Racks (ABR), Modified angled Bar Racks (MBR) and Curved-Bar Racks (CBR) (Figure 1, Bates and Vinsonhaler, 1957; Raynal et al., 2013a; Albayrak et al., 2018 & 2020; Beck et al., 2020a &b). The CBRs have been developed in FIThydro (Figure 1d, e and 2).

All four FGSs feature wide clear bar spacing ≥ 25 mm and are classified as mechanical behavioural fish protection barriers (Fig. 1). Depending on fish size and bar spacing, they may partly function as physical barriers, i.e. preventing fish with minimum body dimensions greater than the clear bar spacing from passage. Louvers are made of vertical straight bars placed at an angle β = 90° to the flow direction mounted in a rack (Fig. 1a). The rack is placed across an intake canal at an angle to the flow direction of typically α= 15° to 30°. Classical ABRs function similar to louvers but their bars are placed at 90° to the rack axis, so that β varies with the main angle α, i.e. β = 90°− α (Fig. 1b), whereas MBRs have an independent variation of α and β with β ≠ 90°−α (Fig. 1c; Raynal et al., 2014; Albayrak et al., 2018 & 2020,). The CBRs consist of a series of vertical curved-bars instead of straight bars. The plan view angle between the upstream bar tip and the flow direction ranges from β = 45° to 90°, while the angle at the downstream end of the bar is optimally δ = 0°, i.e. parallel to the flow direction in the power canal (Fig. 1d, e and 2). All these four FGS types with clear bar spacings of s ≥ 25 mm guide fish to a bypass with hydrodynamic cues created by the bars instead of physically blocking fish from a water intake. When approaching the structure, fish should be able to perceive the elevated pressure and velocity gradients around and between the bars, resulting in avoidance behaviours. The velocity component parallel to the rack Vp, guides the fish towards the bypass. Effective guidance of such FGSs depends also on maintaining the ratio between Vp and rack normal velocity Vn above 1, i.e. Vp / Vn > 1 upstream of the bypass (Courret & Larinier, 2008). Furthermore, to ensure that fish can swim actively along the FGS without exhaustion, the rack normal velocity should be smaller than the sustained swimming speed of fish, i.e. Vn < Vsustained. A general value of Vsustained= 0.50 m/s is recommended for smolts and silver eels (Raynal et al., 2013b) as a first proxy. In general, the value of Vsustained = 0.50 m/s is recommended for the design of a FGS, if the fish fauna is not specified; else, Vsustained should be target fish specific. USBR (2006) recommends the ratio of mean bypass velocity Uby,in to the mean approach flow velocity Uo, between1.1 and 1.5 for louvers.

Detailed information and case study performance evaluation of louver systems are presented in USBR (2006). In addition, Albayrak et al. (2018, 2020) investigated the hydraulics and fish protection and guidance efficiencies of Louvers and MBRs in the laboratory. Albayrak et al. (2018) developed a headloss prediction equation for Louver, ABR and MBR. Furthermore, Albayrak et al. (2020) reported the flow fields and fish guidance efficiencies of a Louver with α = 15° and s = 50 mm and MBR configurations with α = 15° and 30°, s = 50 mm and with and without bottom overlays tested with barbel, spirlin, European grayling, European eel and brown trout. The results show that MBRs with α = 15° with and without overlay successfully guided 90% and 80% of the tested fish species, respectively. Furthermore, MBRs with α = 30° with an overlay guided 95% of the fish. Compared to Louvers and ABRs, MBRs reduce the head losses by ~5 times and ~2, respectively (see Table 1). Despite low head losses for MBRs, losses are still relatively high compared to conventional trash racks and the downstream flow field is still asymmetrical, which may negatively affect turbine efficiency.

Due to the flow straightening effect, the new CBR results in ~20 and ~4 folds lower head losses compared to the same Louver and MBR configurations (Table 1) and in quasi-symmetrical downstream flow (Beck, 2020 & Beck et al., 2020b), improving the rack downstream flow field and possibly HPP turbine efficiency. Furthermore, systematic ethohydraulic tests for a hydraulically optimized CBR configuration with β = 45° and s = 50 mm show fish protection and guidance efficiencies above 75% for spirlin, barbel, nase and salmon parr . The efficiency of the laboratory tests were below 75% for brown trout and eel (Beck, 2019 and 2020).
Given the significantly reduced head losses and high fish guidance and protection efficiencies, CBRs developed in FIThydro present a high potential over Louvers, ABRs and MBRs with straight bars for a safe downstream fish migration at hydropower plants at minimum negative economic impacts (for more on CBRs, see Beck, 2020 and FIThydro deliverable 3.4).

''Table 1: Comparison of head losses of FGSs with wide bar spacing for the rack configuration of α = 30°, s = 50 mm, d =100 mm, t = 10 mm (Fig.1).''
{| class="wikitable" style="text-align:center;"
|-
! style="text-align:left;" | FGS type
! Louver
! ABR
! MBR
! style="font-weight:bold;" | CBR
|-
| style="text-align:left;" | Bar angle, β
| 90°
| 60°
| 45°
| 45°
|-
| style="text-align:left;" | Head loss coefficient, ξ
| style="vertical-align:middle;" | 13.7
| style="vertical-align:middle;" | 5.0
| style="vertical-align:middle;" | 2.8
| style="vertical-align:middle;" | 0. 7
|}

=[[Methods, tools, and devices]]=

==During planning==
[[file:velocity_fields_bannwil.jpg|thumb|250px|Figure 1: Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s ]][[file:numerical_modelling_bannwil.jpg|thumb|250px|Figure 1: Exemplary variant study for HPP Bannwil using numerical modelling. Normal (left) and tangential (right) flow velocities at potential FGS positions upstream of the turbine inlets for scenario 1a for FGS angled at 37°]]

To design a FGS with wide bar spacing and its corresponding bypass system (BS) at a given HPP, detailed site-specific information is needed. The information can be obtained from construction plans and measurements on site. It is recommended to (I) identify and utilize fish migration corridors using [[Radio telemetry|radio]] or [[Acoustic telemetry|acoustic]] telemetry technique; (II) consider behaviour and biomechanical properties of target fish species; and (III) match the hydraulic conditions of a FGS-BS to (I) and (II). In order to assess the hydraulics of a FGS-BS, velocity and bathymetry measurements using e.g. an [[Acoustic Doppler current profiler (ADCP)]] should be conducted (exemplary velocity data from the test case HPP Bannwil, Figure 3). Based on such data, a physical or numerical model of the HPP (Feigenwinter et al., 2019) can be constructed. With either model, positioning and geometric optimization of FGS-BS can be done (numerical model results for [[Bannwil test case|HPP Bannwil]], Figure 4, see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.2). Finally, it is recommended to integrate the HPP’s operating conditions and the hydrological boundary conditions of the studied site.

The construction of a FGS-BS at an existing HPP will in most cases lead to a temporary interruption of the HPP operation and thus to production losses. The construction of the rack itself is comparable to the construction of a conventional HPP trash rack. An additional bridge carrying the rack cleaning machine, which in most cases is analogue to conventional machines used at classical intake trashracks (Beck, 2020), should be installed above the FGS-BS.

==During implementation==
Construction of fish guidance structures with wide bar opening requires heavy lifting equipment and both fixing and placing of the structure needs to be done when the hydropower plant is brought to full stop. Installation of racks, cleaning machine and a bypass system requires a suite of skilled labor on civil works.

==During operation==
Similar to the planning phase, after the construction of a FGS-BS at a HPP site, velocity measurements - using e.g. an [[Acoustic Doppler current profiler (ADCP)|ADCP]] - and fish monitoring using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] are recommended to evaluate the effect of the FGS-BS on the flow field and its fish protection and guidance efficiencies. Based on the monitoring results, further optimization of the FGS-BS should be made, if needed.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with wide bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with wide bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|- style="font-weight:bold; text-align:center;"
! style="font-weight:normal; text-align:left;" |
! Louvres and angled bar rack (ABR)
! Modified angled bar rack (MBR)
! Curved-bar rack (CBR)
|-
| style="font-weight:bold;" | Fish species
| All
| Tested on: barbel, spirlin, European grayling, European eel, brown trout
| Tested on: spirlin, barbel, brown trout, nase, European eel, salmon parr
|-
| style="font-weight:bold;" | Power losses
| Significant head losses and strong assymetric turbine admission flow (compared to MBR and CBR)
| High head loss and mild assymetric turbine admission flow (compared to CBR)
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold;" | Certainty of effect
| Very uncertain
| Moderately certain
| Moderately certain
|- style="text-align:center;"
| style="font-weight:bold; text-align:left;" | TLR
| 9
| 4
| 4
|}
{{Fish guidance structures with wide bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Bates, D.W., Vinsonhaler, R. (1957). Use of louvers for guiding fish. Trans. American Fish Soc. 86(1):38–57.
* Beck, C. (2019). Hydraulic and fish-biological performance of fish guidance structures with curved bars. In proc. 38th International Association for Hydro-Environmental Engineering and Research (IAHR) World Congress, Panama City, Panama, https://doi.org/10.3929/ethz-b-000371526.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier, M. (2008). Guide pour la conception de prises d’eau ‘ichtyocompatibles’ pour les petites centrales hydroélectriques (Guide for the design of fish-friendly intakes for small hydropower plants). Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) (in French).
* Feigenwinter, L., Vetsch, D.E., Kammerer, S., Kriewitz, C.R., Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and Expert Knowledge. Sustainability, 11(6).
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014). Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* USBR (2006). Fish protection at water diversions – A guide for planning and designing fish exclusion facilities. Technical Report. U.S. Department of the Interior, Bureau of Reclamation.

[[category:Downstream fish migration measures]][[category:Solutions]] [[Category:developed in FIThydro]]

Fish guidance structures with wide bar spacing

2021-01-26T15:53:22Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:FGS_layouts.jpg|thumb|250px|Figure 1: Different FGS layouts (a) Louver, (b) Angled Bar Rack (ABR), (c) Modified angled Bar Rack (MBR) and Curved-Bar Racks (CBRs) with upstream tip angle of (d) 90° and (e) 45°]]
[[file:CBR_schematic.jpg|thumb|250px|Figure 1: Top view of a schematic CBR arrangement with indicated rack angle α, power canal and bypass. The fish are guided along the rack towards the bypass, where they pass downstream]]

The revised Swiss Waters Protection Act (WPA) of 2011 demands the restoration of water bodies and the elimination of negative impacts of hydropower plants (HPPs) regarding fish migration until 2030. Similar demands are stated by the European Water Framework Directive (WFD) of 2000.

To minimize fish injuries or mortality during turbine passage at Run-of-River (RoR) HPPs and thus to fulfill the demands of the WPA and WFD, mechanical behavioural Fish Guidance Structures (FGS) with wide bar spacing and vertical bars have been developed for using at RoR HPPs and water intakes with high design discharges. These are Louvers, Angled Bar Racks (ABR), Modified angled Bar Racks (MBR) and Curved-Bar Racks (CBR) (Figure 1, Bates and Vinsonhaler, 1957; Raynal et al., 2013a; Albayrak et al., 2018 & 2020; Beck et al., 2020a &b). The CBRs have been developed in FIThydro (Figure 1d, e and 2).

All four FGSs feature wide clear bar spacing ≥ 25 mm and are classified as mechanical behavioural fish protection barriers (Fig. 1). Depending on fish size and bar spacing, they may partly function as physical barriers, i.e. preventing fish with minimum body dimensions greater than the clear bar spacing from passage. Louvers are made of vertical straight bars placed at an angle β = 90° to the flow direction mounted in a rack (Fig. 1a). The rack is placed across an intake canal at an angle to the flow direction of typically α= 15° to 30°. Classical ABRs function similar to louvers but their bars are placed at 90° to the rack axis, so that β varies with the main angle α, i.e. β = 90°− α (Fig. 1b), whereas MBRs have an independent variation of α and β with β ≠ 90°−α (Fig. 1c; Raynal et al., 2014; Albayrak et al., 2018 & 2020,). The CBRs consist of a series of vertical curved-bars instead of straight bars. The plan view angle between the upstream bar tip and the flow direction ranges from β = 45° to 90°, while the angle at the downstream end of the bar is optimally δ = 0°, i.e. parallel to the flow direction in the power canal (Fig. 1d, e and 2). All these four FGS types with clear bar spacings of s ≥ 25 mm guide fish to a bypass with hydrodynamic cues created by the bars instead of physically blocking fish from a water intake. When approaching the structure, fish should be able to perceive the elevated pressure and velocity gradients around and between the bars, resulting in avoidance behaviours. The velocity component parallel to the rack Vp, guides the fish towards the bypass. Effective guidance of such FGSs depends also on maintaining the ratio between Vp and rack normal velocity Vn above 1, i.e. Vp / Vn > 1 upstream of the bypass (Courret & Larinier, 2008). Furthermore, to ensure that fish can swim actively along the FGS without exhaustion, the rack normal velocity should be smaller than the sustained swimming speed of fish, i.e. Vn < Vsustained. A general value of Vsustained= 0.50 m/s is recommended for smolts and silver eels (Raynal et al., 2013b) as a first proxy. In general, the value of Vsustained = 0.50 m/s is recommended for the design of a FGS, if the fish fauna is not specified; else, Vsustained should be target fish specific. USBR (2006) recommends the ratio of mean bypass velocity Uby,in to the mean approach flow velocity Uo, between1.1 and 1.5 for louvers.

Detailed information and case study performance evaluation of louver systems are presented in USBR (2006). In addition, Albayrak et al. (2018, 2020) investigated the hydraulics and fish protection and guidance efficiencies of Louvers and MBRs in the laboratory. Albayrak et al. (2018) developed a headloss prediction equation for Louver, ABR and MBR. Furthermore, Albayrak et al. (2020) reported the flow fields and fish guidance efficiencies of a Louver with α = 15° and s = 50 mm and MBR configurations with α = 15° and 30°, s = 50 mm and with and without bottom overlays tested with barbel, spirlin, European grayling, European eel and brown trout. The results show that MBRs with α = 15° with and without overlay successfully guided 90% and 80% of the tested fish species, respectively. Furthermore, MBRs with α = 30° with an overlay guided 95% of the fish. Compared to Louvers and ABRs, MBRs reduce the head losses by ~5 times and ~2, respectively (see Table 1). Despite low head losses for MBRs, losses are still relatively high compared to conventional trash racks and the downstream flow field is still asymmetrical, which may negatively affect turbine efficiency.

Due to the flow straightening effect, the new CBR results in ~20 and ~4 folds lower head losses compared to the same Louver and MBR configurations (Table 1) and in quasi-symmetrical downstream flow (Beck, 2020 & Beck et al., 2020b), improving the rack downstream flow field and possibly HPP turbine efficiency. Furthermore, systematic ethohydraulic tests for a hydraulically optimized CBR configuration with β = 45° and s = 50 mm show fish protection and guidance efficiencies above 75% for spirlin, barbel, nase and salmon parr . The efficiency of the laboratory tests were below 75% for brown trout and eel (Beck, 2019 and 2020).
Given the significantly reduced head losses and high fish guidance and protection efficiencies, CBRs developed in FIThydro present a high potential over Louvers, ABRs and MBRs with straight bars for a safe downstream fish migration at hydropower plants at minimum negative economic impacts (for more on CBRs, see Beck, 2020 and FIThydro deliverable 3.4).

''Table 1: Comparison of head losses of FGSs with wide bar spacing for the rack configuration of α = 30°, s = 50 mm, d =100 mm, t = 10 mm (Fig.1).''
{| class="wikitable" style="text-align:center;"
|-
! style="text-align:left;" | FGS type
! Louver
! ABR
! MBR
! style="font-weight:bold;" | CBR
|-
| style="text-align:left;" | Bar angle, β
| 90°
| 60°
| 45°
| 45°
|-
| style="text-align:left;" | Head loss coefficient, ξ
| style="vertical-align:middle;" | 13.7
| style="vertical-align:middle;" | 5.0
| style="vertical-align:middle;" | 2.8
| style="vertical-align:middle;" | 0. 7
|}

=[[Methods, tools, and devices]]=

==During planning==
[[file:velocity_fields_bannwil.jpg|thumb|250px|Figure 1: Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s ]][[file:numerical_modelling_bannwil.jpg|thumb|250px|Figure 1: Exemplary variant study for HPP Bannwil using numerical modelling. Normal (left) and tangential (right) flow velocities at potential FGS positions upstream of the turbine inlets for scenario 1a for FGS angled at 37°]]

To design a FGS with wide bar spacing and its corresponding bypass system (BS) at a given HPP, detailed site-specific information is needed. The information can be obtained from construction plans and measurements on site. It is recommended to (I) identify and utilize fish migration corridors using [[Radio telemetry|radio]] or [[Acoustic telemetry|acoustic]] telemetry technique; (II) consider behaviour and biomechanical properties of target fish species; and (III) match the hydraulic conditions of a FGS-BS to (I) and (II). In order to assess the hydraulics of a FGS-BS, velocity and bathymetry measurements using e.g. an [[Acoustic Doppler current profiler (ADCP)]] should be conducted (exemplary velocity data from the test case HPP Bannwil, Figure 3). Based on such data, a physical or numerical model of the HPP (Feigenwinter et al., 2019) can be constructed. With either model, positioning and geometric optimization of FGS-BS can be done (numerical model results for [[Bannwil test case|HPP Bannwil]], Figure 4, see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.2). Finally, it is recommended to integrate the HPP’s operating conditions and the hydrological boundary conditions of the studied site.

The construction of a FGS-BS at an existing HPP will in most cases lead to a temporary interruption of the HPP operation and thus to production losses. The construction of the rack itself is comparable to the construction of a conventional HPP trash rack. An additional bridge carrying the rack cleaning machine, which in most cases is analogue to conventional machines used at classical intake trashracks (Beck, 2020), should be installed above the FGS-BS.

==During implementation==
Construction of fish guidance structures with wide bar opening requires heavy lifting equipment and both fixing and placing of the structure needs to be done when the hydropower plant is brought to full stop. Installation of racks, cleaning machine and a bypass system requires a suite of skilled labor on civil works.

==During operation==
Similar to the planning phase, after the construction of a FGS-BS at a HPP site, velocity measurements - using e.g. an [[Acoustic Doppler current profiler (ADCP)|ADCP]] - and fish monitoring using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] are recommended to evaluate the effect of the FGS-BS on the flow field and its fish protection and guidance efficiencies. Based on the monitoring results, further optimization of the FGS-BS should be made, if needed.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with wide bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with wide bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="text-align:center; vertical-align:bottom;"
|- style="font-weight:bold;"
! style="font-weight:normal; text-align:left;" |
! Louvres and angled bar rack (ABR)
! Modified angled bar rack (MBR)
! Curved-bar rack (CBR)
|-
| style="font-weight:bold; text-align:left;" | Fish species
| All
| Tested on: barbel, spirlin, European grayling, European eel, brown trout
| Tested on: spirlin, barbel, brown trout, nase, European eel, salmon parr
|-
| style="font-weight:bold; text-align:left;" | Power losses
| Significant head losses and strong assymetric turbine admission flow (compared to MBR and CBR)
| High head loss and mild assymetric turbine admission flow (compared to CBR)
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold; text-align:left;" | Certainty of effect
| Very uncertain
| Moderately certain
| Moderately certain
|-
| style="font-weight:bold; text-align:left;" | TLR
| 9
| 4
| 4
|}

{{Fish guidance structures with wide bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Bates, D.W., Vinsonhaler, R. (1957). Use of louvers for guiding fish. Trans. American Fish Soc. 86(1):38–57.
* Beck, C. (2019). Hydraulic and fish-biological performance of fish guidance structures with curved bars. In proc. 38th International Association for Hydro-Environmental Engineering and Research (IAHR) World Congress, Panama City, Panama, https://doi.org/10.3929/ethz-b-000371526.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier, M. (2008). Guide pour la conception de prises d’eau ‘ichtyocompatibles’ pour les petites centrales hydroélectriques (Guide for the design of fish-friendly intakes for small hydropower plants). Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) (in French).
* Feigenwinter, L., Vetsch, D.E., Kammerer, S., Kriewitz, C.R., Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and Expert Knowledge. Sustainability, 11(6).
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014). Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* USBR (2006). Fish protection at water diversions – A guide for planning and designing fish exclusion facilities. Technical Report. U.S. Department of the Interior, Bureau of Reclamation.

[[category:Downstream fish migration measures]][[category:Solutions]] [[Category:developed in FIThydro]]

Fish guidance structures with wide bar spacing

2021-01-26T15:46:59Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:FGS_layouts.jpg|thumb|250px|Figure 1: Different FGS layouts (a) Louver, (b) Angled Bar Rack (ABR), (c) Modified angled Bar Rack (MBR) and Curved-Bar Racks (CBRs) with upstream tip angle of (d) 90° and (e) 45°]]
[[file:CBR_schematic.jpg|thumb|250px|Figure 1: Top view of a schematic CBR arrangement with indicated rack angle α, power canal and bypass. The fish are guided along the rack towards the bypass, where they pass downstream]]

The revised Swiss Waters Protection Act (WPA) of 2011 demands the restoration of water bodies and the elimination of negative impacts of hydropower plants (HPPs) regarding fish migration until 2030. Similar demands are stated by the European Water Framework Directive (WFD) of 2000.

To minimize fish injuries or mortality during turbine passage at Run-of-River (RoR) HPPs and thus to fulfill the demands of the WPA and WFD, mechanical behavioural Fish Guidance Structures (FGS) with wide bar spacing and vertical bars have been developed for using at RoR HPPs and water intakes with high design discharges. These are Louvers, Angled Bar Racks (ABR), Modified angled Bar Racks (MBR) and Curved-Bar Racks (CBR) (Figure 1, Bates and Vinsonhaler, 1957; Raynal et al., 2013a; Albayrak et al., 2018 & 2020; Beck et al., 2020a &b). The CBRs have been developed in FIThydro (Figure 1d, e and 2).

All four FGSs feature wide clear bar spacing ≥ 25 mm and are classified as mechanical behavioural fish protection barriers (Fig. 1). Depending on fish size and bar spacing, they may partly function as physical barriers, i.e. preventing fish with minimum body dimensions greater than the clear bar spacing from passage. Louvers are made of vertical straight bars placed at an angle β = 90° to the flow direction mounted in a rack (Fig. 1a). The rack is placed across an intake canal at an angle to the flow direction of typically α= 15° to 30°. Classical ABRs function similar to louvers but their bars are placed at 90° to the rack axis, so that β varies with the main angle α, i.e. β = 90°− α (Fig. 1b), whereas MBRs have an independent variation of α and β with β ≠ 90°−α (Fig. 1c; Raynal et al., 2014; Albayrak et al., 2018 & 2020,). The CBRs consist of a series of vertical curved-bars instead of straight bars. The plan view angle between the upstream bar tip and the flow direction ranges from β = 45° to 90°, while the angle at the downstream end of the bar is optimally δ = 0°, i.e. parallel to the flow direction in the power canal (Fig. 1d, e and 2). All these four FGS types with clear bar spacings of s ≥ 25 mm guide fish to a bypass with hydrodynamic cues created by the bars instead of physically blocking fish from a water intake. When approaching the structure, fish should be able to perceive the elevated pressure and velocity gradients around and between the bars, resulting in avoidance behaviours. The velocity component parallel to the rack Vp, guides the fish towards the bypass. Effective guidance of such FGSs depends also on maintaining the ratio between Vp and rack normal velocity Vn above 1, i.e. Vp / Vn > 1 upstream of the bypass (Courret & Larinier, 2008). Furthermore, to ensure that fish can swim actively along the FGS without exhaustion, the rack normal velocity should be smaller than the sustained swimming speed of fish, i.e. Vn < Vsustained. A general value of Vsustained= 0.50 m/s is recommended for smolts and silver eels (Raynal et al., 2013b) as a first proxy. In general, the value of Vsustained = 0.50 m/s is recommended for the design of a FGS, if the fish fauna is not specified; else, Vsustained should be target fish specific. USBR (2006) recommends the ratio of mean bypass velocity Uby,in to the mean approach flow velocity Uo, between1.1 and 1.5 for louvers.

Detailed information and case study performance evaluation of louver systems are presented in USBR (2006). In addition, Albayrak et al. (2018, 2020) investigated the hydraulics and fish protection and guidance efficiencies of Louvers and MBRs in the laboratory. Albayrak et al. (2018) developed a headloss prediction equation for Louver, ABR and MBR. Furthermore, Albayrak et al. (2020) reported the flow fields and fish guidance efficiencies of a Louver with α = 15° and s = 50 mm and MBR configurations with α = 15° and 30°, s = 50 mm and with and without bottom overlays tested with barbel, spirlin, European grayling, European eel and brown trout. The results show that MBRs with α = 15° with and without overlay successfully guided 90% and 80% of the tested fish species, respectively. Furthermore, MBRs with α = 30° with an overlay guided 95% of the fish. Compared to Louvers and ABRs, MBRs reduce the head losses by ~5 times and ~2, respectively (see Table 1). Despite low head losses for MBRs, losses are still relatively high compared to conventional trash racks and the downstream flow field is still asymmetrical, which may negatively affect turbine efficiency.

Due to the flow straightening effect, the new CBR results in ~20 and ~4 folds lower head losses compared to the same Louver and MBR configurations (Table 1) and in quasi-symmetrical downstream flow (Beck, 2020 & Beck et al., 2020b), improving the rack downstream flow field and possibly HPP turbine efficiency. Furthermore, systematic ethohydraulic tests for a hydraulically optimized CBR configuration with β = 45° and s = 50 mm show fish protection and guidance efficiencies above 75% for spirlin, barbel, nase and salmon parr . The efficiency of the laboratory tests were below 75% for brown trout and eel (Beck, 2019 and 2020).
Given the significantly reduced head losses and high fish guidance and protection efficiencies, CBRs developed in FIThydro present a high potential over Louvers, ABRs and MBRs with straight bars for a safe downstream fish migration at hydropower plants at minimum negative economic impacts (for more on CBRs, see Beck, 2020 and FIThydro deliverable 3.4).

''Table 1: Comparison of head losses of FGSs with wide bar spacing for the rack configuration of α = 30°, s = 50 mm, d =100 mm, t = 10 mm (Fig.1).''
{| class="wikitable" style="text-align:center;"
|-
! style="text-align:left;" | FGS type
! Louver
! ABR
! MBR
! style="font-weight:bold;" | CBR
|-
| style="text-align:left;" | Bar angle, β
| 90°
| 60°
| 45°
| 45°
|-
| style="text-align:left;" | Head loss coefficient, ξ
| style="vertical-align:middle;" | 13.7
| style="vertical-align:middle;" | 5.0
| style="vertical-align:middle;" | 2.8
| style="vertical-align:middle;" | 0. 7
|}

=[[Methods, tools, and devices]]=

==During planning==
[[file:velocity_fields_bannwil.jpg|thumb|250px|Figure 1: Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s ]][[file:numerical_modelling_bannwil.jpg|thumb|250px|Figure 1: Exemplary variant study for HPP Bannwil using numerical modelling. Normal (left) and tangential (right) flow velocities at potential FGS positions upstream of the turbine inlets for scenario 1a for FGS angled at 37°]]

To design a FGS with wide bar spacing and its corresponding bypass system (BS) at a given HPP, detailed site-specific information is needed. The information can be obtained from construction plans and measurements on site. It is recommended to (I) identify and utilize fish migration corridors using [[Radio telemetry|radio]] or [[Acoustic telemetry|acoustic]] telemetry technique; (II) consider behaviour and biomechanical properties of target fish species; and (III) match the hydraulic conditions of a FGS-BS to (I) and (II). In order to assess the hydraulics of a FGS-BS, velocity and bathymetry measurements using e.g. an [[Acoustic Doppler current profiler (ADCP)]] should be conducted (exemplary velocity data from the test case HPP Bannwil, Figure 3). Based on such data, a physical or numerical model of the HPP (Feigenwinter et al., 2019) can be constructed. With either model, positioning and geometric optimization of FGS-BS can be done (numerical model results for [[Bannwil test case|HPP Bannwil]], Figure 4, see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.2). Finally, it is recommended to integrate the HPP’s operating conditions and the hydrological boundary conditions of the studied site.

The construction of a FGS-BS at an existing HPP will in most cases lead to a temporary interruption of the HPP operation and thus to production losses. The construction of the rack itself is comparable to the construction of a conventional HPP trash rack. An additional bridge carrying the rack cleaning machine, which in most cases is analogue to conventional machines used at classical intake trashracks (Beck, 2020), should be installed above the FGS-BS.

==During implementation==
Construction of fish guidance structures with wide bar opening requires heavy lifting equipment and both fixing and placing of the structure needs to be done when the hydropower plant is brought to full stop. Installation of racks, cleaning machine and a bypass system requires a suite of skilled labor on civil works.

==During operation==
Similar to the planning phase, after the construction of a FGS-BS at a HPP site, velocity measurements - using e.g. an [[Acoustic Doppler current profiler (ADCP)|ADCP]] - and fish monitoring using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] are recommended to evaluate the effect of the FGS-BS on the flow field and its fish protection and guidance efficiencies. Based on the monitoring results, further optimization of the FGS-BS should be made, if needed.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with wide bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with wide bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{{Fish guidance structures with wide bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Bates, D.W., Vinsonhaler, R. (1957). Use of louvers for guiding fish. Trans. American Fish Soc. 86(1):38–57.
* Beck, C. (2019). Hydraulic and fish-biological performance of fish guidance structures with curved bars. In proc. 38th International Association for Hydro-Environmental Engineering and Research (IAHR) World Congress, Panama City, Panama, https://doi.org/10.3929/ethz-b-000371526.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier, M. (2008). Guide pour la conception de prises d’eau ‘ichtyocompatibles’ pour les petites centrales hydroélectriques (Guide for the design of fish-friendly intakes for small hydropower plants). Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) (in French).
* Feigenwinter, L., Vetsch, D.E., Kammerer, S., Kriewitz, C.R., Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and Expert Knowledge. Sustainability, 11(6).
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014). Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* USBR (2006). Fish protection at water diversions – A guide for planning and designing fish exclusion facilities. Technical Report. U.S. Department of the Interior, Bureau of Reclamation.

[[category:Downstream fish migration measures]][[category:Solutions]] [[Category:developed in FIThydro]]

Fish guidance structures with narrow bar spacing

2021-01-26T15:44:14Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="text-align:center; vertical-align:bottom;"
|- style="font-weight:bold;"
! style="font-weight:normal; text-align:left;" |
! Vertically inclined bar rack (VIBR/VIPP)
! Angled vertical bar rack (AVBR)
! Angled vertical streamwise bar rack (AVSBR)
! Angled horizontal bar rack (HBR)
|-
| style="font-weight:bold; text-align:left;" | Fish species
| Tested on: smolt, European eel
| Tested on: smolt, European eel
| N/A
| All
|-
| style="font-weight:bold; text-align:left;" | Power losses
| Low head loss and symmetrical turbine admission flow
| High head loss and mild assymetric turbine admission flow
| Low head loss and symmetrical turbine admission flow
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold; text-align:left;" | Certainty of effect
| Very certain
| Very certain
| Moderately certain
| Very certain
|-
| style="font-weight:bold; text-align:left;" | TRL
| 9
| 9
| 4
| 9
|}

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Fish guidance structures with narrow bar spacing

2021-01-26T15:42:59Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|- style="font-weight:bold;"
! style="font-weight:normal;" |
! Vertically inclined bar rack (VIBR/VIPP)
! Angled vertical bar rack (AVBR)
! Angled vertical streamwise bar rack (AVSBR)
! Angled horizontal bar rack (HBR)
|-
| style="font-weight:bold;" | Fish species
| Tested on: smolt, European eel
| Tested on: smolt, European eel
| N/A
| All
|-
| style="font-weight:bold;" | Power losses
| Low head loss and symmetrical turbine admission flow
| High head loss and mild assymetric turbine admission flow
| Low head loss and symmetrical turbine admission flow
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold;" | Certainty of effect
| Very certain
| Very certain
| Moderately certain
| Very certain
|-
| style="font-weight:bold;" | TRL
| 9
| 9
| 4
| 9
|}

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Fish guidance structures with narrow bar spacing

2021-01-26T15:41:28Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|-
!
! style="background-color:#efefef;" | Vertically inclined bar rack (VIBR/VIPP)
! style="background-color:#efefef;" | Angled vertical bar rack (AVBR)
! style="background-color:#efefef;" | Angled vertical streamwise bar rack (AVSBR)
! style="background-color:#efefef;" | Angled horizontal bar rack (HBR)
|-
| style="background-color:#efefef;" | Fish species
| Tested on: smolt, European eel
| Tested on: smolt, European eel
| N/A
| All
|-
| style="background-color:#efefef;" | Power losses
| Low head loss and symmetrical turbine admission flow
| High head loss and mild assymetric turbine admission flow
| Low head loss and symmetrical turbine admission flow
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="background-color:#efefef;" | Certainty of effect
| Very certain
| Very certain
| Moderately certain
| Very certain
|-
| style="background-color:#efefef;" | TRL
| 9
| 9
| 4
| 9
|}

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Fish guidance structures with narrow bar spacing

2021-01-26T15:36:03Z

Bendikhansen: /* Classification table */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Talk:Bypass combined with other solutions

2021-01-26T15:03:21Z

Bendikhansen:

=Delete?=
*Covered in [[Fish guidance structures with wide bar spacing]] and [[Fish guidance structures with narrow bar spacing]]. [[User:Bendikhansen|Bendikhansen]] ([[User talk:Bendikhansen|talk]]) 15:02, 26 January 2021 (UTC)

Talk:Bypass combined with other solutions

2021-01-26T15:03:07Z

Bendikhansen:

=Delete?=
*Covered in [[Fish guidance structures with wide bar spacing]] and [[Fish guidance structures with narrow bar spacing]] [[User:Bendikhansen|Bendikhansen]] ([[User talk:Bendikhansen|talk]]) 15:02, 26 January 2021 (UTC)

Talk:Bypass combined with other solutions

2021-01-26T15:02:51Z

Bendikhansen: Created page with "=Delete?= *Covered in Fish guidance structures with wide bar spacing and Fish guidance structures with narrow bar spacing~~~~"

=Delete?=
*Covered in [[Fish guidance structures with wide bar spacing]] and [[Fish guidance structures with narrow bar spacing]][[User:Bendikhansen|Bendikhansen]] ([[User talk:Bendikhansen|talk]]) 15:02, 26 January 2021 (UTC)

Bypass combined with other solutions

2021-01-26T15:01:52Z

Bendikhansen:

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
=Introduction=
From the 1980s to the early 2000s, research was conducted, mainly in the USA, Canada and France, to assess the efficiency of surface bypasses combined with conventional bar racks existing at HPPs for turbine protection (solution not too expensive and cumbersome). Most studies focussed on salmonids. The experiments have shown that the efficiency of these systems is heavily dependent on 3 factors (Larinier, et al., 2002):
*The repulsive effect of the bar racks on fish, depending on both the spacing of the bars in relation to fish size, and on the presence of a tangential flow velocity component creating a more or less marked ‘louver’ effect.
*The velocity pattern in the canal intake must enable fish to remain for a sufficiently long time in front of the bar rack in order for them to be guided to the bypass entrance.
*The design of the bypass entrance itself, including its position with respect to the flow organization (Figure 43), its dimensions (large and deep enough to limit repelling effect), and its entrance velocity and discharge.
In brief, for Atlantic salmon smolts, the guidance efficiency of surface bypasses combined with existing bar racks varies between 10-20% to 80-90% depending on the following parameters (Larinier, et al., 2002):
*Very low for bar spacing > 50 mm (10-20% efficiency)
*60-70% efficiency for bar spacing of 30-40 mm and good hydraulic conditions and well-designed bypasses
*80-90% efficiency with bar spacing of 25 mm and good hydraulic conditions and well-designed bypasses
Studies conducted on eels revealed that the efficiencies of surface or bottom bypasses combined with existing bar racks were much lower than for smolts, as eels do not show strong behavioural repulsion and are therefore likely to pass through the racks. Thus, it appeared necessary to implement physical barriers to reach high efficiency for eels (Gosset, et al., (2005); Travade, et al., (2010); Bau, et al., (2013)).

In France, it is considered that the association of an outlet with an existing bar rack can be a solution in some cases where the rack surface is already sufficiently large to respect the criteria on the maximum normal velocity (cf. following subsection) and to allow a reduction of the bar spacing (if not already low enough). But in many cases, the achievement of good efficiencies for smolts and/or eels will require reconfiguring the bar racks, or even the water intake, to implement fish guidance bar racks and louvers.

=[[Methods, tools, and devices]]=

==During planning==
This mitigation measure consists in adding a bypass to an existing conventional bar rack. The configuration of the water intake must be well known (measurement, physical or numerical modelling). The physical installations of the bypasses must be planned according to the power plant geometry and construction works must be adapted to physical forces and the hydropower scheme.
==During implementation==
Installation of bypass system requires a suite of skilled labor on civil works.
==During operation==
The bypass can be subject to clogging. Each bypass must be designed to allow evacuation of debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Bypass combined with other solutions}}

=Classification table=
{{Bypass combined with other solutions}}

=Relevant Literature=
*Larinier, M. and Travade, F. 2002. Downstream migration: problems and facilities. Bulletin Francais De La Peche Et De La Pisciculture 364: 181-207
*Gosset, C., Travade, F., Durif, C. M. F., Rives, J., & Elie, P. (2005). Tests of two types of bypass for downstream migration of eels at a small hydroelectric power plant. River Research and Applications, 21, 1095– 1105.
*Travade, F., Larinier M., Subra S., Gomes P., De-Oliveira E. Behaviour and passage of European Silver Eels (Anguilla anguilla) at a small hydropower plant during their downstream migration. Knowl. Manage. Aquat. Ecosyst., 398 (2010), pp. 1-19
*Bau, F., et al. 2013. Anguille et Ouvrages : migration de dévalaison - Suivi par radiopistage de la dévalaison de l’anguille argentée sur le Gave de Pau au niveau des ouvrages hydroélectriques d’Artix, Biron, Sapso, Castetarbe, Baigts et Puyoo (2007-2010). 2013. Rapport de synthèse.

[[category:Downstream fish migration measures]][[category:Solutions]][[category:Needs improvement]]

Suggested and intended improvements

2021-01-26T14:47:21Z

Bendikhansen:

There have been many excellent suggestions for improvements to the wiki. Not all of them can be implemented within the scope of the FIThydro project, but the wiki development and maintenance will continue after the project ends.

'''If you have additional suggestions, please write them in the discussion page here or email them to wiki@fithydro.eu.'''
=Improvements to come within the FIThydro project=

=Suggestions that are being considered=
==Additional articles==
Add articles for removal of bank protection and removal of debris (sediment measures).
==Improve classification tables==
*Define groups of fish species (gravel spawners, eels, etc)
*Create a column for comments
*Add category to "Does measure require loss of power production". There should be one option if the measure does not influence power production at all and another if it influences it through head loss or loss of efficiency in production (see [[Fish guidance structures with wide bar spacing]] for examples of this))

==Add combination matrix to solution articles==
With the list of which solutions work well together, add tables to Solutions articles for which measures it can be combined with.

==List of articles that need editing (refer to the discussion page or the note at the top of the page)==
*To add an article to this category, add the "Needs improvement" category at the bottom along with the other categories.
<categorytree mode="pages" depth=0 namespaces="Main Category">Needs improvement</categorytree>

Suggested and intended improvements

2021-01-26T14:46:51Z

Bendikhansen: /* List of articles that need editing (refer to the discussion page or the note at the top of the page) */

There have been many excellent suggestions for improvements to the wiki. Not all of them can be implemented within the scope of the FIThydro project, but the wiki development and maintenance will continue after the project ends.

'''If you have additional suggestions, please write them in the discussion page here or email them to wiki@fithydro.eu.'''
=Improvements to come within the FIThydro project=

=Suggestions that are being considered==
==Additional articles==
Add articles for removal of bank protection and removal of debris (sediment measures).
==Improve classification tables==
*Define groups of fish species (gravel spawners, eels, etc)
*Create a column for comments
*Add category to "Does measure require loss of power production". There should be one option if the measure does not influence power production at all and another if it influences it through head loss or loss of efficiency in production (see [[Fish guidance structures with wide bar spacing]] for examples of this))

==Add combination matrix to solution articles==
With the list of which solutions work well together, add tables to Solutions articles for which measures it can be combined with.

==List of articles that need editing (refer to the discussion page or the note at the top of the page)==
*To add an article to this category, add the "Needs improvement" category at the bottom along with the other categories.
<categorytree mode="pages" depth=0 namespaces="Main Category">Needs improvement</categorytree>

Suggested and intended improvements

2021-01-26T14:44:23Z

Bendikhansen: /* Improve classification tables */

There have been many excellent suggestions for improvements to the wiki. Not all of them can be implemented within the scope of the FIThydro project, but the wiki development and maintenance will continue after the project ends.

'''If you have additional suggestions, please write them in the discussion page here or email them to wiki@fithydro.eu.'''
=Improvements to come within the FIThydro project=

=Suggestions that are being considered==
==Additional articles==
Add articles for removal of bank protection and removal of debris (sediment measures).
==Improve classification tables==
*Define groups of fish species (gravel spawners, eels, etc)
*Create a column for comments
*Add category to "Does measure require loss of power production". There should be one option if the measure does not influence power production at all and another if it influences it through head loss or loss of efficiency in production (see [[Fish guidance structures with wide bar spacing]] for examples of this))

==Add combination matrix to solution articles==
With the list of which solutions work well together, add tables to Solutions articles for which measures it can be combined with.

==List of articles that need editing (refer to the discussion page or the note at the top of the page)==
<categorytree mode="pages" depth=0 namespaces="Main Category">Needs improvement</categorytree>

Las Rives test case

2021-01-26T12:35:17Z

Bendikhansen: /* Upstream migration */

[[Category:Test cases]]
{{Fact box for Las Rives}}
{{Relevant SMTDs for Las Rives}}

=Introduction=
The Test Case is located on the river Ariège in the South of France, between Crampagna and Varilhes. The dam of Labarre at the upstream part of the water body constitutes a block to upstream migration and participates to the regulation of flows with its reservoir of 400 000 m3 (17.6 ha).

The hydrology of the Ariège is characterized by a sustained flows in winter, high water levels in spring due to snow melting and low water period from August to October. During the downstream migration period of smolts (March, April, May) the mean monthly discharges range from 41.3 m3/s in March to 79.1 m3/s in May.

The hydropower plant of Las Rives is part of a section of 20 km with 5 hydropower plants. Altogether, there are 7 further HPPs are located upstream and downstream of the Test Case.

=About the hydropower plant=
The HPP of Las Rives is downstream the station of Foix. It has an installed capacity of 2.7 MW and a mean inter-annual discharge of about 41.8 m3/s. There are several creeks and one watercourse flowing into the Ariège before the HPP Las Rives.
===Layout===
The HPP of Las Rives is an run-off-river HPP which bypass reach is 580 meters long.
===The Operator: ONDULIA===
ONDULIA is a green energy producer. It owns 10 hydropower plants, 8 wind farms and one photovoltaic roof. This represents an installed capacity of 77MW thanks to 64 turbines. The mean annual production of their installations is around 180 million kWh, corresponding to the consumption of a city of 70 000 inhabitants. [https://www.ondulia.com/ Read more.]

=Test case topics=
===Downstream migration===
To protect the fish on their downstream migration, the rack in front of the hydropower plant was changed in 2014. Its location was changed from the power plant to the head of the headrace channel. The bar screen with a length of 14m is now located in the head of the headrace channel on the left bank, allowing the integration of the downstream migration flow into the instream flow. There are 3 downstream migration outlets at the top of the bar screen and migration duct, which sections increase with closeness to the downstream migration channel. At the outlet of the downstream migration channel the fish fall from a height of 3.4m into 63 cm of water when the total discharge of the river is smaller than 48.5 m3/s. This low water depth poses question about the conditions of landing of fishes in the pool. An experiment will start in spring 2018 to evaluate the effect of the fall on fishes.
===Upstream migration===
An alternate vertical slot pass is located at the upstream angle of the water intake weir (point of higher rising, right bank). The flow in the fishpass is 0.5 m3/s. 2.75 m3/s of complementary attraction flow are turbined by a new DIVE turbine (2017) at the right bank of the fishpass associated to a fish-friendly bar screen.

===E-flow===
In France, the law of 2006 (LEMA) imposes an e-flow of 1/10 of the mean inter-annual discharge before 1rst January 2014. For the environmental flow in the bypass section a minimum value equal to a tenth of the mean inter-annual discharge of the water course is chosen, which is 4.35 m3/s at Las Rives. In 2001, the E-flow was about 5 m3/s, and thereby greater than the minimum value.

In Las Rives, the operator found a compromise with the authorities to improve downstream migration conditions of fishes by the replacement of the former rack with a more efficient fish friendly trash rack and in return they installed a Dive turbine in order to use a part of the instream flow (2.75 m3/s of the attraction flow of the fish ladder). The operator increased its production and decreased the global mortality rate of the HPP. The replacement of the rack led to higher head losses.

=Pressures on the water body's ecosystem=
Due to 7 hydropower plants located on the Ariège the continuity of the water body is highly affected. Agricultural practices, with their use of pesticides, also have a significant effect on the river.
The Ariège is a low water replenishment for the river Garonne. While there is a water storage upstream of this water body, the upstream hydropeaking management does influence the Ariège’s flow, leaving it with a moderate hydrology and morphology.
=Research objectives and tasks=
At Las Rives the ways for a fish friendly water intake and reception pool are being investigated. For this, the efficiency of the fish friendly water intake is tested and a hydraulic model is done to determine the attractiveness of the bypass. Different shapes of outlets are tested. The effect of consecutive hydropower plants on downstream migration delay of fishes is assessed.
===Research tasks===
The research tasks and field studies conducted at Las Rives are:

* Assessment of the efficiency of a fishfriendly water intake by fish tracking
* Hydraulic measurement in front of the inclined bar rack
* Hydraulic modelling of the water intake
* Studying the hydraulic conditions at the end of the downstream migration duct
* Scenario modelling of several downstream migration measures

=Results=
The Las Rives test case is a medium HPP with a fish friendly water intake in which is tested an inclined bar rack with several technical solutions. The efficiency of the inclined low bar spacing trashrack has been validated by radio telemetry for smolts (81% of efficiency) and eels (100% of efficiency). No cumulative effect on different successive HPPs has been shown during these tests. Depending on the river discharge, the fishes use bypasses as well as the overspill weir. ADCP measurements have been conducted at four cross-sections for different flow discharges, that show well-predicted normal and tangential components of the upstream velocity. This has also been validated by 3D modelling highlighting the attractiveness of the three bypasses, and confirmed by bypass discharge measurements. The landing conditions of the fishes at the foot of the control weir ending the downstream migration duct has also been studied and showed some fish damages (about 30%) which should bring on some modification of the landing zone. Finally, scenario modeling is proposed to see the cost effective solutions for the downstream migration on this site and promote the retained solution. Seven scenario have been compared for the downstream migration and were first analyzed and compared regarding monitoring and production calculation and then implement in a probabilistic network to assess the trade-off between downstream migration efficiency, productivity, and costs of the infrastructures for each scenario.

<gallery mode=packed>
LasRives1.jpg|350px|Las Rives hydropower plant
LasRives2.jpg|350px|Bar screen out of water
LasRives3.jpg|350px|Bar screen in water
LasRives4.jpg|350px|Dump valve for sediments
LasRives5.jpg|350px|Outlet of the downstream migration channel
LasRives6.jpg|350px|Upstream view of the old fish pass
LasRives7.jpg|350px|Fish pass and the new DIVE turbine on the bypassed reach

Las_rives_ADCP_support.png|350px|Support and movement carts system allowing the deployment of the ADCP.
Las_rives_ADCP_output1.png|350px|ADCP cartography of V_t/V_0.
Las_rives_ADCP_output2.png|350px|ADCP cartography of V_n/V_0.
LasRives8.jpg|350px|Passage routes of downstream migrating silver eels at Las Rives, overall in spring 2017 and 2018 (Tomanova S, 2019).
LasRives9.jpg|350px|Measurement with an electro-magnetic flow meter in the downstream migration duct

</gallery>

==References==
* Tomanova S, Courret D, Mercier O, Richard S, De-Oliveira E, Mataix V, Lagarrigue T, Frey A, Tetard S. 2019. Efficiency of downstream passage devices to protect migrating silver eels assessed with radiotelemetry. 5th International Conference on Fish Telemetry, Arendal, Norway, 2019, June 24th-28th., 2019.

* Lemkecher F, David L, Courret D, and Chatellier C, 2018. Field measurements of the attractivity of bypasses for fishfriendly trashrack. Riverflow 2018, 5/8 septembre, Lyon. https://doi.org/10.1051/e3sconf/20184003039

File:Wsf double.png

2021-01-26T10:44:10Z

Bendikhansen: {{Information |author=Dominique Courret |source=Pôle Ecohydraulique AFB |description=Double vertical slots fishway: Puyoo weir on the Gave de Pau. }}

== Summary ==
{{Information
|author=Dominique Courret
|source=Pôle Ecohydraulique AFB
|description=Double vertical slots fishway: Puyoo weir on the Gave de Pau.
}}

File:Wsf crosswall.png

2021-01-26T10:42:53Z

Bendikhansen: {{Information |author=Dominique Courret |source=Pôle Ecohydraulique AFB |description=Dimensions of typical cross-wall of a vertical slot fishway. }}

== Summary ==
{{Information
|author=Dominique Courret
|source=Pôle Ecohydraulique AFB
|description=Dimensions of typical cross-wall of a vertical slot fishway.
}}

File:Wsf single paired.png

2021-01-26T10:42:08Z

Bendikhansen: {{Information |author=Michel Larinier |source=Larinier, M., Travade, F. et Porcher, J. P. 2002. Fishways: biological basis, design criteria and monitoring. 2002, p. 208. |description=Single and paired vertical slot fishway. }}

== Summary ==
{{Information
|author=Michel Larinier
|source=Larinier, M., Travade, F. et Porcher, J. P. 2002. Fishways: biological basis, design criteria and monitoring. 2002, p. 208.
|description=Single and paired vertical slot fishway.
}}

Vertical slot fishways

2021-01-26T10:40:53Z

Bendikhansen:

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:wsf_single_paired.png|thumb|250px|Figure 1: Single and paired vertical slot fishway.]]
[[file:wsf_crosswall.png|thumb|250px|Figure 2: Dimensions of typical cross-wall of a vertical slot fishway]]
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 3: Vertical slot fishway in Chatellerault, France.]]
[[file:wsf_double.png|thumb|250px|Figure 4: Double vertical slots fishway: Puyoo weir on the Gave de Pau.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==
Planning of a vertical slot fishway will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier, including information about the hydropower scheme. Surveying must also be conducted in the area of the river bank where the fishway is planned, including geological surveying. Geographic data should be handled in GIS software for further planning and analyses. The design of the fishway should be conducted with conventional hydraulic and civil engineering calculations and drawing (see FIThydro [https://www.fithydro.eu/deliverables-tech/ deliverable 2.1]). All material used in a fishway must be planned to withstand physical strain from water, floods and frost. Monitoring facilities should basically be planned in the upper part of the fishway.

==During implementation==
Physical implementation of vertical slot fishways requires heavy machinery suited for the river size and its surrounding terrain, such as excavators and trucks. Work with explosives is relevant in most cases and blasted rocks and transportation of material out from the site is common. Surplus rocks should not be disposed at site because of pollution risk. The construction phase includes construction of concrete formwork, casting of concrete and iron reinforcement work.
==During operation==
Injuries on vertical slot fishways from physical wear must be monitored and repaired in order to secure regular fish migration. Maintenance work normally require hand-tools more than heavy equipment, but casting of concrete is typical. Depending of the site, removal of sediment, branches, logs and floating debris in pools and fishway entrance is common. Monitoring systems require regular inspection, depending on product and system.

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=
* Ballu, A. 2017. Etude numérique et expérimentale de l'écoulement turbulent au sein des passes à poissons à fentes verticales. Analyse de l'écoulement tridimensionnel et instationnaire. s.l. : Thèse de doctorat - Université de Poitiers, 2017.
* Ballu, A., et al. 2017. Experimental study of the influence of macro-roughnesses on vertical slot fishway flows. La Houille Blanche. May 2017, 2, pp. 9-14.
* Ballu, A., et al. 2015. Experimental study of the influence of sills on vertical slot fishway flow. The Hague - The Netherlands : Proceedings of the 36th IAHR World Congress, 2015.
* Bombac, M., Cetina, M. et Novak, G. 2017. Study on flow characteristics in vertical slot fishways regarding slot layout optimization. Ecological Engineering. 107 : 126-136, 2017.
* Clay, H. C. 1961. Design of fishways and other fish facilities. s.l. : Department of Fisheries of Canada, p. 301.
* Fuentes-Pérez, JF., et al. 2014. Modeling water-depth distribution in vertical slot fishways under uniform an non-uniform scenarios. Journal of Hydraulic Engineering, 140, 6014016. 2014.
* Larinier, M., Travade, F. et Porcher, J. P. 2002. Fishways: biological basis, design criteria and monitoring. 2002, p. 208.
* Lenne, D. 1990. Circulation des poissons migrateurs : franchissement des buses et étude hydraulique des passes à bassins successifs. s.l. : EN1TRS CEMAGREF, 70 p.
* Liu, M., Rajaratnam, N. et Zhu, D.Z. 2006. Mean flow and turbulence structure in vertical slot fishways. Journal of hydraulic engineering, 10.1061. 2006.
* Puertas, J., Pena, L. et Teijeiro, T. 2004. Experimental approach to the hydraulics of vertical slot fishways. Journal of Hydraulic Engineering, 130. 2004, pp. 10-23.
* Rajaratnam, N., Van der Vinne, G. et Katopodis, G. 1986. Hydraulics of vertical slot fishways. Journal of Hydraulic Engineering. 1986, Vol. 112, 10, pp. 909-927.
* Rajaratnam, N., Katapodis, C. et Solanki, S. 1992. New designs for vertical slot fishways. 1992, pp. 402-414.
* Romao, F., et al. 2017. Passage performance of two cyprinids with different ecological traits in a fishway with distinct vertical slot configurations. Ecological Engineering. 105 : 180-188, 2017.
* Wang, R.W., David, L. et Larinier, M. 2010. Contribution of experimental fluid mechanics to the design of vertical slot fish passes. Knowledge and Management of Aquatic Ecosystems. 2010, pp. 366, 02
* Wu, S., Rajaratnam, N. et Katapodis, C. 1999. Structure of flow in vertical slot fishway. Journal of Hydraulic Engineering 125 (4). 1999, pp. 351-360.

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:27:02Z

Bendikhansen: /* Relevant literature */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==
Planning of a vertical slot fishway will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier, including information about the hydropower scheme. Surveying must also be conducted in the area of the river bank where the fishway is planned, including geological surveying. Geographic data should be handled in GIS software for further planning and analyses. The design of the fishway should be conducted with conventional hydraulic and civil engineering calculations and drawing (see FIThydro [https://www.fithydro.eu/deliverables-tech/ deliverable 2.1]). All material used in a fishway must be planned to withstand physical strain from water, floods and frost. Monitoring facilities should basically be planned in the upper part of the fishway.

==During implementation==
Physical implementation of vertical slot fishways requires heavy machinery suited for the river size and its surrounding terrain, such as excavators and trucks. Work with explosives is relevant in most cases and blasted rocks and transportation of material out from the site is common. Surplus rocks should not be disposed at site because of pollution risk. The construction phase includes construction of concrete formwork, casting of concrete and iron reinforcement work.
==During operation==
Injuries on vertical slot fishways from physical wear must be monitored and repaired in order to secure regular fish migration. Maintenance work normally require hand-tools more than heavy equipment, but casting of concrete is typical. Depending of the site, removal of sediment, branches, logs and floating debris in pools and fishway entrance is common. Monitoring systems require regular inspection, depending on product and system.

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=
* Ballu, A. 2017. Etude numérique et expérimentale de l'écoulement turbulent au sein des passes à poissons à fentes verticales. Analyse de l'écoulement tridimensionnel et instationnaire. s.l. : Thèse de doctorat - Université de Poitiers, 2017.
* Ballu, A., et al. 2017. Experimental study of the influence of macro-roughnesses on vertical slot fishway flows. La Houille Blanche. May 2017, 2, pp. 9-14.
* Ballu, A., et al. 2015. Experimental study of the influence of sills on vertical slot fishway flow. The Hague - The Netherlands : Proceedings of the 36th IAHR World Congress, 2015.
* Bombac, M., Cetina, M. et Novak, G. 2017. Study on flow characteristics in vertical slot fishways regarding slot layout optimization. Ecological Engineering. 107 : 126-136, 2017.
* Clay, H. C. 1961. Design of fishways and other fish facilities. s.l. : Department of Fisheries of Canada, p. 301.
* Fuentes-Pérez, JF., et al. 2014. Modeling water-depth distribution in vertical slot fishways under uniform an non-uniform scenarios. Journal of Hydraulic Engineering, 140, 6014016. 2014.
* Larinier, M., Travade, F. et Porcher, J. P. 2002. Fishways: biological basis, design criteria and monitoring. 2002, p. 208.
* Lenne, D. 1990. Circulation des poissons migrateurs : franchissement des buses et étude hydraulique des passes à bassins successifs. s.l. : EN1TRS CEMAGREF, 70 p.
* Liu, M., Rajaratnam, N. et Zhu, D.Z. 2006. Mean flow and turbulence structure in vertical slot fishways. Journal of hydraulic engineering, 10.1061. 2006.
* Puertas, J., Pena, L. et Teijeiro, T. 2004. Experimental approach to the hydraulics of vertical slot fishways. Journal of Hydraulic Engineering, 130. 2004, pp. 10-23.
* Rajaratnam, N., Van der Vinne, G. et Katopodis, G. 1986. Hydraulics of vertical slot fishways. Journal of Hydraulic Engineering. 1986, Vol. 112, 10, pp. 909-927.
* Rajaratnam, N., Katapodis, C. et Solanki, S. 1992. New designs for vertical slot fishways. 1992, pp. 402-414.
* Romao, F., et al. 2017. Passage performance of two cyprinids with different ecological traits in a fishway with distinct vertical slot configurations. Ecological Engineering. 105 : 180-188, 2017.
* Wang, R.W., David, L. et Larinier, M. 2010. Contribution of experimental fluid mechanics to the design of vertical slot fish passes. Knowledge and Management of Aquatic Ecosystems. 2010, pp. 366, 02
* Wu, S., Rajaratnam, N. et Katapodis, C. 1999. Structure of flow in vertical slot fishway. Journal of Hydraulic Engineering 125 (4). 1999, pp. 351-360.

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:26:21Z

Bendikhansen: /* Methods, tools, and devices */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==
Planning of a vertical slot fishway will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier, including information about the hydropower scheme. Surveying must also be conducted in the area of the river bank where the fishway is planned, including geological surveying. Geographic data should be handled in GIS software for further planning and analyses. The design of the fishway should be conducted with conventional hydraulic and civil engineering calculations and drawing (see FIThydro [https://www.fithydro.eu/deliverables-tech/ deliverable 2.1]). All material used in a fishway must be planned to withstand physical strain from water, floods and frost. Monitoring facilities should basically be planned in the upper part of the fishway.

==During implementation==
Physical implementation of vertical slot fishways requires heavy machinery suited for the river size and its surrounding terrain, such as excavators and trucks. Work with explosives is relevant in most cases and blasted rocks and transportation of material out from the site is common. Surplus rocks should not be disposed at site because of pollution risk. The construction phase includes construction of concrete formwork, casting of concrete and iron reinforcement work.
==During operation==
Injuries on vertical slot fishways from physical wear must be monitored and repaired in order to secure regular fish migration. Maintenance work normally require hand-tools more than heavy equipment, but casting of concrete is typical. Depending of the site, removal of sediment, branches, logs and floating debris in pools and fishway entrance is common. Monitoring systems require regular inspection, depending on product and system.

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:25:46Z

Bendikhansen: /* Methods, tools, and devices */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==
Planning of a vertical slot fishway will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier, including information about the hydropower scheme. Surveying must also be conducted in the area of the river bank where the fishway is planned, including geological surveying. Geographic data should be handled in GIS software for further planning and analyses. The design of the fishway should be conducted with conventional hydraulic and civil engineering calculations and drawing (see FIThydro [https://www.fithydro.eu/deliverables-tech/ deliverable 2.1]). All material used in a fishway must be planned to withstand physical strain from water, floods and frost. Monitoring facilities should basically be planned in the upper part of the fishway.

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:25:30Z

Bendikhansen: /* Methods, tools, and devices */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==
Planning of a vertical slot fishway will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier, including information about the hydropower scheme. Surveying must also be conducted in the area of the river bank where the fishway is planned, including geological surveying. Geographic data should be handled in GIS software for further planning and analyses. The design of the fishway should be conducted with conventional hydraulic and civil engineering calculations and drawing (see Fithydro [https://www.fithydro.eu/deliverables-tech/ deliverable 2.1]). All material used in a fishway must be planned to withstand physical strain from water, floods and frost. Monitoring facilities should basically be planned in the upper part of the fishway.

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:14:45Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:<math>Q</math> = flow discharge (m3/s)

and

:<math>b</math> = width of the slot (m)

:<math>H_1</math> = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:<math>g</math> = acceleration due to gravity (9.81 m/s2)

:<math>\Delta H</math> = drop between the two pools (m)

:<math>C_d</math> = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:13:40Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

Where:

:Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:12:42Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:11:53Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \Delta H) * 0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:11:33Z

Bendikhansen:

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

:<math>Q = C_d * b * H_1 * (2g * \delta H) * 0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:08:31Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

𝑄=𝐶𝑑𝑏𝐻1(2𝑔∆𝐻)0.5
<math>Q = C_d * b * H_1 * (2g * H) * 0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:07:57Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

𝑄=𝐶𝑑𝑏𝐻1(2𝑔∆𝐻)0.5
<math>Q = C_d * b * H_1 * (2g * ΔH) * 0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:04:39Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula:

𝑄=𝐶𝑑𝑏𝐻1(2𝑔∆𝐻)0.5
<math>Q=C_d*b*H_1*(2g*ΔH)*0.5</math>

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T10:02:32Z

Bendikhansen: /* Introduction */

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula: 𝑄=𝐶𝑑𝑏𝐻1(2𝑔∆𝐻)0.5

:Where Q = flow discharge (m3/s)

and

:b = width of the slot (m)

:H1 = head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

:g = acceleration due to gravity (9.81 m/s2)

:∆H = drop between the two pools (m)

:Cd = discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Vertical slot fishways

2021-01-26T09:59:29Z

Bendikhansen:

[[file:icon_upstream.png|right|150px|link=[[Upstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
'''Note: This article will be finished with the submission of deliverable 3.3 and 3.4 in October, 2020'''
=Introduction=
[[file:vertical_slot_fishway.jpg|thumb|250px|Figure 1: Vertical slot fishway in Chatellerault, France.]]
This type of fishway was developed in North America (Clay, 1961), following several studies on models. The pools may have one or two deep slots (Figure 1), depending on the size of the watercourse and the discharge available. The advantage of having two slots is to be able to increase the flow in the device, instead of an attraction flow injection system or to compensate a moderate head drop at the entrance.

The geometry of cross-walls with deflectors has been the subject of a number of studies ( (Rajaratnam, et al., 1986), (Lenne, 1990), (Larinier, et al., 2002), (Romao, et al., 2017)) and, from the compilation of geometrics characteristics of about thirty vertical slot fishways built in France (Wang, et al., 2010), the dimensions of a typical cross-wall can be proposed (Figure 2):

The flow from the slot is oriented and tends to be directed to the middle of the pool at an angle of 30-45°, resulting in efficient energy dissipation in all the water volume of the pool. When there are two slots, the flow converges and meets in the central section of the pool, creating calm zones on each side of the pool immediately downstream from the walls.

Hydraulic organization of the flows in the pools has also been the subject of numerous studies ( (Rajaratnam, et al., 1986) (Lenne, 1990) (Rajaratnam, et al., 1992), (Wu, et al., 1999), (Puertas, et al., 2004) (Liu, et al., 2006)). Criteria are recently given to obtain a proper organization of the flows in the pools (Wang, et al., 2010). The pool’s length L is generally 7 to 12 times the width of the slot b. For a basin length of 10 b and a fishway slope of 5%-7.5%, a pool’s width B equal to 7-7.5 b could be adopted so as to obtain a two-recirculation zone flow topology and avoid the jet impacting the side opposite the slot. The study of fish behavior (trout and chub) in a ¼ scale vertical slot fishway model, testing different pool width B on slot width b ratios, showed a better rate of fish passage for the two-recirculation zone flow topology than a unique recirculation zone flow topology (obtained when B/b <7). For different pool lengths, one can recommend keeping the same width / length ratio (0.7-0.75). In case of double-slots fishway, the pool width is usually 9 to 10 times b (Larinier, et al., 2002).

A sill can be installed at the base of the slot, especially to limit flow in the device. Sill forces the orientation of the jet to the side opposite the slot, with the hydraulic consequences of reducing the flow topology to one recirculation zone. Moreover, the flows immediately downstream from the sill will tend to plunge (Ballu, et al., 2015).This flow pattern appears less favorable for fishes, after testing with trout on a ¼ scale model (Ballu, 2017). As far as possible, taking into account these experiments, we recommend not installing any sill in the slot.

The flow through a vertical slot fishway can be expressed by the formula: 𝑄=𝐶𝑑𝑏𝐻1(2𝑔∆𝐻)0.5

Where Q: flow discharge (m3/s)

b: width of the slot (m)

H1: head at the slot (m), i.e. the difference between the water level upstream of the slot and that of the slot crest

g: acceleration due to gravity (9.81 m/s2)

∆H: drop between the two pools (m)

Cd: discharge coefficient of the slot

The coefficient of discharge is dependent on the slot configuration/layout ( (Bombac, et al., 2017; Romao, et al., 2017)), width and the water depth ( (Rajaratnam, et al., 1986) (Wu, et al., 1999), (Fuentes-Pérez, et al., 2014)), the design of the baffle and the global geometry of the pools (Puertas, et al., 2004), the slope (Wang, et al., 2010) or even the presence of sill in slot (Ballu, et al., 2015) or roughness on the bottom of the pool (Ballu, et al., 2017)). In general, it may vary from 0.65 to 0.85, depending of the configuration of these parameters.

The great advantage of the vertical slot fishway is that it can accommodate significant variations in the upstream water level, provided that the level downstream is subjected to similar variations. The conditions of velocity and turbulence remain very stable, whatever the water levels in the fishway, and fish can pass through the fishway, swimming at its preferred depth

=[[Methods, tools, and devices]]=

==During planning==

==During implementation==

==During operation==

=Relevant MTDs and test cases=
{{Suitable MTDs for Vertical slot fishways}}

=Classification table=
{{Vertical slot fishways}}

=Relevant literature=

[[category:Upstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Placement of spawning gravel in the river

2021-01-04T09:39:22Z

Bendikhansen:

[[file:icon_habitat.png|right|150px|link=[[Habitat]]]]
[[file:icon_sediment.png|right|150px|link=[[Sediments]]]]

Note that this measure is included in both the habitat and sediment categories.
=Introduction=
[[file:Eggs gravel.PNG|thumb|250px|Figure 1: Salmon eggs in gravel. The picture on the left shows high egg survival (transparent = alive) in placed spawning gravel. The picture on the right shows low survival rate in natural spawning gravel where sand has filled in much of the substrate]]
[[file:spawning_gravel_model.png|thumb|250px|Figure 2: Example of simulation results from a hydrodynamic model. Flow velocity map for ﬂow rate of 15.4 m3/s is shown at the top and for 100 m3/s at the bottom.]]
[[file:spawning_gravel_excavator.png|thumb|250px|Figure 3: Excavator placing spawning gravel in a river.]]

River regulations often change the natural flow regime and the sediment connectivity, introducing changes to the substrate composition both in the bypass section and downstream the outlet of the hydropower plant. This is often leading to a reduction in magnitude, frequency and duration of floods that impact the substrate composition, typically leading to fine materials clogging the substrate and possibly creating an armoured layer. An armoured layer will inhibit the spawning of fish species laying their eggs in the substrate, potentially reducing the number of eggs deposited in the substrate, increasing the predation and possibly also reducing the survival of eggs, e.g. due to low oxygen levels in the hyporheic zone. As such, the areas supporting spawning can be reduced due to regulation and hence represent a limiting factor ('bottleneck') for the fish population.
The grain size distribution of the spawning gravel to be placed in the river must be correct for the species of concern. The spawning fish should be able to dig and lay their egg in the added gravel. Fine sediments should not be able to clog the gravel. The shape of the stones should be similar to the natural conditions in the river, and sharp-edged stones from blasting, often available close to a hydropower projects, should only be used if considered appropriate for the species of concern. If the gravel is not sufficiently 'clean', it should be washed prior to deposition in the river to avoid particle pollution and possibly increased clogging downstream.
Before placement of spawning gravel in the river is made, the hydraulic conditions where the spawning gravel is placed must be investigated. The gravel must be located in a part of the river that does not dry out during low flow conditions, in areas with sufficient through-flow of fresh, oxygen-rich water to the eggs, and in areas that are not exposed to out-wash/flushing during high flow and flood events.
This measure has been implemented in several rivers in Norway (Pulg et al 2017). It is a fairly inexpensive measure to introduce, it stimulates the natural population and seems to achieve very good results in all rivers it has been used.

=[[Methods, tools, and devices]]=

==During planning==
A first step in considering placement of spawning gravel as a measure would be to assess if the total and distribution of spawning areas are limiting the development of fish population, i.e. diagnosis in the environmental design terminology. The spawning areas are often assessed by visual inspection of the river, i.e. by foot beside the river, by wading or from boat. Aerial photos can also in some cases assist this step. When the spawning areas are identified, they can be mapped in a GIS and the total area and their distribution assessed. For Atlantic salmon, spawning areas are considered being large if more than 10% of the total river has suitable spawning conditions, moderate if between 1-10% and small if less than 1% (Forseth and Harby 2013). The distribution/spread is considered large if more than 500 meters between identified spawning areas, medium if between 200-500 meters, and small if less than 200 meters. These threshold values are considered indicative for Atlantic salmon, but they may be different for other fish species.

<table style="height: 207px;" border="1" width="764">
<caption>Table 1: A system for an overall classification of spawning habitat for Atlantic salmon (Forseth and Harby 2013).</caption>
<tr style="height: 13px;">
<td style="height: 13px; width: 264px;"> </td>
<td style="height: 13px; width: 121px;"> </td>
<td style="height: 13px; width: 357px; text-align: center; vertical-align: middle;" colspan="3">
Extent of spawning habitat as a percentage of river area
</td>
</tr>
<tr style="height: 15px;">
<td style="height: 15px; width: 264px;"> </td>
<td style="height: 15px; width: 121px;"> </td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 103px;">
Small (<1%)
</td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 129px;">Moderate (1-10%)</td>
<td style="text-align: center; vertical-align: middle; height: 15px; width: 113px;">Large (>10%)</td>
</tr>
<tr style="height: 20px;">
<td style="height: 46px; width: 264px; text-align: center; vertical-align: middle;" rowspan="3">Distance between spawning habitats (across all segments)</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 121px;">
Large (>500m)
</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 103px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 129px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 20px; width: 113px;">Moderate</td>
</tr>
<tr style="height: 13px;">
<td style="text-align: center; vertical-align: middle; height: 13px; width: 121px;">Medium (200-500m)</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 103px;">Small</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 129px;">Moderate</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 113px;">
Large
</td>
</tr>
<tr style="height: 13px;">
<td style="text-align: center; vertical-align: middle; height: 13px; width: 121px;">Small (<200m)</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 103px;">Moderate</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 129px;">Large</td>
<td style="text-align: center; vertical-align: middle; height: 13px; width: 113px;">
Large
</td>
</tr>
</table>

Hydraulic analysis can support the identification of the best location to place the spawning gravel, in order to meet the preferences of the fish of concern. For typical gravel spawners, it is recommended to avoid locations with too slow-flowing water and areas exposed to flushing during high flow conditions.

A high number of hydro-dynamic and hydro-morphodynamic tools are available for such analysis with different functionality and data needs, ranging from more simplistic 1-dimensional (1D) hydraulic tools, to highly advanced 3-dimensional (3D) tools solving a range of partial differential equations (Navier-Stokes equations) in all directions. They all require detailed description of the bottom topography of the areas the gravel might be placed, and the flow regime the river will be subject to. As average flow velocities will not be sufficiently detailed to identify the best locations, 2D- or 3D models will be required. Examples of such models are [[River2D]], [[HEC-RAS|HEC-RAS 2D]], Flo2D/3D, Mike21c, OpenFoam and Telemac 2D and 3D (see Chapter 9.1 for references).

==During implementation==
The implementation of the measure would require access to substrate of suitable grain size distribution, shape and of proper mineral composition, preferably similar to the substrate naturally present in spawning areas. In order to transport and place the new material at the right locations in the river, heavy machinery such as dumpers and tractors would be needed. In case where the site is difficult to access, use of helicopters can be the best option. The dumping of the substrate in the river would normally require supervision of a biologist, hydraulic engineer or another experienced person in order to secure the right positioning of the substrate, proper thickness of substrate layer and finish of the surface preparation. Hydro-morphodynamic models can also be used to guide the positioning.
The construction work will often require use of heavy machinery. Depending on the location of the river and how accessible it is and the costs, the transport of gravel will typically be made by dumper or by helicopter. If helicopter is used, the gravel can normally be dumped directly into the river, under the supervision of a biologist or another experienced person. If the new material is transported into the site by dumpers, an excavator will normally be needed at the site. This will also require the presence of an experienced person to ensure the correct placement and thickness of the gravel.

Habitat measures in regulated rivers must often be maintained unless the natural functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. How often the maintenance must be made will differ from river to river and can vary from for instance every 5 year to every 20 years. Rivers with intense growth of moss, algae and macrophytes would need more frequent maintenance than rivers with cold water and low nutrient concentrations (less growth).

==During operation==

Habitat measures in regulated rivers must often be maintained unless the natural functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. How often the maintenance must be made will differ from river to river and can vary from for instance every 5 years to every 20 years. Rivers with intense growth of moss, algae and macrophytes would need more frequent maintenance than rivers with cold water and low nutrient concentrations (less growth).

=Relevant MTDs and test cases=
{{Suitable MTDs for Placement of spawning gravel in the river}}

=Classification Table=
{{Placement of spawning gravel in the river}}

=Relevant Literature=
*Pulg, U., Barlaup, B.T., Skoglund, H., Velle, G., Gabrielsen, S.E., Stranzl, S.F., Espedal, E.O., Lehmann, G.B., Wiers, T., Skår, B., Normann, E., Fjeldstad, H-P. 2017. Tiltakshåndbok for bedre fysisk vannmiljø: God praksis ved miljøforbedrende tiltak i elver og bekker. Uni Research AS.
*Forseth, T., and Harby, A. 2014. Handbook for Environmental Design in Regulated Salmon Rivers. NINA Special Report 53. Trondheim: Norwegian Institute for Nature Research.

[[category:Habitat measures]][[category:Sediment measures]][[category:Solutions]]

Fish guidance structures with wide bar spacing

2020-12-14T10:18:33Z

Bendikhansen: /* During planning */

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:FGS_layouts.jpg|thumb|250px|Figure 1: Different FGS layouts (a) Louver, (b) Angled Bar Rack (ABR), (c) Modified angled Bar Rack (MBR) and Curved-Bar Racks (CBRs) with upstream tip angle of (d) 90° and (e) 45°]]
[[file:CBR_schematic.jpg|thumb|250px|Figure 1: Top view of a schematic CBR arrangement with indicated rack angle α, power canal and bypass. The fish are guided along the rack towards the bypass, where they pass downstream]]

The revised Swiss Waters Protection Act (WPA) of 2011 demands the restoration of water bodies and the elimination of negative impacts of hydropower plants (HPPs) regarding fish migration until 2030. Similar demands are stated by the European Water Framework Directive (WFD) of 2000.

To minimize fish injuries or mortality during turbine passage at Run-of-River (RoR) HPPs and thus to fulfill the demands of the WPA and WFD, mechanical behavioural Fish Guidance Structures (FGS) with wide bar spacing and vertical bars have been developed for using at RoR HPPs and water intakes with high design discharges. These are Louvers, Angled Bar Racks (ABR), Modified angled Bar Racks (MBR) and Curved-Bar Racks (CBR) (Figure 1, Bates and Vinsonhaler, 1957; Raynal et al., 2013a; Albayrak et al., 2018 & 2020; Beck et al., 2020a &b). The CBRs have been developed in FIThydro (Figure 1d, e and 2).

All four FGSs feature wide clear bar spacing ≥ 25 mm and are classified as mechanical behavioural fish protection barriers (Fig. 1). Depending on fish size and bar spacing, they may partly function as physical barriers, i.e. preventing fish with minimum body dimensions greater than the clear bar spacing from passage. Louvers are made of vertical straight bars placed at an angle β = 90° to the flow direction mounted in a rack (Fig. 1a). The rack is placed across an intake canal at an angle to the flow direction of typically α= 15° to 30°. Classical ABRs function similar to louvers but their bars are placed at 90° to the rack axis, so that β varies with the main angle α, i.e. β = 90°− α (Fig. 1b), whereas MBRs have an independent variation of α and β with β ≠ 90°−α (Fig. 1c; Raynal et al., 2014; Albayrak et al., 2018 & 2020,). The CBRs consist of a series of vertical curved-bars instead of straight bars. The plan view angle between the upstream bar tip and the flow direction ranges from β = 45° to 90°, while the angle at the downstream end of the bar is optimally δ = 0°, i.e. parallel to the flow direction in the power canal (Fig. 1d, e and 2). All these four FGS types with clear bar spacings of s ≥ 25 mm guide fish to a bypass with hydrodynamic cues created by the bars instead of physically blocking fish from a water intake. When approaching the structure, fish should be able to perceive the elevated pressure and velocity gradients around and between the bars, resulting in avoidance behaviours. The velocity component parallel to the rack Vp, guides the fish towards the bypass. Effective guidance of such FGSs depends also on maintaining the ratio between Vp and rack normal velocity Vn above 1, i.e. Vp / Vn > 1 upstream of the bypass (Courret & Larinier, 2008). Furthermore, to ensure that fish can swim actively along the FGS without exhaustion, the rack normal velocity should be smaller than the sustained swimming speed of fish, i.e. Vn < Vsustained. A general value of Vsustained= 0.50 m/s is recommended for smolts and silver eels (Raynal et al., 2013b) as a first proxy. In general, the value of Vsustained = 0.50 m/s is recommended for the design of a FGS, if the fish fauna is not specified; else, Vsustained should be target fish specific. USBR (2006) recommends the ratio of mean bypass velocity Uby,in to the mean approach flow velocity Uo, between1.1 and 1.5 for louvers.

Detailed information and case study performance evaluation of louver systems are presented in USBR (2006). In addition, Albayrak et al. (2018, 2020) investigated the hydraulics and fish protection and guidance efficiencies of Louvers and MBRs in the laboratory. Albayrak et al. (2018) developed a headloss prediction equation for Louver, ABR and MBR. Furthermore, Albayrak et al. (2020) reported the flow fields and fish guidance efficiencies of a Louver with α = 15° and s = 50 mm and MBR configurations with α = 15° and 30°, s = 50 mm and with and without bottom overlays tested with barbel, spirlin, European grayling, European eel and brown trout. The results show that MBRs with α = 15° with and without overlay successfully guided 90% and 80% of the tested fish species, respectively. Furthermore, MBRs with α = 30° with an overlay guided 95% of the fish. Compared to Louvers and ABRs, MBRs reduce the head losses by ~5 times and ~2, respectively (see Table 1). Despite low head losses for MBRs, losses are still relatively high compared to conventional trash racks and the downstream flow field is still asymmetrical, which may negatively affect turbine efficiency.

Due to the flow straightening effect, the new CBR results in ~20 and ~4 folds lower head losses compared to the same Louver and MBR configurations (Table 1) and in quasi-symmetrical downstream flow (Beck, 2020 & Beck et al., 2020b), improving the rack downstream flow field and possibly HPP turbine efficiency. Furthermore, systematic ethohydraulic tests for a hydraulically optimized CBR configuration with β = 45° and s = 50 mm show fish protection and guidance efficiencies above 75% for spirlin, barbel, nase and salmon parr . The efficiency of the laboratory tests were below 75% for brown trout and eel (Beck, 2019 and 2020).
Given the significantly reduced head losses and high fish guidance and protection efficiencies, CBRs developed in FIThydro present a high potential over Louvers, ABRs and MBRs with straight bars for a safe downstream fish migration at hydropower plants at minimum negative economic impacts (for more on CBRs, see Beck, 2020 and FIThydro deliverable 3.4).

''Table 1: Comparison of head losses of FGSs with wide bar spacing for the rack configuration of α = 30°, s = 50 mm, d =100 mm, t = 10 mm (Fig.1).''
{| class="wikitable" style="text-align:center;"
|-
! style="text-align:left;" | FGS type
! Louver
! ABR
! MBR
! style="font-weight:bold;" | CBR
|-
| style="text-align:left;" | Bar angle, β
| 90°
| 60°
| 45°
| 45°
|-
| style="text-align:left;" | Head loss coefficient, ξ
| style="vertical-align:middle;" | 13.7
| style="vertical-align:middle;" | 5.0
| style="vertical-align:middle;" | 2.8
| style="vertical-align:middle;" | 0. 7
|}

=[[Methods, tools, and devices]]=

==During planning==
[[file:velocity_fields_bannwil.jpg|thumb|250px|Figure 1: Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s ]][[file:numerical_modelling_bannwil.jpg|thumb|250px|Figure 1: Exemplary variant study for HPP Bannwil using numerical modelling. Normal (left) and tangential (right) flow velocities at potential FGS positions upstream of the turbine inlets for scenario 1a for FGS angled at 37°]]

To design a FGS with wide bar spacing and its corresponding bypass system (BS) at a given HPP, detailed site-specific information is needed. The information can be obtained from construction plans and measurements on site. It is recommended to (I) identify and utilize fish migration corridors using [[Radio telemetry|radio]] or [[Acoustic telemetry|acoustic]] telemetry technique; (II) consider behaviour and biomechanical properties of target fish species; and (III) match the hydraulic conditions of a FGS-BS to (I) and (II). In order to assess the hydraulics of a FGS-BS, velocity and bathymetry measurements using e.g. an [[Acoustic Doppler current profiler (ADCP)]] should be conducted (exemplary velocity data from the test case HPP Bannwil, Figure 3). Based on such data, a physical or numerical model of the HPP (Feigenwinter et al., 2019) can be constructed. With either model, positioning and geometric optimization of FGS-BS can be done (numerical model results for [[Bannwil test case|HPP Bannwil]], Figure 4, see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.2). Finally, it is recommended to integrate the HPP’s operating conditions and the hydrological boundary conditions of the studied site.

The construction of a FGS-BS at an existing HPP will in most cases lead to a temporary interruption of the HPP operation and thus to production losses. The construction of the rack itself is comparable to the construction of a conventional HPP trash rack. An additional bridge carrying the rack cleaning machine, which in most cases is analogue to conventional machines used at classical intake trashracks (Beck, 2020), should be installed above the FGS-BS.

==During implementation==
Construction of fish guidance structures with wide bar opening requires heavy lifting equipment and both fixing and placing of the structure needs to be done when the hydropower plant is brought to full stop. Installation of racks, cleaning machine and a bypass system requires a suite of skilled labor on civil works.

==During operation==
Similar to the planning phase, after the construction of a FGS-BS at a HPP site, velocity measurements - using e.g. an [[Acoustic Doppler current profiler (ADCP)|ADCP]] - and fish monitoring using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] are recommended to evaluate the effect of the FGS-BS on the flow field and its fish protection and guidance efficiencies. Based on the monitoring results, further optimization of the FGS-BS should be made, if needed.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with wide bar spacing}}

=Classification table=
{{Fish guidance structures with wide bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Bates, D.W., Vinsonhaler, R. (1957). Use of louvers for guiding fish. Trans. American Fish Soc. 86(1):38–57.
* Beck, C. (2019). Hydraulic and fish-biological performance of fish guidance structures with curved bars. In proc. 38th International Association for Hydro-Environmental Engineering and Research (IAHR) World Congress, Panama City, Panama, https://doi.org/10.3929/ethz-b-000371526.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier, M. (2008). Guide pour la conception de prises d’eau ‘ichtyocompatibles’ pour les petites centrales hydroélectriques (Guide for the design of fish-friendly intakes for small hydropower plants). Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) (in French).
* Feigenwinter, L., Vetsch, D.E., Kammerer, S., Kriewitz, C.R., Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and Expert Knowledge. Sustainability, 11(6).
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014). Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* USBR (2006). Fish protection at water diversions – A guide for planning and designing fish exclusion facilities. Technical Report. U.S. Department of the Interior, Bureau of Reclamation.

[[category:Downstream fish migration measures]][[category:Solutions]] [[Category:developed in FIThydro]]

Template:Suitable MTDs for Placement of spawning gravel in the river

2020-12-14T10:13:31Z

Bendikhansen:

{| class="wikitable"
! colspan="2" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant MTDs
|-
|colspan="2"|[[Suitable MTDs::Acoustic telemetry]]
|-
|colspan="2"|[[Suitable MTDs::BASEMENT]]
|-
|colspan="2"|[[Suitable MTDs::Bedload monitoring system]]
|-
|colspan="2"|[[Suitable MTDs::CASiMiR]]
|-
|colspan="2"|[[Suitable MTDs::FLOW-3D]]
|-
|colspan="2"|[[Suitable MTDs::HEC-RAS]]
|-
|colspan="2"|[[Suitable MTDs::LiDAR]]
|-
|colspan="2"|[[Suitable MTDs::OpenFOAM]]
|-
|colspan="2"|[[Suitable MTDs::Radio frequency identification with passive integrated transponder (PIT tagging)]]
|-
|colspan="2"|[[Suitable MTDs::Radio telemetry]]
|-
|colspan="2"|[[Suitable MTDs::River2D]]
|-
|colspan="2"|[[Suitable MTDs::Sediment simulation in intakes with Multiblock option (SSIIM)]]
|-
|colspan="2"|[[Suitable MTDs::Shelter measurements]]
|-
|colspan="2"|[[Suitable MTDs::Structure from motion (SfM)]]
|-
|colspan="2"|[[Suitable MTDs::TELEMAC]]
|-
! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;" |Relevant test cases !! colspan="1" style="text-align: center; background-color:#2cb4da; color:#ffffff;"|Applied in test case?
|-
|[[Altheim test case]]||Yes
|-
|[[Günz test case]]||-
|}

Hydropeaking tool

2020-12-02T13:24:17Z

Bendikhansen: /* Other information */

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Quick summary=
[[file:hydropeaking_tool_principle.png|thumb|250px|Figure 1: Principle of the hydropeaking tool for categorization of regulated rivers according to the potential impacts of hydropeaking on fish population (source: ).]]
[[file:hydropeaking_tool_assessment.png|thumb|250px|Figure 2: Combinations of hydropeaking effects and vulnerability for total impact assessment (source:[1]).]]

Developed by: SINTEF Energy Research

Date: Under development

Type: [[:Category:Tools|Tool]]

=Introduction=
The ''Hydropeaking Tool'' was designed to assess the impacts of hydropeaking on fish populations in regulated rivers. It is available as an Excel file.
The hydropeaking tool is based on a method for assessing impacts from hydropeaking developed for salmonids at SINTEF Energy as a part of the [[https://www.cedren.no/english/home CEDREN]] EnviPeak project (Norwegian Research Council, Grant number 193818).

In FIThydro, the Hydropeaking Tool has been developed also for Iberian barbel and grayling, in addition to salmonids. Factors, criteria and thresholds that determine the assessment for these species have been modified based on available literature and expert knowledge.

=Application=
In the Hydropeaking tool, the impacts from hydropeaking are divided into two axis: direct effects from hydropeaking and vulnerability of the fish population to the additional impact from hydropeaking. The starting point is not a natural river, but a hydropower regulated river that are operating without peaking. The effect axis characterises the possible ecological impacts of peaking from how physical conditions such as flow, water level and water covered area changes, given the hydropower system and river morphology. The vulnerability axis characterises how vulnerable the system is to further influence from peaking. Both axis may be evaluated separately, but we also provide a system to combine them and obtain an overall assessment of hydropeaking (Figure 1).

The current version of the Hydropeaking Tool is available in Microsoft Excel. The user has to enter input values for effects and vulnerability parameters for the studied river in corresponding tables. These input values can be obtained from numerical modelling, analysis of water level/discharge time series, and fieldwork.

The outputs from the Hydropeaking Tool are the score of effects factors, the score of vulnerability factors, and the score for the combined assessment (Figure 2).

The Hydropeaking Tool aims at being used to assess existing or planned hydropeaking operations. It also gives the user a possibility to see which parameters have a low score, helping to identify where mitigation should be concentrated.

=Relevant mitigation measures and test cases=
{{Suitable measures for Hydropeaking tool}}

=Other information=
The Hydropeaking tool is described as a part of [https://www.fithydro.eu/deliverables-tech/ deliverable D3.2] of the FITHydro project. Application of the tool is also a part of the deliverable.

=Relevant literature=
*Harby et al., J. 2016. A method to assess impacts from Hydropeaking. Proceedings of 11th International Symposium on Ecohydraulics, Melbourne, Australia.
*Bakken, T.H., Forseth, T and Harby (2016), Miljøvirkninger av effektkjøring: kunnskapsstatus og råd til forvaltning og industri. NINA Special Report 62, Trondheim, Norway.
*Forseth, T and Harby (2014), [[https://www.nina.no/archive/nina/PppBasePdf/temahefte/053.pdf A. Handbook for environmental design in regulated salmon rivers]]. NINA Special Report 53, Trondheim, Norway.

=Contact information=
atle.harby@sintef.no

[[Category:Tools]] [[Category:developed in FIThydro]]

File:IBR las rives.png

2020-11-19T15:06:16Z

Bendikhansen: {{Information |author=Dominique Courret |source= |description=Construction and installation of the inclined trash racks of the HPP of Las Rives (France). }}

== Summary ==
{{Information
|author=Dominique Courret
|source=
|description=Construction and installation of the inclined trash racks of the HPP of Las Rives (France).
}}