Migration barrier removal - Revision history

Bendikhansen: Text replacement - "category:Measures" to "category:Solutions"

2020-10-26T10:03:06Z

Text replacement - "category:Measures" to "category:Solutions"

Bendikhansen: /* Relevant literature */

2020-09-30T18:53:48Z

Relevant literature

Bendikhansen: /* Relevant literature */

2020-09-30T18:53:07Z

Relevant literature

Bendikhansen: /* During implementation */

2020-09-30T18:48:45Z

During implementation

Bendikhansen: /* During planning */

2020-09-30T18:47:22Z

During planning

Bendikhansen at 12:05, 6 April 2020

2020-04-06T12:05:15Z

Bendikhansen at 12:44, 12 March 2020

2020-03-12T12:44:38Z

Bendikhansen: Text replacement - "=Useful MTDs=" to "=Relevant MTDs and test cases="

2020-01-21T14:21:41Z

Text replacement - "=Useful MTDs=" to "=Relevant MTDs and test cases="

Bendikhansen at 14:14, 20 January 2020

2020-01-20T14:14:05Z

Bendikhansen: /* Classification table */

2020-01-20T14:10:29Z

Classification table

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 *Jepsen, N., Aarestrup, K., Økland, F. and Rasmussen, G. 1998. Survival of radiotagged Atlantic salmon (''Salmo salar L.'') – and trout (''Salmo trutta L.'') smolts passing a reservoir during seaward migration. Hydrobiologia 371/372: 347-353.
 *Koed A, Jepsen N, Aarestrup K, Nielsen C (2002) Initial mortality of radio-tagged Atlantic salmon (''Salmo salar L.'') smolts following release downstream of a hydropower station. Hydrobiologia 483: 31−37
-[[category:Downstream fish migration measures]][[category:Measures]]
+[[category:Downstream fish migration measures]][[category:Solutions]]

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 =Relevant literature=
 *Fjeldstad, H-P, Barlaup, B.T., Stickler, M, Gabrielsen, S.-E. and Alfredsen, K. 2012. Removal of weirs and the influence on physical habitat for salmonids in a Norwegian river. River Research and Applications; 28, pp. 753-763.
-*Jepsen, N., Aarestrup, K., Økland, F. and Rasmussen, G. 1998. Survival of radiotagged Atlantic salmon (Salmo salar L.) – and trout (Salmo trutta L.) smolts passing a reservoir during seaward migration. Hydrobiologia 371/372: 347-353.
+*Jepsen, N., Aarestrup, K., Økland, F. and Rasmussen, G. 1998. Survival of radiotagged Atlantic salmon (''Salmo salar L.'') – and trout (''Salmo trutta L.'') smolts passing a reservoir during seaward migration. Hydrobiologia 371/372: 347-353.
-*Koed A, Jepsen N, Aarestrup K, Nielsen C (2002) Initial mortality of radio-tagged Atlantic salmon (Salmo salar L.) smolts following release downstream of a hydropower station. Hydrobiologia 483: 31−37
+*Koed A, Jepsen N, Aarestrup K, Nielsen C (2002) Initial mortality of radio-tagged Atlantic salmon (''Salmo salar L.'') smolts following release downstream of a hydropower station. Hydrobiologia 483: 31−37
 [[category:Downstream fish migration measures]][[category:Measures]]

@@ Line 22: / Line 22: @@
 =Relevant literature=
+*Fjeldstad, H-P, Barlaup, B.T., Stickler, M, Gabrielsen, S.-E. and Alfredsen, K. 2012. Removal of weirs and the influence on physical habitat for salmonids in a Norwegian river. River Research and Applications; 28, pp. 753-763.
 [[category:Downstream fish migration measures]][[category:Measures]]

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 ==During implementation==
-Physical implementation of migration barrier removals requires heavy machinery suited for the river size and its surrounding terrain, such as excavators and lorries. It must be considered how the different parts of the barrier, such as rocks and boulder, can be used as elements in the new habitat. Under normal conditions, none or only small volumes of substrate need to be transported to or from the construction site. Here, it is crucial that the labour involved has the relevant experience to make the best decisions while adjusting the physical habitat and that they have the required understanding of the planning documents and purpose of the measures
+Physical implementation of migration barrier removals requires heavy machinery suited for the river size and its surrounding terrain, such as excavators and lorries. It must be considered how the different parts of the barrier, such as [[Placement of stones in the river|rocks]] and boulders, can be used as elements in the new habitat. Under normal conditions, none or only small volumes of substrate need to be transported to or from the construction site. Here, it is crucial that the labor involved has the relevant experience to make the best decisions while adjusting the physical habitat and that they have the required understanding of the planning documents and purpose of the measures
 ==During operation==

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 ==During planning==
-Planning of fish barrier removal will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier. This includes measurements of water covered area, water edges and river slope and the bathymetry of the area. Geographic data should be handled in GIS software for further planning and analyses. The construction planning should be supported with simple hydraulic modelling or calculations, such as the models River2D, HEC-RAS 2D or OpenFoam (see Chapter 9.1 for references). The physical adjustments should then be planned according to the hydraulic calculations, assuring a stable bottom substrate and hydraulic conditions suitable for fish migrations
+Planning of fish barrier removal will start with mapping and surveying of the barrier itself and the river reach upstream and downstream of the barrier. This includes measurements of water covered area, water edges and river slope and the bathymetry of the area. Geographic data should be handled in GIS software for further planning and analyses. The construction planning should be supported with simple hydraulic modelling or calculations, such as the models [[River2D]], [[HEC-RAS]] 2D or [[OpenFOAM]]. The physical adjustments should then be planned according to the hydraulic calculations, assuring a stable bottom substrate and hydraulic conditions suitable for fish migrations
 ==During implementation==

← Older revision		Revision as of 12:05, 6 April 2020
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		+	[[file:icon_downstream.png\|right\|150px\|link=[[Downstream fish migration]]]]
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	=Introduction=		=Introduction=
	Not only is a hydropower dam a barrier in itself, it also changes the upstream river reach into a more lake-like habitat. Increased fish mortality due to predation at downstream migration barriers and dammed reaches may in some cases result in greater mortality than turbine passages (Jepsen et al. 1998; Koed et al. 2002). If connectivity for is to be restored, it should initially be considered whether the migration barrier can be removed. It is often the best and most long-term solution if the goal is to recreate connectivity. Here, the solution focuses on power-regulated rivers where dams will basically be maintained but also in power-regulated rivers there are possibilities for removing obstacles. In particular, smaller weirs have been removed in residual flow reaches or minimum flow reaches with great success (Fjeldstad et al. 2012).		Not only is a hydropower dam a barrier in itself, it also changes the upstream river reach into a more lake-like habitat. Increased fish mortality due to predation at downstream migration barriers and dammed reaches may in some cases result in greater mortality than turbine passages (Jepsen et al. 1998; Koed et al. 2002). If connectivity for is to be restored, it should initially be considered whether the migration barrier can be removed. It is often the best and most long-term solution if the goal is to recreate connectivity. Here, the solution focuses on power-regulated rivers where dams will basically be maintained but also in power-regulated rivers there are possibilities for removing obstacles. In particular, smaller weirs have been removed in residual flow reaches or minimum flow reaches with great success (Fjeldstad et al. 2012).

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 =Classification table=
 {{Migration barrier removal}}
 [[category:Downstream fish migration measures]][[category:Measures]]

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 Physical habitat measures in regulated rivers must often be maintained to ensure that functions related to flow and sediments are restored, such as flood events and connectivity of the sediments. The frequency of the maintenance will be very site-specific.
-=Useful MTDs=
+=Relevant MTDs and test cases=
 {{Suitable MTDs for Migration barrier removal}}