Life4Fish project
Liège, 05 March 2018
Hydropower and good health of aquatic ecosystems:
from current to future innovative solutions
http://pousse-toidemonsoleil.eklablog.com
Pierre SAGNES
Agence Française pour la Biodiversité
Pôle écohydraulique AFB-IMFT
Toulouse, France
2009 : Climate and energy package
Goal renewable sources represent at least 20%
of Europe’s gross e ergy o su ptio y 2020.
The gross electricity generation from renewable energy sources in the EU-28(source: Guidance document on hydropower development and Natura 2000, N2K Group, Feb. 2015)
Introduction
Introduction
2011: 23 000 hydropower installations
91% = small ones 13% of total production
9% = large ones 87% of total production
(Source: Hydropower generation in the context of the EU WFD.
EC DG Environment, Arcadis, 2011, 168 p.)
European directives antagonism between:
the development of green energy (hydropower…the restoration of ecological continuity
Insuring goods
and persons
protection
Restoration of ecological continuity everywhere = excessive cost !
Need to prioritize the most valuable sites in terms of ecological value
Need of a diagnosis
Potential impacts of hydropower on freshwater ecosystems
Hydropower
- Construction phase
- Operation
- Maintenance
- Renovation
- End of operation
Upstream potential impacts:
Modification of the thermal regime
Accumulation of sediment in the reservoir
Increase in evaporation
Release of Greenhouse gases
Changes in Water quality
Changes in basin/chanel form and substrate
Changes in primary production
(plankton/periphyton)
Growth of aquatic macrophytes
Favour invasive species
Changes in riparian vegetation
Changes in communities composition:
blockage of migrations
mortality in turbines
modification of biotope
Karcham Wangtoo, I dia’s iggest p ivate hydropower plant (courtesy: Jaiprakash
Hydropower Limited)
Potential impacts of hydropower on freshwater ecosystems
Downstream potential impacts:
Modification of daily, seasonal and annual flows
Changes in water quality
Reduction of sediment transport
Changes in channel morphology
Modification of floodplains
Modification of coastal deltas
Changes in plankton and periphyton
Growth of macrophytes
Changes in riparian vegetation
Changes in freshwater species diversity
blockage of migrations
mortality in turbines
modification of biotope
decrease in lateral connections
Needs, impacts and solutions
Sediment transport: needs
(source : Handbook for environmental design in regulated salmon rivers, Forseth T. & Harby A. Eds., NINA Special
Report 53, 2014)
Exploitation of river bed sediments by juvenile salmon during their early development
http://flickrhivemind.net/Tags/barbel/Timeline
Sediment transport: impacts
© J.R. Malavoi
© Laboratoire d'Hydrographie et de Géomorphologie Fluviatile (Liège, Belgium)
Lateral erosion
Pavement
Needs, impacts and solutions
Sediment deposition
Lack of fine sediments
Needs, impacts and solutions
+ disconnection of lateral habitats,
lowering of grounwater table,
clogging of downstream habitat during operations of sediment evacuation
Upstream views during an operation of sediment evacuation in Génissiat dam (Rhône River, France, 2000)
Sediment transport: impacts
© P. Sagnes© P. Sagnes
Needs, impacts and solutions
Sediment transport: solutions
(source: Suivi de la reproduction naturelle des grands salmonidés migrateurs sur le bassin de la Dordogne en
aval du Sablier (départements de la Corrèze et du Lot) – Automne/hiver 2014/2015, rapport Migado, 2015)
Use of gravel as spawning habitats by Salmonids after an artificial sediment deposit (Maronne River)
Building of a new
fish pass
+ increase of
minimum flow
(12 m3/s)
in the by-passed section
Needs, impacts and solutions
Sediment transport: solutions
(source: Suivi de la reproduction naturelle
des grands salmonidés migrateurs sur le
bassin de la Dordogne en aval du Sablier
(départements de la Corrèze et du Lot) –Automne/hiver 2014/2015, rapport
Migado, 2015)
Number of spawning grounds in
the Maronne River, between 1999
and 2015
Sediment inputs in the by-passed section
(1300 m3) (1100 m3)
Fish needs water!
Needs, impacts and solutions
Flow dynamics: needs (1)
Water depth (m)
Water depth preferences for 3 life-stages of European grayling
(Thymallus thymallus)(source: Mallet et al., 2000, Habitat preference of European grayling in a
medium size stream, the Ain River, France. J. Fish Biol., 56, 1312-1326)
Upstream and downstream of the Little Nerang Dam (Australia)
Downstream the Aspen dam, Roaring Fork River, USA
(July 2012)
http://aspenjournalism.org/2014/04/30/aspen-agrees-to-leave-more-water-in-the-fork
Needs, impacts and solutions
Flow dynamics: impacts (1)
The Seine River (Poissy station):
average monthly discharge
Lateral migration of Pike
Needs, impacts and solutions
Flow dynamics: needs (2)Fish needs flow dynamics!
Needs, impacts and solutions
Flow dynamics: impacts (2)
Flow regime of Porma River (Spain), before (blue: 1942-1968) and after (pink: 1969-2004) regulation
through Juan Benet dam operation(source: Forecaster European Project, http://forecaster.deltares.nl/index.php?title=Hydrological_regime_modification)
Reversal of flow regime
© J-M. Olivier, UMR CNRS 5023
Chautagne by-passed channel (Rhône river, France) before (left) and after (right) the increase of
minimum flow.
- direct reconnection of cut-off channels to the river
- dredging of isolated pools within the channels
Rhône River:
- increase of the minimum flow in some bypassed sections,
- seasonal modulation of minimum flow following biological needs
In association with:
Needs, impacts and solutions
Flow dynamics: solutions
Pierre Bénite by-passed channel
(Rhône River, France) before (left)
and after (right) the increase of
minimum flow
(source: Suivi scientifique du programme
de restauration hydraulique et écologique
du Rhône - Un observatoire dynamique de
l’état é ologi ue du fleuve, Rappo t d’état d’ava e e t, 4
Needs, impacts and solutions
Flow dynamics: solutions
Proportion of rheophilic species before and after restoration (Pierre Bénite, Rhône River)
Average
(after restoration)
(source: http://
restaurationrhone.
univ-lyon1.fr/)
(source: Etude pour la définition d'indicateurs pour la
caractérisation des éclusées dans le bassin Adour-Garonne,
Courret D. et Larinier M., rapport pour l'Agence de l'Eau
Adour-Garonne, 2008)
http://www.cedren.no
Needs, impacts and solutions
Flow dynamics: impacts (3)
Discharge of the Maronne River (Basteyroux, France)
downstream the Hautefage HPP (1-31 jan. 2006)
http://hydropeaking.boku.ac.at/
Needs, impacts and solutions
Flow dynamics: impacts (3)
http://www.nature33.fr © Epidor
Stranded fish and gammarus
http://www.debits-dordogne.fr © Epidor
Dried eggs
Dried salmonids
spawning areas(Armand & Courret, 2011)
Stop all hydropeaking operations
Needs, impacts and solutions
Flow dynamics: solutions (3)
Stop hydropeaking during
biologically sensitive periods
Change HPP characteristics
e.g. create a buffer or demodulation pond
Base flow,
Maximum flow,
Range,
Increase and decrease gradie ts…
Modify hydropeaking characteristics
Level potential spawning substrates for
lithophilic species,
Remove potential trapping zones,
Provide hydraulic shelters oulders, …
Change channel morphology to
reduce sensitivity
http://www.grimselstrom.ch/kwoplus-en-US/stilling-basin-innertkirchen
Needs, impacts and solutions
Flow dynamics: solutions (3)
Project of a buffer pond to reduce hydropeaking effects on the Aare River (Switzerland)
- Stilling basin with a volume of 50'000-80'000 m3
- Reduction of hydro-peaking from 8:1 to 5:1
- Energy increase of 2 GWh per year
- Investment: 15 million Francs
Needs, impacts and solutions
Fish migration: needs
Daily movements of a brown trout(source: Ovidio et al., 2007)
Seasonal migration of brown trouts
(source: Meyers L. Thuemler T.F., Kornely G., 1992.
Seasonal movements of brown trout in Northeast
Wisconsin. North. Am. Jour. Fish. Managt. 12 : 433-441)
A salmonid trying to reach upstream habitats on the Maronne River (Hautefage, Corrèze, France)
Needs, impacts and solutions
Fish upstream migration: impacts
Fish are stopped or lose time
Needs, impacts and solutions
Fish upstream migration: solutions
http://www.michigan.gov/dnr
Trapping and road transport
A result of the optimisation/rebuilding of fish-passes
+ an increase of minimum flow:
Needs, impacts and solutions
Fish upstream migration: solutions
(source: Migradour)
36 44 49
123
61
216217
236298
178
350422
374343
425
811
2014: increase of
minimum flow
Number of
adults of
Atlantic
Salmon
(Artix, Gave
de Pau,
from video
counts)
years
424
1190
Aquaportail.com
http://seauxs.free.fr
La Sarthe - www.photosapiens.com
High slope
Low width
Low discharge
Low mean water depth
High mean water velocity
High particle size
High oxygen concentration
Low slope
Higher width
High discharge
Higher mean water depth
Lower mean water velocity
Low particle size
Variable oxygen concentration
Needs, impacts and solutions
Upstream habitats: needs
A little tributary of the Drôme River (France)
Serre-Ponçon dam (Durance River, France)
Needs, impacts and solutions
Upstream habitats: impacts
Creation of deep and slow-flowing habitats
© P. Sagnes
Sira-Kvina hydropower system in Vest-Agder county, Norway
(source: Handbook for environmental design in regulated
salmon rivers, Forseth T. & Harby A. Eds., NINA Special
Report 53, 2014)
Needs, impacts and solutions
Upstream habitats: impacts
The natural longitudinal gradient can be heavily modified
lmportant problem because no solution, except dam lowering… or destru tio !
Water volume in the reservoir will lose 99%:
from 1 700 000 m3 to 13 000 m3
and from 3,5 km to 300 m long
Needs, impacts and solutions
Upstream habitats: solutions
Current Poutès dam (Allier River, France)
17m
Future Poutès dam (Allier River, France)
<5m
(source: www.nouveau-poutes.fr)
Needs, impacts and solutions
Fish downstream migration: impacts (1)
Fish are stopped or lose time
(source: Etude du comportement de dévalaison des smolts
de saumon atlantique (Salmo salar) au droit de la retenue
de Poutès Allie , F a e à l’aide de la télé ét ie acoustique 2D, oral presentation, EDF, Alleyras, Onema,
Saumon Sauvage, 2015)
A fish trajectory in the reservoir of Poutès dam
(Allier River, France)
Mean time in the reservoir: 13.7 days
(Min: 19 hours ; Max: 45 days)
Atlantic Salmon smolts :
25% spend more than 23 days
Solution (1):
+ =
Needs, impacts and solutions
Fish downstream migration: impacts (2)
Fish can be killed, hurt or disoriented after passage through turbines
4 types of potential solutions:
- Targeted shutdowns of turbines
- Fish-friendly turbines
- Behavioural barriers associated with bypasses
- Material barriers associated with bypasses
To avoid fish passage through turbines:
3 weeks
31/03 22/04
Ex : salmon smolts
May be possible for some species (short migrating period)
0%
different years
Ex: silver eels
(Very) difficult for other species…
6 months
migrating
individuals
migrating
individuals
100%
Problem = to target and anticipate
downstream migration events
May induce important losses in terms of
energy production
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Targeted shutdowns of turbines
VLH (Very Low Head) turbines:– drop height range: 1.4 to 2.8 m
– discharge of 10 to 30 m3/s
–100 to 500 kW
Archimedes or hydrodynamic screws:– drop height range: 1.0 to 10 m
– discharge of 0.5 to 5.5 m3/s
– up to 300 kW.
Fish injection in a VLH turbine
(to test its Fish-Friendly potentialities)http://www.vlh-turbine.com/testfish
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Fish-friendly turbines
http://www.vlh-turbine.com/turbine
Water wheels and other potential fish-friendly tur i es…need biological tests before accepting their "ichtyocompatibility" in France.
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Fish-friendly turbines
Test of an infrasound
barrier to protect eel
migrating
downstream (Gave
de Pau, 2008 and
2009, au Baigts and
Biron dams)
Devices that guide fish towards a safe route by
means of diverse stimuli: noise, light,
electricity, bubbles, chain screens…
Light screen
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Behavioural barriers
Results sometimes promising in lab, but
much less during in situ tests (sensitive to
hydraulic conditions, species-dependent)
Needs of research, development and new tests
Ex: guide walls (or surface masks) for surface migrating species
Ex : Bellows Falls (Connecticut, USA) : mask height = 4,5 m
(water depth 9 m), angled at 40° Efficiency of 84% (smolts)
Must be quite deep and angled (towards a bypass) to be efficient.
Not efficient for bottom-oriented species, such as eel.
3 bypasses
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Material barriers
By-passes combined to existing trashracks
Efficiency for smolts: 10-20% to > 80%, depending on the repulsing effect (bar spacing) and fish
guidance (flow conditions)
Less efficient for eel as the repulsive effect of trashrack is lower
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Material barriers
3 crucial functions to ensure:
– Stop the fish and avoid them to go through the turbines
– Guide them towards bypasses
– Transfer them downstream without any damages
Low spacing trashrack combined with one or
several by-passes
Needs, impacts and solutions
Fish downstream migration: solutions (2)
Material barriers: fish-friendly water intake
Angled trashrack
Inclined trashrack
A way of working together… A current collaboration between:
Operation, economic feedbacks:
Water intake characteristics,
Cleaning of bar racks,
Loss of hydraulic load,…
and HydroelectriciansEcohydraulics R&D team
Hydraulic & Biological efficiency feedbacks
Pôle Recherche et Développement en Ecohydraulique
A possible balance between economic and ecological needs
https://www.pinterest.com
Need of modernising powerplants
Need of improving ecosystems functioning
A possible balance between economic and ecological needs
Albbruck-Dogern HPP (Rhine River)
(Source: WFD and hydromorphological pressures –Technical Report. Case studies potentially relevant to
the improvement of ecological
status/ potential by restoration/ mitigation
measures, 2006)
Run-off facility built in 1933, long derivation
No power plant on the weir
Low residual flow (3-8 m3/s)
New concession for the hydropower plant
and building of an additional hydropower plant by the weir
Aim = increase of power generation together
with improvement of the ecosystem.
- Increase of residual flow up to 200 m3/s in 2009-2010
- Construction of a nature like fish pass, creation of a
nature like bed structure in the diversion with gravel bars,
revitalisatio of for er gravel isla ds…- Costs for hydropower development = 51 million EUR
- Costs for ecological measures = 4 million EUR
Improvement of the
ecological conditions and
increase of the annual
energy output of about 87
GWh/year.