Environmental Impacts of Hydropower Production - How can we - - PowerPoint PPT Presentation

HydroVision INDIA

19-21 April 2012, New Delhi

Session 8c Addressing Environmental Considerations

Environmental Impacts of Hydropower Production - How can we Avoid/Mitigate Negative Effects on the Aquatic System?

Stefan Schmutz & Rafaela Schinegger

Institute of Hydrobiology and Aquatic Ecosystem Management, University of Natural Resources and Life Sciences, Vienna, Austria

Stefan Schmutz

• Introduction
• Hydro power and its ecological consequences

– Impoundment – Hydro peaking – Reservoir flushing – Migration barriers

• Restoration of migration corridor

– Residual flow

• Calculation of environmental flow - EF in Austria
• Preserving aquatic ecosystem services

Contents

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Stefan Schmutz

Consequences 3.5 TWh/a by 2015

Directive on Energy from renewable resources

Barrier not passable or fish Barrier passable or fish Planned hydropower plant 3

Stefan Schmutz

Impoundments

Stefan Schmutz

Impoundments

• Loss of fluvial habitat
• Aggregation of fine

sediments

• Clogging of river bed
• Loss of habitat diversity

Disruption of longitudinal continuity

• Fish migration
• Sediment transport

Loss of lateral connectivity

• Decoupling river - floodplain
• Loss of inundation area
• Reduced inundation

frequency

• Disruption of lateral fish

migration

5 Schmutz et al., 2010

Stefan Schmutz

Impoundments

• Loss of fluvial habitat
• Aggregation of fine

sediments

• Clogging of river bed
• Loss of habitat diversity

Disruption of longitudinal continuity

• Fish migration
• Sediment transport

Loss of lateral connectivity

• Decoupling river - floodplain
• Loss of inundation area
• Reduced inundation

frequency

• Disruption of lateral fish

migration Floodplain channel systems Diverting part of the river to floodplain Channel restoration (upstream part only) Fish pass facilitiesFloodplain channel systems Diverting part of the river to floodplain Channel restoration (upstream part only) Fish pass facilities

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Stefan Schmutz

Impoundments

• Loss of fluvial habitat

Aggregation of fine sediments Clogging of river bed Loss of habitat diversity Disruption of longitudinal continuity Fish migration Sediment transport Loss of lateral connectivity Decoupling river - floodplain Loss of inundation area Reduced inundation frequency Disruption of lateral fish migration Floodplain channel systems Diverting part of the river to floodplain Channel restoration (upstream part only) Fish pass facilities

Limited enhancement

• ptions for

impoundments

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Stefan Schmutz

Impoundments

• Loss of fluvial habitat cannot be

compensated by restoration measures Long-term function of implemented measures Loss of fluvial habitat Aggregation of fine sediments Clogging of river bed Loss of habitat diversity Disruption of longitudinal continuity Fish migration Sediment transport Loss of lateral connectivity Decoupling river - floodplain Loss of inundation area Reduced inundation frequency Disruption of lateral fish migration Floodplain channel systems Diverting part of the river to floodplain Channel restoration (upstream part only) Fish pass facilities Floodplain channel systems Diverting part of the river to floodplain Channel restoration (upstream part only) Fish pass facilities

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Stefan Schmutz

Hydro peaking

• Peak flow

Flushing effects Stranding effects Temperature alterations Minimum flow Altered habitat quality and quantity

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Stefan Schmutz

Hydro peaking

• Peak flow

Flushing effects Stranding effects Temperature alterations Minimum flow Altered habitat quality and quantity

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Influence of hydro peaking on the fish stock of the Bregenzerach

Stefan Schmutz

Hydro peaking

• General solutions

Removal of hydro peaking Application of ecological flow Ecological flow Applying minimum flow Dampen peak flow

• Altered HP operation
• Compensation reservoir
• Coordination of power

plants Methodologies and criteria Peak flow Flushing effects Stranding effects Temperature alterations Minimum flow Altered habitat quality and quantity

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Stefan Schmutz

Hydro peaking

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Reaction of brown trout (Bregenzerach) to

• increased residual flow and
• elimination of hydro peaking

Stefan Schmutz

Hydro peaking

• Reaction to hydro-peaking

widely unknown for most fish species

• Lacking national and

European standards

• Few case studies available

(AT, N)

• Lack of monitoring (good

status)

• Interaction with morphology

Peak flow Flushing effects Stranding effects Temperature alterations Minimum flow Altered habitat quality and quantity General solutions Removal of hydro peaking Application of ecological flow Ecological flow Applying minimum flow Dampen peak flow

• Altered HP operation
• Compensation reservoir
• Coordination of power

plants Methodologies and criteria

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Stefan Schmutz

HyTEC – Hydromorphology and Temperature Experimental Channel

tw, vm

Stefan Schmutz

• Reservoir & impoundment flushing
• Water quality degradation

Turbidity Suspended solids Oxygen depletion Toxics Habitat alteration Deposition of fine sediments Clogging of river bed

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Stefan Schmutz

Reservoir & impoundment flushing

• Water quality degradation

Turbidity Suspended solids Oxygen depletion Toxics Habitat alteration Deposition of fine sediments Clogging of river bed Flushing management Flushing during high flows Flushing outside reproductive period of fish species Limit SS concentrations Adjust flushing frequency Dredging Morphological adaptations of impoundments Improving sediment transport

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Stefan Schmutz

Reservoir & impoundment flushing

• Detailed criteria and limits

for guaranteeing water quality standards during flushing

• Innovative design of

impoundments for better sediment transport

• Long term sediment

transport at catchment leve Water quality degradation Turbidity Suspended solids Oxygen depletion Toxics Habitat alteration Deposition of fine sediments Clogging of river bed Flushing management Flushing during high flows Flushing outside reproductive period of fish species Limit SS concentrations Adjust flushing frequency Dredging Morphological adaptations of impoundments Improving sediment transport

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Stefan Schmutz

Migration barriers

• Disruption of upstream fish

migration Spawning migrations Feeding migrations Habitat shifts Recolonisation after floods Drift of larvae and juveniles Habitat fragmentation Fragmented populations

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Stefan Schmutz

Migration barriers

• Upstream solutions

Barrier removal Fish pass Upstream fish passes Nature-like fish bypass channels Nature-like pool passes Ramps Vertical slot fish pass Design and biological criteria Downstream solutions Spill flow (over weir) Turbines Downstream fish facilities

• Avoiding entrainment

into water intakes and guiding fish into bypass facilities

• Fish friendly turbines

Others (transportation) Disruption of upstream fish migration Spawning migrations Feeding migrations Habitat shifts Recolonisation after floods Drift of larvae and juveniles Habitat fragmentation Fragmented populations

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Stefan Schmutz

Migration barriers

• Lacking European

standards

• EIFAC Working Group
• n FISH PASSAGE

BEST PRACTICES

• Attraction flow
• Evaluation of fish passes
• Lack of methods to monitor

the effectiveness of fish passes

• Downstream migration is

considered as more problematic than upstream migration

• Technologies are less

advanced

• Downstream migratory

behaviour for most species unknown (only for some species) Disruption of upstream fish migration Spawning migrations Feeding migrations Habitat shifts Recolonisation after floods Drift of larvae and juveniles Habitat fragmentation Fragmented populations Upstream solutions Barrier removal Fish pass Upstream fish passes Nature-like fish bypass channels Nature-like pool passes Ramps Vertical slot fish pass Design and biological criteria Downstream solutions Spill flow (over weir) Turbines Downstream fish facilities

• Avoiding entrainment

into water intakes and guiding fish into bypass facilities

• Fish friendly turbines

Others (transportation)

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Stefan Schmutz

Restoration of migratory corridor

Rivers > 100km2 > 5 000 impassable barriers

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Stefan Schmutz

Restoration of migratory corridor

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Stefan Schmutz

Minimum flow

• Habitat degradation

Altered habitat quality

• Flow velocity
• Water depth
• Substrate and sediment

load

• Water temperature

Habitat loss Altered habitat quantity

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Stefan Schmutz

Minimum flow

• General solutions

Removal of water withdrawal Application of ecological flow Ecological flow Minimum flow Dynamic flow (incl. groundwater and floodplain) Methodologies and criteria Habitat degradation Altered habitat quality

• Flow velocity
• Water depth
• Substrate and sediment

load

• Water temperature

Habitat loss Altered habitat quantity

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Stefan Schmutz

Minimum flow

• Lacking European standards
• State-of-the-art report COST

action 626 Habitat models developed for target species only Transferring habitat model result to ecological status Lack of monitoring of environmental flow allocation (good status) Interaction with morphology Dynamic flow General solutions Removal of water withdrawal Application of ecological flow Ecological flow Minimum flow Dynamic flow (incl. groundwater and floodplain) Methodologies and criteria Habitat degradation Altered habitat quality

• Flow velocity
• Water depth
• Substrate and sediment

load

• Water temperature

Habitat loss Altered habitat quantity

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Stefan Schmutz

Calculation of environmental flow

• Based on

– Hydrologic parameters

• NNQt (lowest daily flow)
• MJNQt (mean annual low flow)
• MQ (mean flow)

– Biocoenotic criteria

• Fish
• Macro invertebrates
• Algae, riparian vegetation, floodplain vegetation

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Stefan Schmutz

Calculation of environmental flow

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Stefan Schmutz

Austrian environmental flow regulation

seasonality of natural relocation and type-specific composition of sediments sufficient flow during spawning season diversity of type-specific, seasonal habitats (for different age stages) type-specific conditions of oxygen and temperature

• Minimum depht/flow velocities for fish habitats

Natural mean annual flow < 1m3/s Natural mean annual flow > 1m3/s Minimum flow > Lowest daily flow (natural) 50% mean annual low flow 33% mean annual low flow Dynamic flow 20% of actual flow (recommended)

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Stefan Schmutz

Habitat models for individual EF assessment

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Stefan Schmutz

Hydromorphological criteria for good ecological status in Austria

Discharge fluctuations (hydro peaking)

• < 1:3, 80% of river bed covered during down-surge

Impoundment

• reduction of mean flow velocity < 0.3m/s (per cross section) occurs only

locally on short stretches Connectivity

• anthropogenic migration barriers have to be passable all-the-year

Morphology

• dynamic of shoreline and river bed are modified only on short stretches

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Stefan Schmutz

Provision services food / aquatic biomass fish, algae water for consumptive use drinking, irrigation, domestic & industry water for nonconsumptive use energy, transport, regulation e.g. cooling, fire extinction,..) Regulatory services climate regulation / bioclimatic services temperature balance / compensation, evapotranspiration

(Millennium Ecosystem Assessment, adapted)

Cultural services recreation research & education bioindication, references,… genetic pool regulation & regeneration of biocoenoses reproduction / self- renewal of biozoenoses / regulation of population, habitat provision regulation of material / nutrient cycles water retention / renewal of water resources, erosion regulation / retention of soils and sediments, water purification / primary production

Aquatic ecosystem services

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Stefan Schmutz

Consequences

Directive on Energy from renewable resources

Schmutz et al., 2010

Production of 2.8 TWh/a 15 HPP 14 HPP 107 HPP 803 HPP 100 200 300 400 500 600 Reservoirs Run-off the river Mixture Small HPP Impounded river length [km]

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Stefan Schmutz

Ecomasterplan

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Stefan Schmutz

Well-trained experts are needed!

http://www.wau.boku.ac.at/al.html

Stefan Schmutz

Thank you for your attention!

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