Environmental impacts of hydro-peaking

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Alexandrina Jennings
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1 Environmental impacts of hydro-peaking Tor Haakon Bakken 1, Roser Casas-Mulet 2 & Michael Puffer 2 1 SINTEF Energy Research & CEDREN 2 NTNU & CEDREN

2 Structure of my talk CEDREN and research on renewable energy Overview of EnviPEAK environmental impacts of hydropeaking Results from studies on physical processes Results from some of the fish studies Mitigating measures Supplementary results from Ulrich Pulg

3 Centre for environmental design of renewable energy CEDREN 3

analysis CO 2 -capture and storage Transportation New climate

4 Climate agreement in Parlament (2008) Energy efficiency Renewable energy CO 2 -neutral heating Energy systems Institutional framework analysis CO 2 -capture and storage Transportation New climate agreement in Parlament (2012) 8 research centres for renewable energy established

5 EcoManage HydroPEAK EnviPEAK EnviDORR BirdWind PROJECTS OptiPol SUSGRID Social GOVREP Environm Economy + PILOTS

6 EnviPEAK Physical and biological impacts in running waters Hydro-dynamics, erosion and sedimentation Temperature and ice River pearl mussel Benthos Salmonid Fish Fish Mammals Birds.and some research in lakes/reservoirs

7 Example hydro-peaking regimes Flow at outlet of HP-plant Period 1 Flow measurements 20 km downstream outlet Period 2

8 Example hydro-peaking regimes Discharge station: Several start/stop episodes every day. No release/production in the week-ends. Discharge station: Constant production in the week-days, no production in the week-ends

9 Definition and drivers Unclear definition, but characteristics are: More rapid start/stop than natural hydrological processes More frequent changes than naturally An element of periodicity Max value (much) lower than e.g. annual flood Drivers are: Sale of power when high price Balancing the grid Development of non-regulated power production

10 Coupling physical and biological studies Photo UNI Research

11 Coupling physical and biological studies Photo: SINTEF

12 Coupling physical and biological studies Photo: SINTEF

13 Photo: Arne Jensen, NINA

14 How much water is needed? and what about the dynamics

Prior research about hydro-peaking The impacts are largest in rivers, smaller in reservoirs, lakes & fjords The larger and more frequent variations the

15 Prior research about hydro-peaking The impacts are largest in rivers, smaller in reservoirs, lakes & fjords The larger and more frequent variations the larger impacts The impacts are determined by time and location specific characteristics (type of HP-plant, type of ecosystem, time of the day/year, etc.)

Nidelva, Trondheim Impacts in rivers Stranding as a problem Rapid changes (decreases) in water level might cause stranding Reduced changes in water level drops reduce the risk of stranding Highest

16 Nidelva, Trondheim Impacts in rivers Stranding as a problem Rapid changes (decreases) in water level might cause stranding Reduced changes in water level drops reduce the risk of stranding Highest risk of stranding in cold water (winter), at day-time and in river sections with coarse substrate Fish can survive stranding Harby et. al, 2004 and other publications Thumb of rule: Water level drops slower than 13 cm/hour

Dynamic mesohabitat HEC- RAS Physical habitat analysis 3D hydraulic

17 Microscale Meso-scale Catchment scale Approach Hydropower operation simulation nmag Operational strategies Stranding areas calculation Dynamic mesohabitat HEC- RAS Physical habitat analysis 3D hydraulic model STAR CCM GW-SW interactions Salmon survival Physical and Biological processes

Study site: Lundesokna river system Water level (m) 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.

Power Plants 3 Interbasin transfers Increasing flow Peak flow Dewatering curve 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45 0 15 30 45

18 Study site: Lundesokna river system Water level (m) Sokna Håen Håen Sama Samsjøen Holtsjøen Total catchment area: 395 km 2 Average annual runoff: 381 Mm 3 /year Installed capacity: 61 MW Average annual production: 278 GWh 3 Regulated reservoirs 3 Power Plants 3 Interbasin transfers Increasing flow Peak flow Dewatering curve Regular hydropeaking operations

19 Geometry Data collection DATA TYPE EQUIPMENT Differential GPS Laser scan OUTPUT x, y, z points + Camera mounted to helicopter

20 Discharge (m3/s) Hydraulic Data collection DATA TYPE EQUIPMENT Pressure transducers ADCP OUTPUT Discharge Water levels Velocity profiles Water level elevation (m)

21 Model tools: The nmag program: Macro-scale Simulates hydropower operations for whole systems with several power plants, reservoirs and transfers

22 Meso-scale 1D: Dynamic mesohabitat prediction Aim: To develop a tool to predict mesohabitat changes linked to flow variations using a 1D hydraulic model Tools: Hec-RAS / ArcGIS Norwegian Mesohabitat Classification method (Borsany, 2005) Field assessment Comparison

23 Meso-scale 1D: Dynamic mesohabitat prediction Field Assessment:

Elevation (m) Meso-scale 1D: Dynamic mesohabitat prediction Comparison: Field assessment Surface pattern Surface gradient Surface velocity Water depth Hec-RAS simulation Froude number Water level /

24 Elevation (m) Meso-scale 1D: Dynamic mesohabitat prediction Comparison: Field assessment Surface pattern Surface gradient Surface velocity Water depth Hec-RAS simulation Froude number Water level / distance Average velocity Depth L_SF_Subcritical_15.3Q Plan: L_SF_Subcritical_15.31Q Station (m) Legend WS PF 1 Ground Bank Sta OWS PF 1

at each extremity 100-120 m - Add 1 : 1 transect in between 50-60 m - Add 3 : 3 transects in between 25-30 m - Add 7

25 Meso-scale II: Stranding areas calculation Aim: To find the 'optimum' geometrical representation in a 1D to quantify stranding areas Tools: Hec-RAS High quality field data: geometry and hydraulic data Approach: - Basic : One transect at each extremity m - Add 1 : 1 transect in between m - Add 3 : 3 transects in between m - Add 7 : 7 transects in between m - Add 15 : 15 transects in between 6-7 m - Add 31 : 31 transects in between 3-4 m

26 Meso-scale II: Stranding area calculation Results: More transects

27 Meso-scale 3D: Steady simulation

28 Meso-scale 3D: Unsteady simulation Film Simulation

29 Micro-scale: GW-SW interactions Aim: To assess the surface vs subsurface water dominance in the hyporheic zone during both dewatering and watering events stranding and egg survival Experimental Setting:

The results vary very much within short distances (very heterogenic), due to diff.

30 Results: Micro-scale: GW-SW interactions Hydraulic processes differ between flow decrease and increase: Water level increases in hyporheic zone than it decreases The results vary very much within short distances (very heterogenic), due to diff. in conductivities The water temperature determined by surface water/ groundwater ratio

31 Integrating energy production and impacts on the ecosystem Hydrology Energy production simulations Habitat quality Hydraulics

32 Integrating energy production and impacts on the ecosystem Hydrology Energy production simulations Habitat quality Hydraulics

33 Stranding experiment in Ims, Norway Preliminary results from winter experiment Unpublished results: Puffer, Berg and more

34 Hydropeaking experiment in Paltamo, Finland Preliminary results from winter experiment The effects on fat are a little larger in the Summer experiments. Unpublished results: Puffer, Berg, Vehanen and more

35 Hydropeaking experiment in Paltamo Preliminary results from winter experiment The effects on body mass are significant! Unpublished results: Puffer, Berg, Vehanen and more

36 Habitat preferences of juvenile Atlantic salmon Experimental setup: Fish density 1 fish/m 2 vs. 3 fish/m 2 Intercohort competition large fish present vs. absent Time of day daytime vs. nighttime Season of the year summer, autumn, winter & spring

37 Winter No density effect! Unpublished results: Puffer, Berg, Vehanen and more

38 Conclusion habitat preferences Highest probability of finding small fish in shallow habitats: Spring Autumn night time Hydro-peaking events during these times most problematic Unpublished results: Puffer, Berg, Vehanen and more

39 Measures to reduce conflicts Administrative measures Selection of plants dedicated to hydro-peaking Compensation Habitat restoration Master plan for hydro-peaking Operational measures Measures at

39 39 Measures to reduce conflicts Administrative measures Selection of plants dedicated to hydro-peaking Compensation Habitat restoration Master plan for hydro-peaking Operational measures Measures at each individual plant Start/stop speed at plant Timing and frequency Base-flow Physical/biological measures instream Dampening reservoir Habitat restoration, leading of water, gravel Stocking Etc. Go to All publications

Summing up Physical studies: Methods to increase efficiency of data collection developed Methods to increase precision and volume of data developed Models and model integration further

40 Summing up Physical studies: Methods to increase efficiency of data collection developed Methods to increase precision and volume of data developed Models and model integration further developed Several tools "ready to use Fish: less physiological stress than expected? Fish and spawning wait for Ulrich Pulg, UNI The results need to be verified, handled statistically and 'peer-reviewed'

41 EnviPEAK Physical and biological impacts in running waters Hydro-dynamics, erosion and sedimentation Temperature and ice River pearl mussel Benthos Salmonid Fish Fish Mammals Birds.and some research in lakes/reservoirs

42 42 Information about CEDREN (official web-site) (project leader EnviPEAK) (Director of CEDREN)