Matthieu CHANSEAU, Michel LARINIER

2. Fish passage facilities, fish pass efficiency and monitoring techniques Matthieu CHANSEAU, Michel LARINIER Association Migrateurs Garonne-Dordogne (MIGADO) ONEMA-GHAAPPE

3. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • REGULATIONS • A french law adopted in 1984 requires that any hydro plant must include facilities to guarantee free passage (upstream and downstream) for migratory species • at existing plants in rivers classified as necessary for 'migratory fish' • at new or relicenced plants in all rivers (even those not classified as migratory rivers) • an obligation to ensure upstream and downstream passage • Species considered in the french law • 8 diadromous fish : salmon, sea trout, lamprey (2), shads (2), sturgeon, eel • 3 « riverine » fish : trout, grayling and pike • European Water Framework Directive : concept of ecological continuity • the passage of all species has to be taken into account in a more determined way

4. M. CHANSEAU et M. LARINIER MIGADO / ONEMA AN OVERVIEW OF DAMS IN THE DORDOGNE BASIN

5. M. CHANSEAU et M. LARINIER MIGADO / ONEMA Fish pass facilities

6. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • DENIL FISH PASS • Selective for small species • Can tolerate only moderate variations in upstream water level • Easier and cheeper than others FP • Discharge generally less than 1 m3/s • Small river

7. A Denill fish pass on a Dordogne tributary

8. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • POOL FISH PASS • Most frequently used type of FP in France and in the Dordogne basin • Several types for all species if • Drop from 15 cm to 35 cm • Dissipated power 100-200 W/m3 • Pool hydrodynamic • All rivers • All species

9. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Ex. : Bergerac pool fish pass (Dordogne river) • Discharge between 2 and 6 m3/s • Upstream level variation : 2 m • Attraction flow up to 5 m3/s

10. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Ex. : Mauzac pool fish pass (Dordogne river) • Discharge : 1 m3/s • Upstream level variation : 1 m • Attraction flow up to 5 m3/s

11. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Ex. : Iffezheim pool fish pass (Rhine river)

12. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FISH LIFTS • Generally used in 8 m and higher dams • Very large numbers of fish • Some problems with small species ; not • adapted to eel • Small overall dimensions • Low sensitivity to upstream water • level variations • But • High operating costs • Low efficiency for small fish because fine • screens (< 3 cm) require for maintenance

13. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Ex. : Tuilieres fish lift (Dordogne river) • Discharge : 1 m3/s • Attraction flow up to 5 m3/s • Cost : 1.3 M€

14. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Ex. : Golfech fish lift (Garonne river)

15. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FISH LOCKS • No more considered to be an option in France

16. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • « NATURAL » FISH PASS • Large diversity of types : from rough ramps to bypass channels • All species • Low slope  moderate heigh

17. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Carennac rough ramp (Dordogne river)

18. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • EEL FISH PASS • First pass built 15 years ago • Nylon brushes installed on PVC plates • Recent experiments to test other more robust and less expensive substrates • Very low discharge and important slope (up to 45° and more)

19. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Tuilieres eel fish pass (Dordogne river) • - 1997

20. TITLE : Fish passage facilities M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Mauzac eel fish pass (Dordogne river) - 2007

21. TITLE : Fish passage facilities M. CHANSEAU et M. LARINIER MIGADO / ONEMA • Golfech eel fish pass (Garonne river) - 2008

22. DOWNSTREAM DEVICES

23. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • About 2 000 hydropower plants in France (40 in Dordogne basin) • One of the most important problem : turbine mortality • Experimental studies in the 90’ for salmon and since 2000 for eel • More complicated problems • Actually, no real satisfactory solution for large dams • Principles • Physical barriers which exclude fish from the turbine intakes • Behavioural barriers which guide, attrack or repell fish • System which ensure downstream passage without damage

24. M. CHANSEAU et M. LARINIER MIGADO / ONEMA 50% 100% 20% 10% 2-5% • For eel : mortality x 4/5

25. Turbine Mortality : empirical formulas - M% = f(turbine characteristics, fish length) Probability to pass by the turbines or by the dam - Ratio turbine flow / river flow - Configuration of the intake canal and dam - Migratory fish behaviour Power house Turbined flow Turbine mortality Dam Flood gates flow

26. Ex. on the Dordogne basin for salmon smolt • Mean mortality of 20% • One obstacle (Tuilieres) is responsible for 70% of mortality

27. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • BY-PASS COMBINED TO COVENTIONAL TRASHRACKS • Surface by-pass for salmon smolt • Surface and bottom by-pass for eel

28. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • BEHAVIOURAL BARRIERS • Sound and electricity • Low efficiency (0-15%) • Light • Improve efficiency • for smolt

29. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • BEHAVIOURAL BARRIERS • Surface guide walls for salmon • smolts) • Only one device in the World • (Connecticut river) – 75% • But in 2009, another one in • Tuilieres on Dordogne river !

33. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • DOWNSTREAM PASSAGE Trapping and transport

34. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • STOPPING POWER STATION AND OPENING GATES • High energetic cost • Good knowledge of migration timing • Goog knowledge of fish behaviour •  first experimentation in Tuilieres in 2009 (eel)

35. FISH PASS EFFICIENCY

36. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FISH PASS EFFICIENCY • Need of efficiency is variable and depends on • the species (ex. : for cyprinids, avoid isolation of the populations) • the location of obstacles • the numbers of obstacles • Efficiency difficult to determine • Percentage of passage (%) • Delays (hours, days) • Number of fish • Number of species • Hydraulic conditions • Efficiency depends on • Location • Discharge / Attractivity • Hydraulic conditions • Maintenance For salmon, the whole population on spawning ground

37. 4 entrances M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FISH PASS LOCATION

38. Ex. Mauzac (Dordogne river)

39.  50% to 70% for salmon

40. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • DISCHARGE / ATTRACTIVITY • Generally between 2 and 10% of concurent flow • Fish pass entrance in a not disturbed area Ex. Mauzac (Dordogne river)

41. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • HYDRAULIC CONDITIONS • Current speed • 2.5 m/s for large species • 1.5 m/s for small species • Drop : between 0.2 and 0.5 m • Dissipated power : 100 W/m3 up to 300 W/m3 • Minimal depth between 0.2 and 0.4 m For all fish For large fish

42. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • MAINTENANCE • One of the main problem on french fish passes • Natural fish passes are less sensitive Ex. on Dordogne tributaries (summer 2007)

43. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FINALLY • For salmon : up to 100% without delay • For shad : between 50% and 75% • For eel : ??? • For lamprey : > 75% ? • For others species : ???

44. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • DOWNSTREAM DEVICES EFFICIENCY • Location of by-pass

45. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • DOWNSTREAM DEVICES EFFICIENCY • Flow between 2% to 10% of the turbine discharge • Low current velocity (< 0.8 m/s) • Local hydraulic conditions (for ex. no upwelling)

46. BPD : 1.8 m3/s 1.5 m upstream trashrack upwelling removal by deflector BPD : 0.8 m3/s 1.5 m upstream trashrack BPD : 0.6 m3/s 6m upstream trashrack Bypass efficiency

47. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • FINALLY • Efficiency for smolts between 55% and 90% • Efficiency for eel between 20% and 60% • For others species : ???

48. MONITORING TECHNIQUES Trapping Automatic resistivity counter Video control Telemetry TIRIS tag

49. M. CHANSEAU et M. LARINIER MIGADO / ONEMA • TRAPPING • Fish species recognition • Biological characteristics • But risks of injury (death) or stress • High manpower requirement • No continuous real-time data • (with or without mark/recapture operations)