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

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

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

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

Selective for small species 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

A Denill fish pass on a Dordogne tributary

Most frequently used type of FP in France and in the Dordogne basin 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

Ex. : Bergerac pool fish pass (Dordogne river) 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

Ex. : Mauzac pool fish pass (Dordogne river) 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

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

Generally used in 8 m and higher dams Very large numbers of fish 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

Ex. : Tuilieres fish lift (Dordogne river) 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€

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

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

Large diversity of types : from rough ramps to bypass channels 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

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

First pass built 15 years ago Nylon brushes installed on PVC plates 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)

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

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

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

DOWNSTREAM DEVICES

About 2 000 hydropower plants in France (40 in Dordogne basin) 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

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

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

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

BY-PASS COMBINED TO COVENTIONAL TRASHRACKS 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

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

Surface guide walls for salmon smolts) Only one device in the World 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 !

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

STOPPING POWER STATION AND OPENING GATES High energetic cost 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)

FISH PASS EFFICIENCY

Need of efficiency is variable and depends on 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 Maintenance For salmon, the whole population on spawning ground

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

Ex. Mauzac (Dordogne river)

 50% to 70% for salmon

DISCHARGE / ATTRACTIVITY Generally between 2 and 10% of concurent flow 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)

Dissipated power : 100 W/m3 up to 300 W/m3 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

One of the main problem on french fish passes 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)

For salmon : up to 100% without delay For shad : between 50% and 75% 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 : ???

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

DOWNSTREAM DEVICES EFFICIENCY 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)

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

Efficiency for smolts between 55% and 90% 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 : ???

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

Fish species recognition Biological characteristics 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)

AUTOMATIC RESISTIVITY COUNTER Low cost But no fish recognition M. CHANSEAU et M. LARINIER MIGADO / ONEMA AUTOMATIC RESISTIVITY COUNTER Low cost But no fish recognition Only 3 sizes Tuilieres counter (Dordogne river)

Fish species recognition Continuous real-time data M. CHANSEAU et M. LARINIER MIGADO / ONEMA VIDEO CONTROL Fish species recognition Continuous real-time data But not all biological characteristics Problem with turbidity

Special counting system

Comparison of shad passages at Tuilieres and Mauzac video stations Shad passages and water discharge at Mauzac station

Expensive technique (equipment and manpower) M. CHANSEAU et M. LARINIER MIGADO / ONEMA TELEMETRY Expensive technique (equipment and manpower) But very precise informations about Fish behaviour Delays… The best technique to understand the problems and to find adapted solutions

Atlantic salmon (Mauzac – Dordogne river) Year 2008 0 / 5 upstream Delay up to 3 months All fish received at the new fish pass entrance 0 fish received at the old fish pass entrance Good location of the new entrance But low attractivity

Power plant Trap Pool Inlet canal Discharge Canal canal de fuite 10 m 10 m BR OC EC T DC FC T1 T3 RB Sb FP Bb

SEA LAMPREY Golfech (Garonne river) Year 2007 21 sea lamprey just below Golfech 2 pass upstream 19 come into fish lift and 17 go out !

Individual informations Passive mark : small reception area M. CHANSEAU et M. LARINIER MIGADO / ONEMA TIRIS and PIT TAG Relatively Low cost Individual informations Passive mark : small reception area SHAD and LAMPREY (Mauzac – 2005) 75% of fish use the new fish pass entrance

M. CHANSEAU et M. LARINIER MIGADO / ONEMA IN CONCLUSION Progress in technology as a result of in situ experiments and assessment of existing structures A multi-disciplinary approach, calling on both engineers and biologists, is necessary Residual impact of dams on diadromous species is significant, even with « efficient » fish passage facilities. The best way to restore longitudinal continuity : remove dams where possible

THE BEST SOLUTION FOR FISH M. CHANSEAU et M. LARINIER MIGADO / ONEMA THE BEST SOLUTION FOR FISH NO DAM !