Steve_Cryer-Vienna
description
Transcript of Steve_Cryer-Vienna
![Page 1: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/1.jpg)
Fish Ladders & SHP Fish Ladders & SHP -- UK UK ExperienceExperience
British Hydropower AssociationSteve Cryer - Chairman
![Page 2: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/2.jpg)
Fish Passes to enable the Upstream and Downstream Migration of
Salmonids are enshrined in legislation
• Salmon and Freshwater Fisheries Act England and Wales 1975
• Salmon (Fish Passes and Screens) Scotland Regulations 1994
• Fisheries Act Northern Ireland 1966
![Page 3: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/3.jpg)
Fish Pass Issues
• New development schemes• Existing schemes on rivers that have
relatively small weirs• Existing schemes with larger weirs and
dams circa >5m
![Page 4: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/4.jpg)
Fish Pass Types
• Pool and Step with variations• Borland Lift• or alternatively none at all - loss of
spawning grounds above the SHP abstraction point being ameliorated by hatcheries supplementing fish stocks
![Page 5: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/5.jpg)
Typical Pool and Step Design
![Page 6: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/6.jpg)
Typical Pool and Step Design
• Pools need to be large enough and deep enough to keep turbulence to a minimum
• The height of the step is kept to circa <0.5m to encourage fish to move up
• The sides need to be high enough to prevent fish from jumping out
• The velocity of the water through the steps must be within the swimming speed of the target species of fish
![Page 7: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/7.jpg)
![Page 8: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/8.jpg)
Typical Pool and Step Design• Denil design• Diagonal Baulk• Pool and steps being built of natural rock formations etc.• Pool and weir with underwater orifice as shown below• These tend to be the exception rather than the rule
![Page 9: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/9.jpg)
Optimum Position of a Fish Pass• The Fish Pass is located
close to the intake screen It is important to ensure the correct angle of the screen in relation to the river flow to reduce the velocity through the screen to less than the body length speed of the target species and attract them into the fish pass
![Page 10: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/10.jpg)
Alternative Fish Pass Arrangement
• With this design the fish are allowed to enter the Headrace and are returned to the river via a bywash, situated in front of the turbine screen
• This arrangement is generally found at old mill sites
![Page 11: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/11.jpg)
Borland Lift
![Page 12: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/12.jpg)
Borland Lift Performance Assessment
• Underwater cameras in the tailrace and exit chamber
• Fish counters at the entrance and exit points• This provides information to optimise the
operation of the lift i.e. flowrates, duration time of operation, number of operations and time of day for these operations
• Ongoing studies.
![Page 13: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/13.jpg)
Fish Pass Assessment
Brief overview of a study undertaken on the River Tavy at Abbey Weir,
Tavistock in South West England UK
![Page 14: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/14.jpg)
River Tavy Low Flow Scenario
![Page 15: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/15.jpg)
River Tavy Low Flow Scenario
![Page 16: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/16.jpg)
River Tavy High Flow Scenario
![Page 17: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/17.jpg)
Abbey Weir and Fish Pass
![Page 18: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/18.jpg)
Fish Tracking at Abbey Weir
![Page 19: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/19.jpg)
Sample of Tracking Results
![Page 20: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/20.jpg)
Abbey Weir and Fish Pass• It can be seen from the results that fish
behaviour is unpredictable - female fish?• The maximum time recorded from fish
entering and leaving Station TV5, when it has ascended the weir, is 12hours
• The minimum time is in minutes• Despite the design not conforming to the
general standard the passage of fish is not unduly impaired
![Page 21: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/21.jpg)
Abbey Weir and Fish Pass
• The results to the study indicate that the fish pass at Abbey Weir does work, despite not conforming to an ideal design.
• More work needs to be done to verify the data, tagging a greater number of fish and looking at a greater range of flow scenarios
• But I do not expect the results to change that much
![Page 22: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/22.jpg)
Abbey Weir and Fish Pass• We have learnt several lessons over this• It is important to carry out field as well as
desk top studies when examining the performance of existing weirs
• Discussions with local people and long term anglers. In this instance it revealed that the anglers do not fish the pools immediately downstream of the weir as there is little likelihood of a catch
![Page 23: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/23.jpg)
Abbey Weir and Fish Pass• Historical research can reveal some interesting aspects• Here it was found that a step and pool pass did exist at
this site in 1928• It was modified to the current arrangement at the
insistence of the owner of the river at the time “The Duke of Bedford” (who also had extensive fishing rights upstream and downstream of the weir) before granting permission for the hydro plant to be built
• How this design came about we do not know but it is effective
![Page 24: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/24.jpg)
Abbey Weir and Fish Pass
There are two wise principles it is good to follow
• BATNEEC – Best Available Techniques Notwithstanding Excessive Economic Costand a favourite with Engineers
• If its not broken don’t fix it
![Page 25: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/25.jpg)
Finally a thoughtStudies of fish passes are expensive
So --- who paysIt is likely that the investment and revenue stream for SHP will not be able to fund this work. Should this cost be shared with the community that wishes to benefit from environmental improvement
![Page 26: Steve_Cryer-Vienna](https://reader033.fdocuments.in/reader033/viewer/2022051423/568c4bd31a28ab49169db6da/html5/thumbnails/26.jpg)
THANKYOU