Fish Safety

VisAdvies offers various services for determining the fish safety of pumps, turbines and engineering structures

Natural passage

VisAdvies does many baseline surveys of the fish safety of existing engineering structures through monitoring. This type of study involves placing a trap at the outlet side of a structure. At hydropower plants, this is often done in combination with FishCounter. By examining the catch, the damage pattern of passing fish can be determined. After determining the damage pattern, advice is given and which measures are necessary to improve fish safety.

VisAdvies has extensive experience in investigating natural passage and offers a wide range of monitoring set-ups.
Natural passage
Fish safety test

Fish safety test

Besides natural passage, the fish safety of engineering structures can also be determined by means of a "Fish Safety Test" (FST). In this type of test, fish are forced through a engineering structure and then collected behind it to determine the mortality rate and any damage incurred. To account for any delayed mortality, fish are kept in storage for up to 48 hours. This allows an informed statement to be made about the actual fish safety of pumps, turbines and other engineering structures.

VisAdvies carries out FST’s according to NEN 8775 "Fish safety - Method for determining the fish safety of pumps, jacks and enclosed water turbines used in pumping stations and hydropower plants" under the standards committee 390 020 "Environmental quality".
This standard defines the methods by which a FST is carried out so that the results are comparable nationwide. Among other things, agreements have been made on the fish species used, numbers, confidence intervals and storage and origin of the fish. The standard was drawn up by a committee including water managers, manufacturers of augers, pumps and turbines and consultancies. VisAdvies was instrumental in drafting the initial NEN and was part of the committee.

Theoretical determination

VisAdvies has extensive experience in fish safety and also provides support in the development phase of fish-safe pumps and turbines. During this process, the existing design is analysed and recommendations are given to improve fish safety. In addition, fish safety can be modelled and the effects of the turbine or pump on fish mortality of common species can be estimated. VisAdvies has extensive experience in fish safety testing of turbines and pumps. By combining field and theoretical research, VisAdvies can make a good estimate of where the hazards of turbines and pumps lie and how they can be reduced
Would you like more information or a quotation? Then contact one of our staff members.
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Hayco van der Veen
(+31) 6 53 74 52 65
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