FishFlow Innovations
Dissel 4 1671 NG , Netherlands

FishFlow Innovations develops and builds innovative fish migration facilities and protection systems. Our mission is to contribute to solve migration barriers for fish and prevent damage to fish through our tailor-made products.

All our products have been developed with particular attention for the natural preference and behaviour of fish. The focus of FishFlow Innovations on the natural behaviour and preferences of fishes results in the development of facilities that fishes eagerly utilise and that enable passage without injury or mortality

FishFlow Innovations offers the following fish-friendly migration facilities:

• the siphon fish ladder
• the siphon eel ladder
• the fishway for pumping stations
• the fish-friendly screw pump
• the fish-friendly turbine
• the screw pump annex hydroturbine
• the fish-friendly axial pump
• strobe lights for fish deterrence
• the fishsafe cooling water intake (rotary drumscreen)
• the guidance system for hydropower stations
• the airlift
• the silent bow thruster

In the Netherlands large numbers of dams, weirs, and sluices, which contribute to the management of the water level, present barriers for migrating fish by blocking or restricting connections between adjacent water bodies. The FishFlow fish ladder is a facility that restores or improves the possibilities of upstream migration past such barriers.

The FishFlow siphon fish ladder is based on the principle of a poorly functioning siphon; i.e. a siphon with an air bubble. This bubble is an essential element of the construction because the volume of the bubble defines the flowrate through the system. The siphon fish ladder is equipped with a vacuum pump that controls the volume of the air bubble to prevent change of flowrate due to import or export of gas from the water. An aeration valve is provided as a safety precaution to make sure that the siphon can not start running at its maximum flowrate in case the vacuum pump would malfunction and pump uninterruptedly. The water that is being siphoned consequentially flows over a conventional fish ladder to the downstream section of the river or stream.

The presence of this type of fish ladder offers upstream migrating fish the possibility to pass barriers at their own convenience by swimming against the gentle current at any time. The FishFlow fish ladder is suitable for all sizes of fish and is equipped with small slopes in front of each partition to enable bottom-dwelling fishes to pass the fish ladder as well.

The FishFlow siphon fish ladder has a number of advantages over conventional fish ladders:

• adjustable flow-rate
• low costs of construction
• low energy requirement
• flexible positioning
• no need to acquire lands
• maintenance friendly
• flexible design
• adjustable for integration in the landscape or decorative, or educational purposes

The FishFlow siphon fish ladder is a flexible system that can be fit to serve as a passage for weir, dams, and dikes. The system can also be used to provide a migration route between tidal waters and inland waters.

During a visit to a pumping station in 2002 Marcel Klinge, fishbiologist at Witteveen+Bos Consulting Engineers, discovered large scale fish mortality at the station. Shortly afterwards he expressed his concern about fish mortality in pumping stations to Gerard Manshanden, professional fisherman at Lake IJsselmeer. Gerard told Marcel that he happened to just have had an idea for a fishpassage to safely guide fish around the potentially lethal pumps of pumping stations! They decided to work out the idea together. The cooperation has resulted in the construction of the first “fishway for pumping stations” in the Meerweg pumping station, near Groningen in the conservancy area of the Hunze en Aa’s Waterboard, in 2005.

The cooperation between G.A.M. Manshanden Productie B.V. and Witteveen+Bos Consulting Engineers has been formalised In a joint-venture. In october 2006 the company FishFlow Innovations B.V., of which both G.A.M. Manshanden Productie B.V. and Witteveen+Bos Consulting Engineers are shareholders, was launched. As of January 1st 2012 FishFlow Innovations will be fully owned by G.A.M. Manshanden Productie B.V.