Diverting

Diverting

Fish diversion applications are usually associated with irrigation or water supply undertakings, power plant cooling water abstraction or hydropower generation. FGS fish deflection systems are also used to protect fish at land-drainage pumping stations and to divert upstream or downstream migrating fish into fish counting and trapping stations for scientific purposes.

The principle of behavioural fish diversion is to introduce a repellent stimulus into the required exclusion zone to block entry into the hazard area, e.g. a water intake. For a bank-line intake on a river or estuary or for an offshore intake in a lake or at sea, a simple blockage stimulus will often be adequate and a SPA or SILAS™ system is used. But where a large proportion of the available water flow is entering the intake, e.g. at an irrigation or hydropower intake, accurate guidance of fish into a purpose built bypass or into ‘safe’ flow will require a carefully designed diversion system using a BAFF.

FGS provides a full planning and design service to implement the required solution. This involves:

  • Assessment of site layout, bathymetry and hydraulics, including hydraulic modelling if required.
  • Review of fish species, their swimming ability and their sensitivity to acoustic and light stimuli.
  • Acoustic modelling of proposed fish deflection system using FGS’s PrISM acoustic modelling tool.
  • Design of deployment and retrieval system
  • Integration with existing plant control systems.

Fish diversion systems are available for short-term hire, long-term lease or purchase.