Author(s)

M. C. M. Bruijs, F. T. Vriese & D. Bijstra

Abstract

In The Netherlands, current legislation/permits require that fish impingement at cooling water intakes do not have a significant effect on fish populations. To evaluate the impact of impingent at existing intakes, but also to assess the potential impact of planned intakes, no proper evaluation methodology is yet available. The Dutch Water Authorities are in progress with developing an evaluation method for impingement and entrainment at cooling water intakes as part of the new cooling water abstraction guidelines. The evaluation method is based on a spreadsheet model. The authorities still aim to apply population level effects as the main parameter, although it is recognized that this approach is very difficult. When an effect on population level is recognized, it is important to be able to reduce the ingress of fish and increase survival of impinged fish. For both existing and planned (cooling) water intakes, a variety of technical and operational measures are available. However, there are in principle no general Best Available Techniques (BAT) available that can be applied. To choose the measures that can be considered as BAT for a specific location, it requires a stepwise approach (Best Available Approach) that includes local evaluation of biological and technical aspects. This paper describes the current development of an evaluation method and the permit requirements for cooling water abstraction in The Netherlands. It also

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