Author(s): L. Guiot; L. Cassan

Linked Author(s):

Keywords: Fish passage; Hydraulic structures; Sluice gates; Saint-Venant equations; Glass eel

Abstract: Hydraulic structures used for water control in agricultural open-channel networks behave as obstacles to fish passage. Hydraulic management strategy can improve fish passability while maintaining agricultural purpose. Agricultural open-channel networks could be sustainable fish habitats, or facilitate the connection between sustainable fish habitat areas. However, hydraulic structures used to control water levels or discharge in agricultural open-channel networks may create flow conditions which are unpassable for fish. These situations create a loss of fish habitats, and disconnections between water bodies favourable for fish. Sluice gates are an example of these structures. They are very commonly used in agricultural open-channel network to keep water level around a target value. They imply local flow contractions, which involve local water velocities increase. These velocities may stop fish migrating from downstream to upstream open-channel networks. Their management could be modified to improve local fish passage without much disturbing their hydraulic efficiency. Local solutions enhance fish passage independently of other hydraulic structure on the network. In this study, two different gate management strategies were tested to improve fish passage at hydraulic structure within the network. The impact of the management is evaluated with a one dimensional modelling of the network.

DOI: https://doi.org/10.3850/978-981-11-2731-1_307-cd

Year: 2018