Fishway Solutions in Connection with Hydro-Electric Plants and Regulated Rivers in Norway
Proceedings of the International Symposium on Fishways '95
The Organizing Committee for International Symposium on Fishways '95 in Gifu
Following brief, general information on fishway construction on regulated rivers in Norway, eight facilities are described. The height of waterfalls or dams in these examples vary from 3 m to 35 m. Most of the facilities described are on rivers carrying Atlantic salmon. Almost all of them consist of one or more fish ladders of the weir and pool type, with a height of 40-60 cm between each pool. A specially interesting case is the fishway built at Rygene on the Nidelva river in southern Norway. The upper part of this fishway takes the form of a pressure chamber placed inside a dam; the chamber transfers fish to the basin upstream from the dam. The system has been operating for three years and the results are good. It is cheaper to build this kind of fishway in a dam than to construct fish ladders of the ordinary weir and pool type.