Author(s): A. Ervine; B. Couvel; J. Stuart; C. Carnie
Linked Author(s):
Keywords:
Abstract: This paper considers the passage of salmon through a fish ladder at Tongland Dam, Scotland. The fish pass has been in existence for about 50-60 years, and in recent times has not functioned satisfactorily in the upper parts of the pass, where passage is through submerged orifices rather than free overflows from pool to pool. The salmon are apparently unable to proceed past the submerged orifice section of the pass. The paper looks at the results of a physical model study of the Tongland fish pass, carried out at the University of Glasgow on behalf of Scottish Power together with the Carnie Consultancy. Initial testing revealed the problem to be a combination of high velocities at the submerged orifices, excessive turbulence in the form of eddies shed from each orifice gate, together with a surging pattern which exists from one pool to the next. The paper investigates various ways to counter these problems including additional weirs inserted diagonally in each pool, as well as the possibility of additional submerged orifices designed to reduce both velocity, turbulence and surging effects. The paper concludes with a look at the modifications carried out to the fish pass at the dam and what effect there has been on the ability of salmon to make a speedy and successful passage through the difficult section. There will be one years field data of the new arrangement to review.
Year: 1999