Dollar Weir Fish Pass Improvements

Overview

Dollar weir on the River Devon is a barrier to migratory fish. A fish pass was first constructed 30+ years ago and it consisted of a simple box pass on the front of the weir. As science has progressed, our understanding of how fish use fish passes has improved and it became apparent small works could be carried out to the existing fish pass to make it better for migratory fish such as salmon, sea trout and brown trout. 

The works

The works consisted of increasing the wall height of each chamber in the fish pass. By increasing the depth of pools this allowed fish to gain more momentum to traverse from one pool to the other.  Concrete walls were created on each box to raise the height of each chamber by 200mm which would increase the amount of water in the pass making it easier for fish to get upstream. 

In the summer of 2016, contractors started work on the fish pass but were met with delays due to high water levels. Eventually though, they managed to get in and carry out the works. 

Monitoring work is being carried out above and below to monitor if this project was a success. 

Funder

This project was funded by the Stirling and Clackmannanshire Environment Trust which operates under the Scottish Landfill Communities Fund.