Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Gauging weir retrofit using cylindrical clusters for upstream fish passage of non-salmonids (#160)

Daniella Montali-Ashworth 1 , Andrew Vowles 1 , Gustavo deAlmeida 1 , Paul Kemp 1
  1. Engineering and Environment, University of Southampton, Southampton, Hampshire, United Kingdom

Gauging weirs act as barriers to longitudinal river connectivity, often preventing fish from moving between different habitats for spawning and feeding, which can lead to population decline. Although many fish passage designs exist, they are often more effective for salmonid compared to non-salmonid species. A new fish passage design has been developed, comprising of a staggered array of cylindrical clusters, which when mounted onto the downstream face of gauging weirs, improves fish passage whilst not effecting gauging or accumulating debris. Flume experiments have been undertaken to determine the influence of varying fish pass geometry (cluster diameter and spacing) which influences the wake width and length created by the clusters. Six different cluster configurations were tested (combination of 0.03, 0.05 and 0.07m diameter clusters and 0.1 and 0.15m spacings) where fish movement through the pass was monitored using video footage and their positions tracked using LoggerPro. This presentation will discuss the passage efficiency of this fish pass and space use of fish when swimming through a staggered array of cylindrical clusters, the relationship between passage and wake geometry and the implications of this design for future fish passage research.