Rock-weir fishway II: design evaluation and considerations

ABSTRACT

The flow characteristics of a rock-weir type nature-like fishway are determined by the configuration of the stream channel and passage structures. For a fishway to be effective, the rock-weir hydraulics must be compatible with the swimming capabilities of the target fish species. This study optimized the design characteristics of rock-weir fishways by simulating the water depth and velocity for different channel characteristics and geometries, which govern the fish resting zones, volumetric dissipated power and ultimately upstream fish passage performance. This study provided recommendations on effective pool spacing, bed slope, weir height, weir angle and weir arrangements for designing rock-weir fishways. These design recommendations are based on fishway hydraulics and should provide suitable hydraulics for fish migration and sufficient slow velocity areas for fish resting in rock-weir fishways for specific structure geometries and channel characteristics.

KEYWORDS:

• Flow velocity
• fish resting zones
• energy dissipation
• fish swimming performance, rock-weir fishway
• water depth

Acknowledgments

This research is made possible through grants from the Natural Sciences and Engineering Research Council (NSERC) of Canada and Ecofish Research Ltd. The manuscript benefitted from the constructive comments of two anonymous reviewers.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was made possible through grants from the Natural Sciences and Engineering Research Council (NSERC) of Canada and Ecofish Research Ltd. under an NSERC Industrial R&D Fellowship programme.