Skookumchuck Dam Fish Sluice CFD Modeling

WSE was tasked with provinding CFD (3D) modeling of an existing fish sluice and proposed replacements for the Skookumchuck Dam. The model results were used to evaluate the quality and feasibilty of downstream fish passage at the dam and to evaulate and improve conceptual level designs of a replacement sluice.

Role/Services: WSE prepared a detailed terrain surface of the approach to the dam from existing LiDAR and additional Structure-From-Motion derived terrain data we collected using a drone. WSE also built a 3D surface model of the existing dam, sluice chute, and sluice gate based on dam design drawings. We used a HEC-RAS 2D model to detemine appropriate model boundary conditions and 3D model mesh extents. We then built a CFD model of the approach to the sluice and the sluice itself in Flow3D using nested meshes with a mesh size as small as 0.25 inches to capture the complex hydraulics around the sluice gate. The model was run for a range of flows and reservoir elevations. Flow streamlines and velocities were evaluated with fish biologists, who concluded that the existing sluice produced poor conditions for downstream fish passage. WSE worked collaboratively with the fish biologists to develop and model an alternative sluice design, and refine the design based on the CFD model results.

Outcome: The results of the CFD model were an invaluable tool for communicating the issues with the existing sluice, and developing a conceptual design of a replacement. The proposed sluice is currently in further design.