FEATURED PROJECT: Removeable Spillway Weir

Thompson Metal Fab shop fabricated for the US Army Corp of Engineers a Removable Spillway Weir (RSW). The RSW measured 70’ W x 105’ H x 68’ D and consumed approximately 950 tons of steel.

The RSW is designed to move juvenile fish. Fish tend to be surface oriented and surface flow is thought to be a more effective method to pass fish than the pressurized method where fish are pushed to a depth of 50’ to flow under spill-gates. The expected advantage of the RSW is to improve passage conditions for fish by reducing injury and passage delays at the dams. It is anticipated that the surface flow will result in more efficient juvenile fish passage rates (more fish per unit of flow) than conventional deep gates at the spillway, as well as potential for lower dissolved gas levels in the river by more efficient use of water to bypass juvenile fish below the dam.