DMAD Dam Rehabilitation, Phase II Spillway Replacement

The DMAD Canal Company contracted Bowen Collins & Associates for the design planning, design, permitting, bidding, and construction period services for the Spillway Replacement Project on the DMAD Reservoir. The new design required spillway that was equipped to pass the probable maximum flood and constructed to resist future erosion with increased foundation stability. After multiple spillway configurations modeling iterations, an 8-cycle concrete labyrinth weir spillway was selected. This labyrinth configuration increased the effective weir length of the spillway to 1,200-ft contained within a 293-ft span. Hydraulic modeling of the new structure allowed BC&A to further optimize the spillway chute and stilling basin to ensure that the project’s flow capacity and stability requirements were met while keeping project costs down.