Prosser Diversion Dam Improvement Project

The goals of the Prosser Diversion Dam Improvement project are to develop and design project alternatives that increase fish survival at the Prosser Diversion Dam and related facilities to promote recovery of healthy and harvestable fish populations and comply with current environmental standards. This project exhibits multiple mechanisms intended to improve juvenile survival, including reconfiguring facilities to reduce mortality as juvenile salmonids pass through the diversion and back to the river (e.g. replace or reconfigure the intake gates, bypass system, etc.); reconfiguring the facilities to guide fish away from the diversion so that they remain in the river (e.g., in-river screening, etc.); decreasing the quantity of water diverted into Chandler Canal, increasing the amount of water that remains in-river; and decreasing juvenile fish delay and mortality related to passage over the dam. These goals can be met through design, operational, and potentially construction/reconstruction of various elements of the headworks, spillway, canal, fish screens, fish bypass systems, fish ladders, dam modifications, changes to downstream associated structures, pump exchange, electrification of the hydraulic pumps, power subordination, and other related structural, fish monitoring, and water conservation projects.