Determining Minimum Drawdown Elevations in Lake Powell Using CRSS

Minimum drawdown elevations have not been defined for Lake Powell, which is a gap in Lake Powell’s management that threatens hydropower generation and downstream ecosystems. To resolve this gap, we ran nine simulations using the Colorado River Simulation System (CRSS) model to evaluate four potential minimum drawdown elevation thresholds. The scenarios implemented two inflow based operational rules. An elevation of 3,500 ft is the preferred minimum drawdown elevation because it balances basin demands, ecosystem stability, and hydropower performance.