Climate Vulnerability Assessment for Possible Hot-Dry and Warm-Wet Future Climates for Dams in California

An evaluation of the change in hydrologic hazards under future climate conditions was completed to assess potential climate vulnerabilities. Hydrometeorological data were adjusted based on global climate model output to quantify the effects of climate change for four climate scenarios. Predicted changes in temperature and precipitation were used to represent hot-dry (hotter temperatures with diminished precipitation magnitudes) and warm-wet (warmer temperatures with enhanced precipitation magnitudes) for the time horizons 2050 and 2070.

The Stochastic Event Flood Model (SEFM) was used to develop climate-adjusted hydrologic hazards: peak magnitude-frequency relationships for reservoir inflow and outflow rates, and inflow and outflow volume, as well as water surface elevation.

Changes in precipitation were greatest in winter months for synoptic-scale storms. Increases in temperatures were greatest in the summer months. Hydrologic loading curves increased from baseline for the warm-wet scenarios and decreased for the hot-dry scenarios. Local storm hydrologic loading curves decreased for both scenarios.