Water-Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Simulating the Regulated Rivers of California’s West Slope Sierra Nevada

Climate warming is expected to affect the beneficial uses of water in the Sierra Nevada,
impacting nearly every resident of California. This paper describes the development and results
from an integrated water resource management model encompassing water operations and
hydropower generation for the west slope Sierra Nevada spanning the Feather River basin in
the north to the Kern River basin in the south at the weekly time step. This model application
includes management of reservoirs, run-of-river hydropower plants, water supply demand
locations, conveyances, and instream flow requirement. Model validation indicates that most
major hydropower turbine flows were simulated well, with wetter years modeled more
effectively than drier years. The results of this work indicated that hydropower generation will
be reduced by approximately 8 percent with 6°C (10.8°F) warming, consistent with other
studies, with a conservative parameterization of no change in precipitation. Reservoir
operations adapt to capture earlier and greater runoff volumes that result from earlier and greater runoff due to climate warming. Seasonal compensation in operations is insufficient to
overcome warming mediated losses.