Open Access Senior Thesis
Bachelor of Arts
W.M. Keck Science Department
Increased average annual temperatures due to anthropogenic climate change will impact snowpack in the Sierra Nevada region in two ways. First, an increasing share of precipitation will fall as rain instead of snow. Second, snowpack will melt earlier in the season. Earlier runoff driven by precipitation type change and earlier snowmelt necessitates earlier releases of water from dams for flood control. These earlier releases reduce the amount that can be stored for water supply. Analysis of instrumental and model snow water equivalent (SWE) data shows that climate models relied upon in state decision-making capture changes in peak SWE magnitude, but they do not estimate timing of peak SWE well. Future reductions in peak SWE magnitude and vulnerability of surface water storage infrastructure necessitates increased reliance on groundwater basins to store water. Groundwater pumping allocations combined with a replenishment credit can incentivize the diversion of floodwater for underground storage, which would help mitigate economic harm that arises from climate change impacts on snowpack as well as implementation of the 2014 Sustainable Groundwater Management Act.
Greenspan, Kyle; Williams, Branwen; and Williams, Heather, "Preparing for Uncertain Water Futures: An Analysis of Climate Change Impacts on Southern Sierra Nevada Snowpack, Infrastructure Vulnerability, and Implications for San Joaquin Valley Groundwater Management" (2023). Pitzer Senior Theses. 181.