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Title: Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century

The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of California, which is the most populous and agriculturally productive in the United States, depends on an extensive artificial water storage and conveyance system primarily for irrigated agriculture, municipal and industrial supply and hydropower generation. Here we take an integrative high-resolution ensemble approach to examine near term climate change impacts on all imported and local sources of water supply to Southern California. While annual precipitation is projected to remain the same or slightly increase, rising temperatures result in a shift in precipitation type towards more rainfall, reducing cold season snowpack and earlier snowmelt. Associated with these hydrological changes are substantial increases in both dry and flood event frequency and intensity. On one hand, the greater probability of drought decreases imported water supply availability. On the other hand, earlier snowmelt and significantly stronger winter precipitation events pose increased flood risk requiring water releases from reservoirs for flood control, also potentially decreasing water availability. As a result, lack of timely local water resource expansion coupled with climate change projections and population increases may leave the areamore » in extended periods of shortages.« less
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  1. Loyola Marymount Univ., Los Angeles, CA (United States); Univ. of California, Los Angeles, CA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Loyola Marymount Univ., Los Angeles, CA (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; 32112413
Published Article
Journal Name:
Environmental Research Letters
Additional Journal Information:
Journal Volume: 11; Journal Issue: 9; Journal ID: ISSN 1748-9326
IOP Publishing
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1325600; OSTI ID: 1326510