The Future of Dams in California February 7, 2018 Alvar Escriva-Bou, Research Fellow Urban Water Institute’s Spring Water Conference Palm Springs, CA

California relies (and will rely) heavily on nearly 1,500 reservoirs

Most of California’s dams were built in the mid-20th century…

…so they need infrastructure and operational upgrades Most were designed based on simplistic assumptions about hydrology and earthquakes More than 90 need major upgrades to better handle large floods or withstand earthquakes Operations also need to be updated to work with improved forecasting technology and account for climate change

New dams can improve flexibility, but costs are high Increased storage would improve reliability and allow greater flexibility But California has dams at the best locations, so new dams will be costly It’s essential to rethink the management of surface and groundwater storage in a more integrated way SOURCE: California Water Commission

Some dams are ripe for removal High environmental costs, concerns about earthquake safety, and reduced benefits can prompt dam removal Over the past 30 years, 36 small dams have been removed In 2015, breaching of the San Clemente Dam on the Carmel River was the largest in CA’s history Several other large dams have been targeted NOTE: The reroute channel of the Carmel River, Monterey County, after the removal of the San Clemente Dam

Notes on the use of these slides These slides were created to accompany a presentation. They do not include full documentation of sources, data samples, methods, and interpretations. To avoid misinterpretations, please contact: Alvar Escriva-Bou escriva@ppic.org 415-291-1125 @AlvarEscriva Thank you for your interest in this work.

The Future of Dams in California February 7, 2018 Alvar Escriva-Bou, Research Fellow Urban Water Institute’s Spring Water Conference Palm Springs, CA