by Yiqing “Gracie” Yao and Jay Lund California’s Central Valley produces much of the nation’s food, including about 40% of the country’s fruits and nuts and has the nation’s second most pumped aquifer system. Its drier southern portion, the San Joaquin Valley, has decreasing surface water supply reliability due to frequent and prolonged droughts, stricter…

by Peter Moyle, Karrigan Börk, John Durand, T-C Hung, and Andrew L. Rypel 2020 was a bad year for delta smelt. No smelt were found in the standard fish sampling programs (fall midwater trawl, summer townet survey). Surveys designed specifically to catch smelt (Spring Kodiak Trawl, Enhanced Delta Smelt Monitoring Program) caught just two of…

by Jay Lund Deltas globally adjust with changes and fluctuations in external conditions, internal dynamics, and human management.  This is a short history of big changes to California’s Sacramento-San Joaquin Delta (Delta) in the past and present, and its anticipated future.  This history is important for understanding how many of the Delta’s problems have developed,…

by Jay Lund Yes, California will have another multi-year drought.  California has immense hydrologic variability, with more droughts and floods per average year than any other part of the country.  California’s water users, managers, and regulators should always be prepared for droughts (and floods).  Eventually, California will have a multi-year drought worse than any we…

By Ted Grantham, Jeanette Howard, Belize Lane, Rob Lusardi, Sam Sandoval-Solis, Eric Stein, Sarah Yarnell and Julie Zimmerman Over the past three years, a team of scientists from universities, NGOs, and state agencies across California have been working to provide guidance on how to better manage river flows for freshwater ecosystems throughout the state. A…

By: Nick Framsted Clear Lake is one of California’s oldest and most unique natural features. Nestled in Northern California’s coastal mountains, Clear Lake is the largest lake completely within California and is the oldest lake in North America with sediments dating back 480,000 years (Sims et al. 1988). Rich mineral deposits around the lake were…

By Claire Kouba and J. Pablo Ortiz Partida California’s hydrologic future is muddled by a fundamental uncertainty: will the state get wetter or drier? Climate models disagree on this question, but provide insights on other important water management questions. The wetter or drier question has been studied often in government reports (DWR CCTAG, 2015; U.S.…

By: Amber Manfree, Peter Moyle, Ted Grantham The recent removal of the sediment-filled York Dam in Napa County has reconnected two miles of steelhead trout habitat that has been blocked for over a century. While the dam itself was small and non-functional, it took nearly 30 years to accomplish removal. Thousands of barriers to stream…

by Miranda Bell-Tilcock, Jamie Sweeney, and Malte Willmes Down the dark corridors of the Watershed Sciences building are freezers of dead fish. Frozen Chinook Salmon carcasses and their dissected eyes and muscles in neat vials are stacked next to White Sturgeon fin clips, Striped Bass scales, and tubes of stomach contents. This might sound like…

by Jay Lund 2020 was terrible, and as a water year (WY), October 2019 – September 2020, it is over.  A dry winter (drier than 2014-2015 in Sac. Valley), COVID-19, deep recession and unemployment, wildfires, racial violence and unrest, extreme high temperatures, water documents disappearing from State of California websites, and finally a very unpresidential…

by Lorie Srivastava Climate change is affecting natural resources in California, with water being one of the most important in the state. Water is critical for municipalities, agriculture, industry, and habitat/environmental purposes. Will future supply meet future demand? How will the economic value of water change over this century? The economic value of raw –…

by Jay Lund Today’s water struggles have deep roots. In our shared summer confinement, we hopefully have some time for some deeper reading on California water.  Here is a small collection of older writings on California water, the youngest of which is still older than me.  Beyond historical interest, these early writings have useful perspectives…

by Dylan K. Stompe, Peter Moyle, Avery Kruger, John Durand The San Francisco Estuary is a dynamic and altered estuary that supports a high diversity of fishes, both native and non-native. These species have substantial recreational, commercial, and intrinsic value to people. Since the 1950s, various agencies and UC Davis have established long-term surveys to…

by Kristin Dobbin, Darcy Bostic, Michael Kuo and Jessica Mendoza In 2012 California passed the Human Right to Water (AB 685) which declares all Californians have the right to safe, clean, affordable and accessible drinking water. Two years later during a record-breaking drought, California passed another piece of historic legislation known as the Sustainable Groundwater…

by John R. Durand, Fabian Bombardelli, William E. Fleenor, Yumiko Henneberry, Jon Herman, Carson Jeffres, Michelle Leinfelder-Miles, Jay R. Lund, Robert Lusardi, Amber D. Manfree, Josué Medellín-Azuara, Brett Milligan, and Peter Moyle Droughts are common in California. The drought of 2012-2016 had no less precipitation and was no longer than previous historical droughts (Figure 1),…