California WaterBlog

by Alvar Escriva-Bou, Jay Lund, Josue Medellin-Azuara, and Thomas Harter Earlier this year, the first local Groundwater Sustainability Plans (GSPs) were submitted to California’s Department of Water Resources for basins with the most severe groundwater overdraft.  To comply with the Sustainable Groundwater Management Act, these plans must address any “significant and unreasonable” impacts of groundwater…

by Peter Moyle, Jeanette Howard, Ted Grantham “Nowhere is the biodiversity crisis more acute than in freshwater ecosystems” (Tickner et al. 2020) Weeks of being confined indoors under shelter-in-place orders increases our appreciation of the natural world. Walking and exercising outdoors, especially along a local stream like Putah Creek, is one of the best ways…

By Thomas Harter, Steph Tai, and Karrigan Bork In 1972, the U.S. Clean Water Act (CWA) created a permit system for point source discharges to navigable waters of the United States – rivers, lakes, and coastal waters – with the goal of restoring and protecting their water quality. Typically, these permits are issued by the…

by Dylan K. Stompe Striped bass are an iconic and recreationally important fish species throughout the United States, including within their native range on the Atlantic Coast. Based on their value as a sport fish and as table fare, striped bass were one of the early introductions to the San Francisco Estuary (SFE). Their life-history…

by Peter Moyle, Center for Watershed Sciences, UC Davis Delta smelt are an endangered species and the latest estimates of their numbers indicate they will likely not be around much longer as wild fish. When I first started working on them, in the 1970s, they were abundant and frequently caught in various sampling programs. One…

by Nestle J. Frobish Today the Megalopolitan Water District of California (a consortium of southern California and Bay Area urban water suppliers) proposed building a new aqueduct to take water from the Sacramento River to Bay Area and southern California cities.  The aqueduct, depicted below, would avoid the subsurface uncertainties of a Delta tunnel, ease…

by Jay Lund Not again! There was not a “Miracle March” to follow California’s precipitation “Flat-line February.”  Instead, we’ve had a “Meh March.” With the near-end of its wet season, California’s 2020 water year is and will be dry.  The Northern Sierra 8-gage Precipitation Index is now about 25 inches, and might increase about 10%…

By Alyssa Obester, Sarah Yarnell, and Ted Grantham The California Environmental Flow Framework was recently highlighted in the 2020 Water Resilience Portfolio to address the seemingly impossible task of establishing of how much water our rivers and streams need to support healthy ecosystems. While many methods for setting environmental water needs exist, the Framework provides…

by Peter Moyle, Dylan Stompe, and John Durand The Sacramento splittail is a lovely, silvery-white fish that lives primarily in Suisun Marsh, the north Delta and other parts of the San Francisco Estuary (SFE; Moyle et al. 2004). The name comes from its unusual tail, in which the upper lobe is larger than the lower…

    By Jay Lund February has been amazingly dry in California, if anyone hasn’t noticed.  No precipitation at all in February, a dry forecast, about 51% of seasonal Sacramento Valley precipitation (a bit less for the San Joaquin and Tulare basins), and only about half (45-57%) of normal snowpack for this time of year. …

By Bill Fleenor, Amber Manfree, and Megan Nguyen This is a re-posting from January 22, 2017.  Reminders on how things work are sometimes useful. (The whole series, with links below, is thought-provoking.) In 2010, John DeGeorge of RMA, Inc used animated model results to illustrate specific flow and water quality issues in the Delta to…

by Kat Kerlin My husband and I fell in love a couple of months ago. It was with a house by a river. (See what I did there?) This is the river that was a stone’s throw away when we were engaged 13 years ago. The river we’ve brought our children to every summer of…

by Peter Moyle The striped bass is a favorite sport fish in the San Francisco Estuary (SFE), especially the Delta, because of its large size, sporting qualities, and tasty flesh. Historically, it supported major commercial and sport fisheries but the commercial fishery was shut down long ago and the sport fishery is in long-term decline.…

by Jay Lund The 1957 California Water Plan was ambitious for its time, and successful in its own way for a time. This plan was the ultimate major water project development plan arising from a century of struggles to orient and organize a society transplanted from the humid eastern US to California’s highly variable Mediterranean…

by Jay Lund Conditions in the Sacramento-San Joaquin Delta are changing, changing in new ways, and changing rapidly.  Changes are rampant not only in climate, but also in ecosystem structure, economic structure and globalization, invasive species, infrastructure, water demands, environmental regulations, and societal objectives.  Although the Delta always has  changed, often rapidly, we are seeing…

by Peter Moyle, Karrigan Bork, John Durand, Tien-Chieh Hung, Andrew Rypel A recent biological opinion (BiOp) released by the U.S. Fish and Wildlife Service (FWS) concluded that a proposed  re-operation of California’s largest water projects will avoid driving the federally threatened Delta smelt to extinction. The plan proposes increasing water exports from the Central Valley…

by Jay Lund California’s water policy community continues to be embroiled on how best to manage what remains of California’s native aquatic ecosystems, particularly for the Sacramento-San Joaquin Delta and its tributaries.  One aspect of this controversy is the dedication and use of habitat and flow resources to support native fishes. There is general agreement…