-
What Water is Covered by the Clean Water Act?
by Karrigan Bork It is important if a stream, river, wetland, or even a dry ditch is protected by the Clean Water Act (CWA). The CWA is a federal law “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.”[1] But the Act doesn’t cover all waters. Waters covered by the…
-
Groundwater Law – Physical – “the water budget myth”
by Jay Lund This week’s short post is on groundwater law – from the viewpoint of physics. Water policy, management, and human law often misunderstand how groundwater and surface water work physically. Bredehoeft, et al. (1982) distill a longstanding lament of many groundwater experts, “Perhaps the most common misconception in groundwater hydrology is that a…
-
$24.6 Billion National Flood Insurance Program Debt Explained in One Chart
by Kathleen Schaefer As we are enter another hurricane season, the National Flood Insurance Program (NFIP) is on its 12th short-term extension since September 30, 2017. And after having $16 billion in debt forgiven, it remains $24.6 billion in debt (Horn 2019). Many people are asking, how did we get here? While “its complicated,” much…
-
Ties Between the Delta and Groundwater Sustainability in California
by Mustafa Dogan, Ian Buck-Macleod, Josue Medellin-Azuara, and Jay Lund Groundwater overdraft is a major problem globally and has been a persistent and growing problem in California for decades. This overdraft is predominantly driven by the economic value of water for agricultural production and cities. Spurred by the recent drought, California passed legislation requiring the…
-
Challenges and opportunities for integrating small and rural drinking water stakeholders in SGMA implementation
By Kristin Dobbin, Jessica Mendoza and Michael Kuo The Sustainable Groundwater Management Act (SGMA) is an historic opportunity to achieve long-term sustainable groundwater management and protect drinking water supplies for hundreds of small and rural low-income communities, especially in the San Joaquin Valley. Past research indicates that few of these communities are represented in the…
-
Drought, Fish, and Water in California
by Peter Moyle With a big collective sigh of relief, Californians rejoiced that we have largely recovered from 2012-2016 drought[1]. Streams are flowing. Reservoirs are full. Crops are watered. Native fishes are reproducing But this not a time for complacency; if the 2012-2016 drought, the hottest and driest on record, had lasted another year or…
-
Sustaining integrated portfolios for managing water in California
by Jay Lund Summary: This post reviews some lessons from portfolio water management in California and identifies roles for state government in facilitating development and implementation of effective portfolios. To better align state regulations and funding with these goals, a more adaptable structure for state planning is suggested. Effective integration of local, regional, and state…
-
Flood Mapping in California: The Good, the Bad, and the Ugly
by Kathleen Schaefer and Nicholas Pinter FEMA flood insurance rate maps (FIRMs) are the principle tool for managing the National Flood Insurance Program (NFIP). They identify properties whose owners may be required to purchase flood insurance and help set flood insurance premiums across the US. FEMA is required to assess FIRMs at least every five…
-
Economic Tradeoffs in Groundwater Management During Drought
by Kathleen Stone and Rob Gailey Domestic well users in some areas were greatly impacted by additional agricultural groundwater pumping during California’s 2012-2016 drought, which substantially compensated for reduced surface water supplies. Implementation of the 2014 Sustainable Groundwater Management Act (SGMA) should improve long-term groundwater availability during drought for all system users by requiring groundwater…
-
Some common questions on California water (Part II)
by Jay Lund and Josué Medellín-Azuara This is the second installment of answers to some common questions regarding water problems in California. Part I examined some common questions on water supplies (questions 1-5). Part II looks more at common questions on water uses and demands. 6. Wouldn’t more agricultural water use efficiency end California’s water…
-
A water portfolio planning report card for California
by Jay Lund Governor Newsom recently called for a state portfolio of actions to manage water under rapidly changing climate and other conditions. This post reviews the state of water portfolio planning in California today. In this complex changing world, major problems are rarely solved with a single solution or a single problem-solver. Portfolio-based planning…
-
Evaluating Landscape Effects of Turf Replacement
Erik Porse, Stephanie Pincetl, Diane Pataki, and Tom Gillespie Outdoor landscapes in California use water for irrigation, especially during summer. Outdoor water use is the largest portion of residential water use, especially in hotter inland areas and cities with larger lots. While lawns have value for recreation and aesthetics, replacing existing turf lawns with well-designed…
-
Some common questions on California water (Part I)
by Jay Lund People are interested in California water problems, and they ask reasonable questions. Here is a first installment of short science-based answers to some reasonable questions often heard at public and private discussions of water in California. (Longer answers are possible, of course.) Why doesn’t California just build desalination plants to end water…
-
The California Water Model: Resilience through Failure
by Nicholas Pinter, Jay Lund, Peter Moyle A review of 170 years of water-related successes in California suggests that most successes can be traced directly to past mistakes. California’s highly variable climate has made it a crucible for innovations in water technology and policy. Similar water imperatives have led to advances in water management in…
-
Fish are born free, but are everywhere in cages this spring
by Carson Jeffres, Eric Holmes, and Andrew Rypel State, federal, and local governments, water users, and the public are all concerned with the survival of salmon. Over decades, and especially recent years, most salmon runs have severely declined in California. Part of sustaining salmon populations is improving the survival and fitness of young salmon as…
-
Some springtime reading on California water
Jay R. Lund, Director, Center for Watershed Sciences and Professor of Civil and Environmental Engineering, University of California – Davis California is a wonderful place to study water. So many interesting and important problems, thoughtful and insightful authors, and much to be learned. Here is a selection of readings (updated from a 2012 post) on…
-
When do water bonds pass? Lessons from past elections
By Cassidy Craford and Hannah Safford Californians cite drought and water-supply challenges as some of the most important environmental issues facing the state today. A whopping 85% of California voters agree that water supply is a “big problem” or “somewhat of a problem” in their region. Population growth, dated infrastructure, and climate change are combining…
-
Portfolio Solutions for Safe Drinking Water – Multiple Barriers
by Jay Lund Only some parts of the world have safe drinking water almost ubiquitously, and only in the last century. (We lucky few!) In these countries, drinking water safety relies on a complex portfolio of actions and accountability by individuals, industries, and diverse layered units of government. The provision of safe drinking water…
-
Climate Warming Brings New Water to California’s Delta
April 1, 2019 By Nestle J. Frobish The California Department of Water Resources is working to employ the ongoing break-up of the Antarctic ice cap to provide a vast supply of water for California. Current plans are to employ ocean tugs to bring ice bergs into San Francisco Bay for docking in the State Water…
-
Groundwater and agriculture: a comparison of managing scarcity and droughts in France and California
By Josselin Rouillard Overview of French and Californian agricultural groundwater management France and California face a common challenge of managing overdraft in intensively exploited aquifers. As of 2018, large areas of France and California have overexploited groundwater (see maps below). And both regions have passed landmark groundwater legislation, the Loi sur l’Eau et les Milieux…
All Archives
- March 2026 (3)
- February 2026 (4)
- January 2026 (4)
- December 2025 (14)
- November 2025 (5)
- October 2025 (5)
- September 2025 (5)
- August 2025 (6)
- July 2025 (4)
- June 2025 (5)
- May 2025 (4)
- April 2025 (5)
- March 2025 (4)
- February 2025 (4)
- January 2025 (4)
- December 2024 (5)
- November 2024 (4)
- October 2024 (4)
- September 2024 (5)
- August 2024 (4)
- July 2024 (4)
- June 2024 (5)
- May 2024 (4)
- April 2024 (5)
- March 2024 (4)
- February 2024 (4)
- January 2024 (5)
- December 2023 (5)
- November 2023 (4)
- October 2023 (5)
- September 2023 (4)
- August 2023 (4)
- July 2023 (4)
- June 2023 (4)
- May 2023 (4)
- April 2023 (5)
- March 2023 (4)
- February 2023 (4)
- January 2023 (5)
- December 2022 (4)
- November 2022 (3)
- October 2022 (5)
- September 2022 (3)
- August 2022 (4)
- July 2022 (4)
- June 2022 (4)
- May 2022 (5)
- April 2022 (4)
- March 2022 (4)
- February 2022 (4)
- January 2022 (5)
- December 2021 (4)
- November 2021 (4)
- October 2021 (5)
- September 2021 (4)
- August 2021 (4)
- July 2021 (5)
- June 2021 (4)
- May 2021 (6)
- April 2021 (4)
- March 2021 (4)
- February 2021 (4)
- January 2021 (5)
- December 2020 (4)
- November 2020 (4)
- October 2020 (4)
- September 2020 (1)
- August 2020 (4)
- July 2020 (3)
- June 2020 (3)
- May 2020 (4)
- April 2020 (4)
- March 2020 (6)
- February 2020 (1)
- January 2020 (3)
- December 2019 (4)
- November 2019 (2)
- October 2019 (4)
- September 2019 (4)
- August 2019 (4)
- July 2019 (3)
- June 2019 (5)
- May 2019 (4)
- April 2019 (5)
- March 2019 (3)
- February 2019 (2)
- January 2019 (3)
- December 2018 (1)
- November 2018 (5)
- October 2018 (2)
- September 2018 (1)
- August 2018 (4)
- July 2018 (1)
- June 2018 (2)
- May 2018 (4)
- April 2018 (5)
- March 2018 (4)
- February 2018 (5)
- January 2018 (4)
- December 2017 (5)
- November 2017 (2)
- October 2017 (5)
- September 2017 (5)
- August 2017 (5)
- July 2017 (5)
- June 2017 (3)
- May 2017 (3)
- April 2017 (5)
- March 2017 (4)
- February 2017 (4)
- January 2017 (4)
- December 2016 (4)
- November 2016 (4)
- October 2016 (5)
- September 2016 (4)
- August 2016 (4)
- July 2016 (4)
- June 2016 (4)
- May 2016 (4)
- April 2016 (5)
- March 2016 (4)
- February 2016 (4)
- January 2016 (5)
- December 2015 (4)
- November 2015 (4)
- October 2015 (5)
- September 2015 (3)
- August 2015 (4)
- July 2015 (4)
- June 2015 (5)
- May 2015 (4)
- April 2015 (5)
- March 2015 (5)
- February 2015 (6)
- January 2015 (2)
- December 2014 (3)
- November 2014 (4)
- October 2014 (4)
- September 2014 (2)
- August 2014 (4)
- July 2014 (4)
- June 2014 (6)
- May 2014 (4)
- April 2014 (5)
- March 2014 (3)
- February 2014 (2)
- January 2014 (3)
- December 2013 (2)
- November 2013 (2)
- October 2013 (4)
- September 2013 (3)
- August 2013 (1)
- July 2013 (3)
- June 2013 (3)
- May 2013 (4)
- April 2013 (4)
- March 2013 (2)
- February 2013 (1)
- January 2013 (2)
- December 2012 (1)
- November 2012 (3)
- October 2012 (3)
- September 2012 (2)
- July 2012 (1)
- June 2012 (1)
- May 2012 (3)
- April 2012 (1)
- March 2012 (4)
- February 2012 (4)
- January 2012 (2)
- December 2011 (2)
- November 2011 (4)
- October 2011 (3)
- September 2011 (2)
- August 2011 (4)
- July 2011 (4)
- June 2011 (5)
- May 2011 (2)
- April 2011 (4)
- March 2011 (4)
- February 2011 (3)
- January 2011 (1)