A wrap-up of posts published on Maven’s Notebook this week …
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In California water news this week …
How are water managers adapting to a smaller Sierra snowpack?
“As average temperatures rise across the western United States, snowpack in the Sierra Nevada is dwindling. This year, Reno recorded its latest-ever frost date on November 19. When snow does fall, climate change has increased the likelihood of more extreme storms. This winter provided an example: in mid-February, a heavy snowstorm hit the Donner Pass region, triggering the deadliest avalanche in California’s modern history. For the most part, however, warming temperatures mean precipitation falls as rain instead of snow, changing the decisions water managers make about storing runoff from the Sierras, which supplies drinking water to millions in both California and Nevada. Reservoirs—the manmade lakes that store water—were originally designed with snowpack in mind. Snow would accumulate throughout the winter and melt slowly in spring and summer, filling reservoirs during the dry season. Each reservoir has flood space that water managers keep empty during winter in case a heavy storm fills the reservoir quickly. Now, with more rain running off the mountains than snow, this flood space is filling earlier in the season. That requires water managers to release more water during winter, without the promise of snowmelt to replenish it in spring and summer. … ” Continue reading from the Sierra Nevada Ally.
Conservation groups sue feds to save fish from California water flows
“The San Francisco Baykeeper and others sued the federal government on Monday, accusing it of harming fish protected by the Endangered Species Act. The Center for Biological Diversity, Friends of the River and Baykeeper claim that pumping excessive amounts of water from the Sacramento-San Joaquin River Delta hurts fish like the Central Valley steelhead, North American green sturgeon and Chinook salmon. The U.S. Bureau of Reclamation’s operation of the Central Valley Project affects factors like water temperature and salinity. Those factors, along with the volume and direction of the water, cause fish to swim into harmful environments, the conservation groups say in their suit. The Central Valley Project is a large system that moves water from the delta to the Central Valley, mostly for agricultural use. In addition to changing water temperature, it also blocks access to fish breeding areas, the groups say. “The delta is the irreplaceable home of iconic and endangered California fish, like salmon and steelhead, and we can’t let Trump’s reckless pumping destroy it,” said Harrison Beck, staff attorney with the center, in a statement. “If the Trump administration continues to pump as much water as it can out of the delta ecosystem, we may lose these native fish forever. We can’t allow mass extinction when it’s entirely avoidable.” … ” Read more from the Courthouse News Service.
SEE ALSO: Lawsuit challenges Trump’s water operations plan (Action 5), press release from conservation groups
SF Baykeeper pursues appeal against Water Board amid extinction crisis
“On March 2, 2026, San Francisco Baykeeper, represented by Earthjustice, filed its opening brief in the California Court of Appeal seeking to overturn the Sacramento Superior Court’s 2024 ruling on Phase 1 of the State Water Resources Control Board’s update to the Bay-Delta Plan. The Board has failed to uphold its mandate to protect native fish that rely on river flows into the Delta, in the face of catastrophic losses. When river flows are too low, water temperatures rise, toxic algae proliferate, and the amount of oxygen in the water decreases—among other habitat disruptions—causing fish populations to plummet. Fall-run Chinook salmon populations, for example, have declined by over 85 percent since the 1980s. These precipitous drops have devastating effects, not only on the ecosystem, but on Native American communities and commercial and recreational fisheries. Toxic algal blooms facilitated by low river flows also harm people who try to recreate in or near the San Joaquin River. … ” Read more from the San Francisco Baykeeper.
Conservation groups and Tribes request release of overdue state report on 2022 Merced River drying
“Friends of the River, American Rivers, Big Sandy Rancheria, and the Southern Sierra Miwuk Nation have formally requested that the State Water Resources Control Board immediately release its long-promised analysis of the 2022 Merced River drying event. In a February 24, 2026 letter to State Water Board Chair Joaquin Esquivel, the coalition called on the Board to finalize and publish its report examining how approximately four miles of the lower Merced River went completely dry, from bank-to-bank, for nearly four months in the summer and early fall of 2022. The Board publicly committed in January 2024 to complete and release an analysis of the event for public review sometime in 2024. As of early 2026, no report has been made available. “A major California river ran completely dry for months,” said Keiko Mertz, Policy Director of Friends of the River. “The public deserves to know exactly what happened, why it happened, and what the State plans to do to prevent it from happening again.” … ” Continue reading this press release.
Delta Stewardship Council hears appeals on the Delta Conveyance Project
“On February 26 and 27, 2026, the Delta Stewardship Council (Council) held a two-day public hearing to address ten appeals challenging the California Department of Water Resources’ (DWR) Certification of Consistency (C20257) with the Delta Plan for the proposed Delta Conveyance Project (DCP). DWR proposes to add two new water diversions on the Sacramento River in the north Delta near the community of Hood in Sacramento County, from which it would convey up to 6,000 cubic feet per second of Sacramento River water through a 45-mile underground tunnel to the south Delta for export to State Water Project contractors in the Bay Area, San Joaquin Valley, and Southern California. During the hearing, the Council and public weighed in with comments and questions directed at whether DWR’s consistency certification is supported by substantial evidence in the record. … ” Read more from Somach Simmons & Dunn.
As promised, state delivers tough subsidence guidelines prompting some valley water managers to cry foul
“Though some valley groundwater managers say new state guidelines “move the goal posts” on subsidence, state regulators gave fair warning of what was coming. At a September workshop Deputy Director of the Department of Water Resources Paul Gosselin told attendees the new guidelines would require hard commitments and detailed action plans to stop the rapid sinking that has damaged canals and sunk such large sections of the San Joaquin Valley, the resulting “bowl” can be seen from space. “We are going to get everyone in the room to put their cards on the table,” Gosselin promised during the workshop in Delano Sept. 10. The guidelines, released by the Department of Water Resources in January, outline how agencies should manage aquifers to avoid further subsidence, or land sinking from excessive groundwater pumping. … ” Read more from SJV Water.
Board staff recommends Delta-Mendota Subbasin return to DWR oversight under SGMA
“State Water Resources Control Board staff today released a Staff Assessment of the Delta-Mendota Subbasin recommending that the State Water Board return the subbasin to the Department of Water Resources’ (DWR) oversight under the Sustainable Groundwater Management Act (SGMA). The five-member board will consider acting on the staff recommendation at an April 7, 2026, board meeting. The release of the Staff Assessment begins a 30-day public comment period that ends April 1. The Staff Assessment of the subbasin’s 2024 groundwater sustainability plan found that Delta-Mendota’s 23 groundwater agencies made significant progress in adequately addressing deficiencies identified in their 2022 sustainability plans. The progress includes addressing groundwater quality concerns, establishing a mitigation program for drinking water wells and resolving coordination issues by adopting one plan for the entire subbasin. … ” Continue reading from the State Water Board.
State to consider excluding “small pumpers” from groundwater regulations
“Small farmers pumping less than 20 acre feet per year in the Tule and Tulare Lake subbasins may see some respite from the state’s groundwater reporting sanctions. The state Water Resources Control Board announced that it would consider excluding small pumpers from the May 1 reporting deadline. The Water Board will discuss the exclusion at its April 7 meeting. Those wishing to submit a public comment before the meeting, may email comments to SGMA@waterboards.co.gov with the subject line “Comments – Minimal Impact Exclusions” by March 30 at 12 p.m. Information on how to attend the April board meeting in person or virtually are not yet available. Smaller pumpers may be excluded as they thave minimal impact on groundwater extractions, a statement from the Water Board read. … ” Read more from SJV Water.
Study improves understanding of food safety risks in California Central Coast produce
“A major five-year study on California’s Central Coast led by the U.S. Food and Drug Administration and the Western Center for Food Safety at the University of California, Davis, is helping scientists better understand how harmful bacteria can move through the environment. Often called the nation’s “salad bowl,” growing more than 400 crops, including a large portion of the country’s leafy greens, the Central Coast has been linked to several foodborne illness outbreaks. In 2020, the FDA asked the Western Center for Food Safety at UC Davis to play a central role in a large-scale environmental study to better understand where disease-causing bacteria come from and how they spread. The study was built on close collaboration. Researchers worked in partnership with the FDA, the California Department of Food and Agriculture, ranchers, landowners and growers. “This was a five-year collaborative effort to test the environment within and surrounding produce fields, such as soil, surface water, sediment and air,” said Rob Atwill, a principal investigator for the Western Center for Food Safety and epidemiologist with the UC Davis Weill School of Veterinary Medicine. … ” Read more from UC Davis.
Increased abundance of Sacramento and Klamath River Chinook points to improved salmon season
“Both the Sacramento and Klamath River systems saw increased numbers of Chinook salmon return to spawn in 2025 compared to the previous two years, pointing to a potential increase in fishing opportunities in the ocean and rivers this year. Dr. Michael O’Farrell of the National Marine Fisheries Service forecasts a current adult salmon ocean abundance of Sacramento River Fall Chinook to be 392,349, based on a model used to determine West Coast fishing seasons every year. The information was released at a meeting held by the California Department of Fish and Wildlife (CDFW) on February 27 at the Resources Building in Sacramento. The forecast is based largely on the number of jack (two-year-old) salmon that returned to spawn in 2025. The 2025 jack count of 63,369 was the highest since 2011, the result of very rainy, wet conditions in the Central Valley during 2024. … ” Read more from the Daily Kos.
Congressman John Garamendi launches Delta National Heritage Area passport program
“Congressman John Garamendi has announced the launch of the Sacramento-San Joaquin Delta National Heritage Area’s Passport Program, a brand-new way to experience the cultural and natural riches of the California Delta. Tomorrow, Saturday, February 28, Congressman Garamendi and the Delta Protection Commission (DPC) will commemorate this new program with a ceremonial first passport stamp during the city of Rio Vista’s Lunar New Year Celebration. “I have spent my career fighting to protect and elevate the Sacramento–San Joaquin Delta, and today I’m proud to partner with the Delta Protection Commission and Diane Burgis to launch California’s first and only National Heritage Area Passport Program,” said Congressman Garamendi. “This exciting new initiative will inspire a new generation to explore the Delta’s breathtaking landscapes, rich history, and vibrant communities. Through the Passport Program, visitors can capture stories, preserve memories, and discover America’s natural and cultural treasures in a hands-on way. I invite everyone to visit the Sacramento–San Joaquin Delta National Heritage Area and experience the Delta for themselves.” … ” Read more from the Delta Protection Commission.
Why thinning a forest could get you more drinking water
“You might appreciate snowpack as something to sled, ski, or snowboard on. But beyond the slopes, vast masses of snow melt as winter turns to spring, feeding rivers and streams, which go on to hydrate towns and cities and crops. We’re talking incredible amounts of water: California, for instance, gets 30 percent of its supply from the snowpack in its Sierra Nevada mountains. But across the American west, that bounty is in trouble as the climate quickly changes: The region is currently in the grip of a severe snow drought, as more precipitation falls as rain. At the same time, higher temperatures are desiccating the landscape, fueling massive wildfires once all that snow melts away. Not helping matters is a long history of fire suppression — quickly stamping out blazes has allowed dry vegetation to accumulate, adding yet more fuel to the flames. Scientists seem to have found a way to help alleviate the West’s fire and ice problems simultaneously, at least in Washington state. … ” Read more from Grist.
West coast waters experiencing another large marine heatwave
“A massive marine heatwave has dominated waters off the West Coast since last summer. This marks only the third time on record that such a large section of the coastal ocean has remained so warm for so long—particularly into winter months—without it being an El Niño, NOAA scientists report. NOAA Fisheries and our partners are tracking possible heatwave impacts, which can include harmful algal blooms that can sicken marine mammals and close shellfish fisheries. At one point last September, the current marine heatwave rivaled the enormous 2013–2016 marine heatwave known as “The Blob” in terms of size and surface temperatures. The current heatwave has raised the temperature of waters along the West Coast roughly 3 to 4 degrees Fahrenheit above normal. On September 9, 2025, the northeast Pacific reached its highest ever average temperature of 20.6 degrees Celsius, or about 69 degrees Fahrenheit. That’s almost a half-degree warmer than ever before. Past marine heatwaves shook up marine ecosystems that drove shifts of species, die-offs, and other disruptions of ecosystems in the Northeast Pacific Ocean. … ” Read more from NOAA.
In commentary this week …
Improvement in water supplies from the Delta is possible
Scott Hamilton, President, Hamilton Resource Economics, writes, “Delta science issues are complex and controversial, stakeholders are passionate, and disadvantaged communities and farmers — too busy with their daily lives to weigh in — have been caught in the firefight. The longest running issue is determining what actions might benefit endangered fish. This is surprising because salmon and smelt have been the subject of recovery efforts for three decades, but their numbers continue to decline. While the scientific knowledge base continues to grow, the progress toward recovering native fish species has not met expectations. The target for the latest controversy is “Action 5.” Action 5 is an effort by the U.S. Bureau of Reclamation (the Bureau) to export more water from the Delta to help ease the pain farmers are suffering as a result of the Sustainable Groundwater Management Act. It looks to modify a number of Delta regulations that the Bureau believes are not well supported by science. … ” Read more from the Valley Ag Voice.
Building the Abundant Water Coalition
Edward Ring, Director of Water and Energy Policy at the California Policy Center, writes, “If enough people in California agreed on a state water strategy, the political obstacles would be overcome. If every major water agency, every farming association, and a critical mass of environmental groups were all committed to a specific set of policies and projects, then elected politicians would be bound to adhere to those priorities. Regulatory relief, legislative actions, executive orders, agency directives, and sources of funding would all align. So what would it take for Californians to rediscover a consensus so durable that the state could embark on a water project for the 21st century that rivals the massive projects of the 20th century? It isn’t as if there aren’t proposals out there. The California Department of Water Resources has the California Water Plan, updated in 2023. Along with SB 72, passed in 2025, it calls for 9 million acre feet of additional supply, conservation, or storage by 2040. … ” Read more from Edward Ring.
Changing the rules
Chris Shutes, Executive Director of the California Sportfishing Protection Allliance, writes, “A 2/12/26 letter from four San Joaquin Valley congressmen pleaded with Governor Newsom to waive a Delta outflow requirement in 2026. The requirement is the “Port Chicago standard” in Water Rights Decision 1641 (D-1641), in effect since 2000. Additional letters from the “Coalition for a Sustainable Delta” and from Westlands Water District made similar requests. The letters seek to immediately jettison one of the few existing rules that protects flow and water quality in the Bay-Delta estuary. The common talking point of the letters is how exporting or storing required flow to San Francisco Bay would avoid the “loss” of 600,000 acre-feet of water. We’re talking about water committed to protecting fish, wildlife, and water quality. Exporters have no right to this water. … ” Read more from the California Sportfishing Protection Alliance.
New AI data centers will pose a threat to California’s already limited water resources
Ann Hayden, vice president of climate resilient water systems at Environmental Defense Fund, writes, As the data center boom accelerates to power the rise of artificial intelligence, concerns about the impacts of these behemoth structures typically focus on their energy consumption. While energy impacts are important, leaders in arid regions around the world should be just as attentive to water use — for cooling servers and power generation. If local and state leaders don’t quickly step up with a smart, proactive response, already over-allocated water systems across the western U.S., and indeed the world, will shift even further out of balance, with existing water needs pitted against a new competitor. This is a recipe for heightened water inequity and strain on already challenged communities and ecosystems. In order to make sure that developers don’t just seek out locations where land is cheap or communities are less equipped to push back against big tech, California and other states should require disclosures from companies on the projected water use for each proposed data center. … ” Read more from the San Francisco Chronicle.
In regional water news this week …
Klamath water users respond to Bureau of Reclamation’s management plan
“The Klamath Water Users Association is closely watching whether upcoming release plans by federal agencies will provide enough water for Klamath Basin irrigators. The Bureau of Reclamation released its 2026 annual operations plan Tuesday for the Klamath Project. The plan outlines how water will be managed during the 2026 water year and establishes the operational framework for irrigation deliveries, Upper Klamath Lake elevations, and Klamath River flows under biological opinions that were adopted in 2024 by the National Marine Fisheries Service and the U.S. Fish and Wildlife Service. The plan identifies a goal of up to 350,000 acre-feet of Project water supply by maximizing stored water in Upper Klamath Lake for irrigation, dependent on hydrologic conditions, and staying in compliance with the 2024 biological opinions. … ” Read more from the Herald & News.
Lake County seeks $2 million in federal funding to upgrade sewage system after Clearlake spill
“The Lake County Board of Supervisors is seeking $2 million in federal funding to repair and upgrade the southeast wastewater collection system — an aging series of sewer mains and pipelines that failed in early January and sent 2.9 million gallons of raw sewage into a Clearlake neighborhood. During the Board of Supervisors meeting Tuesday, supervisors directed county staff to pursue the funding through Rep. Mike Thompson, D-St. Helena, and the congressional appropriations process to help repair aging infrastructure and prevent similar failures from happening in the future. Congressional appropriations requests are highly competitive and must be approved by lawmakers as part of the federal spending process, county officials clarified during the meeting. … ” Read more from the Lake Record-Bee. | Read via the Mendocino Beacon.
Inside the cleanup at Englebright Lake after New Colgate Powerhouse pipe burst
“Almost all of the oil and debris have been removed from Englebright Lake in Yuba County after a major pipe failed back on Feb. 13. Buckets of oil came tumbling down that day, being damaged along the way and some of them spilling into the water and onto anything in it. CBS News Sacramento was granted a close-up tour of the cleanup efforts. “The water and sediment that flowed downhill and impacted the facility hit a storage shed that had multiple types and quantities of petroleum-based oils,” said Ryan Hanson, a lieutenant with California’s Department of Fish and Wildlife. Yuba Water Agency workers immediately installed three levels of log and oil booms to box in debris in the area where the river starts to pour into the lake. … ” Read more from CBS Sacramento.
New Colgate Powerhouse failure: SYRCL tracks water quality and salmon impacts on Yuba River
“On February 13, 2026, a catastrophic failure occurred at Yuba County Water Agency’s New Colgate Powerhouse during routine testing of a newly installed section of pipe, releasing approximately 400 acre-feet of water in a sudden flood that destroyed much of the facility and sent massive amounts of sediment into the Yuba River upstream of Englebright Reservoir. While the immediate crisis has passed, SYRCL is monitoring water quality impacts and long-term implications for the watershed. On Saturday February 14th, approximately 18 hours after the penstock pipe failure at the Colgate Powerhouse, SYRCL’s Watershed Science Staff began collecting water quality samples to track the impacts of the ruptured pipe and associated landslide on downstream water quality. Samples were collected at Rice’s Crossing, just downstream of the incident, and at Bridgeport as a control site on the South Yuba, that was unaffected by the incident. We sampled for a suite of parameters including dissolved oxygen, temperature, pH, conductivity, and turbidity. Most of the parameters were within normal range, except for turbidity, which was significantly elevated. Turbidity is a measure of cloudiness of the water and serves as a proxy for suspended sediments; it is measured in NTUs or Nephelometric Turbidity Units. … ” Continue reading from the South Yuba River Citizens League.
Tuolumne County seeks $6.3M state funding for emergency water reservoir after canal damage
“The Tuolumne County Board of Supervisors will meet on Tuesday, March 10, to consider sending a formal request to Governor Gavin Newsom for $6.3 million in state funding for a critical water infrastructure project. The funding would support construction of the Sierra Pines Raw Water Reservoir, a shovel-ready project designed to protect public health, fire safety, and disaster response. The request follows severe damage to the Pacific Gas and Electric Main Tuolumne Canal during a multi-day winter storm on Feb. 17. More than 200 trees fell onto the canal, damaging wooden flumes and forcing PG&E to halt water flows. The interruption cut off 95% of Tuolumne Utilities District’s drinking water supply, leaving the county reliant on limited tank storage and small groundwater wells. … ” Read more from Channel 10.
2026 marks a key decision year for groundwater management in the Salinas Valley.
“Eight years ago, a milestone law for climate adaptation took effect to ensure California could maintain adequate water supplies for generations to come. The Sustainable Groundwater Management Act, or SGMA, created a 25-year roadmap by which local agencies would begin modeling, implement sustainability plans and enforce compliance. While still early in the overall timeline, 2026 marks a significant decision year as the Salinas Valley Groundwater Sustainability Agency brings together feasibility studies, modeling and economic analysis to formulate a set of projects and management actions to carry forward. “It’s a big year of decision-making and getting the whole community behind it,” says Piret Harmon, general manager of SVBGSA. “We need to choose a suite of projects to move forward, and that’s going to happen this summer.” … ” Read more from Monterey Now.
Supervisor seeks law to halt human compost near Fresno County river. Is it safe?
“A Fresno County supervisor says he’ll introduce an ordinance to halt a type of human composting he recently learned has been used near the San Joaquin River, but advocates say he’s jumping the gun unnecessarily. The soil made from human remains in question was placed in a field at the Sumner Peck Ranch, land on Friant Road owned by the San Joaquin River Parkway and Conservation Trust less than 3 miles south of Lost Lake. Supervisor Garry Bredefeld said he was recently made aware of the composting, which includes a process that turns a person’s body into soil. He said he was not familiar with the process, but said using the compost on trust land was “stupid.” Bredefeld also sits on the board for the San Joaquin River Conservancy, a state agency that is different from trust, which is a nonprofit. “The stupidity and the lack of common sense is absolutely breathtaking. This public land is culturally significant and environmentally sensitive,” Bredefeld said at a Thursday news conference in downtown Fresno. … ” Read more from the Fresno Bee via MSN News.
Story Map: Got Water? Importance of retaining Southern California’s water
“Southern California has experienced one of the wettest winter seasons in recent history during the 2025-2026 wet season. The California Department of Water Resources recorded 10 inches of rain, or 204% of average precipitation, in the Southern California Region . This rainfall has been very beneficial in alleviating drought conditions, with 2026 being the first year since December 2000 that California had 0% drought conditions. However, about 9.59 inches of water washes off drought-stricken soil and hardscape like pavement and buildings annually. Efforts to retain this rainfall have facilitated the construction of built infrastructure to capture 27 billion gallons in L.A. County alone. Unfortunately, that is pale in comparison when compared to the 163 billion gallons of water washed into the oceans annually through runoff . The necessity of water retention infrastructure, both rural and urban, is essential to preserving our natural and built environments for generations of Californians to come. … ” Read Story Map from UC Irvine.
California, Arizona and Nevada press Trump administration to rethink Colorado River water cuts
“Leaders of California, Arizona and Nevada are criticizing the Trump administration’s proposals for water cutbacks along the Colorado River, urging it to take a different approach and avoid a court battle. The three downstream states said in letters to the Interior Department this week that the agency’s preliminary outline of five options for cuts ignores the foundational “Law of the River” that has underpinned how seven western states operate for more than a century. Federal officials have so far failed to examine whether their options comply with the 1922 Colorado River Compact, and this is “a fundamental deficiency that must be corrected,” JB Hamby, California’s lead negotiator, wrote in a letter to the Trump administration. … ” Read more from the LA Times. | Read via Yahoo News.
Colorado River water negotiations: States reveal priorities in letters to federal agency
“FOX5 has obtained letters sent by negotiators from Nevada, California, Arizona and Colorado to the U.S. Bureau of Reclamation, revealing where each state’s water priorities lie and what is stalling a deal on Colorado River conservation. The states, despite their divide, have one thing in common: they all dislike the alternatives put forward in the Bureau’s Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead. Four states have emerged as the most vocal opponents of the strategies proposed, and Nevada us among them. In their communication with the Bureau, Nevada’s negotiators highlighted the water-use reductions already made by users in and around Las Vegas. … ” Continue reading at Channel 5.
How a California desalination plant could ease water shortages on the Colorado River
“With desert cities like Phoenix and Tucson bracing for their allotments of Colorado River water to be slashed dramatically, San Diego County’s water agency could for the first time sell some of its water to other states by drawing on its ample supplies from the nation’s largest desalination plant. The San Diego County Water Authority’s board unanimously approved an initial agreement last week to consider selling some of its water to Arizona and Nevada, where cities that depend on the over-tapped Colorado River are expected to face substantial cuts in water supplies. The approach would not involve sending desalinated water to other states, but rather selling some of San Diego County’s allotment of Colorado River water, which in turn would generate funds to increase output at the Carlsbad desalination plant. … ” Read more from the LA Times. | Read via Yahoo News.
Announcements, notices, and funding opportunities …
