A wrap-up of posts published on Maven’s Notebook this week …
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In California water news this week …
California’s ‘unprecedented’ snowmelt will only get worse from heat wave
“Three weeks after Tahoe’s biggest snowstorm in decades, Donner Summit has as much dirt as snow. Feet of powder quickly disappeared, as rain and unusually warm temperatures depleted gains from the February blizzard that had been cheered at the time as a potential season-saving event. California’s snowpack is already its lowest since 2015, and record-shattering March heat arriving next week will make it worse. The rate of melting is “unprecedented,” said Tim Bardsley, a hydrologist at the National Weather Service office in Reno. The entire snowpack, he said, has been wiped away along sunny parts of the Lake Tahoe shoreline. … ” Read more from the San Francisco Chronicle.
Snow drought current conditions and impacts in the West
“Snow drought worsened from February into early March due to record warmth, despite near-normal precipitation across much of the West. Some locations, such as the central and northern Cascades in Washington, were also drier than normal during this period. Every major river basin and state in the West is experiencing a snow drought. Record-breaking high temperatures are forecasted for large parts of the West. Further, the 6-10 and 8-14 day outlooks from NOAA’s Climate Prediction Center lean toward drier-than-normal conditions for almost all of the West along with a strong probability of warmer-than-normal temperatures through March. Record-breaking snow drought conditions are expected to further deteriorate as snow melt begins much earlier for some. As of March 8, Colorado reported record-low statewide snowpack. Stations in the Cascade Range in Oregon and Washington are reporting the greatest snowpack deficits in the West. Some states, such as California, are already experiencing an early melt out of snow. … ” Read the full update from NIDIS.
Signs of strong El Niño emerge. Here’s what California can expect.
“El Niño, the seasonal climate pattern that brings a cascade of global weather impacts, is emerging in the Pacific Ocean, according to new data. There is a 62% chance that El Niño conditions will begin between June and August and last at least through the end of the year, the National Weather Service’s Climate Prediction Center reported on Thursday. La Niña, which started last fall and ruled the winter, is expected to fade out any day. In general terms, El Niño signals a wet winter for California, especially the southern part. But experts cautioned that may not always be true. “Even if a Niño is born in summer, there’s no guarantee that California will get a wet winter,” Alexander Gershunov, a research meteorologist at Scripps Institution of Oceanography at UC San Diego, wrote to SFGATE in an email. … ” Read more from SF Gate.
SEE ALSO: Odds Rise That El Niño Will Soon Bring Weather Extremes, from the New York Times
REPORT: From planning to action: The Mutibenefit Land Repurposing Program’s 2025 progress and impact
“The 2025 Multibenefit Land Repurposing Program (MLRP) Annual Report is now available, detailing program progress and regional activities. Prepared by the Statewide Support Entity with input from block grantees and Department of Conservation staff, it highlights the shift from planning to implementation. The report showcases collaborative efforts to advance groundwater sustainability while benefiting ecosystems, local economies, and communities. Key updates include outreach, planning, and implementation across eight block grant regions, summaries of 23 approved projects, and visual overviews of program-wide progress and engagement. The Multibenefit Land Repurposing Program (MLRP) supports California’s groundwater sustainability by helping communities and growers transition less-viable irrigated agricultural lands to more beneficial uses. Through regional grants, the program fosters proactive, community-led strategies that reduce reliance on groundwater while promoting healthy ecosystems, resilient communities, equitable economies, and regional adaptability. MLRP empowers local planning and coordination to implement projects that balance environmental, economic, and social benefits. … ” Continue reading at Maven’s Notebook.
Salmon numbers rebound in 2026 forecast
“How about some good news for a change! Information from the Golden State Salmon Association and the Pacific Fisheries Management Council forecasts a current adult salmon ocean population of 392,349 in 2026 — more than double last year’s ocean abundance estimate. The Klamath River forecast also jumped to 176,233, up from 82,672 in 2025. For comparison, the upper Sacramento River saw a return of over 60,000 adult salmon to natural spawning areas in 2025 compared to just over 4,000 in 2024, a 15-fold increase. The number of jacks, or two-year-old sub-adult salmon, jumped almost threefold from around 5,500 in 2024 to about 14,500 in 2025. The number of returning jacks is key to forecasting the adult salmon population in the ocean now, which informs how many salmon fishery managers will allow to be caught this year. … ” Read more from the Santa Maria Times.
SEE ALSO: Keeping an eye on ’26 salmon season possibilities, from the Santa Cruz Sentinel
Local agencies across California continue advancements toward groundwater sustainability
“The Department of Water Resources (DWR) has released the final version of California’s Groundwater: Bulletin 118 – Update 2025, the State’s official and most comprehensive report of groundwater monitoring, conditions, and management across California. The report builds upon the previous update in 2020 and contains critical information about the state’s groundwater supplies from 2020 to 2024, a period marked by record-setting dry and wet weather events and increasing ambient temperatures. It shows considerable progress made by California and local agencies towards reaching the goals of groundwater sustainability outlined in the Sustainable Groundwater Management Act (SGMA). Among the successes noted in the report, California has seen improvements in groundwater recharge efforts, drinking well protection, and increased funding for Tribal projects. This release coincides with Groundwater Awareness Week, a time to recognize the vital role groundwater plays in California’s water supply. “Groundwater plays a critical role in our state’s water supply and today’s report shows what we’ve already known: our changing climate and warmer temperatures will continue to increase demand on groundwater supplies as our hydrology changes and tests our water systems,” said Paul Gosselin, DWR Deputy Director of Sustainable Water Management. “It’s more important than ever that state and local agencies continue to work together to achieve the goals we set for California in order to protect this precious resource and the people who rely on it.” … ” Read more from the Department of Water Resources.
SEE ALSO: DWR Releases Final California’s Groundwater: Bulletin 118 – Update 2025, Celebrates Groundwater Awareness Week, from DWR
GroundwaterRecharge.org: Who is Recharge for?
“Earlier this year, Sustainable Conservation put the finishing touches on the “Recharge For…” section of its groundwater recharge resource website, GroundwaterRecharge.org. The dropdown menu allows visitors to learn about managing groundwater recharge based on their affiliation or involvement with the practice. Sustainable Conservation’s Water for the Future team hopes this resource will demystify how, where, and when MAR can be done to effectively and safely increase groundwater supplies for community, agricultural, and ecosystem resilience. Who is groundwater recharge For? It might be quicker to list who it isn’t for. Recharge is a practice that Sustainable Conservation has championed for over a decade largely because of the myriad beneficiaries it creates. The “Recharge For…” dropdown menu focuses on specific benefits and resources for growers, water districts and groundwater sustainability agencies, communities, ecosystems, and policymakers. … ” Read more from Sustainable Conservation.
Unraveling the dynamics of interconnected surface water depletion
“In December 2025, the Groundwater Resources Association of California hosted a two-day webinar to address the complex relationship between Interconnected Surface Water (ISW) and groundwater. The event brought together experts to discuss the science, environmental implications, and policy challenges of ISW, focusing on how groundwater extraction impacts surface water flows and the ecosystems that depend on them. The connection between surface water and groundwater is a critical component of sustainable groundwater management. When groundwater pumping occurs near a stream or river, it can lower the water table and cause surface water to seep downward, a process that can lead to stream depletion. This interaction affects various beneficial users of both surface water and groundwater resources. Dr. Vivek Bedekar, a consultant with SS Papadopoulos and Associates, opened the webinar series by introducing the foundational concepts of ISW depletion. His presentation focused on how groundwater pumping alters streamflow and the need for effective models and management strategies to address these interactions. … ” Read the article at Maven’s Notebook.
Water Supply Assessments under CEQA: Vallejo v. American Canyon clarifies what must (and need not) be included
“On January 14, 2026, a California Court of Appeal upheld the Environmental Impact Report (EIR) certified by the City of American Canyon (American Canyon) and the accompanying water supply assessment (WSA) in City of Vallejo v. City of American Canyon. The California Environmental Quality Act (CEQA) requires a WSA to be prepared for certain large-scale development projects as part of the environmental review process to prove that adequate water supplies will be available for the project once complete. Legal challenges related to the availability of water to supply large developments are becoming increasingly common. The Vallejo case provides some new insights into the scope and details required for a valid WSA under CEQA. The project at issue in the Vallejo case was a 2.4-million-square-foot industrial warehouse complex on 208 acres of undeveloped land in American Canyon. … ” Read more from Allen Matkins.
Second district court of appeal affirms judgment in California’s first comprehensive groundwater adjudication
“On March 5, 2026, the Second District Court of Appeal issued an opinion in Las Posas Valley Water Rights Coalition v. Ventura County Water Works District No. 1, et al., Case No. B330837, affirming the trial court’s judgment in California’s first comprehensive groundwater adjudication since the adoption of the Sustainable Groundwater Management Act (SGMA). Downey Brand represents the Las Posas Valley Water Rights Coalition, a plaintiff group of landowners in the 40,000-acre Las Posas Valley, located in Ventura County. Groundwater from the Las Posas Groundwater Basin is the primary source of irrigation water for the various high-value crops grown in the Valley, including lemons, avocados, and berries. In 2018, the Coalition filed a complaint to initiate a comprehensive adjudication of the Basin following Fox Canyon Groundwater Management Agency’s (“Fox Canyon”) imposition of measures to drastically curtail groundwater pumping. … ” Read more from Downey Brand.
Invasive plants threaten Delta waterways, treatments begin
“California parks officials will begin another season of herbicide treatments in the Sacramento–San Joaquin Delta later this month, targeting invasive aquatic plants that clog waterways, threaten boaters and disrupt marinas and irrigation systems. Starting March 19, California State Parks’ Division of Boating and Waterways (DBW) plans to treat thousands of acres across the Delta and its southern tributaries as part of its 2026 control program. The invasive plants include water hyacinth, South American spongeplant, Uruguay water primrose, Alligator weed, Brazilian waterweed, curlyleaf pondweed, Eurasian watermilfoil, coontail, fanwort and ribbon weed. … ” Read more from the Stockton Record.
SEE ALSO: Water hyacinth has plagued the Delta over the years, photo gallery from the Stockton Record
California water board will soon release a new rule to limit water pollution from dairies in the state
“California dairies are out of balance. Everyone from environmentalists to regulators to the industry agrees that the nitrogen from milk cow manure is ending up where it can pose a health threat. Excess nitrogen from dairies turns into excess nitrate in the soil, spilling into waterways, seeping into groundwater and contributing to widespread contamination of drinking water in the Central Valley. In some counties there, 40 percent of drinking wells are above the safe limit established by the U.S. Environmental Protection Agency, posing health risks like miscarriages and infant mortality. In the next two months, the State Water Board says it will release a long overdue draft order that will chart a course to fix that. A first draft of the board’s thinking came in October 2024, when it proposed a new framework requiring that Central Valley dairies comply with a nitrate drinking water standard of 10 milligrams per liter and meet new rules for storing waste, applying manure to crop fields and providing alternative drinking water to residents when nitrate levels in their water are unsafe. … ” Read more from Inside Climate News.
SEE ALSO: Ten million tons of manure in california are unaccounted for, new report shows, from Sentient Media
Nearly 40% of California produce contains PFAS pesticides, report finds
“A new report shows that nearly 40% of conventionally grown fruits and vegetables tested by California regulators have residues of “forever” or PFAS chemicals, a family of compounds that can be lasting and harmful. The Environmental Working Group, an advocacy group based in Washington, D.C., reviewed California’s own test data and found PFAS pesticide residues on peaches, grapes and strawberries, and about three dozen other types of fruits and vegetables. The chemicals have have increasingly been used in agricultural chemicals in recent years. “Here’s the thing: This is an emerging threat,” said Nathan Donley, environmental health science director for the Center for Biological Diversity, who was not involved in the report. “PFAS pesticides went from being the exception to now they’re the rule.” … ” Read more from the LA Times.
In commentary this week …
Newsom oversees years of failed California water policy
Daniel M. Kolkey, a former judge and former counsel to Governor Pete Wilson, writes, “2026 began in California with two atmospheric rivers and storms, which resulted in precipitation that was 119% of average rainfall for January. However, much of it flowed into the Pacific Ocean. Moreover, by the end of February our statewide snowpack was only 66% of average for this date, constituting a significant decline from 85% at this time last year. This is critical because the snowpack acts as a reservoir that releases water to rivers and supplies man-made reservoirs when the climate is dry. If our existing number of reservoirs — built to supply a smaller population — reach capacity, they cannot store the runoff. We Californians must never lose sight of the fact that our state suffers intermittently from droughts. Indeed, California was suffering from drought when it first became a state in 1850. One of our longest droughts lasted seven years from 1928-1934. And California has suffered drought for 12 of the past 20 years — 2007-2009, 2012-2016 and 2019-2022. It therefore should be obvious that to serve its residents, California must build more water storage facilities that capture and store rain and runoff. … ” Continue reading at the OC Register.
The Delta needs a dike to weather climate change & protect LA water instead of myopic tunnel
Dennis Wyatt, editor of the Manteca Bulletin, writes, “If climate change is happening and sea levels are rising, then why is the State of California pursuing a Delta solution that protects Los Angeles Basin water interests and those of corporate farms at the expense of large swaths of San Joaquin and Sacramento counties? Just like the State of California’s horse-blinder approach to high-speed rail that ignores changing realities, the same is true of the myopic tunnel project to bypass the Delta to keep water flowing into SoCal swimming pools in the event of a “disaster”. The disaster of choice the proponents of the Delta Bypass keep going back to are earthquakes. They justify robbing the Delta of beneficial water to keep its ecological system healthy before it is pumped south to head to faucets accessed to hose down Disneyland pavement by saying a quake could disrupt the LA Basin’s sucking of water from north state watersheds. … ” Read more from the Manteca Bulletin.
DWR continues to improve forecasting as spring heats up in California
DWR Director Karla Nemeth writes, “For California water managers, the painfully sunny skies of March 2026 bear striking resemblance to March 2021. In the spring of 2021, the snowpack was, like now, about half of average. Temperatures were breaking records. Then the news got worse. The snowmelt DWR forecasters expected to drain into reservoirs failed to appear. Unexpectedly, the mountain runoff disappeared into dry soils and a thirsty atmosphere. Caught off guard by this reality, DWR heeded this new climate signal. The work done at DWR over the last five years to understand and track how snowpack translates into water supply means we know a great deal more about what to expect this dry, warm spring. We do not control what, if any, rain and snow will fall in the next month and a half. But we will know a lot more about what water supply to anticipate, thanks to these forecasting improvements since 2021 … ” Continue reading from DWR.
Why groundwater is more important than ever
Richael Young, Senior Director of Water for the Future for Sustainable Conservation, writes, “Groundwater supplies approximately 40% of our state’s water needs, and even more in dry years when less surface water is available. These needs include community drinking water, irrigation water, and baseflows for our rivers, wetlands, and ecosystems. Climate change makes groundwater even more important to California. While our average precipitation isn’t expected to change with climate change, an increasing amount will fall as rain rather than snow. That’s not just bad news for California’s skiers and snowboarders. Snowpack is one of California’s largest and most important reservoirs, storing approximately 15 million acre-feet every year in the Sierras. We rely on the gradual melting of this snow for steady runoff during the spring and summer to sustain rivers, farms, and communities. With climate change shrinking this natural reservoir’s capacity, groundwater management becomes even more vital as we pursue water security. … ” Continue reading from Sustainable Conservation.
Donald Trump has opportunity to make water great again
Arizona State Representative Gail Griffin and U.S. Representative Andy Biggs write, “After decades of finger pointing and failed negotiations over the rights and distribution of the Colorado River, the future of the West stands at a crossroads. The stalemate over water scarcity between seven western states threatens America’s economy and national security. It’s the kind of stalemate that only a grand deal and a major investment can break through to save our region. With the Colorado River under strain, and time running out, America needs a visionary, a builder and a deal maker. Thankfully, we have all three of those in President Donald J. Trump. For over half a century, the construction of large dams and canals was the mark of a truly great president. Beginning with Teddy Roosevelt, the first major water reclamation project in the West—the Roosevelt Dam—was authorized to provide Arizona with water that expanded our country’s agricultural, industrial, and military base. … ” Continue reading at the Arizona Free Press.
Editorial: Clearlake needs the state’s help after sewage spill
The Santa Rosa Press Democrat editorial board writes, “Nearly two months after a ruptured sewer main in Lake County spilled 2.9 million gallons of raw sewage, residents still cannot use their tap water. Instead, they fill buckets, haul water and wait. It is past time that California delivers the assistance those families desperately need. The Press Democrat’s Anna Armstrong and Isabel Beer have documented the crisis in detail. They reported how the Jan. 11 pipeline rupture contaminated the shallow aquifer that supplies private drinking wells across the Burns Valley area of Clearlake. The affected zone quickly grew from 58 properties to more than 160. Lake County Special Districts, the agency responsible for the sewer system, has not made the reporters’ job easy. Officials have not responded to repeated requests for comments. That silence might reflect the fact that the current emergency has overwhelmed them. Even so, residents deserve answers about a disaster that was, by every indication, years in the making. … ” Read more from the Santa Rosa Press Democrat.
In regional water news this week …
How Trinidad’s big water leak highlights a much bigger quandary
“The calls rang out over and over, in the dispassionate water system codes that meant unmistakably: “Something’s wrong. I need you. Help.” Like a little kid pleading for someone – anyone — to respond, the alarm calls on that rainy January morning went to three different phone numbers at 3:02 a.m., 3:04 a.m. and 3:06 a.m. Then minutes later calls went again to all three phones, and yet again, before roping in a fourth phone by 3:35 a.m. No one answered. While 70,000 gallons an hour rushed from a broken pipe, two key Trinidad city workers slept, each thinking the other was supposed to be on call that night. The ensuing water crisis shuttered restaurants for days, dented Trinidad’s water reserve funds and prompted fresh conversations about a long-smoldering pipeline debate. … ” Read more from the Lost Coast Outpost.
Oroville’s Feather River cleanup efforts aimed at protecting salmon population
“Illegal homeless camps along the Feather River are causing concern among locals about the impact on the waterway and its ecosystem. Community members worry that debris from these camps could harm the salmon that spawn in the river each year. Terry Gregg, a local fisherman, has been fishing in the Feather River for decades and expressed his feelings about the matter. “I have a concern for what’s going into the water,” Gregg said. “We’re blessed here to have a wonderful fishery, a healthy fishery that depends on good clean water and the ability to spawn and to navigate to make their life cycle.” … ” Read more from Action News Now.
Smells like swamp’: This Wine Country town is fed up with brown tap water
“In the heart of Napa Valley, St. Helena is home to world-class Cabernet Sauvignon, a historic stone-and-brick downtown and, to locals at least, brown tap water. Some days, clear water flows from the taps in this city of about 5,250 residents between Napa and Calistoga. But other days, some residents say the water looks more like beer or Chardonnay but with less appealing attributes: Silty. Frothy. Stinky. The problem is that naturally occurring minerals, mostly iron and manganese, have built up in the city’s aging pipes, according to city reports. Routine changes in water velocity caused by anything from maintenance projects to seasonal water changes can dislodge the buildup and transform clear water into brown swill. City officials have insisted the water may seem unappealing at times, but it is not harmful and is safe to drink. The city’s reassurances have not satisfied some residents who argue they can’t be expected to consume or bathe in brown water — while still paying some of the Bay Area’s highest water bills. … ” Read more from the San Francisco Chronicle.
Arroyo Grande will ask voters for option to buy state water outside of droughts
“Arroyo Grande voters will decide in November whether the city should have the option to buy state water outside of drought emergencies. On Tuesday, the Arroyo Grande City Council directed its staff to put a measure on the November 2026 ballot that will ask voters whether the city should upgrade its agreement with the California State Water Project from emergency uses only as allowed by Measure E-16 in 2016 to a new as-needed contract. … “ Read more from the San Luis Obispo Tribune.
Monterey’s water supply has improved, but let’s not open the flood gates
Sarah Leeper, president of California American Water, writes, “Monterey has suffered from a decades-long lack of a sustainable water supply. In 2009, these challenges became impossible to ignore when the state imposed a cease-and-desist order banning new water connections until sufficient new water sources could be developed to reduce reliance on the Carmel River. The cease-and-desist order has severely limited Monterey’s ability to build affordable housing, grow businesses and help its economy develop sustainably. It’s completely understandable, then, that people would be eager to have the order modified to remove the moratorium on new connections. But here’s the reality: as proposed, the Monterey Peninsula Water Management District’s request to modify the order would risk reversing the decades of progress made on restoring the Carmel River and improving water security in Monterey. … ” Read more from the Monterey Herald.
Dozens of groups sign joint letter urging Metropolitan Water District to prioritize funding for massive wastewater recycling project
“Nearly fifty organizations and five water-oriented coalitions submitted a joint letter to the Metropolitan Water District of Southern California in advance of today’s Finance, Affordability, Asset Management, and Efficiency Committee meeting, where Metropolitan’s biennial budget will be discussed. The letter signals support for including $150M for planning and design for Pure Water Southern California (PWSC) in MWD’s 2026-2028 biennial budget. PWSC is an ambitious regional wastewater recycling project that would produce up to 150 million gallons of purified water daily once it reaches full production capacity. In addition to creating a new source of local, reliable water, the project would reduce nutrient loads released into the ocean, which would benefit marine life. It would also create 75,000 local job-years to support project construction and operations and maintenance. “Pure Water Southern California is the smartest and most reliable investment Metropolitan’s leaders could make for our region’s water future,” said Bruce Reznik, executive director of Los Angeles Waterkeeper. “We will always have wastewater available for purification and reuse. The same cannot be said for water we might be able to get from the Colorado River, the Bay-Delta, or the potential Sites Reservoir a decade or two from now. Hands down, these are the best dollars Metropolitan could spend when looking for options to insulate us from the deluge-to-drought extremes that continue to plague our region.” A copy of the letter is available here.
Where restoration meets policy: Designing a future where humans and Southern steelhead thrive together
“Southern steelhead trout are one of the most remarkable native fish in California, an often overlooked species that inhabits the waters of our very own Southern California backyard. Known scientifically as Oncorhynchus mykiss, Southern steelhead are a distinct population of steelhead trout found in coastal watersheds from the Santa Maria River south to the U.S.–Mexico border. Unlike resident rainbow trout, steelhead are anadromous, meaning they spawn in inland freshwater streams, migrate to the ocean to grow, and return to freshwater rivers to spawn. In Southern California, their ability to survive in volatile, drought-prone watersheds with high temperatures, seasonal sand berms, and low summer flows is nothing short of extraordinary. Their persistence in some of the most urbanized waters in the state is a testament to the species’ resilience. … ” Read more from Cal Trout.
How to fix the contamination in the Tijuana River? A new report lays out the multi-step solution
“Authorities charged with cleaning up Tijuana River pollution should finish upgrades to wastewater plants on both sides of the border, fund operations as well as construction of those facilities, and plan for eventual wastewater reuse, a report issued today recommended. Those are some key suggestions of the report “Tijuana River Contamination Crisis: A Five-Pillar Framework for Binational Solutions,” released today by the San Diego Regional Chamber of Commerce and the Prebys Foundation. Maria Elena Giner, former Commissioner of the U.S. International Boundary and Doug Liden, a former U.S. Environmental Protection Agency official, authored the report. “For far too long the Tijuana River contamination crisis has been discussed in fragments,” Chris Cate, president and CEO, San Diego Regional Chamber of Commerce said at a press conference on the report, held at the Tijuana River National Estuarine Research Reserve Wednesday. “What’s been missing is a comprehensive binational roadmap that connects the problem to clear, coordinated, and accountable action.” … ” Read more from Cal Matters.
