A wrap-up of posts published on Maven’s Notebook this week …
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In California water news this week …
California has a drinking water problem
“California’s drinking water has elevated levels of a certain contaminant found to be associated with adverse birth outcomes, causing experts to advise that safe water advisories need to be updated. According to a nationwide study led by researchers at Columbia University, parts of the state have levels of arsenic in public drinking water higher than 5 micrograms per liter. While the Environmental Protection Agency (EPA) currently maintains that levels of arsenic in drinking water are safe at 10 micrograms per liter or less, the study found certain health risks were associated with lower levels. Researchers found that consumption of drinking water with levels of arsenic of 10 micrograms or less were connected to a higher chance of babies being born preterm, with lower birth weights, or smaller than expected for their gestational age. … ” Read more from Newsweek.
California’s red line of fire defense faces growing scrutiny
“As California enters the height of wildfire season, Cal Fire aircraft are once again painting red lines across dry hillsides with a substance known as PHOS-CHEK. The fire retardant is used to slow or stop advancing flames. But growing questions about its safety for the environment and for people is prompting scrutiny. PHOS-CHEK is manufactured by Perimeter Solutions, a Missouri-based company with deep roots in industrial chemicals that recently opened a manufacturing facility in Sacramento. The name refers to its key ingredient: ammonium phosphate, a compound also used in fertilizer. It works by coating vegetation in a film that helps prevent combustion. Its trademark red color, which comes from iron oxide—essentially rust—helps pilots see where it has already been dropped. Despite its widespread use, PHOS-CHEK’s full list of ingredients remains secret. … That lack of transparency has drawn concern from researchers like Daniel McCurry, an associate professor of environmental engineering at USC. … ” Read the full story at Capital Public Radio.
Water Supply Strategy update: Adapting to a changing climate
“Climate change is rewriting the rules of our environment, and California is feeling the heat—literally. With temperatures climbing to record-breaking levels both statewide and globally, the impacts are impossible to ignore. At the tail end of the 2020-2022 drought, the Department of Water Resources projected that by 2040, California’s water supply could shrink by 10% due to a thirstier atmosphere, parched landscapes, and a phenomenon known as the “evaporative gap,” where rising temperatures accelerate water loss through evaporation, leaving less to sustain ecosystems, agriculture, and communities. In 2022, the Newsom Administration released the Water Supply Strategy, which focuses on ways to increase water supply and adapt to the more extreme weather patterns caused by climate change. At the June California Water Commission meeting, Anthony Navasero, Drought Coordinator for the Department of Water Resources, and Annalisa Kihara, Assistant Deputy Director of Division of Water Quality at the State Water Board, shared updates on implementing the Water Supply Strategy, highlighting progress in brackish and seawater desalination, advancing groundwater recharge projects, and improving information systems like stream gauges and a new water rights system. …” Continue reading at Maven’s Notebook.
Scientific surveys show continued decline in white sturgeon population
“Recent results from white sturgeon monitoring surveys by the California Department of Fish and Wildlife (CDFW) suggest the white sturgeon (Acipenser transmontanus) population has continued to decline. CDFW fisheries biologists now estimate there are approximately 6,500 white sturgeon between 40-60 inches long in California — down sharply from the previous estimate of approximately 30,000 fish in that size range, based on the 2016-2021 survey average. There may be many reasons for the downward trend, including mortality from harmful algal blooms, poaching, past sport fishing harvest and poor river and Delta conditions. In 2024, CDFW implemented a new method for surveying the white sturgeon population in collaboration with the Pacific States Marine Fisheries Commission and local sturgeon fishing guides. Surveys take place in the spring and fall from San Pablo Bay to Rio Vista and surrounding areas. The methods are based off white sturgeon surveys conducted in Oregon and Washington and modified for use in California. The study design has been peer-reviewed and is the most robust and comprehensive white sturgeon population monitoring survey ever conducted in California. … ” Continue reading from the Department of Fish & Wildlife.
California weather forecasts could soon become less accurate when this data source goes offline
“Storm and surf forecasts in California will become less accurate this year when federal funding for a network of ocean buoys disappears in September. Federal support for the Coastal Data Information Program, operated by UC San Diego’s Scripps Institution of Oceanography, was drastically cut by nearly 70%. The drop in funding, set to take effect Sept. 1, will force some ocean buoys offline, scientists say, making weather forecasts less reliable, compromise public safety and hamper ship operations. “If you lined up a hundred meteorologists and asked them, ‘Are buoy observations important to the forecast process and important to the mission of saving lives?’ every one of them will say, ‘Yes, absolutely,’” said Troy Nicolini, the meteorologist-in-charge at the National Weather Service Eureka office. … ” Read more from the San Francisco Chronicle.
Neutral ENSO conditions likely to last into winter
“Neutral conditions dominating large parts of the eastern and central Pacific are likely to persist throughout the rest of the year and into the upcoming winter, according to a recent NOAA outlook. In the agency’s most recent update, researchers noted that much of the Pacific has anomalies between 0.5 °C to -0.5 °C, meaning neither El Niño nor La Niña is in control. Once surface temperature anomalies reach at least -0.5 °C or colder, a La Niña is considered underway, which has global implications for weather patterns. The agency said that if the status of the El Niño-Southern Oscillation, or what is commonly referred to as the ENSO, were to reach the cool phase later in the year, the changeover would likely not mean a whole lot of change, because the La Niña would be weak. … ” Read more from Fox Weather.
Every mention of ‘water’ in Trump’s Big Beautiful Bill
“The U.S. House passed President Donald Trump’s spending bill on July 3, 2025, that includes tax cuts and cuts to Medicaid and various other programs. The bill now goes to the President to be signed. Initial estimates suggest the bill would add roughly $3 trillion to the national debt.Mentions of water within the bill, as it pertains to the industry, are few and far between. The bill includes funding for a source water protection program and a watershed protection program. Direct mentions of water include: Grassroots Source Water Protection Program, Watershed Protection and Flood Prevention Act, and Water conveyance and surface water storage enhancement. … ” Read more from Water World.
State officials say federal cuts threaten California’s environment
“Budget cuts, staff reductions and other sweeping changes from the federal government are posing real threats to California’s environment and progress against climate change, state officials said Thursday. At a gathering of the state’s top leaders in wildfire response, water resources, natural lands and clean energy, they underscored the ways the Golden State has long worked together with federal agencies — and how actions by the Trump administration are putting that cooperative work in jeopardy. “We want federal agencies to succeed, and in fact we need them to succeed,” said Wade Crowfoot, California’s natural resources secretary, noting that 48% of the state’s land is owned and managed by the federal government. “Because if they fail, it impacts the prosperity and safety of Californians.” … ” Read more from the LA Times.
San Joaquin Valley Water Blueprint pushes for bold water reforms
“The San Joaquin Valley Water Blueprint, a diverse coalition of agricultural, municipal, and community stakeholders, is stepping up efforts to improve water supply reliability in California’s Central Valley. At the heart of their advocacy is support for Executive Order 14181, originally issued under the Trump administration, which lays the groundwork for modernizing water management and increasing overall water deliveries statewide. The Blueprint has formally reached out to several influential leaders—including former President Donald Trump, U.S. Secretary of the Interior Doug Burgum, and California Governor Gavin Newsom—urging them to coordinate on water policy reforms. Their goal: to align regulatory frameworks and accelerate infrastructure improvements that could unlock up to 9 million acre-feet of additional water per year by 2040. … ” Read more from Ag Net West.
State legislators moving forward two bills that would support Ridgecrest’s water security
“As the Indian Wells Valley groundwater basin continues to face critical water reliability challenges, the Indian Wells Valley Groundwater Authority (IWVGA) is supporting two key pieces of legislation currently moving through the California legislature: AB 1413 (Papan) and AB 1466 (Hart). These bills aim to protect the water rights of people not just in the City of Ridgecrest and surrounding communities but throughout the entire state. The Indian Wells Valley groundwater basin is the only current source of water for Ridgecrest, the U.S. Naval Air Weapons Station China Lake, and the entire region. At current pumping rates, this basin could run out of water within 40 years, underscoring the urgent need to implement the region’s state-mandated Groundwater Sustainability Plan. “These bills help protect our local groundwater sustainability plan, which is designed to ensure Ridgecrest has water for generations to come,” said Scott Hayman, chair of the Indian Wells Valley Groundwater Authority. “This gives us and other groundwater authorities throughout California the certainty we need to keep moving forward to protect our drinking water supplies without consumers shouldering the high costs of legal challenges.” … ” Continue reading this press release from the Indian Wells Valley Groundwater Authority.
California has an idea to counter Trump’s megabill: Roll back environmental laws
“California lawmakers reeling from President Donald Trump’s assault on clean energy are considering a controversial strategy to keep projects on track — slashing environmental permitting further. That plan could intensify a fight between clean energy advocates and environmentalists over the trade-offs between building fast and environmental protection that’s already playing out at home. California officials are scrambling to respond to congressional Republicans’ budget “megabill,” signed into law Friday, which demolishes Biden-era tax credits that incentivize construction of large-scale solar and wind projects, home energy efficiency improvements and electric vehicle purchasing — centerpieces of blue states’ strategies to wean themselves off fossil fuels. … ” Read more from Politico.
Warnings ignored: The grim connection between the L.A. wildfires and Texas floods
“Two major climate disasters of 2025 — the Texas flooding that killed more than 100 people and the L.A. wildfires in January that resulted in 30 deaths and wiped out more than 15,000 homes and businesses — highlight the struggles officials face in fully preparing for extreme weather conditions. In both cases, the National Weather Service offered clear warnings of potentially life-threatening weather events; in Los Angeles, warnings were given days before extraordinary winds — of up to 100 mph — slammed a region already suffering from a record-dry fall. Even in Texas, more than a day before catastrophic flooding hit Kerr County, state officials — on July 2 — reiterated the weather service’s warnings that “heavy rainfall with the potential to cause flash flooding is anticipated across West Texas and the Hill Country” through the Fourth of July weekend. But for a variety of reasons, those warnings did not filter down with maximum urgency to various local agencies. … ‘ Read more from the LA Times.
As L.A. bakes, duration of heat waves is accelerating faster than climate change, UCLA study shows
“As sizzling temperatures sweep across Southern California this week, UCLA researchers have released a new finding that the duration of heat waves is increasing faster than global warming. Researchers found that heat waves are not only getting hotter, but also becoming longer at a rate that will accelerate as the planet continues to warm. “Each fraction of a degree of warming will have more impact than the last,” said UCLA climate scientist David Neelin, who helped lead the study. This means that even relatively modest warming can significantly boost the risk of powerful, enduring heat waves — underscoring the need to develop strategies to help keep people, agriculture and infrastructure safe in extreme heat, he said. … ” Read more from the LA Times.
In commentary this week …
Is California’s water infrastructure ready for climate whiplash?
Edward Ring, Director of Water and Energy Policy at the California Policy Center, writes, “If there is anything that might constitute an overwhelming institutional consensus in California, it’s that we are experiencing climate change, and that one of the consequences will be more rain, less snow, and more so-called whiplash between very wet years and very dry years. In an average year these days, 30 million acre feet of water flows through the Sacramento-San Joaquin Delta. But nearly half of that water comes down in the form of a melting Sierra snowpack which in an average year holds 15 million acre feet of water. This snowmelt fills the reservoirs and feeds the rivers from April through June. With climate change, so we’re told, the volume of runoff won’t change. But we’ll get almost all of it in the three months of winter. Do we have a system to handle winter flows into the delta that are twice today’s volume? And if not, for the vast majority who view this scenario as a certainty, why aren’t we building anything? … ” Continue reading this commentary.
California thins its forests, then burns the wood. Is there a better idea?
Opinion columnist Tom Philp writes, “In California’s never-ending effort to thin its forests to prevent devastating wildfires, crews are removing millions of tons of small trees and brush every year. And then most of it goes up in smoke. It is burned, in controlled and intentionally lit fires, before the next fire season. The search for a better solution has been elusive. One proposal to convert much of this biomass into wood pellets, and ship them overseas from Stockton to be burned halfway around the world, drew widespread criticism from environmental groups. This opposition, combined with a worldwide drop in price for these wood pellets, has rural counties rethinking how to create something of market value out of all this material rather than to simply burn it. The new idea is to somehow convert the so-called “biomass” here in California. … ” Read more from the Sacramento Bee.
In regional water news this week …
Young indigenous kayakers about to complete historic river journey, after ‘largest dam removal in US history’
“Ruby Williams’ birthday was not your average 18th. She celebrated it on the Klamath River, with a group of young people making a historic journey paddling from the river’s headwaters in southern Oregon to its mouth in the Pacific Ocean, just south of Crescent City, California. It marked the first time in a century that the descent has been possible, after the recent removal of four dams allowed the river to flow freely. Williams, together with fellow paddler Keeya Wiki, 17, spoke to CNN on day 15 of their month-long journey, which they are due to complete on Friday. At this point, they had just 141 miles (227 kilometers) of the 310-mile (499 kilometer) journey left to go and had already passed through some of the most challenging rapids, such as those at the “Big Bend” and “Hell’s Corner” sections of the river. … ” Read more from CNN.
‘Finally, somebody listened’: The 14-year battle to save Tahoe’s largest ski resort
“Environmental watchdog groups in Lake Tahoe reached a monumental agreement with Palisades Tahoe, the largest ski resort in the region, to significantly downsize a controversial development. The agreement resolves 14 years of conflict over the future of Olympic Valley, located a few miles northwest of the Tahoe Basin. The downsized development plans are part of a settlement reached after seven months of negotiations between the League to Save Lake Tahoe, Sierra Watch and Palisades Tahoe. “This is a resolution to the 14-year fight, and everyone who cares about Tahoe and joined us in standing up to keep Tahoe Truckee true should feel good about this outcome and what we’ve all achieved together,” said Tom Mooers, executive director of Sierra Watch, in an interview Tuesday morning with SFGATE. … ” Read more from SF Gate.
PG&E crews removing Inskip Dam in Tehama County
“Pacific Gas & Electric says they are advancing efforts to remove the Inskip Dam, with the full removal anticipated by the Fall of 2025. According to PG&E, the Battle Creek Salmon and Steelhead Restoration Project aims to modify PG&E’s hydropower facilities in Shasta and Tehama counties to aid the passage of fish like salmon and steelhead. Originally, a fish ladder was planned for the Inskip Dam. However, PG&E later decided the dam would require retrofitting in order to continue operations for several more decades. … ” Read more from Action News Now.
PG&E begins removing Battle Creek Dam to help restore salmon runs
“A major dam is coming down this summer on Battle Creek — and that’s good news for threatened Chinook salmon and steelhead. PG&E has officially begun removing Inskip Diversion Dam, a key barrier that has blocked fish from reaching their cold-water spawning grounds for decades. The project is part of a long-term effort to restore Battle Creek, a vital tributary to the Sacramento River and one of California’s most important watersheds. The momentum has been building for years. The first dam removal on Battle Creek happened in 2010. In 2022, construction wrapped up on another major fish passage fix in North Fork Battle Creek. Now, the Inskip Dam removal represents another milestone in restoring natural flows and reconnecting critical fish habitat. … ” Read more from Active NorCal.
Collaborative salmon recovery efforts taking shape in Butte Creek
“As part of our five-year strategic priorities, the Northern California Water Association is taking a closer look at how local actions throughout the Sacramento River Basin bring these priorities to life. One of our central goals—Vitalizing Healthy Rivers, Landscapes and Communities: Ridgetop to River Mouth Water Management—is being advanced through the sub-priority Energizing our Rivers and Creeks. A promising example of this work is underway, a collaborative effort in lower Butte Creek. This local initiative reflects a broader commitment in the Sacramento River Basin to improve conditions for native fish, particularly spring-run Chinook salmon, by enhancing flows, habitat, and fish passage in a way that integrates community values and landscape needs. … ” Read more from the Northern California Water Association.
‘How did we get here?’: Calif. megadevelopment runs out of water
“It may sound like an end-times warning for California about the existential risk of building megadevelopments in places where water is scarce — but in one Central California community, the worst fears of running out of the precious resource have become a reality. And, even in a best-case scenario, there seemingly is no solution except for one that is both temporary and unfathomably expensive. Diablo Grande is a planned community in the foothills of Stanislaus County, about 30 miles southwest of Modesto. The community was initially approved for construction on 29,000 acres in the early 1990s and was dreamed up as a massive project featuring thousands of homes, half a dozen golf courses and even a hotel. A scaled-back version of the plan was ultimately built — featuring 600 homes and a since-shuttered golf course — and the grand vision of Diablo Grande never came to fruition. … ” Continue reading at SF Gate.
State wants to better understand salt build up in the Central Valley, starting with Kings County
“A state water quality agency hopes to tackle a problem as old as civilization itself – salt build up from irrigation. The Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) is working with local water managers and using state-of-the-art engineering software to understand how groundwater moves through the western Kings and Delta-Mendota subbasins as part of a long-term salt study. The salt study, which began in 2022, aims to develop a Central Valley-wide plan to manage salinity, focusing first on the Kings and Delta-Mendota subbasins. “We’re looking at planning horizons of 50 to 100 years or more to assess how the valley will be changing in terms of salt accumulation, how it changes over time and depending on where you are in the valley,” Tom Grovhoug, an engineering consultant for the Central Valley Salinity Coalition said during a June 30 CV-SALTS webinar. … ” Read more from SJV Water.
How Los Angeles learned to save water
“A decade ago, Jerry Brown, then California’s governor, imposed the state’s first mandatory restrictions on water use. Years of drought had brought about a harsh confrontation with reality: Californians would have to change their relationship with water. “You just can’t live the way you always have,” Mr. Brown said to his fellow Californians at the time. But in California — and most notably in Los Angeles, the state’s most populous metropolitan area — a quiet revolution was already underway, Michael Kimmelman reported for Headway in June: Over the last half century or so, millions more people have moved to greater Los Angeles, settling in increasingly far-flung reaches of the desert and in the mountains, requiring more faucets, toilets and shower heads, producing more garbage and more gridlock on the 405 freeway, reinforcing all the clichés about excess and sprawl. And during this same time, Angelenos have been consuming less water. … ” Read more from the New York Times.
Long live the fire fish
“As some of the worst fires in Los Angeles history swept through the Pacific Palisades and Altadena neighborhoods in January 2025, Rosi Dagit, who was herself evacuated from her home in Topanga, couldn’t stop thinking about the fish. Rosi is the Principal Conservation Biologist with the Resource Conservation District of the Santa Monica Mountains, and the fish keeping her up at night were small Northern Tidewater gobies and Southern Steelhead trout, both federally-listed endangered species in the Topanga Creek watershed, which was on fire. To be clear, Rosi wasn’t concerned about the fish catching on fire. She was concerned with suffocation. Almost the entire Topanga Creek watershed had burned, from ridgeline to ridgeline and down to Topanga lagoon abutting the ocean. As hillsides burn, they begin to destabilize as the vegetation and roots that normally hold the sediment in place disappear. The combination of the water used by fire crews to put out the fires and one of the first significant rainfall events of the 2025 season caused the hillsides to start sliding away in a muddy torrent funneled down through the watershed creeks and streams, burying anything swimming beneath the surface or even washing them out to sea. … ” Continue reading from USC Dornsife.
Metropolitan advances project to help Southern California communities vulnerable in state droughts
“Construction will soon begin on a project to bring additional sources of water to Southern California communities hit particularly hard by the state’s last drought, following a vote by Metropolitan’s board of directors this week. The board voted Tuesday (July 8) to authorize an additional $54 million to complete design and begin construction of the Sepulveda Feeder Pump Stations Project, which will push Colorado River water and stored supplies from Diamond Valley Lake – Southern California’s largest reservoir – into communities that currently have limited access to these resources. These communities rely almost exclusively on water from the northern Sierra, delivered through the State Water Project. “Two years ago, when State Water Project deliveries were severely curtailed because of the record-breaking drought stressing our state, these communities – home to nearly 7 million people – did not have the water they needed to meet demands. Residents and businesses were required to dramatically reduce their water use. In response, our board committed to take immediate action to avoid such water supply shortages in the future,” Metropolitan board Chair Adán Ortega, Jr. said. “Through yesterday’s vote, we are fulfilling that commitment, moving quickly to address this problem.” … ” Read more from the Metropolitan Water District.
Colorado River water guidelines expire soon. What comes next?
“From its headwaters in the Rocky Mountains until it runs dry in Mexico, the Colorado River has nourished those living in the region for thousands of years. That remains true to this day, with more than 80% of Arizona’s population receiving water from the river’s flow. But as supplies dwindle and a high stakes negotiation looms, the future of the Colorado River is murky. Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and Mexico all receive an allotment from the Colorado River based on intricate legal arrangements. Today, the Grand Canyon State is granted 2.8 million acre-feet of water, 60% of which is managed by the Central Arizona Project (CAP). For context, Tempe Town Lake holds approximately 3,000 acre-feet of water. Due to shortages, CAP’s 336-mile canal system is taking 512,000 acre-feet less water from its share, but the current framework governing how and when those reductions occur is set to expire at the end of next year. … ” Read more from Arizona Big Media.
Announcements, notices, and funding opportunities …
NOTICE: Proposed revised notification and/or response levels for PFOA, PFOS, PFHxS and proposed notification and response level for PFHxA
NOTICE of Proposed Rulemaking: Water Storage Investment Program Early Funding
NOTICE: State Water Board conditionally approves USBR’s Sacramento River Temperature Management Plan
NOW AVAILABLE: Final Independent Peer Review Report for the Hydrologic Engineering Center Reservoir Simulation Water Temperature Model
