LOS ANGELES (AP) — Absent a longer term deal on how to share a key but dwindling water source in the U.S. West, three states say they'll cut back significantly to prop up reservoirs in a short-term agreement following the driest winter on record.
Arizona, California and Nevada announced a plan this month to save up to 1 million acre-feet (44 billion cubic feet) of Colorado River water through 2028. That's on top of cuts already announced by the three states and Mexico, bringing the total proposed savings to 3.2 million acre-feet (139 billion cubic feet), or about enough water to serve more than 25 million people a year.
“We have kind of a crisis situation that this past winter has created,” Tom Buschatzke, Arizona’s lead negotiator, said earlier this week. “We need to do everything we can, and that's what our plan does, to find a short-term fix.”
Already, the U.S. Bureau of Reclamation says it will release more water and earlier than usual into the badly depleted Lake Powell, one of the two biggest reservoirs on the river and in the country, to keep its hydropower humming.
The plan from Arizona, California and Nevada needs approval from federal officials and state lawmakers. Still, the states called it ambitious and far-reaching with benefits to the entire river basin.
The river supports 40 million people across seven U.S. states, two Mexican states and Native American tribes. Farmers rely on it, too, to irrigate millions of acres. And some 155 utilities depend on it for hydropower.
Some of the rules that govern the water-sharing agreement expire this year, but negotiations have mostly broken down among the states. About four months have passed since they had any substantive talks. The states in the river's Upper Basin — Utah, Colorado, Wyoming and New Mexico — have suggested a mediator is needed. Meanwhile, the Reclamation Bureau is moving ahead with a plan in case the states don't reach consensus in time.
Kevin Moran, of the Environmental Defense Fund, said he's hopeful the water-reduction pledge is a catalyst for a collaborative solution among the states.
“The Colorado River is tanking," he said. "We are at the 11th hour in needing to have strong and collaborative solutions to protect the health of the river.”
Nevada, Arizona and California make up the river's Lower Basin. Under their proposal, Nevada and Arizona would take about one-third less water of what they're entitled to annually from Lake Mead along the states' border. California, which has the largest and most senior rights to the water, would shrink its use by about 13%.
How those cuts will trickle down hasn't been worked out, but the states say they'll come by August.
The Central Arizona Project manages much of Arizona's share that's delivered through a 336-mile (540-kilometer) canal system to 6 million people in central and southern Arizona. It, too, has a priority system. Farmers, cities, tribes and industry could be affected.
Most of the river's water goes to agriculture. That's evident in the Imperial Irrigation District, the largest single user of the river's water, where much of the nation's winter vegetables are grown.
The Metropolitan Water District of Southern California, which supplies water to 19 million people, relies on the river for about 20% of its supply. Reducing reliance on the Colorado River will stave off worse situations, said board member Mark Gold, but there's still a risk.
The Lower Basin plan also depends on state and federal funding. Among the water-saving measures could be farmers leaving fields dry or replacing thirsty crops like alfalfa with drought-tolerant ones.
In cities, the reduced supply could contribute to higher water bills for residents and businesses, Gold said.
Chronic overuse, drought and rising temperatures linked to climate change mean there's less water in the river than what was divvied up among states more than 100 years ago.
Lake Powell and Lake Mead, reservoirs that are key indicators of the river's health, are not healthy. Both have been declining over time. If they fall below certain levels, that means hydropower production comes to a halt and water can't be delivered to downstream users.
The Bureau of Reclamation announced plans recently to release as much as one-third of the water in Flaming Gorge reservoir upstream of Lake Powell to ensure that doesn't happen. The hydropower from Glen Canyon Dam that holds back Lake Powell serves more than 350,000 homes.
Reclamation officials said they are reviewing the Lower Basin's proposal while still emphasizing that they are looking for a broader agreement.
Becky Mitchell, Colorado's lead negotiator, said the Lower Basin plan is a good first step but doesn't do enough to protect Lake Powell.
The Upper Basin states want the Lower Basin states to commit to avoiding litigation, something that's unlikely.
“While the Lower Division States have made progress, more is needed to protect the Colorado River System now and into the future,” she said in a statement. “These differences highlight the urgent need to come back together with the help of a mediator.”
The seven states are wrangling over who should reduce water use and by how much during a drought that's lasted more than two decades.
Recently, Upper Basin states agreed to federal officials' plan to send nearly one-third of the states' annual water use to Flaming Gorge to protect Lake Powell. Water users with long-standing water rights are also cutting their water use earlier in the season than usual, with some only getting 14% or less of their annual allocations.
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A informational map shows Lake Mead at a higher water level than is seen on Wednesday, Apr. 01, 2026, Boulder City, Nev. (AP Photo/Ty ONeil)
The remains of a boat sit out of the water at the Lake Mead National Recreation Area on Wednesday, Apr. 01, 2026, Boulder City, Nev. (AP Photo/Ty ONeil)
Smoke from wildfires — which are burning more of the Northern Hemisphere as Earth warms — attacks nearly every system in the human body, killing tens of thousands of people a year, numerous medical studies show.
It attacks the body immediately, spiking asthma cases with increased ambulance runs within hours, swamps emergency rooms in a day or so with people suffering from heart attacks and other cardiovascular and lung issues, as well as mental health issues, doctors and scientists told The Associated Press.
Smoke also harms pregnant women, increasing the risk of premature births and low-weight babies who could have breathing problems the rest of their lives, doctors and studies say. And then there are long-term risks connecting prolonged smoke and other air pollution exposure to some cancers and dementia.
After huge global fires in 2018 and 2019, the medical and science communities started looking at the health effects from the smoke with “more and more studies coming out finding that there’s all types of impacts that may not have been so obvious before,” said Dr. Mary Johnson, a Harvard School of Public Health environmental health scientist.
Smoke causes inflammation by triggering the body's immune system to go into overtime to fight the irritant. Scientists have found it can harm the brain, the skin and men's sperm, with almost no system of the body spared, Johnson said. People over 60 become more prone to stroke in wildfire smoke, she said.
“Wildfire smoke is the toxic product of combustion of whatever burned,” which could include houses and cars, said Dr. Courtney Howard, an emergency room physician, chair of the Global Climate and Health Alliance and president-elect of the Canadian Medical Association.
“So really it's a big giant toxic soup of particles and gases.”
Scientists have counted at least 1,000 toxins in wildfire smoke, according to Colorado State University environmental toxicologist Luke Montrose.
“If I gave you a list, you would recognize some of these as being very bad, oftentimes associated with the burning of diesel fuel or cigarette smoke, things like formaldehyde or volatile organic compounds,” Montrose said. “So just the smoke itself can be bad.”
So far this year, more than 5,740 square miles (more than 14,860 square kilometers) of the United States has burned from wildfires, which is 31% more than the average of the previous 10 years on this date, according to the National Interagency Fire Center. The amount of U.S. land burned each year in the 2020s — averaged out over a decade — is now more than twice what it was 30 years ago.
Europe saw a record high amount of land burned in 2025, Canada has had several record or near-record fire years in the 2020s and the Arctic recently has had unprecedented levels of burning.
“Wildfires are becoming more frequent and intense because of climate change, and when a fire happens, you have smoke,” said Colleen Reid, a University of Colorado geographic health professor.
Most of the biggest particles in wildfire smoke fall close to where a blaze is burning, while the smallest particles — the ones that scientists say do the most damage — travel the farthest. In a typical wildfire, the nasty particles that harm human health are about the size of one micron, Reid said.
First those particles have to get by your body's protection, mainly nose hairs and mucus, then they get into your lungs and from there the bloodstream.
Montrose said the particles can be coated in lots of chemicals and have large surface areas. That triggers the body's defense system to “send signals to other cells that say, ‘We have a problem. We need to mount an immune response to this.’ And that’s where you get your acute effect or your effect within minutes, hours or even that day.” It's mostly happening in the hearts and lungs, he said.
And many people die.
On average 24,100 people died each year in the Lower 48 states between 2006 and 2020 due to long-term exposure to tiny particles from wildfire smoke, according to a study this year in the journal Science Advances. A Stanford study projects that U.S. wildfire smoke deaths will increase with climate change and by midcentury hit an annual cost of $244 billion in terms of the economic value the government puts on each life.
On a global scale, wildfire smoke particles cause 677,745 deaths annually, with almost 39% of them children under age 5, according to a 2021 study that combined observations, studies on how the body responds to the particles and computer models to calculate the toll.
The biggest nonlethal effects have to do with the way people breathe, especially those with asthma.
“We did a study here in 2014 after we had about two-and-a-half months of smoke off and on, because we’re in the subarctic so we’re warming at triple the global rate, so in a way we’re kind of canaries in the coal mine of the health impacts of climate change,” Howard said on a clear day from Yellowknife, Canada. “We found a full doubling of emergency department visits for asthma and about 50% increase in pneumonia.”
“Even in individuals that don’t have asthma, the air can be so irritating that you could have difficulty with your respiratory system regardless,” Johnson said, “whether it’s coughing, whether it's chest tightness, whether it’s sore throat, headache.”
Studies have linked smoke to people having more trouble with decision making and other cognitive issues. People come to the emergency room depressed, Howard said. That's why it's important to find a place with clean air — including designated shelters or libraries — to get a break from the smoke and possibly exercise, she said.
Experts suggest people wear high-quality masks when outdoors, even though they don't provide perfect protection. Inside, check windows and doors for seals, invest in a good ventilation system and check air filters, they say.
“Staying away from the smoke is No. 1 if you can,” Johnson said.
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A child looks out from the observation deck of the CN Tower as smoke from wildfires in Northwestern Ontario blankets the city of Toronto, Thursday, July 16, 2026. (Cole Burston/The Canadian Press via AP)
Michael Lesperance weeds his driveway wearing a mask during poor air quality due to smoke from Canadian wildfires Thursday, July 16, 2026, in Grosse Pointe Park, Mich.. (AP Photo/Paul Sancya)
The New York City skyline is seen through a cover of wildfire smoke, in Jersey City, N.J., Friday, July 17, 2026. (AP Photo/Ryan Murphy)
The sun is obscured by wildfire smoke as it rises behind the Marine Corps War Memorial, Friday, July 17, 2026, in Arlington, Va. (AP Photo/Julia Demaree Nikhinson)
The sun is obscured by wildfire smoke as people run in front of the Washington Monument and Lincoln Memorial Reflecting Pool, Friday, July 17, 2026, on the National Mall in Washington. (AP Photo/Julia Demaree Nikhinson)
The Statue of Liberty stands during sunset as smoke from wildfires blankets the sky, Thursday, July 16, 2026, in the Brooklyn borough of New York. (AP Photo/Yuki Iwamura)
National Guardsmen patrol the Lincoln Memorial as the sun, obscured by wildfire smoke, rises above the Washington Monument and the Reflecting Pool, Friday, July 17, 2026, on the National Mall in Washington. (AP Photo/Julia Demaree Nikhinson)
Jimmy Tyner walks along the Detroit River during poor air quality due to smoke from Canadian wildfires Thursday, July 16, 2026, in Detroit. (AP Photo/Paul Sancya)
A person wearing a mask walks in Times Square as smoke from wildfires blankets the sky, Thursday, July 16, 2026, in New York. (AP Photo/Yuki Iwamura)
Hazy skies from Canadian wildfires cover Silver Beach and Lake Michigan, Thursday, July 16, 2026, in St. Joseph, Mich. (Don Campbell/The Herald-Palladium via AP)
Pedestians cross Borden Avenue as the New York City skyline is obscured during poor air quality due to smoke from Canadian wildfires Thursday, July 16, 2026, in the Queens borough of New York. (AP Photo/Frank Franklin II)
A person looks out a window at the Top of the Rock Observation Deck as wildfire smoke hangs over New York, Thursday, July 16, 2026. (AP Photo/Yuki Iwamura)
People look over the New York City skyline shrouded in smoke in Weehawken, N.J., Thursday, July 16, 2026. (AP Photo/Seth Wenig)
