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The situation at a ghostly California lake will likely worsen, scientists say

Prior to mitigation efforts, it was called the dustiest region in America

By Ariana Bindman

In the early 20th century, when Los Angeles was still a nascent city in a dry California basin, William Mulholland, the former head of the Los Angeles Department of Water and Power — and the controversial figure who inspired Roman Polanski’s “Chinatown” — started to capitalize on an opportunity. 

At the time, the mayor of LA, Frederick Eaton, was reportedly sending undercover agents to mislead farmers into selling them their land in Owens Valley, an arid region in California’s Eastern Sierra Nevada, more than 200 miles from LA. That’s because it had water, a precious natural resource that Mulholland promised to dedicate to the citizens of Los Angeles “for all time.” 

After constructing the city’s first 233-mile-long aqueduct in 1913 — and igniting violent protests and legal battles in the process — LA seized so much water that Owens Lake ran dry, exposing its toxic playa to neighboring communities and creating a lasting environmental crisis that’s still being resolved more than a century later. Now, scientists predict that it could worsen as global warming intensifies and natural resources dwindle. 

According to the LADWP, mitigation strategies such as shallow flooding have significantly reduced dust emissions through a complex system of computer-controlled valves, pipes and sprinklers that have been installed across the prehistoric lakebed. According to the department, the lake’s soil must be flooded during “dust season,” which lasts from mid-October to early July. However, a June 2025 report from California researchers says that several dust sources both on and off the lake continue to push air quality past the safety threshold, potentially affecting around 40,000 California residents who live in the region. 

Before officials began to implement these measures, the southern part of Owens Valley was considered the dustiest place in the United States. This dust — fine, chemical particulate matter also known as PM10 — is so small it can embed itself in the lungs, causing a range of health problems such as bronchitis, asthma and pulmonary disease. Its impacts have also been ignored for several decades: It wasn’t until 1974 that the Great Basin Unified Air Pollution Control District was established to rein in this toxic dust, and it wasn’t until 1980 that researchers finally began to study the lake’s dust storms.

Starting in 2000, the Owens Lake Dust Mitigation Program finally implemented about 48 square miles of suppression projects, an area roughly the size of San Francisco. Heralded as the largest endeavor of its kind in the United States, the $2.5 billion program uses enough water to supply 240,000 single-family households each year and seems to be delivering on its promise: According to the LADWP, in 2000, the lake used to emit about 62,000 tons of particles each year, but in 2023, that number dropped to 355 tons. 

LADWP representatives are optimistic about the program overall and told SFGATE that the $2.5 billion investment shows “successful implementation,” given the significant reduction of dust emissions. 

However, Valerie Eviner, a member of the Owens Lake Scientific Advisory Panel, told SFGATE that while most of the dust at Owens Lake has been suppressed since mitigation efforts were first introduced, the Owens Lake region is still emitting harmful pollutants that exceed federal standards. The nearby Keeler and Olancha dunes, for instance, along with flood deposits and human activities, are just a few off-site sources of dust. 

“This is also a social justice issue, as a high proportion of the population is Native American,” Eviner told SFGATE via email on Monday, explaining that out of the approximately 19,000 residents in Inyo County, 13.8% identify as Native American, compared to 1.7% statewide. 

She also expects climate change to exacerbate the lake’s current conditions in several distinct ways. 

In the past, severe storms such as Tropical Storm Kay and Tropical Storm Hilary have flooded Owens’ off-lake dust sources, and when the sediment from those floods recede, they’re more likely to get picked up and carried by the wind, she explained. 

Hotter weather will also likely lead to evaporation, plant loss and soil erosion, she continued. “In addition, when there are droughts (which are predicted to get more frequent in the future), there will be less water runoff from the snowpack in the Sierra Nevada (which provides more water to the Owens Valley than rainfall,” Eviner told SFGATE. 

She also says that the Environmental Protection Agency’s exceptional events rule doesn’t take “‘natural’ causes” such as storms and wildfires into consideration for air pollution data. According to the EPA, these types of events can have an effect on air quality but aren’t “controllable.” But human activity is making both phenomena more severe and frequent. “Current policy just accepts the high air pollution, as long as some practices are followed,” such as alerting local communities to stay indoors, Eviner said. 

While the LADWP is required to mitigate dust at Owens Lake in perpetuity, what that process actually looks like remains a looming question, especially as natural resources dwindle. Standing water, for instance, is critical not just for dust suppression but for the tens of thousands of birds that travel from as far as Canada and South America to rest and feed in the lake, arriving in the spring and fall each year. 

Overall, Eviner said she hopes that more resources will be used to mitigate dust in the dry California region, which has long struggled with air pollution. 

“When focused on ‘business as usual’ in the Owens Valley, the mitigation of dust is daunting, especially with climate change,” she wrote. “But that doesn’t mean it can’t be done.”