Sierra Nevada Mountains near Lone Pine, California, in February.
Sierra Nevada Mountains near Lone Pine, California, in February. Mario Tama/Getty Images

The End of Snow Threatens to Upend 76 Million American Lives

Disappearing snowpack is accelerating the historic drought across the Western US, and so far government responses haven’t matched the scale of the problem.

The Western US is an empire built on snow. And that snow is vanishing.

Since most of the region gets little rain in the summer, even in good years, its bustling cities and bountiful farms all hinge on fall and winter snow settling in the mountains before slowly melting into rivers and reservoirs. That snowmelt, often traveling hundreds of miles from mountain top to tap, sustains the booming desert communities of Las Vegas, Phoenix and Salt Lake City — even coastal Los Angeles and San Francisco. A civilization of more than 76 million people, home to Silicon Valley and Hollywood alike, relies on snow.

Sierra Nevada Snowpack

Lake

Tahoe

CALIFORNIA

Mono

Lake

10 mi

10 km

Lake

Tahoe

CALIFORNIA

Mono

Lake

10 mi

10 km

Lake

Tahoe

CALIF.

Mono

Lake

10 mi

10 km

Source: USGS

“The snow in the mountains is this incredible gift that created California,” said Spencer Glendon, founder of climate outreach initiative Probable Futures and former director of investment research at Wellington Management. “Nobody would build all of that stuff in a climate that was on the brink of being a desert.”

Dangerously high temperatures in the Pacific Northwest and California’s deadly McKinney Fire flung the Western states’ changing climate back into the national spotlight this past week, and it only gets tougher from here. With the Southwest gripped by its worst drought in 1,200 years, there’s less precipitation of any kind these days across the region, especially the crucial frozen variety with its multi-month staying power. Rain, as desperately as it’s needed, isn’t quite the same: Unless it goes into a lake or reservoir, it won’t be available for weeks or months in the future, the way snowmelt can be. What little winter precipitation does arrive now often lands as rain and runs off, long gone by summer. The West’s mountain snowpacks have shrunk, on average, 23% between 1955 and 2022. By the end of the 21st century, California could lose as much as 79% of its peak snowpack by water volume.

Western Snowpack Has Shrunk by 23% Since 1955

Change in April snowpack in the Western US, 1955–2022

–75

–50

–25

0

+25

+50

+75%

Seattle

Portland

Boise

Shasta

Lake

Salt Lake

City

Lake

Oroville

Denver

San Francisco

Lake

Powell

Las

Vegas

Lake

Mead

Albuquerque

Los Angeles

Phoenix

San Diego

100 mi

100 km

–75

–50

–25

0

+25

+50

+75%

Seattle

Portland

Boise

Shasta

Lake

Salt Lake

City

Lake

Oroville

Denver

San

Francisco

Lake

Powell

Las

Vegas

Lake

Mead

Albuquerque

Los Angeles

Phoenix

San Diego

100 mi

100 km

–75

–50

–25

0

+25

+50

+75%

Seattle

Portland

Boise

Shasta

Lake

Salt Lake

City

Denver

San

Francisco

Lake

Powell

Las

Vegas

Lake

Mead

Albuquerque

Los Angeles

Phoenix

San Diego

100 mi

100 km

–75

–50

–25

0

+25

+50

+75%

Seattle

Portland

Boise

Shasta

Lake

Salt Lake

City

Denver

San

Francisco

Lake

Powell

Las

Vegas

Los

Angeles

Albuquerque

Phoenix

200 mi

200 km

Source: EPA

Those dwindling snow levels — a trend that’s extremely unlikely to reverse as temperatures keep rising — will demand hard choices if the 11 states in the Western US are to continue to thrive. So far, responses to the worsening water crisis have not matched the scale of the problem. Building a single reservoir takes years of effort and political will, much less a vast new network of them across multiple states. Proposed desalination plants on the Pacific coast inevitably provoke public resistance over their coveted locations and impact on sea life, with California regulators in May rejecting plans to build one south of Los Angeles despite the governor’s support. Groundwater supplies are limited, and in some parts of California’s Central Valley, they’re already so over-pumped that the land itself is sinking.

Climate models predict that even when the current drought ends, the region will get less precipitation overall in the coming decades than it once did. Columbia University climate scientist Richard Seager’s lab has been modeling the next two decades of rainfall in the US Southwest, and all of the projections show the area will be drier than in the 1980s and 1990s.

“The Southwest has to get it in its head that it’s never going to get back to the levels of water availability that we had in the late 20th century,” he said.

As the West’s snow disappears and it gets progressively drier, will the region still be able to grow thirsty crops like almonds, of which California produces 80% of the entire world’s supply? Or maintain herds of cattle, each cow drinking up to 30 gallons of water per day? Can a part of the country that for decades lured newcomers with cheap land and boundless growth — one whose population surged from just 7 million people in 1910 to more than 10 times that today — keep growing?

“We’re going to see water scarcity limiting population,” said Andrew Schwartz, manager of the Central Sierra Snow Lab, which studies California’s snowpack from a perch near the Donner Pass. “I can’t give you an exact time. All I can say is given the trends in water supply and aridification of the Southwest, it’s probably going to happen sooner rather than later. And it’s probably going to be sooner than people are comfortable with.”

With Less Snow Comes Less Water in California

Snowpack water content as of April 1

60

in.

Trend line

40

20

0

1940

1950

1960

1970

1980

1990

2000

2010

2020

60

in.

Trend line

40

20

0

1940

1950

1960

1970

1980

1990

2000

2010

2020

60

in.

Trend line

40

20

0

1940

1960

1980

2000

2020

Source: Central Sierra Snow Lab, data collected from Onion Creek, California.

Such predictions have dogged the West for years, and its population and economy have kept growing regardless. Some of the credit goes to the region’s residents, changing their habits by ripping out traditional lawns and buying more water-efficient appliances. Some goes to cities like Las Vegas and Los Angeles, using more recycled water and slowly adding storage facilities. California’s urban water use peaked in 2007 and has since fallen back to levels last seen in the early 1990s, according to a recent study by the Pacific Institute, a water think tank.

But the problems posed by thinning rains and shrinking snows have reached a crisis point all the same, with major implications for everything from energy to agriculture. And what’s happening now across the US West is transpiring — or will be soon — across countries like Pakistan, India, China and their neighbors that depend on rivers fed by Himalayan glaciers, which are also slowly retreating.

In the US West, Rocky Mountain snowmelt has dropped so much that the massive reservoirs along the Colorado River are in danger of no longer being able to produce power at their hydroelectric dams — something that’s never happened before — much less supply all the water needed by the seven states that rely on them. Earlier this year, Lake Powell dropped to an elevation of just 32 feet (9.8 meters) above the minimum required for its Glen Canyon Dam to generate electricity, the lowest level since the reservoir was filled starting in the 1960s. The US Bureau of Reclamation, the federal agency responsible for managing the dams on the Colorado, warns there’s a risk the power there could switch off as soon as next summer. And even with significant proposed water cuts, there is a 23% chance that in 2024, water levels could dip to the point where power production at Glen Canyon would be shut down.

Lake Powell Water Levels

UTAH

5 mi

Glen Canyon Dam

5 km

UTAH

5 mi

Glen Canyon Dam

5 km

UTAH

5 mi

Glen Canyon Dam

5 km

Source: USGS

That could raise the specter of blackouts in the US West and force fossil fuel power plants to burn more natural gas, increasing greenhouse gas emissions at a time everyone’s trying to move in the other direction.

“The system is at a tipping point,” said Camille Calimlim Touton, commissioner of the Bureau of Reclamation, during a US Senate committee hearing in June on the drought.

Water Levels Are Low in Major California Reservoirs

July 26, 2022 capacity compared to historical averages

Shasta

4,552 Capacity in thousands of acre-feet (TAF)

Trinity

2,448

Oroville

3,538

Historical

average*

28%

New

Bullards

Bar

966

New

Melones

2,400

37%

of capacity

42%

Sonoma

381

81%

Folsom

977

Don Pedro

2,030

33%

Camanche

417

Sacramento

65%

51%

San Francisco

30%

San Luis

2,041

61%

San Jose

McClure

1,025

Pine Flat

1,000

Millerton

520

Fresno

33%

27%

57%

33%

Bakersfield

Cachuma

193

Castaic

325

42%

33%

Diamond

Valley

810

Casitas

254

Los Angeles

30%

66%

San Diego

50 mi

50 km

Shasta

4,552 Capacity in thousands of acre-feet (TAF)

Trinity

2,448

Oroville

3,538

Historical

average*

28%

New

Bullards

Bar

966

New

Melones

2,400

37%

of capacity

42%

Sonoma

381

Folsom

977

81%

Don Pedro

2,030

33%

Camanche

417

Sacramento

65%

51%

San Francisco

30%

San Luis

2,041

61%

San Jose

McClure

1,025

Pine Flat

1,000

Millerton

520

Fresno

33%

27%

57%

33%

Bakersfield

Cachuma

193

Castaic

325

42%

33%

Diamond

Valley

810

Casitas

254

Los Angeles

30%

66%

San Diego

50 mi

50 km

Shasta

4,552 Capacity in thousands of acre-feet (TAF)

Trinity

2,448

Oroville

3,538

Historical

average*

28%

New

Bullards

Bar

966

New

Melones

2,400

37%

capacity

Sonoma

381

42%

Don

Pedro

2,030

81%

Folsom

977

33%

Camanche

417

Sacramento

65%

51%

San Francisco

30%

San Luis

2,041

61%

San Jose

McClure

1,025

Pine Flat

1,000

Millerton

520

33%

57%

27%

33%

Bakersfield

Cachuma

193

Castaic

325

42%

Diamond

Valley

810

33%

Casitas

254

Los Angeles

30%

66%

50 mi

San Diego

50 km

1

Shasta

4,552 Capacity in thousands of acre-feet (TAF)

2

Oroville

3,538

Historical

average*

4

New

Melones

2,400

3

Trinity

2,448

5

San Luis

2,041

37% of

capacity

42%

28%

30%

33%

6

Don Pedro

2,030

10.

New

Bullards

Bar

966

7

McClure

1,025

8

Pine Flat

1,000

9.

Folsom

977

61%

33%

27%

65%

81%

3

1

2

10

9

San

Francisco

4

6

7

5

8

Los Angeles

50 mi

San Diego

50 km

1

Shasta

4,552 Capacity in thousands of acre-feet (TAF)

2

Oroville

3,538

Historical

average*

4

New

Melones

2,400

3

Trinity

2,448

37% of

capacity

42%

28%

30%

5

San Luis

2,041

6

Don Pedro

2,030

7

McClure

1,025

8

Pine Flat

1,000

33%

61%

33%

27%

3

1

2

San

Francisco

4

6

7

5

8

Los Angeles

50 mi

San Diego

50 km

Source: California Department of Water Resources. *Historical averages represent the average end of month storage between 1991 and 2020.

For many farmers feeling the disappearing snowpack’s impact, the tough choices are already here. Sean Doherty this year didn’t plant 83% of his rice fields in California’s Sacramento Valley, where his family has farmed since the turn of the last century. Two of what should be the state’s wettest months, January and February, brought almost no precipitation this year, and he’s only getting 18% of the water he’s allocated that flows from the state’s largest reservoir, Shasta Lake. He counts himself lucky that he has crop insurance, enough to avoid laying off the 34 people who work for him.

Shasta Lake Water Levels

CALIFORNIA

Shasta Dam

2 mi

2 km

CALIFORNIA

2 mi

Shasta Dam

2 km

CALIF.

2 mi

Shasta Dam

2 km

Source: USGS

“The water is just not there,” said Doherty, 51. This season, in one of his best farming regions, he’s only growing one field of rice and a very small tomato crop, using water he bought from his brother, a neighbor and a friend. The California Rice Commission says only about half of the 500,000 acres of rice typically planted in the state will be grown this year.

Those kinds of cuts to domestic production risk fueling food inflation — US prices are already up more than 10% year on year — and even contributing to lower variety or volumes in supermarkets across the nation. California alone accounts for a third of all vegetables grown in the US and two-thirds of the nation’s fruits and nuts. Its year-round growing conditions don’t exist in much of the country. Plus there’s the economic impact to the US West itself.

“The truckers that drive the tomato harvesters, the warehouses that dry the rice, the crop duster that flies the rice seed on, the company I buy the fertilizer from — they all need something to do and some way to make some revenue for the year,” Doherty said.

Like many farmers in the western US, he relies on a vast system of public works for capturing, storing and moving water, facilities largely built in the first half of the 20th century. The system was planned around having mountain snowpacks that would build in the fall and winter and release water in the spring and summer. Making matters worse, the water sharing agreement on the Colorado River was created about 100 years ago during a time when it rained a lot, said David Gochis, a scientist at the National Center for Atmospheric Research. The agreement no longer matches reality.

“Much of our water system has been built assuming we’re going to have that snowpack available in a consistent way. Now, that’s shifting,” Schwartz of the Central Sierra Snow Lab said.

Snow-depth measurements at Schwartz’s lab, now run by the University of California, Berkeley, stretch back to 1879, when the company building the transcontinental railroad started recording data. Schwartz said you can see a gradual shift away from snow and toward rain all the way back to the 1970s, although it became more pronounced after the 1990s. Seven of the state’s warmest years have occurred since 2014. In 75 years, the Sierras will only consistently get snow in February and March, Schwartz predicts.

“If we do get our disappearing snowpack and it turns to rain — which it will — the question is how to store that?” he said. “It’s all about water security.”

Cross country skiers on melting snow near Donner Summit, in Soda Springs, California, on March 3.
Cross country skiers on melting snow near Donner Summit, in Soda Springs, California, on March 3. Photographer: Nina Riggio/Bloomberg

One obvious solution for California is to build desalination plants along its 840-mile coastline, allowing it to tap the Pacific Ocean. But the facilities, widely used to support growing populations in the Middle East, have never caught on the US. That’s largely because they’re costly to build and operate. They take up prime oceanfront real estate. And they leave behind heaps of brine that can be harmful to water and land alike. There are currently 12 desalination plants in the state, providing a tiny fraction of its water needs. Despite the growing need for water, there’s little appetite to build more.

“People really hold onto the fact that it is going to rain, and that will somehow make the problem disappear,” said Josh Ballard, chief financial officer of Energy Recovery Inc., a San Leandro, California-based maker of desalination-plant components. “I don’t think California has a choice. Over time there is going to have to be more desalination. Otherwise, we are going to have to truly decide to walk away from agriculture, wine and everything else we are doing in the state.”

Outside desalination plants, there are other possible solutions available for dwindling snows, although whether they’re up to the scale of the problem is hotly debated. The Pacific Institute, for example, estimates that greater water efficiency efforts could cut California’s urban water use as much as 48%; increased wastewater recycling could also play a part.

Developing a fix will require everyone — politicians and residents alike — to understand the depth of the problem and realize that the old ways of using water can’t continue without the corresponding snowpack to back it up. It will require policymakers to stop treating the drought as a temporary emergency. Instead, they’ll have to accept that the assumptions the West’s water system was built on — how much would be available, where and when — no longer apply.

“When you are telling people to use less of something that is essential as water, you are talking about a huge economic impact, a huge cultural impact,” said Sandi Matsumoto, California Water Program Director for the Nature Conservancy and member of Governor Gavin Newsom’s California Water Commission. “It is going to take more people, and it is going to take a lot of money.”