Water levels at California's Lake Shasta have dropped to 37 percent of capacity. (Justin Sullivan/Getty Images)
Reservoir levels are dropping throughout the West, as the drought tightens its grip on the region and intense summer heat further stresses both water supply and the surrounding landscape. Many reservoirs are at or approaching historic low levels due to lackluster rainy seasons combined with increasing temperatures due to climate change.
The drought crisis is perhaps most apparent in the Colorado River basin, which saw one of its driest years on record, following two decades of less-than-adequate flows. The nation’s largest reservoir, Lake Mead near Las Vegas, is at its lowest level since the lake filled after the construction of the Hoover dam in the 1930s; it currently sits at 1,069 feet above sea level, or 35 percent of its total capacity. It supplies water to Arizona, Nevada, California and Mexico.
Further upstream, Lake Powell, which feeds Lake Mead, is at only 34 percent of its total capacity. By next spring, Lake Powell is projected to hit its lowest level since it was filled in 1964, possibly jeopardizing its ability to generate power.
California’s two largest reservoirs, Lake Shasta and Lake Oroville, are on track for potential record lows this summer, now at 37 percent and 31 percent of their total capacities, respectively.
Reservoirs in and around California running dry
Maximum capacity
Current storage (as of July 6)
Upper Klamath
44% full
IDAHO
OREGON
Symbols are scaled according to reservoir capacity
UTAH
Shasta
37% full
Oroville
31% full
150
MILES
Lake Powell
34% full
NEVADA
San
Francisco
Don Pedro
61% full
San Luis
31% full
Lake Mead
35% full
Fresno
Las Vegas
Isabella
13% full
ARIZ.
Pacific
Ocean
CALIFORNIA
Los Angeles
U.S.
100 MILES
MEXICO
Reservoirs in and around California running dry
Maximum capacity
Current storage (as of July 6)
IDAHO
Upper Klamath
44% full
OREGON
Symbols are scaled according to reservoir capacity
Shasta
37% full
UTAH
Oroville
31% full
NEVADA
New Melones
50% full
Don Pedro
61% full
San Francisco
San Luis
31% full
Lake Mead
35% full
Fresno
Las Vegas
Isabella
13% full
150
MILES
Lake Powell
34% full
Pacific
Ocean
CALIFORNIA
Los Angeles
ARIZ.
U.S.
100 MILES
MEXICO
Reservoirs in and around California running dry
Upper Klamath
44% full
OREGON
IDAHO
Symbols are sized according to maximum reservoir capacity
Shasta
37% full
Trinity Lake
46% full
UTAH
Oroville
31% full
NEVADA
New Melones
50% full
Maximum
capacity
Don Pedro
61% full
San Francisco
San Luis
31% full
Fresno
Current storage
(as of July 6)
Las Vegas
Isabella
13% full
Lake Mead
35% full
CALIFORNIA
Pacific
Ocean
175
MILES
Lake Powell
34% full
Los Angeles
ARIZ.
UNITED STATES
100 MILES
MEXICO
Reservoirs in and around California running dry
IDAHO
Upper Klamath
44% full
OREGON
Symbols are sized according to maximum reservoir capacity
Shasta
37% full
Trinity Lake
46% full
UTAH
Oroville
31% full
NEVADA
Maximum
capacity
New Melones
50% full
Don Pedro
61% full
San Francisco
San Luis
31% full
Fresno
Current storage
(as of July 6)
Las
Vegas
Lake Mead
35% full
Isabella
13% full
150
MILES
Pacific
Ocean
CALIFORNIA
Lake Powell
34% full
Los Angeles
ARIZ.
UNITED STATES
100 MILES
MEXICO
Reservoirs in and around California running dry
IDAHO
Upper Klamath
44% full
OREGON
Shasta Reservoir
37% full
Trinity Lake
46% full
Symbols are sized according to maximum reservoir capacity
UTAH
Oroville
31% full
NEVADA
New Melones
50% full
Maximum
capacity
Don Pedro
61% full
San Francisco
San Luis
31% full
Pine Flat
27% full
Fresno
Current storage
(as of July 6)
Lake Mead
35% full
Las Vegas
Isabella
13% full
150
MILES
Lake Powell
34% full
Pacific
Ocean
CALIFORNIA
ARIZ.
Los Angeles
UNITED STATES
100 MILES
MEXICO
Amid a warm spring and early-season heat, mountain snowpack never made it into rivers and reservoirs — it simply seeped into bone-dry soils or sublimated directly into the atmosphere. This kind of reduced runoff “efficiency” is expected in a warming climate, and it contributed to the quickly intensifying drought this year in California and other states.
“The reservoir levels in the second year of this drought are what they were during the third or fourth year of the previous drought,” said Jay Lund, a professor and water resources expert at the University of California at Davis.
Lake Shasta water level recedes
during current drought
July 2019:
Reservoir at 94% of capacity
Lake
Shasta
5 MILES
July 2020:
Reservoir at 67% of capacity
5 MILES
July 2021:
Reservoir at 37% of capacity
Detail
below
5 MILES
July 2021
2,000 FEET
Lake Shasta water level recedes
during current drought
July 2019:
Reservoir at 94% of capacity
Lake
Shasta
5 MILES
July 2020:
Reservoir at 67% of capacity
5 MILES
July 2021:
Reservoir at 37% of capacity
Detail
below
5 MILES
July 2021
2,000 FEET
Lake Shasta water level recedes during current drought
July 2019:
Reservoir at 94% of capacity
July 2021:
Reservoir at 37% of capacity
5 MILES
Lake
Shasta
Detail
below
3,000 FEET
Lake Shasta water level recedes during current drought
July 2019:
Reservoir at 94% of capacity
July 2021:
Reservoir at 37% of capacity
5 MILES
Lake
Shasta
Detail below
3,000 FEET
Lake Shasta water level recedes during current drought
July 2019:
Reservoir at 94% of capacity
July 2020:
Reservoir at 67% of capacity
July 2021:
Reservoir at 37% of capacity
5 MILES
Lake
Shasta
Detail below
3,000 FEET
[California facing drought crisis as water shortages mount and fire danger escalates]
As the summer progresses, the levels will continue their decline.
“Certainly, many reservoirs in the state will see levels lower than they’ve seen since 1976-77, maybe even lower,” said Lund, referring to California’s driest water year on record.
Lund said to expect a wide range of impacts from low reservoirs this summer, including reduced hydropower production and reduced water deliveries to agriculture, fish and urban areas downstream.
Impacts will accumulate through the summer
The Western United States entered a months-long dry season already in severe drought, and then extraordinary heat bore down on the region in June, meaning reservoirs, soils and plants are losing even more water through evaporation. With climate change pushing heat to new and more frequent extremes, it’s a safe bet coming months will feature more of the same. In fact, another major heat wave is descending upon California and the West this weekend.
Both the drought and its effects are intensifying at a rapid pace. While these were felt first and most acutely by ranchers who rely on nonirrigated pastures, they have quickly expanded to other sectors as reservoir operators curtail water releases.
A sign at Callville Bay warns boaters of low water levels as visitors prepare to launch a boat on June 21 at the Lake Mead National Recreation Area in Nevada. (Ethan Miller/Getty Images)
The term “shortage” is now both a projection from government agencies and a reality for communities, farmers and ranchers.
In August, a shortage probably will be declared for Lake Mead, which will trigger substantial cuts in water deliveries to Arizona, Nevada and Mexico next year to slow further losses.
California’s vast reservoir network, the State Water Project, is delivering only 5 percent of requested supplies to its 40,000 water rights holders, which is sending reverberations throughout the state. In June, the City of San Jose became the largest urban area to impose water restrictions so far this year, with Santa Clara County declaring a water shortage emergency.
The drastically reduced deliveries from the state have also directly affected farmers, and by extension, smaller communities that rely on well water. Shallow wells are drying up as farms draw more heavily on groundwater; one Central Valley community has already run dry and is importing bottled water for basic needs, Cal Matters reports.
On Thursday, Gov. Gavin Newsom (D) expanded drought emergency status to 50 of the state’s 58 counties. He asked Californians to voluntarily cut water use by 15 percent but did not issue mandatory statewide restrictions.
A farmer pulls a fallen almond tree past the Delta-Mendota Canal at the Gemperle Farms almond orchard in Gustine, Calif., where a third of the acreage has gone dry. (David Paul Morris/Bloomberg)
Faith Kearns, a scientist at the California Institute of Water Resources, said many communities face chronic water supply issues that are exacerbated by drought and groundwater withdrawal.
“My biggest concern is always with ensuring that people have affordable clean water at the household level, and that ecosystems and the life they support can manage,” she wrote in an email. “It's already a struggle that will continue to worsen throughout the dry season.”
[Climate change has gotten deadly. It will get worse.]
In the Klamath River watershed on the Oregon-California border, record low inflows are threatening fish both in reservoirs and downstream, while reduced reservoir releases are cutting off water to farmers. The region is already seeing fish die-offs from low stream levels and warm water temperatures.
Some parts of the West, such as Southern California, are better prepared than others, having boosted backup water sources and enacted conservation measures during the last drought that are paying dividends today. But that doesn’t mean the state has solved its water woes.
“We are still facing many of the same issues we have been for a long time, including dwindling fish populations and drying wells,” Kearns wrote. “That to me indicates that we still have a long way to go.”
When will the drought end?
Even after this summer, rains may not arrive as hoped, and it will probably take more than one good wet season to replenish water lost through missed precipitation and increased evaporation.
“After having been through many more drought years than not over the last decade, I am starting to wonder if we should even be using the term drought,” Kearns said.
Rain deficit in the southwest
10-month precipitation anomaly
Sept. 2020-June 2021
Below
normal
Normal
-70%
-65%
-40%
-25%
NORTH
Upper Klamath
OREGON
Shasta
IDAHO
Chico
Reno
Sacramento
Lake Tahoe
S.F.
NEVADA
CALIFORNIA
Fresno
Lake
Mead
Las
Vegas
Bakersfield
UTAH
L.A.
Flagstaff
San Diego
ARIZONA
Phoenix
Pacific
Ocean
Tucson
100 MILES
Rain deficit in the Southwest
10-month precipitation anomaly
Sept. 2020-June 2021
Below
normal
Normal
-70%
-65%
-40%
-25%
Upper Klamath
NORTH
OREGON
Shasta
IDAHO
Chico
Reno
Sacramento
Lake Tahoe
S.F.
NEVADA
Salt
Lake
City
CALIFORNIA
Fresno
UTAH
Lake
Mead
Lake
Powell
Las
Vegas
Bakersfield
Los
Angeles
Flagstaff
San Diego
ARIZONA
Phoenix
Pacific
Ocean
Tucson
100 MILES
Rain deficit in the Southwest
10-month precipitation anomaly
Sept. 2020-June 2021
Below normal
Normal
-70%
-65%
-40%
-25%
OREGON
IDAHO
Upper Klamath
Salt
Lake
City
NEVADA
Shasta
Chico
Reno
UTAH
Lake Tahoe
Sacramento
Lake
Powell
San Francisco
Lake
Mead
Fresno
Las Vegas
CALIFORNIA
Flagstaff
Bakersfield
ARIZONA
Colorado
River
Phoenix
Los Angeles
Pacific
Ocean
San Diego
100 MILES
Rain deficit in the Southwest
10-month precipitation anomaly
(Sept. 2020-June 2021)
Below normal
Normal
-70%
-65%
-40%
-25%
OREGON
IDAHO
Upper Klamath
Salt
Lake
City
NEVADA
Shasta
Chico
UTAH
Reno
Lake Tahoe
Sacramento
Lake
Powell
San Francisco
Lake
Mead
Fresno
Las Vegas
CALIFORNIA
Flagstaff
Bakersfield
ARIZONA
Colorado
River
Phoenix
Los Angeles
Pacific
Ocean
Salton
Sea
San Diego
100 MILES
Rain deficit in the Southwest
10-month precipitation anomaly
(Sept. 2020-June 2021)
Below normal
Normal
-70%
-65%
-40%
-25%
OREGON
IDAHO
WYOMING
Upper Klamath
Salt
Lake
City
NEVADA
Shasta
Chico
UTAH
COLO.
Reno
Lake Tahoe
Sacramento
Lake
Powell
San Francisco
Lake
Mead
Fresno
N.M.
Las Vegas
CALIFORNIA
Flagstaff
Bakersfield
ARIZONA
Colorado
River
Phoenix
Los Angeles
Pacific
Ocean
Salton
Sea
San Diego
Tucson
100 MILES
Over the last 20 years, human-caused warming has intensified what would have been an ordinary dry period in the Southwest into a potential “megadrought” — in some ways the driest such period in 1,200 years.
[Pacific Northwest heat wave was ‘virtually impossible’ without climate change, scientists find]
On the Colorado River, Lake Powell and Lake Mead have supported the rapid expansion of population and agriculture in the Southwest. The river supplies about 25 percent of the water used in metropolitan Southern California.
“There haven’t been high enough flows to fill them, by any means, for a long time,” Lund said. “We are asking a lot more out of that river than water is flowing into it.”
This raises the question of whether Western states should be doing more to conserve water for next year and beyond.
“There have been some mandatory water restrictions in some parts of the state, but there is concern from a lot of folks in the water management community that those restrictions should be statewide,” Kearns wrote, referring to California.
Lund said it may be wise to accept smaller shortages this year to help stave off major shortages in the future.
“We are not sure when the drought is going to end,” he said. “You want to make sure you have enough water for next year.”
[What questions do you have about climate change? Ask The Post.]
About this story
Daily reservoir storage data from California Department of Water Resources and U.S. Bureau of Reclamation. Satellite images of Lake Shasta via ESA Sentinel 2 satellite. Precipitation anomaly data via WestWideDroughtTracker.
