LAS VEGAS (KLAS) — By the end of September, Lake Mead is expected to be nearly 20 feet below its current level, according to projections released Thursday by the U.S. Bureau of Reclamation.

Lake Mead, which ended the year at 1,044.82 feet, will be down to 1,025.71 feet — a drop of 19.11 feet — according to the operational plan for Hoover Dam, contained in the January 2023 24-Month Study. By the end of December next year, projections indicate the lake will rise to 1,026.91 feet.

The projections are used to guide the management of dams along the Colorado River. A priority to maintain or increase Lake Powell’s level is clearly a priority laid out in the plan. The federal government plans to keep an additional 0.523 million acre-feet — about 170 billion gallons — in Lake Powell between now and April.

While Lake Mead will shrink, every major reservoir above it is projected to rise. And that will continue the following year, when Lake Mead is projected to drop to 1,010.38 feet by September 2024.

FILE – A boat cruises along Lake Powell near Page, Ariz., on July 31, 2021. Federal water officials have announced that they will keep billions of gallons of Colorado River water inside Lake Powell instead of letting it flow downstream to southwestern states and Mexico. (AP Photo/Rick Bowmer, File)

The Colorado River provides water for 40 million people and is the primary water source for Las Vegas. This year, Nevada’s share of the river dropped to 275,000 acre-feet under the Tier 2 drought restrictions. The state used only 242,000 acre-feet in 2021 and was on pace to use about the same last year. An acre-foot is about 326,000 gallons.

The U.S. Bureau of Reclamation intends to build up reservoir levels in Lake Powell and eight other reservoirs on the Colorado River.

Davis Dam and Parker Dam, which are below Lake Mead, will maintain the levels they were at in December 2022. Projections for all the reservoirs included in the report: (Lake levels are expressed as elevations: feet above sea level. They are not depths.)

ReservoirDec. 2022Sept. 2023Sept. 2024
Fontenelle Reservoir6,486.146,495.466,498.19
Flaming Gorge Reservoir6,008.596,015.816,024.19
Taylor Park Reservoir9,307.689,317.289,316.42
Blue Mesa Reservoir7,446.447,482.577,502.77
Morrow Point Reservoir7,141.827,153.737,153.73
Crystal Reservoir6,751.646,753.046,753.04
Vallecito Reservoir7,641.157,635.387,640.52
Navajo Reservoir6,018.456,038.286,060.41
Glen Canyon Dam – Lake Powell3,524.753,548.333,559.47
Hoover Dam – Lake Mead1,044.821,025.711,010.38
Davis Dam – Lake Mohave639.97640.01640.01
Parker Dam – Lake Havasu447.06447.50447.50
(U.S. Bureau of Reclamation, 24-Month Study)

Water releases from Lake Powell will meet or exceed the required 7 million acre-feet, which is mandated by the Colorado River Compact. Releases from Lake Powell will be reassessed as more information about water inflow becomes available, according to the bureau.

The full forecast for Lake Mead appears below:

The projections are calculated based on “most probable” inflows from streams in the Upper Colorado River Basin.

Recent precipitation and snowpack data for the basin indicate that the “atmospheric river” that is carrying moisture from the Pacific Ocean is helping to build up water in the Rocky Mountains. That water, currently about 140% of normal levels, might help replenish stream flows that have been lower during most of the 23-year “megadrought” affecting the desert Southwest.

Experts warn that above-average snowpack levels will only buy time — not solve the ongoing drought.