Not that Lake Mead was around at that time . . . Through the Boulder Canyon Project the federal government created Hoover Dam and Lake Mead. Eventually, Congress named the lake after US Bureau of Reclamation Commissioner Elwood Mead who served in that capacity from 1924 until his death in early 1936. The federal government completed the project just four months before he passed.
Lake Mead reached its highest elevation, 1225.44 feet, in 1983. The current figure shows a decline of 272 feet to an elevation of 1053.66 feet. Lake Mead Water Level It has declined in fits and starts since then. Drought and climate change get the blame for this decline, but actually that decline was in the cards since 1922.
When the seven Colorado River Basin states came together to form the Colorado River Compact in 1922, they divided up water allocations based on the average flow of the river between 1905 and that current year. Climatologists now consider that 16.5 million acre-foot average to have been derived during a wet cycle. While a little outdated, this chart illustrates the river’s diminishing flow. To this day the Colorado River’s flow remains highly erratic and ranges from 3.8 million acre-feet (3.8 MAF) in 2002 to 22.2 MAF in 1984. Climatic Fluctuations, Drought, and Flow in the Colorado RIver (usgs.gov) Without getting into the weeds, the compact under “normal” conditions guarantees a delivery of 15 MAF annually to the seven basin states. Currently the average flow hovers around that guaranteed amount. US Bureau of Reclamation graphic below:
To complicate matters, the US signed the Mexican Water Treaty of 1944 which stipulated that the US allow an additional 1.5 million acre-feet to flow south to Mexico. Mexico, knowing a good deal when they saw it, signed the treaty. Prior to that the Colorado River Compact of 1922 only mentioned deliveries of an unspecified amount to the Republic of Mexico. The Mexican Water Treaty of 1944, which quantifies a commitment made 22 years earlier, puts the Colorado River in a perpetual deficit situation. crcompct.pdf (usbr.gov)
The federal government and the basin states have never seriously addressed the over-allocation issue. Doing so could possibly threaten western agriculture and population growth. Instead, political leaders have simply reacted to declining elevations at Lake Mead as the Lower Basin states reach critical tier shortage levels. While wet years put off decisions for another day, dry years remind us that lake levels are on a downward slope.
As one reader of Cactus Reports pointed out recently, the level of Lake Mead has declined precipitously since 2000. This chart from NOAA shows a drastic decline from 2000 to 2010 of over 140 feet! The federal government took no action, however, until 2007 when the basin states finally agreed to a shortage sharing agreement. The first actual cuts did not take place until over a decade later.
In 2021 the Central Arizona Project took a voluntary Tier 0 cut of 192,000 acre-feet. With declining lake levels CAP took a mandatory Tier 1 cut of an additional 320,000 acre-feet effective this year. Since last December, Arizona, along with California and Nevada entered into a voluntary cut of an additional 500,000 acre-feet. The plan uses $200 million to pay farmers to fallow fields or other water users to get paid to leave water behind Hoover Dam. While this helps, the West must find ways to live with less water, or look for ways to augment supplies. No easy answers lie out there to solve this 100-year-old problem.