The Bobcat ran a previous article on proposed Colorado River water cuts. While out on Bobcat business—hiking a trail and thinking—I bumped into two Coloradans and got into a lively chat about historic water usage and the original agreement. Turns out, I needed to dig deeper myself, so here's what I uncovered to share.
The Colorado River's water rights stem from early 20th-century disputes, forming the intricate
"Law of the River" rooted in the 1922 Colorado River Compact. That pact split the basin into the
Upper Basin (Colorado, Utah, Wyoming, New Mexico, and a sliver of Arizona) and Lower Basin
(Arizona, California, Nevada) at Lee Ferry—a key geologic point near Page, Arizona, where the
Upper Basin must deliver 7.5 million acre-feet MAF every decade to the Lower. It promised 7.5
MAF per basin 15 MAF total, even though real flows average just 1213 MAF—setting up
overuse from day one.
U.S. Supreme Court decision securing federal reserved water rights for indigenous lands.
Navajo, Hopi, and others were left without quantified shares.
Mexico fared little better until the 1944 Treaty locked in its 1.5 MAF slice, stretching supplies
thinner.
How it unfolded and what MAF even means
Let's break down the timeline real quick, along with the big unit everyone's fighting over: MAF
(million acre-feet). Picture one acre-foot as roughly 326,000 gallons—enough to water about
enough to water about two households for a year. The Upper Basin's job? Pump 7.5 MAF (that's 75 million acre-feet total) down to Lee Ferry every decade, plus half of Mexico's share, all with the feds keeping score.
1922 Compact: Drew the line at Lee Ferry between Upper and Lower basins, flat-out ignoring tribes and Mexico.
1944 Treaty: Finally looped in Mexico with its 1.5 MAF guarantee.
1963 Arizona v. California: Supreme Court stepped in after Arizona dug in its heels, locking
down Lower Basin splits.
Arizona's Verde Valley hooks into this through Gila River tributaries rolled into its 2.8 MAF Lower Basin piece.
Unfair in 2026? You Bet
Fast-forward to today: Warming's knocked flows down 20%, Lake Mead's scraping historic
lows, and the whole system's over-promising by 12 MAF a year. Upper states have to rein in
growth just to make deliveries; California hangs onto juicy senior rights; tribes are still battling for their due; and those post-2022 talks are grinding toward fixes—but those stubborn MAFnumbers aren't budging easy.
The 2026 Costs Hitting Home
Lake Mead's nosedive kicked in the 2019 shortage playbook, and it's getting real:
Lower Basin: Tiered pain—Arizona's taking the brunt 400,000500,000 AF yanked,
mostly via Central Arizona Project, while California and Nevada get off lighter.
Mexico: Slashed to 1.35 MAF 150,000 AF gone, plus extra conservation asks.
Upper Basin: Nothing carved in stone yet, but they're eyeing Lake Powell releases. States
totally whiffed the February 14 deadline for post-2026 rules, so federal heavy hands might
step in.
Talks have tossed around ideas like Arizona eating a 27% cut, California just 10%, Nevada 17%
—aiming for about 3 MAF total U.S. savings. It all slams Arizona's Verde Valley farms hardest,
echoing how tribes got left out in the cold during this bone-dry 2026.
