Driven in part by the ongoing western megadrought, the foundation governing how Colorado River water is shared may be cracking, threatening drinking water supplies for millions from Denver to Los Angeles, farmers and ranchers throughout the southwest, and the ecosystems that rely on water flowing through the 1,450 miles of the Colorado and its tributaries.<\/p>\n
The U.S. Bureau of Reclamation should start planning to modify the Glen Canyon Dam, which plugs the Colorado to form Lake Powell. The plan will help ensure water and sediments will continue to flow through the Grand Canyon, and into Lake Mead, the nation\u2019s largest reservoir.<\/p>\n
In late June, Colorado\u2019s representative to the Upper Colorado River Commission told an audience<\/a>, \u201cwe stand on the brink of system failure.\u201d<\/p>\n Earlier last month the leader of the Colorado River Authority of Utah suggested some states are considering an \u201camicable divorce<\/a>\u201d from the 103-year old Colorado River Compact, which established the basic rules for apportioning Colorado River water among its seven-member states.<\/p>\n Despite a 2026 deadline, the Bureau and seven states have been grappling unsuccessfully with how to share the river equitably. There is significantly less water in the river compared to what was expected when the Compact was ratified: 12.5 million acre-feet annually this century, compared to no less than 17.5 million acre-feet assumed in 1922.<\/p>\n Lake Powell, the nation\u2019s second-largest reservoir, was almost full in 1999. Today it is less than one-third full.\u00a0 The reservoir\u2019s water level has dropped 29 feet compared to the same date last year<\/a> — almost three feet in the last two weeks \u2014 and it will continue to drop, as rivers feeding it are running about 36% below average.<\/p>\n In mid-July, the Bureau forecast that by December 2026, under \u201cprobable minimum inflow\u201d conditions, the reservoir could reach \u201cminimum power pool elevation,\u201c below which the dam would be unable to generate power. If the reservoir continued to drop it would eventually reach the river outlet works, the only remaining method for getting water through the dam.<\/p>\n These outlets were never intended to be used on a continuous basis, and have been damaged previously from extended use. When the water level in the reservoir reaches the elevation of the outlet works it is known as \u201cdead pool,\u201d even though water at the face of the dam would 240-feet deep.<\/p>\n At dead pool limited water could flow to the Grand Canyon, which starts a few miles below the dam, and into Lake Mead, the nation\u2019s largest reservoir, eventually threatening those dependent on Colorado River water in Arizona, California and Nevada. It also could require the upper basin states, including Colorado, which receives about 40% of its water supply from the Colorado River, to curtail their use of the river\u2019s water.<\/p>\n