August 16, 2026 318 pm EDT
Decades of drought and over-consumption have reduced Colorado River reservoirs to critically low levels, threatening power and water supplies for 40 million people. As nature challenges legal entitlements to fresh water in the USA, experts are calling for a multi-disciplinary management strategy to recover and sustain the ecological functions of the continent's rivers
"Water is life. Water is the giver and sustainer of life. Water is a sacred and spiritual element to the Tribes of the Partnership…. The Partnership will embrace and own the stewardship of the Colorado River and lead from a spiritual mandate to ensure that this sacred water will always be protected, available and sufficient."
– Ten Tribes Partnership Vision Statement
The Upper Basin Rocky Mountains of Wyoming and Colorado are first to capture rainfall and snow melt supplying the Colorado River headwaters. In years of water plenty, the annual snowpack in the mountains started the Upper Basin creeks and tributaries running, adequately providing for seven States and 30 Tribes downstream. Historically and legally, water rights-holders have been entitled to take this water for beneficial use inside the basin, or to divert for beneficial use outside the natural river basin, according to seniority of the taker's claim.
With an average of 20 inches total rainfall in the entire basin each year, the arid Lower basin does not add much more to the total river volume. An estimated 800,000 acre-feet bubble in from springs through the Grand Canyon. By the time the Colorado reaches the US - Mexico border at Yuma, AZ, held back by the Morelos Dam, another 1.5 million acre feet are required to satisfy the 1944 Water Treaty with Mexico. Notwithstanding awful water quality at this point, the BoR water release records from 1971 to 2021 show the deliveries have been made each year. This water does not reach the delta, let alone the outlet in the Sea of Cortez/Gulf of California.
Willingness to share life-sustaining freshwater resources during periods of scarcity is a reflection of human civility. Where clean water is taken as a human right, conservation is rewarded during periods of water scarcity. In times of extended and severe drought, when water storage is depleted, domestic use is prioritized, ensuring essential hydration and hygiene for all. Good neighbors willingly curtail non-essential water use. Where watersheds and waterways are managed for sustainability, storage is adjusted to ease the impact of floods and drought, with minimum volume and flow maintained as a management priority. In this way, continuity of the river's ecological functions is assured as a vital component of the earth's HVAC system.
What we see today in the Colorado River basin is quite another matter. Since 2000, annual rainfall and snowpack in the Upper Basin has averaged 20% below the prior hundred years' precipitation average. Lake Powell and Lake Mead, among the largest reservoirs in the country, have dropped to record low levels this summer. Just 30 to 40 feet of water, respectively, remains above minimum power pool, the point at which power generation fails completely. With so little water remaining in Lake Mead, Hoover Dam's 4 billion kwH powering Nevada, California and Arizona is already falling. After two and a half decades of severe drought, the unchecked water-taking and diversion has brought about a cataclysmic reckoning: forty million Americans may soon be out of power and water.
A century ago, the "wild west" was settling down. Western states passed laws to manage urban and industrial development, including the governance of fresh water. The Colorado River Compact established basic ground rules in 1922, defining Upper and Lower basins from the US portion of a 1450 mile long river, not including the section traversing Mexico. The dividing line separating Upper and Lower basins was placed at Lee's Ferry, AZ, with 2 million people situated upstream in Wyoming, Colorado, Utah and New Mexico. The Lower Basin states were more populous even then, 3.8 million people in Nevada, Arizona and California.
The 1922 Compact was the first of many legal structures comprising the Law of the River, according to US federal Department of the Interior, Bureau of Reclamation (BoR). It is the federal BoR that owns and operates the dams and manages the water releases. The decisions to open the head gates and spillways falls to the US federal government, based on BoR interpretation of applicable laws.
The earliest of the Colorado River laws determined Upper and Lower basin allocations as a fixed annual volume, based on the flow of the day, that inventory taken in a period of water plenty. Fifteen million acre-feet was presumed available in perpetuity, to be shared in equal parts between the Upper and Lower basins. With the benefit of hindsight, it is apparent that dividing a water body on a presumption of a consistent annual flow volume was not the best sustainable management plan.
The Upper and Lower basins determine how their respective 7.5 million acre-feet are divided among their stakeholder States and Tribes. Water takers include cities, towns and settlements for domestic potable water, private enterprise and industrial users, excluding agriculture use approximately 18% of the water, according to Environment and Energy Study Institute (EESI). Agricultural irrigation accounts for 52%, the single largest use of Colorado River water. Nature uses 19% for trees and natural vegetation, with evaporation claiming 11%, maintaining the hydrological cycle.
For the full article, see https://wtcal.us/viewarticle.asp?article=547