The Colorado River is in the middle of a slow-motion crisis driven by overuse and a warming climate. River flows have dropped roughly 20% over the past century, the two largest reservoirs in the country have lost dramatic amounts of storage, and the river no longer reaches the sea. At the same time, seven U.S. states, dozens of tribal nations, and Mexico are negotiating new rules that will govern the river for decades to come, with a draft plan released in early 2026.
Why the River Is Shrinking
The Colorado River’s decline is not simply a drought that will end when rain returns. Research from the U.S. Geological Survey shows that streamflow in the Upper Colorado River Basin drops by about 5% for every degree Fahrenheit of warming. That relationship has already produced a 20% reduction in flow over the past century. Higher temperatures melt mountain snowpack earlier, reduce the reflectiveness of snow (which causes it to absorb more heat), and increase evaporation from soils and reservoirs before water ever reaches a faucet or farm.
This distinction matters. A drought implies a temporary dry spell followed by recovery. What climate scientists describe on the Colorado is closer to aridification: a permanent shift toward less water in the system, even in years with decent snowfall. Wet winters can temporarily refill reservoirs, but the long-term trend is downward. The river now supports more than a trillion dollars in annual economic activity across the Southwest while carrying significantly less water than it did when those economies were built.
Lake Mead and Lake Powell
The river’s health is most visible at its two giant reservoirs. Lake Powell, behind Glen Canyon Dam in Utah and Arizona, and Lake Mead, behind Hoover Dam on the Nevada-Arizona border, together act as the river’s savings account. Both dropped to historically low levels in 2022 and 2023, triggering federal shortage declarations that forced water cuts to downstream states. Bureau of Reclamation projections from April 2025 model Lake Powell’s elevation reaching around 3,570 feet and Lake Mead around 1,053 feet by late 2026, with roughly 7.9 million acre-feet of storage in each. Those numbers represent a partial recovery from the worst lows but remain well below full capacity.
When Lake Mead drops below certain thresholds, the federal government declares tiered shortages that reduce deliveries to Arizona, Nevada, and Mexico first, with California’s senior water rights protecting it until conditions worsen further. These shortage triggers have been the primary enforcement mechanism for conservation, and their future design is a central question in the ongoing negotiations.
Where the Water Goes
Agriculture consumes the vast majority of Colorado River water. Of the river’s agricultural share, nearly two-thirds goes to crops like alfalfa and other hay used to feed beef and dairy cattle. This makes livestock feed the single largest draw on the river, a fact that has pushed fallowing programs to the center of conservation efforts.
Starting between 2015 and 2018, the federal government began compensating farmers for voluntarily taking fields out of production or reducing irrigation. Since the Inflation Reduction Act passed in 2022, the government has been spending roughly $1.3 billion per year on these programs. Some farmers fallow entire fields. Others have experimented with alternative forage crops like triticale that use less water, or used the downtime to rehabilitate aging irrigation infrastructure. The programs are voluntary and temporary, which makes them politically viable but limits how much water they can save in any given year.
Cities across the Southwest have also made significant cuts. Las Vegas recycles nearly all of its indoor water. Phoenix and Tucson have invested in water reuse and aquifer storage. Municipal conservation has been effective, but because cities use a much smaller share of the river than farms, even dramatic urban savings can only do so much.
The Post-2026 Negotiations
Several key agreements that govern the Colorado River expire at the end of 2026. These include the 2007 Interim Guidelines that established the shortage-sharing framework, the 2019 Drought Contingency Plans that added emergency conservation measures, and international agreements with Mexico under the 1944 Water Treaty. All of them need to be replaced.
The Bureau of Reclamation is leading a multi-year process to write new operating rules for Lake Powell and Lake Mead. In November 2024, the agency publicly released a set of alternatives, and in January 2026 it published a draft Environmental Impact Statement laying out options. The Upper Basin states (Colorado, Wyoming, Utah, New Mexico) and the Lower Basin states (Arizona, Nevada, California) have submitted competing proposals, and tribal nations with significant but historically underserved water rights are pushing for a larger role in the final framework.
The stakes are enormous. These new rules could govern the river for decades, determining how deeply states must cut during shortages, whether cuts are shared more equally between the Upper and Lower Basins, and how much water is set aside to keep reservoirs from reaching dangerously low levels. The 20% flow decline already baked into the system by warming means the old allocation of 16.5 million acre-feet per year, split between the basins and Mexico, no longer matches reality. The new rules will have to close that gap.
A River That No Longer Reaches the Sea
The Colorado River once flowed continuously from the Rocky Mountains to the Gulf of California, sustaining a vast wetland delta in Mexico. Today, upstream dams and diversions in both countries consume virtually all of the river’s flow. Little to no water passes downstream of Morelos Dam on the U.S.-Mexico border, and the delta has largely dried out, its wetlands degraded and its riverbanks barren.
In 2014, the U.S. and Mexico cooperated on an unprecedented experiment: a pulse flow that released 106,000 acre-feet of water into the dry delta channel over about eight weeks. It was a historic moment, but the volume was only 5% of the magnitude and 10 to 15% of the duration of the seasonal peak flows that were typical in the early 1900s. Still, satellite imagery showed the delta greened up noticeably. Groundwater recharged, benefiting native trees and shrubs. By 2015, vegetation had declined from the post-pulse peak but remained greener than before the release, suggesting the single pulse stimulated plant growth for at least a year.
Whether repeated pulse flows could meaningfully restore the delta remains an open question. No follow-up releases of similar scale have occurred, and with every acre-foot of water fiercely contested upstream, dedicating significant flows to the environment requires political will that has been difficult to sustain.
What Comes Next
The Colorado River is caught between two pressures that aren’t going away. Climate warming will continue reducing flows regardless of precipitation patterns. Meanwhile, population growth and existing agricultural commitments keep demand high. The post-2026 negotiations represent the best opportunity in a generation to realign the rules with the river’s actual capacity, but reaching agreement among states with deeply different interests and legal positions has historically taken years of conflict before compromise.
For the roughly 40 million people who depend on the river, the practical reality is a future with less water. Cities will continue investing in recycling, desalination, and efficiency. Farmers will face growing pressure to shift crops, fallow fields, or sell water rights. And the river’s ecosystems, already stripped of most of their historical flow, will depend on whether negotiators choose to set aside even a small share for the environment in whatever deal eventually emerges.