Reduced Water Flow from the Colorado River for Arizona, Nevada, and Mexico

• Arizona and Mexico are once again receiving less water from the Colorado River.
• States are working on new regulations for water management.
• Reduction in mandatory water shortages has been in effect since 2022.

DENVER — Arizona, Nevada, and Mexico are again receiving less water from the Colorado River, as drought continues in the West, federal officials announced on Friday.

The Colorado River is a vital water source for seven U.S. states, 30 Native American tribes, and two Mexican states. The reduction in available water is projected to affect federal reservoirs, such as Lake Powell and Lake Mead, which supply every September to Bureau of Reclamation.

Arizona is expected to lose 18% of its overall allocation of Colorado River water, while Mexico will lose 5%. Reductions for Nevada will remain at 7%. California does not report any shortages, as it has senior water rights and is the last state to lose water during times of scarcity.

Decades of overuse and the consequences of ongoing drought, exacerbated by climate change, have led to significantly higher demand for water than what is physically available from the river. Low reservoir levels at Lake Mead have triggered mandatory shortages since 2022, with the largest cuts in 2023, which have severely impacted farmers in Arizona.

At the same time, states are working on achieving agreements for the upcoming year regarding new long-term rules for river management in dry years. The Trump administration set a deadline for mid-December to reach a previous agreement, otherwise federal intervention is threatened. Negotiations are ongoing, as states are prohibited from discussing how much water they typically plan to give back.

The original Compact of the Colorado River from 1922 was based on water allocations that do not exist in today’s climate. This leaves states in the upper basin, such as New Mexico, Colorado, Wyoming, and Utah, to deal with significantly less water after the necessary quantity is directed to states in the lower basin: Nevada, Arizona, and California. Much of the water is also lost through evaporation and aging infrastructure.

Equitable distribution of river water in an era of climate change has posed challenges for many years, as all major users do not want to give up anything, expecting more dry years ahead. There must be enough water in the reservoirs to reach the tunnels that transport water downstream, and, ideally, more water for generating electricity. Basic infrastructure, such as Hoover Dam, depends on certain water levels in Lake Mead for energy generation.

Mandatory cuts and emergency releases of water are "reactive," said John Berggren, regional manager with the Western Resource Coalition. "If we want to have a stable Colorado River, and not just react to crisis after crisis, we need large allocations to be enshrined in new rules," he added.

States are considering a so-called natural flow approach for river management, where the lower basin receives a certain percentage of the average natural flow over the previous number of years.

States in the lower basin aim to eliminate deeper cuts, developing voluntary conservation plans. "Without all these measures, the river would be in a very poor state," said J.B. Hamby, chair of the Colorado River Board of California.

Tags: USA/Politics/Weather