Politics · United States · 2 hrs ago
Arizona joins Nevada lawsuit over proposed Colorado River water cuts
Arizona has joined Nevada’s lawsuit against the Trump administration’s proposed cuts to their Colorado River water shares.
The federal restrictions could reduce water supplied to Arizona, California and Nevada over the next two years, depending on the river’s condition.
The river’s major reservoirs, Lake Mead and Lake Powell, are at historically low levels after years of overuse and a changing climate.
Upper-basin states would be spared the proposed cuts, a point that has drawn criticism from lower-basin leaders.
The states sharing the river missed several deadlines to agree on how to manage its water, prompting federal intervention.
If reservoir levels fall far enough, water may no longer flow downstream, a condition known as “deadpool.”
Arizona says the lawsuit protects its water rights while leaving room for cooperation with Nevada and California.
Arizona has joined Nevada’s lawsuit challenging proposed federal cuts to their shares of Colorado River water.
The Interior Department announced restrictions this summer that could reduce supplies to lower basin states over the next two years, depending on river conditions.
Arizona Governor Katie Hobbs said the state is taking legal action because the federal government is threatening cuts and is not holding upper basin states accountable for water deliveries.
The upper basin states were exempted from the proposed cuts, drawing criticism from lower basin leaders.
Lake Mead and Lake Powell have fallen to historically low levels amid overuse and a changing climate.
- Who
- Arizona has joined Nevada in its lawsuit against the Trump administration.
- What
- Arizona is challenging proposed cuts to its share of Colorado River water.
- When
- Arizona announced its move on Friday; the article was published on October 17, 2026.
- Where
- The dispute concerns Colorado River water shared by lower and upper basin states.
- Why
- Arizona says the federal government is threatening severe cuts and is not holding upper basin states accountable for water deliveries owed to Arizona.
Lower basin states
Upper basin states
Responsibility for shortages
Lower basin states
Upper basin states argue that downstream states are responsible for reservoir shortages and should face the largest cuts.
Upper basin states
Not stated.
Proposed cuts
Lower basin states
Arizona and Nevada oppose the proposed cuts to their water shares.
Upper basin states
Not stated.
Water deliveries
Lower basin states
Arizona says the federal government should hold upper basin states accountable for water deliveries owed to Arizona.
Upper basin states
Not stated.
The Interior Department announced restrictions that could reduce supplies to lower basin states over the next two years, depending on river conditions.
The federal government intervened after the states failed to reach consensus on Colorado River water management.
Arizona joined Nevada’s lawsuit challenging proposed cuts to their water shares.
- Arizona
- Joined Nevada’s lawsuit
- Potential cuts
- Could affect lower basin water supplies over the next two years
- Lower basin states
- Arizona, California and Nevada
- Upper basin states
- Wyoming, Colorado, Utah and New Mexico
- Major reservoirs
- Lake Mead and Lake Powell are at historically low levels
What people are saying
We are drawing a line in the sand
I am taking this legal action alongside Nevada because the federal government refuses to hold the Upper Basin accountable for the water deliveries they owe Arizona, and is threatening to force draconian cuts that go well beyond the Lower Basin Agreement
intervention in the Nevada lawsuit is necessary at this time for Arizona to protect its legal rights to Colorado River water while preserving a path forward to achieving a collaborative outcome with California and Nevada to protect the Colorado River system