Arizona joins lawsuit challenging Colorado River cuts

Nearly eight weeks after the federal government slashed Arizona’s
share of Colorado River water by nearly a third, the state’s Department
of Water Resources joined a Nevada lawsuit challenging the Bureau of
Reclamation decision.

The state department and Arizona Governor
Katie Hobbs say the bureau failed to hold the four upper basin states
accountable for water delivery obligations to the three lower basin
states, which absorbed all federal reductions imposed in August.

“Arizona
has always been willing to do our part to protect the Colorado River,
but we will not accept a forced federal plan that solves this crisis on
the backs of our families, farmers, and businesses,” Hobbs said in a
Friday afternoon press release. “We are drawing a line in the sand.”

The bureau’s plan follows years of negotiations over post-2026 operating guidelines that missed several deadlines and ultimately deadlocked. The upper basin states, Colorado, Utah, Wyoming and New Mexico, refused mandatory cuts, citing senior priority under the Law of the River.

Under the plan, the lower basin states, Arizona, Nevada and California, will collectively cut 3.5 million acre-feet over the next two years. Arizona will give up the most,
760,000 acre-feet annually for two years. With another 300,000
acre-feet in voluntary conservation, the state will lose more than 1.8
million acre-feet by the end of water year 2028.

An acre-foot is
about 326,000 gallons, enough to cover one acre with a foot of water and
typically supply three average households for a year.

The plan includes no mandatory cuts for the upper basin.

“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,” Hobbs said in the press release. “While we ensure our
voice is heard in court, we’ll continue working alongside Nevada and
California to implement the Lower Basin Agreement and prevent a
devastating cut to Arizona’s Colorado River water.”

The Lower
Basin Agreement is a deal between Arizona, California and Nevada to
protect the river and avoid future federal cuts that could slash more
than 77% of the Central Arizona Project’s allocation. The canal supplies
more than 30% of Arizona’s water. Under the agreement, the lower basin
states commit to conserving more than 3.2 million acre-feet in 2027 and
2028.

Nevada sued Aug. 24,
three days after the Bureau of Reclamation announced a plan to cut the
state’s allocation by 210,000 acre-feet annually, about 71% of its
300,000 acre-foot entitlement.

Nevada’s share is just 3.3% of
water allocated to the lower basin states and Mexico, but supplies 90%
of water used in the Las Vegas Valley.

Without it, the already dry state could shrivel.

Nevada says the federal plan
violates the Administrative Procedure Act, National Environmental
Policy Act and Law of the River. It wants a judge to halt implementation
and vacate the operating plan and environmental impact statement
authorizing it.

Arizona officials say they were similarly shortchanged.

“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,” said Tom Buschatzke, director of the
Arizona Department of Water Resources.

Hobbs said joining the
lawsuit will allow Arizona to protect its interests and challenge parts
of the final environmental impact statement and record of decision that
she says unlawfully fail to require upper basin reservoirs to deliver
water to Lake Mead, created by the Hoover Dam at the Grand Canyon’s west
end.

Lake
Mead and Lake Powell, created by the Glen Canyon Dam at the canyon’s
east end, are at 27% and 22% capacity, respectively, while upper basin
reservoirs remain above 60%. Both lakes are nearing “deadpool,” the level at which water can no longer flow through their hydropower-generating dams.

The
federal plan sets cuts for the next two years, but future, potentially
steeper lower basin cuts will depend partly on Lake Powell’s elevation.
The bureau will conduct 24-month studies to determine the highest
release possible while keeping the lake at 3,510 feet, just 140 feet
above deadpool.

If that release is at or below 6 million
acre-feet, it will trigger reconsultations to further reduce lower basin
use by as early as June 2027. A 7 million acre-foot release would avoid
further consultations.