LOS ANGELES, Aug. 24 (Xinhua) -- The U.S. state of Nevada filed a federal lawsuit on Monday challenging the federal government's newly adopted Colorado River management plan, marking the first legal challenge to rules issued three days earlier for sharing reduced water supplies among western U.S. states.
The lawsuit was filed by the state, the Colorado River Commission of Nevada and the Southern Nevada Water Authority. It asks the District Court for the District of Nevada to set aside the Interior Department's decision and block its implementation until alleged legal and technical problems are addressed, according to the Nevada governor's office.
The Interior Department said the rules would reduce combined annual water deliveries to the three Lower Basin states -- Arizona, California and Nevada -- by about 1.54 billion cubic meters in each of 2027 and 2028. Under the federal framework, the four Upper Basin states -- Colorado, New Mexico, Utah and Wyoming -- would face voluntary rather than mandatory conservation measures.
The two-year operating rules are scheduled to take effect on Oct. 1, while the accompanying record of decision establishes a framework through 2036, according to federal decision documents.
Nevada's objections center on that longer-term framework, which authorizes larger reductions in dry years, according to the complaint. Nevada Governor Joe Lombardo said the plan could reduce southern Nevada's Colorado River allocation by more than 70 percent.
"This isn't about political posturing; this is a matter of survival for a community that represents about two-thirds of our state's citizens and the lion's share of its economy," Lombardo said in a statement on Monday.
The complaint places the deepest reductions from 2029 under severe-shortage conditions. Nevada would give up about 62 million cubic meters annually in 2027 and 2028 under a sharing arrangement proposed by the Lower Basin states, according to the Interior Department.
That reduction would amount to roughly 17 percent of Nevada's annual allocation of about 370 million cubic meters.
The lawsuit alleges that the federal decision violates the Administrative Procedure Act, the National Environmental Policy Act and the system of compacts, federal statutes, court decisions and regulations governing the river, known as the "Law of the River."
It also alleges that federal officials failed to adequately assess potential effects of deeper cuts on southern Nevada's economy, public health and water infrastructure, and did not sufficiently consider an alternative proposed by the Lower Basin states.
The complaint names Interior Secretary Doug Burgum and Bureau of Reclamation Commissioner Aubrey Bettencourt, along with their agencies, as defendants.
The Interior Department said the rules are intended to keep reservoir operations reliable and protect federal infrastructure while allowing for adjustments as drought conditions evolve and negotiations among the seven basin states continue.
The seven basin states have yet to reach an agreement on longer-term rules for sharing reduced supplies, according to the department's decision documents.
The latest available Bureau of Reclamation data showed that Lake Mead and Lake Powell, the Colorado River's two largest reservoirs, remained at record-low levels. ■
