A California irrigation district has filed a legal challenge to a plan designed to protect a water source that serves 40 million people in the U.S. West.
The drought contingency plan seeks to keep two Colorado River reservoirs from dropping so low they cannot deliver water or produce hydropower.
The Imperial Irrigation District didn't sign on to the multi-state plan over concerns about a massive, briny lake southeast of Los Angeles.
Imperial is alleging another powerful California water agency, the Metropolitan Water District, violated environmental laws in pledging to contribute California's share of water under the drought plan.
Imperial's petition filed in Los Angeles County Superior Court on Tuesday came the same day President Donald Trump approved the drought plan.
MWD did not immediately respond to a request for comment Wednesday.