The federal government is designating $4 billion from the Inflation Reduction Act for drought mitigation work in the Colorado River basin.

On Wednesday, the Department of the Interior announced that total, indicating that $500 million will go to efficiency upgrades in the river’s Upper Basin states of Colorado, Utah, New Mexico, and Wyoming. Another chunk of IRA money will be set aside for direct payments to farmers and ranchers to forgo water deliveries from Lake Mead in the river’s Lower Basin, primarily in Arizona and California. Federal officials are not specifying how much money will be available for that first round of payments.