Fresh off a phenomenal winter snowpack, water levels on the Colorado River are going up for the first time in years.

As a result, federal officials will announce this week that they are easing water restrictions in the Southwest starting next year, three sources familiar with the plan told CNN, lifting the region from a Tier 2 water shortage to a Tier 1. It’s a remarkable turnaround that will give back billions of gallons of Colorado River water to millions of people in the Southwest, primarily in Arizona and Nevada.

But they can’t breathe a sigh of relief. Officials, farmers and tribes are bracing for more difficult negotiations on how to divvy up the river when the current interstate agreement expires in 2026.