Southwestern water leaders are set to finalize a drought plan for the Colorado RiverMonday at Hoover Dam.

The drought contingency plan has been years in the making and is a response to ongoing dry conditions on the river. 

“This is a big deal. It’s a big deal for the basin. It’s a big deal for the river, and for all the states who depend on the river,” Marlon Duke, the Bureau of Reclamation spokesperson, said. 

The Colorado River provides water to 40 million people in seven U.S. states and Mexico. 

In Arizona, California and Nevada, the plan sets up a series of cutbacks to the river’s users should its biggest reservoir -- Lake Mead -- continue to drop.

Further upstream, states like Colorado and Utah are looking to the plan to figure out how to use less water and boost another big reservoir -- Lake Powell.