PHOENIX (AP) — Arizona water users are starting work on an ambitious plan to lessen the impact of Colorado River water shortages.

About 40 people recently were named to a committee that will meet for the first time Thursday.

They’ll be working on a drought contingency plan that’s part of a larger effort to keep Lake Mead on the Arizona-Nevada border from dropping drastically.

The lake level determines if water deliveries to Arizona, California and Nevada can be met. A shortage never has been declared but federal officials say there’s a 50 percent chance in 2020.

The Arizona committee wants to present the plan to the state Legislature in January. Its work will focus on any excess river water, central Arizona farmers, water conservation and a water savings program for tribes.