The Colorado River has always been a critical water source for California, Nevada, and Arizona. Climate-change induced drought over the last decade or more has reduced river flows, and reservoir levels, to the point where drastic cuts in water use will soon be mandated by the federal government. Negotiations between the states involved as to how to divide up the available water will be necessary, but ultimately each state will be faced with significant reductions in their water allotments.
https://www.politico.com/news/2022/07/06/colorado-river-drought-california-arizona-00044121