In Trump administration’s plan, California, Arizona and Nevada face about a 20% cut to water supply over two years

Nevada filed a federal lawsuit on Monday challenging the Trump administration’s new plan for the imperiled Colorado River, launching what could become the first of many court battles over the waterway that supplies 40 million people, dozens of tribes and 5.5m acres of farm land across the American west.

The federal plan, issued Friday, cut roughly 20% from the water supplied to lower basin states – Nevada, Arizona and California – over the next two years, with a potential for harsher cutbacks in the future, based on conditions.