EXPLAINER: Western states face first federal water cuts

U.S. officials are expected to declare the first-ever water shortage from a river that serves 40 million people in the West

WASHINGTON -- U.S. officials on Monday are expected to declare the first-ever water shortage from a river that serves 40 million people in the West, triggering cuts to some Arizona farmers next year amid a gripping drought. Water levels at the largest reservoir on the Colorado River — Lake Mead — have fallen to record lows. Along its perimeter, a white “bathtub ring” of minerals outlines where the high water line once stood, underscoring the acute water challenges for a region facing a growing population and a drought that is being worsened by hotter, drier weather brought on by climate change. States, cities, farmers and others have diversified their water sources over the years, helping soften the blow of the upcoming cuts. But if current conditions persist — or intensify — additional cuts in coming years will be more deeply felt. Lake Mead was formed by building Hoover Dam in the 1930s. It is one of several man-made reservoirs that store water from the Colorado River, which supplies drinking water, irrigation for farms and hydropower to Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and parts of Mexico.