DENVER, April 24 — The West’s already stretched water supplies received no relief in March, as near-record high temperatures and below-normal precipitation wilted crucial watershed lands from the Pacific Northwest to the Sierra Nevada and the deserts of New Mexico.

Mountain snows melted and evaporated away with the wind and heat, leaving places like the Salt River and Verde River Basins in central Arizona with only about 30 percent of their historic average spring runoff. Runoff from the Colorado River that feeds Lake Powell, the reservoir that straddles the Utah-Arizona border, was projected to come in at 53 percent of average.

Water