West’s Biggest Reservoir Is Back on the Rise, Thanks to Conservation, Snow

LAS VEGAS—The largest reservoir in the Western U.S., Lake Mead, is rising again after more than a decade of decline, and at least some credit goes to the local National Hockey League team.

“Reality check!” Ryan Reaves, right wing for the Vegas Golden Knights, yells as he body-slams a man through a plate-glass window for excessive lawn watering in a television commercial. “Vegas is enforcing water waste big time.”

Ads like this began airing last year as part of a campaign by the Southern Nevada Water Authority to persuade the more than two million residents of this sprawling desert metropolis to use less water. Using a carrot-and-stick approach, including paying landowners to remove grass and fining for overuse, the agency said it has cut total Colorado River water consumption by 25% over the past two decades, even as the population it serves has grown around 50%.