Rains brought by Hurricane Norbert are causing record flooding in the southwestern United States, straining dams in Arizona and Nevada, sources report.
Norbert — advancing through the U.S. after hitting Mexico’s Baja Coast over the weekend — dumped more than six inches of rain in areas near Phoenix, Tucson, Las Vegas and other major metropolitan areas, causing flash floods of up to 15 feet in some areas and killing several people.
Officials from the Clark County Regional Flood Control District in Nevada said a dam on the Muddy River near the Moapa River Reservation, about 45 miles northeast of Las Vegas, was particularly close to being overtopped.
Flooding near Moapa washed away significant portions of Interstate-15 and other roads, causing a 50-mile closure that will last a minimum of several days, according to the Nevada Department of Transportation.
Meanwhile, officials with southwest Arizona’s Maricopa County Flood Control District said its 140 flood-control structures and 22 dams were “operating well”.
“That being said, after this is over we need to re-look at those structures and look at other areas of need,” chief engineer Bill Wiley said in a press conference.
The bulk of the flooding has taken place in the Colorado River Basin, which, as a region, has experienced significant drought in recent years.
HydroWorld.com reported in July that Lake Mead — impounded by Hoover Dam and located east of Las Vegas — had dipped to historically low levels.
The U.S. Bureau of Reclamation, which operates Hoover and the upstream Glen Canyon Dam, said in August that releases from Glen Canyon are expected to increase in the coming Water Year, though water levels are still lower than historically average.