LAS VEGAS — Tourists and truckers were told Wednesday to prepare for several more days of disruptive detours around a closed stretch of busy Interstate 15 in southern Nevada that crumbled in chunks during intense flash flooding.
Crews were working to repair the freeway as Gov. Brian Sandoval declared a state of emergency late Tuesday and dispatched officials to begin estimating the cost of damage after Monday’s storm wiped out swaths of the vital interstate and swamped parts of Clark County and an Indian reservation.
“We hope to have one lane in each direction open by the weekend,” Nevada Department of Transportation spokeswoman Julie Duewel said.
The National Weather Service said more than 4 inches of rain fell in less than two hours in the area during what might have been most intense storm in 30 years in the Muddy River valley and rural Moapa area about 50 miles northeast of Las Vegas.
The sudden torrent of runoff down sunbaked washes toward the Virgin River and Lake Mead also scoured out part of a main Union Pacific rail freight line and swelled a river so high that a Utah national park was briefly shuttered.
The same storm, spawned by seasonal monsoon moisture and the remnants of Tropical Storm Norbert, dumped heavy rain throughout the Southwest and set a single-day rainfall record Monday in Phoenix.
During the height of the storm, about 190 people were evacuated from the Moapa Band of Paiutes reservation after tribal officials warned that waters were close to breaching a Muddy River dam.
But in a “near miss,” the water stopped short of spilling over, said Erin Neff, spokeswoman for the Clark County Regional Flood Control District.
A subdivision with about 30 homes flooded several miles downstream, in Overton, and Clark County firefighters counted 18 rescues in the area, many involving submerged cars.
