Thursday, Aug. 23, 2012 | 2:18 p.m.
Wednesday's near-record rainfall tested the Las Vegas Valley’s flood-control system, but outside of localized street flooding, officials are reporting no serious damage from the storms.
For that good fortune, give some credit to $100 million spent just last year to improve the valley's network of channels, drains and detention basins designed to corral overflowing flood waters.
Wednesday's rainfall — 1.65 inches at McCarran International Airport — was the second-highest daily amount in the airport’s history, according to the National Weather Service.
Gale Fraser, general manager of the Clark County Regional Flood Control District, said because the rain fell steadily throughout the day, its impact was less severe compared to storms in 1999, 2003 or 2007, which dropped similar amounts of rain over much shorter time frames.
Fraser said significant improvements made to the flood-control system after a deadly storm in 1999 that caused $20 million in damage also helped mitigate the effects of Wednesday’s rain.
“All indications are that our flood-control network worked as designed,” he said. “There’s no doubt in my mind that 10 years ago this (storm) would have caused a lot more problems.”
The regional flood-control network comprises 573 miles of channels and underground storm drains, plus 90 detention basins, which capture excess water during flash floods and slowly release it, Fraser said.
In 2011, the flood control district spent $100 million on 11 projects adding channels, drains and basins, he said.
Swollen flood channels drew many onlookers, including 17-year-old Henderson resident William Mootz, who was swept down Pittman Wash behind the Target store near Stephanie Street and Sunset Road Wednesday morning. The search for him resumed Thursday.
The Pittman Wash originates at St. Rose Parkway near the Henderson Executive Airport and stretches 11 miles toward Boulder Highway. Water carried through the wash ultimately flows into the Las Vegas Wash, which empties into Lake Mead.
Fraser said the flood control district measured the flow of water through Pittman Wash on Wednesday at 5,000 cubic feet of water per second (one cubic foot is 7.48 gallons).
On a typical day, the flow of water in the wash is less than five cubic feet per second, according to a flood control official. Water is still draining from the channel system Thursday.
Damage from Wednesday’s storms was limited. Officials from Las Vegas, Henderson and North Las Vegas all reported no serious damage, outside of some debris, rocks and dirt that was washed into roadways.
The lake at Lake Las Vegas rose significantly during the storm, flooding some of the area immediately around the shore, said resident Don Logay.