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Traffic lights at two Roanoke intersections were still out of service Thursday.
STEPHANIE KLEIN-DAVIS | The Roanoke Times
Like a river of milk chocolate, the Lick Run Greenway floods an area near Commonwealth Avenue in Roanoke on Wednesday.
Thursday, July 11, 2013
The historic deluge that poured rain on northern Roanoke on Wednesday afternoon left crews scrambling Thursday morning to assess the damage the floodwaters had caused.
Parts of northwest Roanoke and northern Roanoke County were under water into the early morning hours, leaving behind problems that may not be fully understood for days or even weeks, according to Roanoke transportation manager Mark Jamison.
Wednesday's cloudburst was a very localized flash flood event. Rainfall amounts were extremely heavy in spots, but heavy rain was not widespread across Southwest Virginia, or even across the Roanoke Valley.
While rain fell throughout the valley on Wednesday, the historic torrential downpours occurred only in northern and northwestern sections of Roanoke and adjacent Roanoke County.
That happened to fall over the city's official rain gauge, at Roanoke Regional Airport, where the 3.35 inches measured in an hour constituted somewhere between a once-in-200-years and a once-in-500-years event, the National Weather Service in Blacksburg announced Thursday.
Doppler radar estimates and some unofficial rain gauges showed that more than 4 inches may have fallen in an hour near the Peters Creek and Hollins areas.
Meanwhile, some parts of the valley to the south and west got less than an inch total. A later storm poured some heavy rain into the Roanoke River's headwaters southwest of the city, but it was not enough to send the river out of its banks in the city as happened last week.
Instead, Wednesday's storm overwhelmed some of the area's creeks and streams.
Peters Creek was at the epicenter of the rain. During the downpour, between 3 and 4 p.m. Wednesday, it overflowed onto the adjacent road and into neighborhoods along its banks.
City engineer Phil Schirmer said a particularly high number of residents were affected because of how many homes, businesses and streets are in the creek's flood plain, but any area hit by that much rain could be vulnerable.
"If we had a rainfall of this intensity, virtually any area in the city could see flooding," Schirmer said.
Despite the severe weather, there have not been any reported injuries from the storm. Two people died in last week's heavy rains.
Wednesday's mayhem, Schirmer said, was also partially a product of the already saturated ground and the abnormally heavy rain. In coming weeks, other neighborhoods could see flooding. Anyone who owns property near streams or creeks, Schirmer said, should be ready for flooding.
"They all have the potential for it now," he said. "Hope for the best but prepare for the worst."
Jamison, in charge of the city's transportation crews, had workers in early Thursday morning attempting to assess damage to roads that were submerged in the floods, a situation that is hard to prepare for.
"While the intersections are actually holding water and flooded, there's not much you can do," Jamison said.
Once the water receded from roads, he said, crews found that numerous washouts had developed along shoulders and the pavement was littered with debris.
Jamison said two traffic lights remained out of service Thursday as his teams worked to install new electrical equipment. Controls for the traffic lights at the Orange Avenue and Gainsboro Road intersection and the Williamson Road and Wells Avenue intersection were completely submerged Wednesday.
He said the signals should be restored at some point today.
Schirmer said widespread flooding of residences near Peters Creek was also a concern. He said efforts to contain flooding on the city's creeks may not be feasible. Instead, he said, a possible solution could be to gradually eliminate properties situated in flood plains.
He said he couldn't recall similar flooding in Peters Creek since at least 1989.
One street remained closed in the city Thursday evening, Jamison said. Northwood Drive Northwest, just off Peters Creek Road, was shut down because a pipe underneath the road could be unstable.
For now, Jamison said, crews are trying to clean up what they can and log the problems that need to be addressed in coming weeks. He said it is still too early to gauge all the effects of Wednesday's rain.
"My guys are pretty good at dealing with these kind of issues," he said. "But yesterday was not normal."
Staff writer Kevin Myatt contributed information to this story.
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