Murrysville and Export assess damage from weekend storm, flooding
Friday’s downpour generated so much stormwater that it destroyed a culvert built by Murrysville public works crews along Lyons Run.
“Forty-eight tons of R-7’s and asphalt are now somewhere else,” Murrysville Public Works Director Bill Paiano said in a memo to town officials in his initial assessment of the damage to public infrastructure.
R-7 is a type of “rip-rap,” in this case 2- to 3-foot stones meant to stabilize hillsides and prevent road washouts. It was among several pieces of infrastructure unable to withstand the forces of nature unleashed Friday evening.
“We have asphalt damage in some locations, road berms that need rebuilt, damage to stormwater pipes and some road regrading that needs done,” Murrysville Chief Administrator Michael Nestico said Monday morning. “That’s just the early assessment. Public works is out today looking at bridges and other infrastructure.”
A stubborn thunderstorm that parked itself over a relatively small region — roughly running west to east between Turtle Creek and Export, and north to south between southern Plum and Penn Township’s Harrison City neighborhood — dumped nearly 4 inches of rain in just a few hours Friday, according to the National Weather Service.
Its highest measured total was 3.96 inches of rain, reported from Trafford. Municipalities said there were no estimates yet on the potential cost of the damage.
In Export, the borough’s flood-control project functioned exactly as designed, diverting a massive amount of stormwater through an underground culvert in order to keep Turtle Creek from overflowing its banks in the borough.
“When the flood-project flow gets that high, it doesn’t allow water to come into the creek from (the northern side) of town,” Export Borough Council President Barry Delissio said. “We have flaps that shut to keep water from flowing toward businesses.”
Water flowing down the hill from above, however, had no place to go, Delissio said.
“Apparently, a little bit of water got into some of the Washington Avenue businesses, but I didn’t hear reports of anyone who had to put up sandbags,” he said.
Delissio said he planned to take a look at a section of the flood-control project on Monday to search for signs of damage. The U.S. Army Corps of Engineers, which helped build the project, also plans to send a crew to inspect the underground culvert.
“After seeing video of how the stormwater was coming out, the culvert definitely got cleaned out,” Delissio said.
SEE MORE STORM COVERAGE:• Flooding hammers areas near Murrysville, Turtle Creek
• Residents in Murrysville, Export clean up from Friday' deluge
• Little time to dry: More storms headed to Pittsburgh region
In Murrysville, even the preliminary list of damaged infrastructure was lengthy. It included:
• Asphalt damage to a bridge on Old William Penn Highway near the worst of Friday’s flooding
• Damage that will require a complete regrade of Woodbrook Drive, an unimproved road off Kilmer Court
• Work clearing debris that is trapped against municipal bridges crossing Turtle Creek
• Three spots with damaged asphalt on Pleasant Valley Road
• 48 tons in combined asphalt damage and 2- to 3-foot “rip-rap” rock washed away from the Lyons Run culvert; public works officials said the entire culvert will need to be rebuilt
• Cleaning of all pipes and inlets throughout the town
• Small landslides, pipe damage and berm damage on Meadowbrook Road
“I’m sure this is a fraction of what will surface in the week to come,” Paiano wrote in an email summary to Murrysville officials.
Elsewhere, Westmoreland Heritage Trail officials urged caution for anyone using the trail between Export and Trafford, where heavy flooding caused washouts and other damage.
“They’re on the trail right now with about six or eight people looking at it,” said Westmoreland Heritage Trail board President Stan Rudge. “Right now, the worst of it that I know about is right near Ginny’s Neighborhood Pizza in Murrysville. But we’ll have a better idea soon.”
Lions Club damage
The Level Green Lions Club expects it will cost $15,000 or more to repair portions of the asphalt parking lot that were damaged by flooding at its community building along Murrysville Road in Penn Township.
On Friday, debris washed downstream and blocked the point where a local creek enters a pipe underneath the parking lot.
“The creek overflowed, and it was like a river running through here,” said Isaac Schindler of Claridge, whose Schindler Asphalt Seal Coating crew was busy Monday starting the repairs. “There was a whole slab of asphalt it picked up.”
Todd Zavolta, Lions Club president and township emergency management deputy, said the floodwater came within a foot of the two-story building, which wasn’t damaged. About 20 children who were attending a session at building tenant FSQ Sports Training sheltered in place until the water receded, Zavolta said.
“The kids stayed upstairs,” he said. “We were very fortunate that way. The amount of water coming up here was unbelievable.”
The center was able to host events over the weekend, after the Lions cleared away the debris and blocked off sections of the parking lot that were torn up in the flood.
Saturated soil
Ryan Utz, associate professor of water resources at Chatham University in Pittsburgh, said Friday’s rain was a worst-case scenario in some ways.
“The soil was already saturated from rain we’d previously gotten,” Utz said. “That week, all the space in the soil was getting filled up with water, so when more rain came, there was no place to go other than over the ground.”
Beyond soil saturation, a lot of buildings in Pittsburgh and its suburbs are built in flood plains, Utz said.
“Downtown Pittsburgh is a flood plain,” he said. “That doesn’t happen as much anymore because of the dams and flood control they have.”
But it does still happen, evidenced by the occasional closure of riverside locations like the Mon Wharf, the Point and the “bathtub” section of I-376 near the Fort Pitt Bridge.
Utz said much of the region’s stormwater infrastructure is not just old: It’s designed for a different climate.
“There’s a simple atmospheric physics law: Warmer air can hold more water vapor,” he said. “That’s why there are rainforests around the equator, and that’s why Antarctica is the world’s largest desert. Events like Friday’s storm have become more frequent.”
National Weather Service meteorologists said a day that was already full of rain ended with a miniature cold front butting up against warmer, unstable air and forming a small storm that stayed in place instead of blowing elsewhere.
“These events are probably going to continue to become more frequent,” Utz said. “What we saw Friday isn’t fully attributable to climate change, but more events like it are happening as climate change continues.”
Patrick Varine is a TribLive reporter covering Delmont, Export and Murrysville. He is a Western Pennsylvania native and joined the Trib in 2010 after working as a reporter and editor with the former Dover Post Co. in Delaware. He can be reached at pvarine@triblive.com.
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