These areas are most prone to flash flooding around Pittsburgh, expert says

Pittsburgh has seemingly been hit with heavy rainfall after heavy rainfall recently, and during flash flooding, roads can turn into rivers and vehicles are submerged and even swept away. KDKA meteorologist Trey Fulbright talked to an expert about where flash flooding is the most problematic in the Pittsburgh area and the reasons behind it. 

"Pittsburgh has a lot of hilly terrain, and the slopes, the water runs off fast here because of the hilly terrain and also because we got a lot of development, a lot of impervious surfaces — streets, parking lots and whatnot — and that creates really fast runoffs," said Jason Shafer, a meteorologist and chief innovation officer at PowerOutage.com

This prompted Shafer to map out where natural stream crossings intersect roads, which can become submerged and wash away during excessive rainfall. So which parts of our city are most prone to flash flooding? 

Shafer says No. 1 was Sawmill Run in the South Hills. 

"That was number one just because it also has a pretty large area, about almost 20 square miles that it covers," Shafer said. "So, there's a lot of coverage of risk in there."

After that was Girty's Run near Millvale, Ross and Shaler. 

"That has a pretty narrow run, a narrow kind of shape to its topography so the water can accumulate there," Shafer said. "That's a lot of water that comes together right near Millvale that causes a lot of risk."

And No. 3: Little Pine Creek and the Pine Creek complex. 

"That was up near Etna and Shaler, so also on the north side there where water comes in," Shafer said. "Those two in the Pine Creek area, we had a pretty catastrophic event where there were eight fatalities in 1986 with a flash flood." 

Shafer has identified seven other corridors with similar characteristics. Those include Campbell's Run, Streets Run, McLaughlin Run, Squaw Run, Painters Run, Thompson Run and Nine-Mile Run. 

So what can be done to more effectively warn commuters before flash flooding? 

"Maybe we should pre-stage a few assets, either police or fire, at critical intersections ahead of this event," Shafer said. 

"One of the solutions for technology could be putting in a camera system — and some of these cameras may exist that PennDOT already owns — but pointing it at critical areas of the road and the water, right, where a human operator can see water coming up over the road, but you could also train something on a computer vision or AI that can do that and recognize that."

Even with the hope of new technology, commuters must remain vigilant. If you come across a flooded roadway, turn around and don't drown.