Landslides, flooded roads a headache
Holly Tonini/Observer-Reporter
A landslide along the westbound lane of Route 40 on Lincoln Hill in Canton Township
Holly Tonini/Observer-Reporter
A car passes through a one-lane section of California Drive in California Borough.
Holly Tonini/Observer-Reporter
A landslide has closed Bunola River Road in Forward Township, near the Monongahela Bridge.
Southwestern Pennsylvania is one of the most landslide-prone areas in the United States.
Blame its topography: steep hillsides and layers of soft, slippery shales and claystones.
But add in record rainfall and wildly fluctuating temperatures, and the result has been an onslaught of landslides.
“We’ve got a lot of landslides, more than we’ve had in several years,” said Reed Kiger, a supervisor for Franklin Township, Greene County. “I couldn’t begin to tell you how many we’ve had. Every day we find a new one somewhere. We’ve just had so much rainfall.”
Currently, in the Pennsylvania Department of Transportation’s District 12 – which encompasses Washington, Greene, Fayette and Westmoreland counties – there are approximately 250 locations where roadways are affected in some way by landslides, according to Valerie Petersen, PennDOT spokeswoman.
Last year was the wettest year on record for most of Southwestern Pennsylvania, and the region is off to a wet start this year.
“We have not had three days in a row of dryness since mid-December,” said Shannon Hefferan, a meteorologist with the National Weather Service is Pittsburgh. “There just has been no time for the ground to dry out.”
Landslide damage, along with road repair and mitigation efforts, cost PennDOT and municipalities throughout the region millions of dollars annually.
Kiger said a slip at Liberty Street, probably caused by heavy rainfall, will cost approximately $250,000 to repair.
According to PennDOT, crews in Washington County can spend more than 3,500 hours on slide repair in the summer.
Southwestern Pennsylvania’s changing climate makes it likely damaging landslides and flooding will continue.
Dr. Chad Kauffman, an earth sciences professor at California University of Pennsylvania, pointed to the National Climate Assessment report, released in November, which indicates the region will experience increases in total precipitation during the winter and spring, and an increase in heavy rainfall.
“There can still be dry years and drought, but there is a growing compendium of information that the Northeast is on an upward trend toward precipitation,” said Kauffman. “Not only is the region getting wetter, but the intensity and rate of rainfall seems to be increasing. The challenge for us is we live in complex regions with unique geography, dense populations and complex drainage patterns. It presents a whole host of challenges.”
According to the report, by 2035, the Northeast is projected to be more than 3.6 degrees Fahrenheit warmer on average than during the pre-industrial era.
Other factors contribute to landslides and flooding in the region. Among them: increased development and destruction of natural areas.
Municipalities are adapting, and addressing how to manage rainfall and slides that impact drainage and sewer systems.
Peters Township implemented a stormwater management program several years ago, and the municipality regularly replaces aging storm sewers and makes sure the pipes are adequately sized.
“We are, like everyone else, constantly addressing the special problems that arise as a result of the increase and intensity in the amount of rainfall,” said Paul Lauer, Peters Township manager. “It’s not only the amount of rainfall, it’s actually the way the rain falls. We have more intense storms over a short period of time, and the existing infrastructure gets overwhelmed. It is a challenge.”