Pennsylvania DCNR Warns Heavy, Rain Flooding Boost Risk of Landslides

Recent heavy rain and flooding has increased the danger of landslides on moderate to steep slopes, according to scientists in the Bureau of Topographic and Geologic Survey in the Department of Conservation and Natural Resources (DCNR).

"Landslides could be an issue in areas not otherwise susceptible to them, particularly in central and eastern Pennsylvania," DCNR Senior Geologist Helen Delano said.

Delano noted mountainous areas with steep slopes are the places with the greatest possibility of shallow mud and debris slides, and rock falls.

"Emergency and property managers and local officials, and any property owners with steep slopes should be aware of the potential for landslides," Delano said. "Periodic inspections of slope conditions on and adjacent to critical infrastructure, as feasible, are recommended during and after periods of the heavy rainfall."

Movement of shallow landslides is most likely to initiate during periods of intense rainfall, but movement of deeper landslides may be delayed as water pressure in pores in rock rise in response to the rainfall. 

Delano noted motorists should watch for rocks and debris and downed trees on roads, or collapsed pavement or guard rails along roads, particularly on roads that border steep embankments.    

Near a stream or channel, residents should be alert for any sudden increase or decrease in water flow and for a change from clear to muddy water. Such changes may indicate landslide activity upstream, and indicate a need to quickly move away from the area.

Some tips should you anticipate or encounter a landslide:

  • Quickly move out of the path of the landslide.
  • If escape is not possible, curl into a tight ball and protect your head.
  • After a landslide, stay away from the slide area. There may be danger of additional slides.
  • Notify local emergency officials.
  • Check for injured and trapped persons near the slide, without entering the direct slide area. Direct rescuers to their locations.

SOURCE Pennsylvania Department of Conservation and Natural Resources