Flooding a Concern Along Icy Pittsburgh-Area Rivers

Mar 3, 2015

Ice flowing under the Roberto Clemente Bridge on the Allegheny River could contribute to flooding along the Ohio River later this week.
Credit Chris Squire / 90.5 WESA

The Allegheny River remains frozen, and there is still ice on the Monongahela and Ohio Rivers, though barge traffic is getting through. Now, with rain forecast for the next couple of days the concern turns to flooding.

“There’s always a threat of flooding, particularly when you have ice and when it starts to move it can jam up in narrow valleys or behind bridges and cause water to rise behind the jam very quickly,” said Lewis Kwett, hydraulic engineer with the Pittsburgh division of the U.S. Army Corps of Engineers.

The National Weather Service has rain in the forecast for tonight and Wednesday, and that is expected to change back to snow showers later in the week. Flood watches have been issued for Tuesday and Wednesday for the Ohio River and areas in Allegheny, Armstrong, Beaver, Fayette, Greene, Indiana, Washington and Westmoreland Counties. Rainfall amounts could also be enough to cause flooding at the Monongahela River Parking Wharf, according to the National Weather Service.

“There is certainly some concern for the navigation industry and there will be some rises that will possibly put some of the lower Mon locks: Lock 4 Charleroi, Lock 3 Elizabeth could be out of service,” said Kwett.

But, all of this is not unusual for late winter and early spring, according to Kwett; so the Corps are ready to handle what the weather brings.

“We’re operating our projects to optimize the response to any flood event,” he said, “but especially with ice on the rivers and even on some of the smaller tributaries people need to be aware that ice jams can cause localized flooding that can be very difficult to predict and can develop very rapidly.”