YORK, Pa. — From the Wyoming Valley Levees in northeast Pa. to Indian Rock Dam in southern Pa., heavy rain from Hurricane Agnes put flood mitigation infrastructure to the test across Pennsylvania. Since then, improvements in both technology and infrastructure have been made to help us handle the next storm even better.
Indian Rock Dam in York County experienced it's biggest rainfall event during Hurricane Agnes in 1972. Steve Young, Head Dam Operator for Indian Rock Dam, says the reservoir saw a dramatic increase in water during the event.
“On the 21st of June it was 15.57, the reservoir elevation. On the 22nd of June it was 64.54 feet and rising. So, that’s a dramatic difference," Young says.
The flooding from Agnes was the first and only time Indian Rock Dam has seen spillway flow. While the city of York still experienced devastating flooding during the storm, Indian Rock Dam prevented it from being even worse.
Indian Rock Dam is just one of many flood mitigation projects in place across Pennsylvania. From dams, to levees, reservoirs, and more, there are multiple groups that have flood mitigation at top of mind.
One of those groups is the Susquehanna River Basin Commission (SRBC). Ben Pratt, a Water Resources Engineer at SRBC, says one of the big improvements in flood preparation has come upstream.
“The other thing we didn’t have during Agnes were flood control reservoirs," Pratt told FOX43. "We had some in place, but there were some that were built after Agnes that have had a significant impact in terms of reducing flood risk in parts of the upper Susquehanna.”
From the Susquehanna itself to its tributaries like the Codorus Creek, flooding from Agnes occurred at all levels.
Alex Baldowski, Levee Safety Program Manager at the Baltimore District Army Corps of Engineers, says that Hurricane Agnes was a 1,000 year flood event for the Codorus Creek and much of the surrounding area.
He says that the levees around the Codorus in downtown York were overtopped in many cases during Agnes. This, combined with interior flooding, resulted in the devastating flooding the city experienced.
Since then, Baldowski says a lot has changed around the levees.
“Over the past few years the army corps has received about 15 or 16 million dollars to make repairs to the Codorus Creek project. One of them here is the Penn Street flood wall. It’s almost 600 feet of floodwall replacement and it ties out with the Penn Street Bridge over here and there are other improvements to be made along the way, such as rehabilitating conduits," he says.
Earlier this year, the U.S. Army Corps of Engineers, Baltimore District announced it would receive $62 million in supplemental funding. Some of this funding goes towards the Codorus Creek Project and Indian Rock Dam.
The Wyoming Valley Levee Project also received over $11 million in support of flood risk mitigation benefitting the communities of Plymouth, Kingston-Edwardsville, Hanover, Wilkes-Barre, and more.
In addition to building and maintaining flood infrastructure across Pennsylvania, improving technologies are also a big help these days.
“Our forecasting capabilities 50 years ago are not nearly what they are today. We have access to far more data now and so we’re far more able to understand and predict events like Agnes," says Pratt.
The Susquehanna River Basin Commission has joined forces with the US Army Corps of Engineers and other groups to form the Silver Jackets. The group is an interagency team that comes together to reduce flood risk and damages.
One of those projects is the Susquehanna Flood Warning and Response System. This tool for Wyoming Valley officials and emergency managers provides flood inundation data so they are better able to prepare for flooding at different levels.
It’s a project they hope to expand in the future.
Between improvements in infrastructure, technology, and interagency teamwork, experts say we are in a better position to handle flooding today, though there are still things that need to be done.
“It’s not a question of whether or not it will happen again, it’s really a certainty. Mother Nature will always one up herself, I’ve learned that over my years in the business," Pratt tells FOX43. "And so with that we can certainly expect to see another type of Agnes event, whether that’s next week, next month, or in another hundred years, that’s the question.”