PS Flood Barriers Case Study: Lower Merion Township

Wynnewood, Pennsylvania

Wynnewood, Pennsylvania, is a community located in Lower Merion Township about ten miles west of Philadelphia. Running through the township is Mill Creek, an aptly named river that has helped to power the area’s various mills for more than two centuries. The paper products produced by these mills were used for many of America’s earliest documents and currency. Today, the township is a suburban residential community with nearly 60,000 people and is one of the wealthiest townships in the United States.

In 2005, an intense storm hit Wynnewood, dumping up to six inches of rain in just a few hours, causing flash flooding. It was a rare occurrence, and no one expected it to happen again for decades. But in 2009, a similar storm of the same intense nature struck the area. Again, several inches of rain fell in a short period of time, and flash flooding occurred.

Along with several other important buildings, the township’s sanitary sewer pump station (located on the banks of Mill Creek) was flooded during each event.

Sharing the township’s rich history, the building is more than 100 years old and all of the community’s wastewater gravity lines feed into its pumping station, which in turn sends the sewage to Philadelphia to be treated. Fortunately for residents, crews were on hand during each storm to keep the pumps running, saving the area from a number of environmental and public safety concerns.

While there was no sewer backup as a result of the storms, there was damage within the building, and the township’s engineers (a team from Pennoni) knew they had to do something. “We looked at several different options and manufacturers for flood protection,” says Tom Gourlay, the Pennoni engineer who worked directly with the township’s sanitary and sewer division. “There were a lot of different methods of protection and most involved some sort of locking mechanism or pneumatic system. However, we didn’t want crews to have to run out in the middle of a storm to deploy anything.” Eventually, Gourlay found PS Flood Barriers. “It was the first manufacturer I came across whose product looked and acted like a regular door,” says Gourlay, “and the more I looked at its flood doors and talked with experts, it all seemed too good to be true. To be honest, I was skeptical at first. They told me they had completed another project nearby with the same doors, so I went to see it for myself.”

Pennoni tested the PS Flood Barriers Pedestrian Flood Door with 3.5 feet of water, and the door successfully stayed watertight.

Once Gourlay saw the flood doors firsthand, there was no doubt left in his mind. Pennoni facilitated the purchase of six flood doors from PS Flood Barriers – five single Pedestrian Flood Doors and one paired configuration that included a monorail system. “All of the doors are stainless steel and unbelievably durable,” says Gourlay. “One of our specifications was that the doors needed to pass a 3.5-foot water test, and they passed easily. They are really a unique product.” The doors weren’t the only thing that impressed Gourlay. “On a technical level, the fabrication department did an outstanding job,” he says. “The drawings and submittals, the welds, the calculations – everything was very detailed. As an engineer, I thought it was nice to have them fabricate the door to fit the existing opening rather than the other way around.”

The rest of Gourlay’s team was equally excited by the products from PS Flood Barriers. “I remember talking to the contractor on the job,” Gourlay recalls. “He said that if he ever did another project like this, he would strongly recommend these doors. When you have the person who is installing the doors come to you out of the blue and say that this is an incredible product, you know you made the right decision.”

The project in Lower Merion Township officially wrapped up in 2013, and thankfully, the community hasn’t experienced any intense storms since then. “Everyone feels reassured now,” says Gourlay. “It might be 100 years until the next time we see another storm like those two, but just from feeling the weight of the doors and seeing how they shut, we know we’re not going to have a problem.”