Price tag for flood-reduction equipment discussed
Flood reduction for Williamsport’s residents hit hard by flooding in the Grafius Run watershed could grow close to $1 million.
During a third public meeting held by Rettew and the city on Wednesday, the first phase of a flood-mitigation project was estimated at $800,000. That also includes the cost of two self-contained trash racks with mechanical abilities that will remove debris collected during storms on Grafius Run and an unnamed tributary that contribute to periodic flooding
The meeting brought about 20 individuals to the Trade and Transit Centre II building, many of them impacted by the flooding over the years.
One of the trash racks, which are estimated at $400,000 apiece, might be positioned along Freedom Road near the junction with Bloomingrove Road and another would be near Grafius Run at a location to be decided, according to Jeri McClune, chief engineer of water resources for Rettew.
Adam Winder, acting general manager of city Streets and Parks, said the department will continue to rectify flood situations as best it can by manning the backhoe, a green machine that picks out debris and logs and cleans catch basins.
Grafius Run has 100-plus years of history of periodic flooding, said Jim Caldwell, project manager with Rettew.
The drainage area encompasses 3 square miles, or 1,900 acres, he said.
When a 100-year flood event occurs, 7,600 gallons of water flow — per second — from Loyalsock Township downward into the city.
Rettew was hired to look at methods of debris control and ways to increase culvert capacity, recapture overflows and analyze the existing drainage and culvert system.
Regardless, the engineers said that, one day, a storm will exceed the flood-mitigation capacity and there will continue to be overflows no matter what system is in place.
“Water seeks its own path,” Caldwell said.
The purpose of the first phase of the project is to recapture the overflows that occur at the unnamed tributary along Bloomingrove Road and on Grafius Road, he said.
One solution is to build a high point near Bloomingrove Road and stop the water before it goes down the road, onto Grampian Boulevard and Market Street.
The engineers said they want to direct as much water as they can into a culvert near Elmira Street.
For Grafius Run, the water that flows down Highland Terrace would be controlled before it flows south along Elmira Street and into that neighborhood.
McClune said the company appreciated the pictures and videos of flooding events provided by residents.
He noted that rainfall amounts are recorded at Williamsport Regional Airport but they don’t always coincide with larger amounts falling to the north of the city and in the Grafius Run watershed.
For example, according to WeatherUnderground, houses have weather stations throughout the run’s watershed and above it. One station registered rainfall in Hepburn Township, about a half-mile north of the Grafius Run watershed.
During an Oct. 29 event lasting over 24 hours, the watershed recorded 4 inches of rain, which is what can occur on average during a storm happening once every 10 years.
However, the deluge that occurred Oct. 20-21, 2016, brought the watershed 4.33 inches of rain in four hours, which is the average for a storm occurring once in every 200 years, McClune said.
The system has existing culverts that are aged at points along the drainage area and include stone arch and cement that must be analyzed as part of the overall project.
“We’re not solving the problem, totally,” McClune said. “We can lessen and decrease” the problem, he said. “We can’t completely end the problem.”
However, if there is funding to be found, the self-cleaning trash rack would increase capacity by 50 percent by additional walls and the racks pulling up and dumping the debris in the back.
“We met with Loyalsock Township and Lycoming County officials,” said Rebecca Haladay, city engineer.
The anticipation is to hold additional public meetings with flood-mitigation information early next year, she said.