Washington officials want to redirect a tributary stream that runs behind the American Legion to help mitigate flooding, erosion and potential infrastructure issues.
Carrol Ehrhart, a project manager with the engineering company Skelly and Loy, presented the project to City Council Monday. She said the project will comply with requirements the city needs to meet with its Municipal Separate Storm Sewer System (MS4) permit as well as improve the stream banks, reduce sediment, increase flood storage and protect a sanitary sewer line that runs under the stream.
“The stream will be moved closer to the Legion and their parking lot,” said Lynn Galluze, the city’s computer systems coordinator. “It will have better banks and will help with the erosion.”
One of the main reasons for redirecting the stream, Galluze said, is the fact that there’s a sanitary sewer line that runs through the middle and along the creek bed. Ehrhart said there’s been so much erosion in that stream that the pipe is exposed, and the city is concerned that it could be damaged or compromised if they don’t move the stream, which is a tributary to Catfish Creek.
“You can actually see the sanitary sewer pipe because of the amount of erosion,” Ehrhart said. “If it gets hit by debris, it’s very vulnerable to damage. We have a dual purpose here, because we’re protecting our infrastructure.”
Galluze said part of the project will include excavating a floodplain along the stream that will help reduce flooding downstream.
“Further down the creek there’s an area that always gets flooded, so in doing this it helps the flooding overall, so the water doesn’t end up in the middle of town,” she said. “Everything that we’re doing helps.”
As part of the city’s MS4 permit, they are required to reduce pollution. Ehrhart said that sediment is “the best metric” for reducing pollution and that “stream restoration” is the most efficient way to reduce sediment.
“The intensity of our storms becoming more severe is causing our stream banks to collapse and that creates the sediment,” she said.
The engineering and design of the project is being funded through a $145,000 grant the city received through the state Department of Environmental Protection’s Growing Greener program. Galluze said the city will bid out the construction part of the project and hopefully secure more grants for that portion of the project. The estimated cost of the total project is about $1.3 million.
On Oct. 17, Todd Moses, senior geomorphologist with Skelly and Loy, will present the project to members of the American Legion and answer any questions they may have, Ehrhart said.
“It’s probably going to change the way they use their land a little bit,” Ehrhart said of the Legion’s location at168 Park Ave. “Instead of having that large expansive area that they have to mow and maintain, the stream will move a little closer to them.”