MANSFIELD — A $1.2 million seepage mitigation project at the 73-year-old Clearfork Reservoir dam will cost another $110,200 to purchase required “wetlands credits.”
The Mansfield Board of Control approved the expense Tuesday at the request of city engineer Bob Bianchi.
“We have 0.91 acres of Category 2 wetlands that needs to be filled in as part of the project,” Bianchi said. “Thus, we have to purchase 1.9 wetlands credits at a cost of $110,200.”
A wetland credit is a unit of trade used to offset ecological losses that occur in waters of the U.S., which are regulated by the EPA or the U.S. Army Corps of Engineers.
They are purchased to satisfy environmental mitigation permit needs prior to impacting wetlands or waters.
The money will go to The Nature Conservancy, an environmental organization that protects “nearly 65,000 acres of Ohio’s lakes, forests, rivers and rolling hills,” according to its website.
The money helps the conservancy create and protect additional wetlands.
In explaining the need for the project in 2021, Bianchi told Mansfield City Council that water has been seeping under and through portions of the dam since the 1970s. He stressed there was no threat to the dam’s soundness.
“There is no potential problem right now,” Bianchi said. “This is to prevent a potential problem. The dam is functioning as intended and we have no concern for any major problems.”
The project, which requires permits from the Ohio EPA, the U.S. Army Corps of Engineers and the Ohio Department of Natural Resources, will install a filter berm covering about two acres, according to Bianchi, stopping the flow of water through the soil.
The earthen dam, built in 1949, created the 4.4-billion gallon reservoir that supplies the majority of the city’s water.
Bianchi said in 2021 the city had not been able to procure grant funds for the work and money for the project will come from the city’s water fund, allocated in the annual budget.
According to the website damsafety.org, all dams have some seepage as the impounded water seeks paths of least resistance through the dam and its foundation.
Seepage must, however, be controlled to prevent erosion of the embankment or foundation materials or damage to concrete structures, according to the website.
