Jefferson Lake Dam is located in Jefferson County and is part of Jefferson Lake State Park. The dam was constructed to create Jefferson Lake in 1934. The dam impounds approximately 61,600,000 gallons of water and has a drainage area of 7.4 square miles. Jefferson Lake Dam consists of a single 25-foot-tall zoned fill embankment with a 50-foot-wide concrete ogee weir principal spillway that discharges into Rippy Run. The total length of the embankment is 236 feet. The dam also has an 18-inch-diameter concrete pipe lake drain that passes through the west side of the embankment. Jefferson Lake Dam does not have an emergency spillway. Jefferson Lake Dam is classified by the State of Ohio as a Class I dam; namely, a dam that has characteristics in which failure would result in probable loss of life.
The concrete ogee weir principal spillway is severely deficient with regards to discharge capacity. The dam does not currently pass the minimum design flood standard as required in Ohio Administrative Code 1501:21-13-02. Concrete around the principal spillway is deteriorated and in need of rehabilitation. Additionally, the lake drain is no longer functional and is in need of complete replacement.
Preliminary alternatives for the remediation of these problems were considered and a recommended alternative was selected. Based upon the configuration of the existing structure, constructing roller compacted concrete (RCC) overtopping protection on the structure is the recommended alternative for rehabilitation. This alternative will involve construction of a sheet pile cutoff wall on the upstream and downstream slope to support multiple lifts of RCC overtopping protection. The concrete ogee weir spillway will be rehabilitated with patch repairs. Additionally, a new 24-inch-diameter cast iron/HDPE pipe siphon lake drain will be installed and the current 18-inch-diameter concrete lake drain pipe will be grouted and abandoned in place. Construction will begin in Spring 2014 and is scheduled to be completed in September. The total cost of construction is $1.3 million.