Why Remove the Dam?
Spanning six counties, the Olentangy River is noted for its scenic beauty and diverse wildlife, including fish, mollusks, insects, migratory birds, beavers, otters, and raccoons. In recognition of the river’s value for people and wildlife, the Ohio Department of Natural Resources designated a 22-mile stretch of the Olentangy— from the Delaware Dam to Wilson Bridge Rd.— as a State Scenic River.
However, as the river flows south into heavily populated Franklin County, human impacts become more obvious. Runoff from storm sewers, sanitary sewer overflows, and a series of lowhead dams all affect water quality and natural habitat. In particular, the area around the Fifth Avenue Dam, just south of the Ohio State University Campus, fails to meet EPA water quality standards.
At 8 feet tall and 470 feet wide, the Fifth Avenue Dam is the largest of 10 lowhead dams on the river. Upstream of the dam, the river forms a deep stagnant two-mile long pool in an area where it should naturally flow in a series of riffles and smaller pools. This ponding behind the dam decreases the river’s ability to assimilate organic wastes from urban runoff and combined sewer overflows. Higher temperatures and lower dissolved oxygen levels in the pool negatively affect fish and aquatic insect populations.
Constructed in the mid 1935 to provide a source of cooling water for the OSU power plant, the dam no longer serves any function. In fact, it creates a safety hazard for canoeists and kayakers, as evidenced by a 2008 drowning at the dam. Lowhead dams are nicknamed “drowning machines” because they form a hydraulic current that traps the victim against the base of the dam and makes rescue difficult.
For all of these reasons, the 2003 Watershed Action Plan for the Lower Olentangy recommended the dam’s removal. If the dam were removed, Columbus would join a growing national trend which recognizes that dam removal results in cleaner rivers and increased public safety.