SI-4E1 (12/1/04 version)
Case Study: St. John's Dam Removal


  • The St. Johns Dam was located on the Sandusky River upstream of the City of Tiffin in Seneca County. The dam was identified in the 2003 Sandusky Basin Report as a significant cause of non-attainment of the designated warm water habitat aquatic life use.
  • The Ohio Department of Natural Resources (ODNR), Division of Water determined the dam was unsafe and had to be either repaired or demolished.
  • The ODNR Division of Natural Areas and Preserves (DNAP), Scenic Rivers Section, approached the owner and offered to pay for removal of the structure through the Scenic Rivers License Plate Fund.
  • Ohio Department of Transportation (ODOT) helped fund the project conditioned upon receiving stream mitigation credits for restoration of the dam-pooled area.
  • ODOT conducted ecological evaluations of the fourteen miles of impounded area (including the main stem of the Sandusky River and the tributaries to the Sandusky River within the impounded area), and 79,755 linear feet was approved for mitigation credit.
  • A research team has been assembled to conduct a comprehensive five-year pre- and post-removal study to evaluate the extent to which a formerly impounded river recovers over time after dam removal.