Case Study: St. John's Dam Removal Project, Sandusky River

Summary

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. In addition, the Ohio Department of Natural Resources (ODNR), Division of Water determined that the dam was unsafe and had to be either repaired or demolished. the dam was considered a significant cause of water quality impairment to the Sandusky River, and would be very costly to repair, removal options were explored. 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. Later, the Ohio Department of Transportation (ODOT) also agreed to help fund the project conditioned upon receiving stream mitigation credits for restoration of the dam-pooled area. ODOT, ODNR and the dam owner worked with Ohio EPA and the U.S. Army Corps of Engineers (ACE) to gain approval for the dam removal and mitigation credits. The dam was successfully removed in November 2003. Initial qualitative project results look promising, and the project partners plan to continue monitoring the effects of the dam removal over the next five years.

Background

The St. Johns dam was erected in the late 1800s and bought by the Ohio American Water Company (OAWC) in 1935. OAWC made improvements in 1942. The structure was used to create a reserve water source in the event that the water plant in Tiffin needed supplemental water. ODNR Division of Water inspected the dam in 1999, and ordered OAWC to repair or destroy the dam because of safety issues. The OAWC had the dam evaluated and determined that it would cost $300,000.00 make necessary repairs. In 2003, ODNR Division of Natural Areas and Preserves (DNAP), Scenic Rivers Section, approached OAWC and offered to pay for the removal of the structure through the Scenic Rivers License Plate Fund, conditioned upon ODNR receiving ownership of the structure and adjacent land.

ODNR was granted right of entry to remove the structure in 2003, and received a determination of no jurisdiction for Application No. 2003-00586 (0) from the USACE Buffalo District Regulatory Branch dated January 27, 2003. In this letter, the USACE stated that if all concrete debris generated as a result of the dam removal was removed from the river to an upland location during the same day the dam was demolished, that a finding of no jurisdiction would be warranted.

In March 2003, the ODNR Division of Natural Areas and Preserves (DNAP) employed ODNR Division of Civilian Conservation Corps (CCC) to remove the dam. In May 2003, the CCC breached the dam (removed approximately fifteen feet of the dam on the left descending bank of the Sandusky River). Due to fiscal constraints the CCC program was eliminated in June 2003.

Because ODOT has an ongoing need to provide stream mitigation for past and future transportation projects, ODNR approached ODOT for assistance to complete the dam removal in June 2003. ODOT agreed to participate in the dam removal project, contingent on the regulatory resource agencies (USACE and Ohio EPA) agreeing to allow ODOT use of the St. Johns Dam Removal project as a "pooled stream mitigation area," whereby ODOT would be able to use the resulting stream restoration to mitigate ODOT transportation projects.

To begin the necessary steps to accomplish this task, between March and June 2003 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) on the Sandusky River behind the St. Johns Dam.

Upon completion of the fieldwork, ODOT Office of Environmental Services sought approval from Ohio EPA and the US Army Corps of Engineers-Buffalo District on the establishment of the site as a pooled stream mitigation area. Ohio EPA agreed that the dam removal was a valid stream mitigation project. Thus 79,755 linear feet could be established as mitigation credits, with the possibility of additional "secondary credits."

On August 11, 2003, ODOT submitted the project to the USACE Buffalo District and met with them on the following day to discuss the proposed project as a pooled stream mitigation area. While ODOT did not receive a written concurrence on the project, the USACE-Buffalo District agreed "in concept" to the proposed project being utilized as a pooled stream mitigation area. The final approval(s) and mitigation framework for the St. Johns Dam pooled stream mitigation area will occur directly in the final 404 permit and 401 Water Quality Certification.

Ecological Benefits

Some of the expected ecological benefits that will be gained by completing the project include:

  • Restore this segment of the Upper Sandusky River watershed to free flowing condition, which will facilitate migration of or open spawning areas for aquatic species;.
  • Significantly improve the biological community indices, flow regime, and bed-load transport;
  • Based on the most recent basin study of the Sandusky River (OEPA 2003), the St. Johns Dam "severely impairs the attainment of the designated WWH use... by heavy siltation, limited habitat and lack of discernible flow. The recreational use provided by the St. Johns Dam is not sufficient justification for recommending the MWH use. Biological sampling on the St. Johns Dam failed to attain the designated WWH Aquatic Life use." Removing the dam should improve existing conditions.

Removal of the St. Johns Dam

Final dam removal plans were prepared by ODOT and a contract for the demolition and removal of the St. Johns Dam was awarded by ODOT on October 22, 2003. During the week of November 17, 2003, Mosser Construction successfully completed the demolition and removal of the St. Johns Dam. Representatives of ODOT-OES, ODNR, and The Ohio State University were present for the dam removal. By the end of construction day one, riffle/run complex immediate upstream of the impounded area had appeared (see Figures 1 and 2).

On June 29, 2004, staff from ODNR and ODOT canoed the eight-mile stretch of the former dam pool to evaluate stream morphology and the effects of the dam removal. Staff encountered five new riffle run complexes that had formed naturally under the new flow regime. These initial results are encouraging. A more comprehensive analysis of the effects of the dam removal project will be conducted during a five-year monitoring period, discussed below.

Monitoring Plan

A research team has been assembled to conduct a comprehensive five-year pre- and post-removal study, which has never been done before in Ohio, to see how a formerly impounded river naturally recovers over time. The monitoring team includes: ODNR Divisions of Geological Survey, Natural Areas and Preserves, Water and Wildlife; OSU; and Heidelberg College Water Quality Lab.

  • Primary Mitigation Area - The following will be monitored by ODOT, ODNR, and The Ohio State University within the primary mitigation area.
    • ODNR will collect samples to generate IBI, ICI and QHEI scores at five existing OEPA habitat and biological monitoring sites above the dam and below the dam. The frequency of monitoring will be twice a year over the next five years following the removal of the St. Johns Dam.
    • ODOT will perform QHEI evaluations every two miles on the main stem of the Sandusky River starting at the first riffle downstream of the dam to the riffle located at the end of the dam impoundment. The frequency of monitoring will be once a year on the first, third, and fifth monitoring years following the removal of the St. Johns Dam.
    • ODNR Division of Geological Survey will survey substrate composition and conduct channel morphology analysis for five years after the removal of the St. Johns Dam.
    • The Ohio State University will conduct unionid mollusk inventories at the riffle below the dam and at one of the OEPA habitat and biological monitoring sites above the dam once every year for five years after the removal of the St. Johns Dam.
  • Secondary Mitigation Area - The following will be monitored by ODOT and ODNR within the secondary mitigation area. ODOT would like to reserve the right to request additional linear footage for secondary mitigation areas if the following monitoring indicates a significant improvement in the biology or habitat of the Sandusky River and adjacent stream segments.
    • ODNR will conduct IBI, ICI and QHEI evaluations at an OEPA habitat and biological monitoring site located at the mid point between the riffle at the end of the dam impoundment area and the Indian Mill Dam on the main stem of the Sandusky River twice a year for the next five years following the removal of the St. Johns Dam.
    • ODOT will conduct QHEI evaluations on tributary watercourses with watersheds greater than 1 sq. mi. and HHEI evaluations on all tributary watercourses with watersheds less than one sq. mi. between the St. Johns Dam and the Indian Mill Dam. The monitoring of these streams will be conducted within segments of these streams defined as secondary mitigation areas. All QHEI and HHEI assessments will be conducted on the first, third, and fifth years following the removal of the St. Johns Dam.

The ODNR monitoring efforts will be funded, in part, from state scenic river license plate profits.

Expected Findings

Based on preliminary qualitative evaluations of the mitigation project, it is expected that the dam removal will result in improved water quality and eventual attainment of the Warm Water Habitat designated use in the affected segment of the stream. The project partners are hopeful that this study can be used to help promote additional dam removal projects in Ohio.

Additional Information

For additional information on this project please contact:

Bob Gable, Scenic Rivers Manager
Ohio Department of Natural Resources
Department of Natural Areas and Preserves
(614) 265-6443

Bob Vargo, Scenic Rivers- Northwest OH
Ohio Department of Natural Resources
Department of Natural Areas and Preserves
(419) 981-6319

Donald E. Rostofer, Environmental Specialist 2
Ohio Department of Transportation
Office of Environmental Services (Ecological Section)
1980 West Broad Street, Columbus, OH 43223
(614) 387-3057

Michael Pettegrew, Environmental Supervisor
Ohio Department of Transportation
Office of Environmental Services (Ecological Section)
1980 West Broad Street, Columbus, OH 43223
(614)-466-7102

Special thanks to the Ohio Department of Transportation Office of Environmental Services for providing the information used to compile this case study.

 

Figure 1. St. Johns Dam on the Sandusky River, prior to dam removal

 

Figure 2. Site of former St. Johns dam immediately after dam removal. Note the riffle/run complex that is beginning to form naturally in the location of the former dam pool.