Owner/Client
Ohio Department of Natural Resources
Location
Western Ohio
CEC Services
- Geotechnical Engineering
- Predevelopment Site Investigations
- Site Infrastructure Maintenance/Rehabilitation
- Slope Stability/Retaining Structure Design
- Aquatic & Terrestrial Habitat Surveys
- Clean Water Act, Section 401/404 Permitting
- Threatened & Endangered Species Surveys/Wildlife Surveys
- Wetlands & Waters Delineations
- 3D Scanning
- Topographic Surveys
- Architectural History Investigations
- Construction Services
- Structural Engineering
Owner Objective
The 274-mile-long Miami and Erie Canal once connected Cincinnati to Toledo and was constructed between 1825 and 1845. The historic Six Mile Creek Aqueduct, which carries the canal over Six Mile Creek, was built in the 1840s. The aqueduct lies downstream of Grand Lake St. Marys and carries a significant amount of water from the lake in the canal over Six Mile Creek. The Ohio Department of Natural Resources (ODNR)’s Division of Parks and Watercraft and Division of Engineering work together to maintain, manage, and conduct necessary repairs to this section of historic Miami and Erie Canal Heritage Corridor.
During a routine inspection, it was discovered that the northern downstream wing wall of the aqueduct had toppled into the stream. The ODNR contacted CEC to assist in conducting remedial action planning to stabilize the structure, to design a permanent restoration, and to acquire necessary permits. The aqueduct is a valued piece of Ohio’s canal history and is eligible for inclusion in the National Register of Historic Places; therefore, repair strategies needed to maintain its historic masonry appearance while using modern construction techniques.
CEC Approach
CEC developed a restoration strategy and design while working to obtain permits for both the emergency stabilization and the proposed permanent repairs. The repair strategy was developed using non-invasive investigations, such as ground-penetrating radar and 3D laser scanning, to assess the structure’s integrity. CEC engaged an architect-historian to provide input on repairs that would preserve the historic appearance of the structure and to assist in consultation with the State Historic Preservation Office. CEC’s civil, geotechnical, and structural engineers collaborated on a design that blended modern and traditional materials and techniques. Meanwhile, project permitting required CEC to mobilize in-house biologists specializing in freshwater mussels and endangered bats to relocate and protect these sensitive species.
After the initial wing wall failure, the aqueduct was again jeopardized by back-to-back extreme spring floods that washed away much of the temporary stabilization and further damaged the structure. The ODNR asked CEC to mobilize an around-the-clock emergency response to monitor the structure for signs of failure and to immediately report, if necessary, a structural failure to protect those located downstream from a potentially catastrophic flood. CEC designed a method to:
• Dewater and temporarily re-route the canal flows away from the aqueduct; and
• Restabilize the aqueduct structure, which had been further damaged and was at severe risk of failure.
CEC’s flexibility and responsiveness as these events unfolded kept the complex restoration design, agency notifications, and permitting coordinated and on schedule.
The aqueduct repairs are complete and it now appears as though it never experienced near-failure. In appreciation, the ODNR is placing a bronze plaque near the structure that thanks CEC and the entire project team.
