Restoring connectivity

Removal of the Ballville Dam began with installation of ice-control structures downstream and notching the dam (right side).

Removing the 105-year-old Ballville Dam in Fremont, Ohio.

By Kurt Keopf and Tucker Fredericksen

Built in 1913, the historic Ballville Dam sits on the Sandusky River in the heart of Fremont, Ohio, previously serving as a source for hydroelectric power generation and later as the city’s water supply. In 2013, the role of the dam was eliminated when the City of Fremont opted to build an off-line, up-ground drinking water reservoir to serve as the primary source of water for city residents and businesses, addressing environmental concerns related to the dam’s deterioration, the associated sea wall, and fluctuating nitrates and other pollutants along the Sandusky River.

The City of Fremont needed to develop a plan for how to address and potentially remove the 407-foot-long and 34-foot-high structure. During the next few years, various studies from state and national agencies analyzed the disposition of the Ballville Dam, and in 2014, Fremont city council passed an ordinance to remove the dam, with city voters approving the decision the following year.

The Challenge

Conversations among local, state, and federal agencies about the future of the 105-year-old Ballville Dam lasted for more than 20 years — to remove or refurbish the dam was controversial for groups, including Fremont residents and officials, wildlife conservation organizations, the Ohio Department of Natural Resources, and the U.S. Fish & Wildlife Service. Concerns were largely on water quality and the environmental impacts that releasing the built-up sediment behind the dam would cause. Others recognized the clear benefits of a free-flowing, newly exposed 22 miles of river and the subsequent positive impact on recreational activities and fish populations.

First, the design and demolition process needed to address the more than 800,000 cubic yards of stored sediment so that the release was structured to minimize the impact on downstream aquatic ecosystems. Additionally, the U.S. Army Corps of Engineers (USACE) concluded that Ballville Dam was collecting river ice that would otherwise accumulate in the City of Fremont and potentially cause flooding.

Lastly, creating an area that was accessible and attractive to the community into the future was a top concern for Fremont.

The Solution

Working in partnership with design firm Stantec, MWH Constructors utilized the design plan for removing the dam and restoring the river to its natural free-flowing form while mitigating the impacts of releasing the sediment. Project goals included improving water quality, managing impoundment sediment, and minimizing ecological impacts.

Previous project success as the construction manager at-risk on the City of Fremont’s Water Pollution Control Center, an upgrade to the city’s wastewater system, led to the city’s selection of MWH Constructors as the general contractor and construction manager for the Ballville Dam removal. MWH Constructors was responsible for deconstructing the dam and seawall, constructing a permanent fence at the seawall site, and managing complete restoration of the riverbank, including seeding, tree and wetland planting upstream and at the dam, and ensuring the project was completed on time and on budget.

Addressing flooding concerns — An initial step in the project was to create an ice-control structure (ICS) that would mitigate the ice control function of the dam once it was removed in order to protect the floodwall and potential flooding in downtown Fremont which is downstream of the dam. Stantec and the City of Fremont worked with the USACE to design and permit the ICS utilizing the USACE’s design guidance document developed by the USACE Cold Regions Research and Engineering Laboratory (CRREL).

Fifteen piers that are 6 feet in diameter and 15 feet on center were installed across a portion of the Sandusky river approximately 200 feet downstream of the dam. These piers make up the new ICS and were installed in the fall of 2016.

Choosing the team — An extensive process was used to select the dam demolition and riverbank restoration subcontractor. A request for qualifications was issued and six contractors responded. The submissions were shortlisted to three contractors, with the final selection process determined by a combination of price and project approach. After review of the proposals, MWH Constructors recommended, and the owner agreed, to award the contract to The Great Lakes Construction Co. (TGLCC).

Notching the dam — The dam was removed in two stages in accordance with the approved U.S. Fish and Wildlife Service (USFWS) Environmental Impact Statement (EIS), beginning with a notch in October 2017 and complete removal of the dam in 2018. The intent of the two-stage removal was to attempt to control the amount of sediment exported from the impoundment over time instead of a sudden large release. The timing of the notching and dam removal was also designed to coincide with historic lower flow times, again in attempt to mitigate the amount and timing of the sediment release.

MWH Constructors led construction of the notch — a 10-foot-deep and 20-foot-wide cut in the dam’s southern side. The notch allowed the river to take its natural course, forcing the water level in the dam’s impoundment to drop. Lowered water levels allowed for dewatering a large portion of the sediment collected behind the dam. This dewatering strategy was included in the construction plan to directly address concerns regarding the release of built-up sediment into the Sandusky Bay and Lake Erie. Using specialized equipment, dewatered sediment was successfully removed from the river channel and incorporated into the restoration efforts above the normal water level.

Removing the dam — In July 2018, MWH Constructors and TGLCC began deconstruction of the Ballville Dam, removing large portions of the dam in phases. Phase one, completed in June, involved establishing safe access and staging for demolition. During phase two, the team enlarged the previously installed notch on the south side of the dam down to bedrock. The balance of the dam was removed from the south to the north. All scour holes were filled and the concrete was processed onsite and used for bank stabilization. Following demolition, the Stantec engineering team gathered post-demolition data and provided the construction team with direction in restoring the river and bank.

MWH Constructors worked closely with TGLCC and the City of Fremont to ensure all aspects of the removal ran smoothly and on schedule. The demolition portion of the project took approximately one month, leaving only a small portion of the northern part of the dam intact, to memorialize the location of the dam. Additionally, a permanent observation platform will be constructed as part of the final restoration.

Riverfront restoration — The City of Fremont envisioned a park-like setting for the new Sandusky Riverfront that included walking pathways, permanent observation decks, and areas for residents to drop in kayaks and canoes. The updated area will bring life back to the riverfront and likely become a highly sought-after spot for fishing in Fremont. Following project completion in 2019, the Ohio Department of Natural Resources plans to study the river to determine the overall environmental impact of the dam’s removal.

As part of riverfront restoration efforts, the project team identified opportunities to reduce landfill waste and repurpose materials. Most of the concrete from the old dam was processed onsite and used to fill scour holes at the bottom of the dam and as fill for stabilizing the bank during restoration. MWH Constructors managed the restoration process of permanent seeding and tree and wetland planting. Approximately 52 acres around the dam and upstream will be reseeded with 9,400 bare root trees, 10,900 live stakes, and 210 containerized trees also planted. The seeding and planting are intended to beautify and stabilize the river bank and surrounding area and develop the wetlands as required by the USACE 404 and Ohio EPA 401 permits. The complete restoration of the river banks and remaining sediment will help manage erosion in the future and fully restore and improve the Sandusky river habitat.

Community engagement — Local interest from past and present Fremont residents ran high throughout the project and specifically during deconstruction of the dam. To address this public interest in a safe way, MWH Constructors and TGLCC built a designated viewing platform near the construction site entrance. Livestream video of the demolition and progression of the project were also posted online.

The multi-phased approach to removing the Ballville Dam proved to be the most efficient, economical, and effective approach to restoring the Sandusky River. Project teams worked together to shape project goals, timeline, and budgets to this deconstruction model, ultimately keeping the project under budget and completed one month ahead of schedule. Following completion in 2019, the area will experience more consistent flow and is expected to be a popular recreational attraction for residents and visitors for years to come.

Kurt Koepf, project manager, MWH Constructors, has 36 years of experience in the water and wastewater industry and has successfully managed numerous water or wastewater treatment projects in Ohio. He works closely with owners and project teams to develop, coordinate, and monitor all aspects of a project. He provides valuable insight into local and regional resources and capabilities.

Tucker Fredericksen, city engineer, City of Fremont, Ohio, has more than 20 years of experience as a civil and municipal engineer. He specializes in design, project and construction management, and planning of the city’s infrastructure systems including water, sanitary, storm, streets, intersections, multi-use trials, and other critical systems.