Additional repairs to Wellesley Dam set to begin

Additional repairs to the embankment at the Grand River Conservation Authority (GRCA)’s Wellesley Dam will begin as early as Tuesday, May 20, 2025.

Engineering assessments were completed at the Wellesley Dam throughout April and May to provide recommendations to address the safety and stability of the structure. While emergency repairs were completed quickly following the weather event and high water levels in early April, further repairs to the embankment are required to address dam safety and public safety concerns identified in the assessments. An engineering assessment of the concrete spillway has been completed and the GRCA is awaiting results of this study to determine if additional repairs may be required.

R&M Construction of Acton, Ontario, has been hired to complete the embankment repairs, which are expected to begin on May 20 and completed by early June, weather permitting. To accommodate construction, the pedestrian path on the dam and adjacent embankment will remain closed, and people are reminded to obey all safety signage. Once all repairs have been completed, the discharge gate will be returned to service, and the pond will be filled to its normal level.

It is anticipated that the engineering design, condition assessment and construction required to return the pond to normal water levels may be greater than $100,000. A detailed report on the repairs will be provided to the GRCA board in June.

Following the pond draw down in April, GRCA staff attended the site to move any stranded fish and wildlife. While further negative impacts to wild life are not anticipated, residents are encouraged to report any wildlife in distress to the Province of Ontario.

Background

The Grand River watershed experienced a mixed precipitation event from April 2 to April 3, 2025, including snow, freezing rain, thunderstorms and significant amounts of overall precipitation. Water levels in some river systems were already elevated at the time, due to previous rainfall and snow melt in late March 2025.

The extremely high water levels resulted in damage to the GRCA’s Wellesley and Baden dams, both of which are former mill dams that do not serve a flood control or flow augmentation function as part of the GRCA’s water control infrastructure. In both cases, water either overtopped the dams’ embankments or seeped through the embankments. The high water levels also resulted in the loss of operation of gate discharge equipment at Wellesley Dam. GRCA staff were present at both locations during the weather event and were able to immediately identify the separate occurrences as dam safety incidents, which would impact the stability and safety of these structures. Emergency repairs were initiated, and both sites were stabilized within hours of the dam safety incidents being identified.

Future Studies

For Wellesley Dam, the GRCA will be initiating a future study to complete a comprehensive conditions assessment of the structure and identify recommendations for future work. For Baden Dam, an additional study may be required.

In both cases, the studies would consider the long-term future of these structures that is cost-effective and mitigates risk to the public, the dam structure and the environment. Possible alternatives may include repair, modification or decommissioning of the dams. Any studies related to the long-term future of these structures will incorporate consultation with interest holders, including the municipalities, local community and First Nations.

For more information about the Wellesley and Baden dam safety incidents, please refer the GRCA’s April 17, 2025 news release.

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Media Contacts:

Serena Catania, GRCA Supervisor of Communications and Marketing
Phone (519) 621-2763 x2240  |  Email scatania@grandriver.ca

Lisa Stocco, GRCA Director of Strategic Communications and Environmental Education
Phone 519-621-2763 x2316  |  Email lstocco@grandriver.ca