MNRF Response to Cooper Pond Dam Incident
Dear Christine Condy,
Thank you for your detailed correspondence regarding the recent events at Cooper’s Pond Dam and their potential impact on Three Mile Lake and surrounding properties.
We acknowledge the seriousness of the concerns raised, particularly in relation to water quality, infrastructure damage, and community safety. Your observations and historical context are noted and appreciated.
I would like to take this opportunity to share with you some additional information that may be helpful to better understand the context of the situation.
The Ministry of Natural Resources (MNR) owns the dam on Cooper’s Pond. The structure is a non-operating dam, originally constructed to support wildlife management and to promote duck habitat.
Over time, a beaver dam became established on top of the MNR dam structure causing upstream water levels to rise above intended levels. As part of regular maintenance of the dam structure, MNR initiated a project to remove the beaver dam and associated debris to allow the dam to function as intended.
In advance of the beaver dam removal, MNR confirmed that the culvert under Windermere Road was free of obstructions.
On Wednesday, October 15, 2025, a contractor hired by MNR removed a portion of the beaver dam from the MNR dam structure.
On Thursday, October 16, 2025, MNR conducted a site visit and confirmed that the culvert under Windermere Road was functioning as intended.
On Saturday, October 18, 2025, MNR received an email indicating that Wonder Beach Road (downstream of Windermere Road) was covered by water.
On Monday, October 20, 2025, MNR returned to the Cooper’s Pond Dam and placed sandbags in the breach of the beaver dam on top of the MNR dam structure to reduce the flow of water from Cooper’s Pond and alleviate downstream impacts.
The immediate issue of water flowing over Wonder Beach Road appears to be addressed for the time being. MNR intends to continue releasing water from Cooper’s Pond in a controlled manner to gradually lower water levels ahead of winter. This approach is intended to reduce the risk of uncontrolled release of water and support infrastructure resilience through the seasonal transition.
The drainage route from Cooper’s Pond into Three Mile Lake remains unchanged. Water leaving Cooper’s Pond continues to pass over the MNR dam structure and flow downstream under Windermere Road, under Wonder Beach Road, and into Three Mile Lake. While the volume of water may have increased temporarily, the natural flow path of the watershed remains unchanged.
Windermere Road, which falls under the authority of the District Municipality of Muskoka, has a culvert that appears to have managed the recent increased water flow without issue.
Wonder Beach Road, which is situated within the municipal road allowance, has two culverts that form part of the drainage route from Cooper’s Pond into Three Mile Lake. One culvert has completely failed and is in a severely deteriorated state. The second culvert appears to be structurally sound and in good physical condition, but the installation of the culvert is limiting its ability to effectively convey water through the site.
Based on current observations, the root cause of water overtopping Wonder Beach Road appears to be the failure of water management infrastructure located on municipal property. The Township of Muskoka Lakes has informed MNR that, although Wonder Beach Road is situated on municipal property, it is not maintained by the Township.
Local property owners have shared that Wonder Beach Road regularly floods during the spring snowmelt and believe the culvert was damaged by heavy trucks this summer.
MNR Biologists are actively involved throughout the project to help assess ecological impacts, guide mitigation efforts, and support informed decision-making. MNR consulted with the Ministry of the Environment, Conservation and Parks (MECP), who advised they do not expect any adverse environmental impacts and do not need to regulate the water release from Cooper’s Pond.
MNR has also met with representatives from the Township of Muskoka Lakes to discuss next steps and explore collaborative solutions to help remedy the situation and reduce future risks.
Please be assured that your message has been received and is being reviewed by the appropriate teams within the Ministry. We understand the importance of maintaining open communication with affected communities and stakeholders, and we are committed to ensuring that all relevant information is considered as we continue to assess the situation.
At this time, MNR is coordinating with internal and external partners to monitor conditions and support the continued drawdown of water levels at Cooper’s Pond. This work is being carried out with consideration for downstream impacts, infrastructure concerns, and ecological factors.
Thank you for reaching out and sharing your concerns.
Sincerely,
Adam Wakefield
District Manager | Bracebridge-Minden-Parry Sound District
Ministry of Natural Resources | Ontario Public Service
705-773-4236 | adam.wakefield@ontario.ca