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Trent-Severn Waterway National Historic Site of Canada

Dam Replacement at Lock 37

Parks Canada will work in partnership with others along the canals to foster recreation, tourism and economic development in innovative ways that will contribute to local economies.

What is the Dam at Lock 37?

Bolsover Dam is located at Lock 37 on the Trent-Severn Waterway – a part of what is known as the historic Talbot section. The relatively unchanged appearance and operation of this section of man-made canal between Lake Simcoe and Balsam Lake is one of the main reasons that the Trent-Severn Waterway is designated a National Historic Site.

The dam at Lock 37 is a mass concrete gravity structure with a height of 12.3 m (maximum at the piers) and length of 68 m. The difference in water levels (head) between upstream and downstream of the dam is approximately 6.7 m. It was built in 1902-1903 and was identified for replacement as part of ongoing asset monitoring and recapitalization programme on the Trent-Severn Waterway. 

What will the new dam look like?

Many factors are being considered in determining the design of a new structure including safety, operation, cost, policy, and the importance of this section of a national historic site that Parks Canada works hard to protect. Parks Canada will use modern construction techniques to improve the structure and ensure its longevity for future generations, while also striving to maintain the look of this culturally significant landscape. 

What will the work entail?

The construction phase will include: removal of the existing dam, construction of a new dam in the same location, and all associated works to facilitate the construction including the installation and removal of two cofferdams one above and below the dam. This work also involves establishing a flow diversion system, the salvage of historical operational features, and de-mobilization including removal of the cofferdams, flow diversion system and all associated temporary ancillary works that facilitate the construction effort.

It is anticipated that the project could take approximately 2 years of construction to complete. 

What will construction mean for visitors and area residents?

Construction may affect visitors by limiting services and restricting their access to the site. Public safety is a primary concern for the Dam at Lock 37 project. Parks Canada will communicate with residents and stakeholders to ensure that they are aware of project details and timelines. 

Marking sure it’s done right:

Due to the magnitude and cost of this project there has been a complex series of actions taken, including: an Environmental Assessment; a Cultural Resource Assessments; consultation with Natural Resources Canada has occurred and property surveys made; Parks Canada has obtained permission under the Navigable Waters Protection Act (NWPA) to make changes to the navigable approach at Lock 37 Bolsover.

Public safety is a priority for Parks Canada. Our directive for this type of infrastructure provides guidance on dam safety and follows safety guidelines developed by the Canadian Dam Association. A dam assessment report received in 2006 advised that if dam failure were to occur, it would do so in the form of water flow piping under the existing dam and, therefore, the likelihood of catastrophic failure of the dam was minimal.

Parks Canada has taken action to protect the public by increasing surveillance, developing response plans and modifying operations during winter conditions to mitigate any safety concerns. An additional detailed engineering assessment of the dam was undertaken with the aim of determining the level of risk to the public and to develop options for the replacement of the dam structure. Since that time, Parks Canada has been actively working toward the construction of a replacement dam.

For more information please contact: 705-750-4900