Community Update: Replacement of Scotts Mills Dam at Lock 19

Trent-Severn Waterway National Historic Site

February, 2019 - Following an in-depth planning and design process, Parks Canada and partners at Public Service and Procurement Canada will move forward with construction to replace the dam at Scotts Mills Lock 19 this spring. This project is part of over $125M investment in Parks Canada assets in the City of Peterborough, through an unprecedented five year program of infrastructure work across Parks Canada sites.

Engineering inspections have demonstrated that the current dam at Lock 19 is nearing the end of its useful life. The Scotts Mills Dam at Lock 19 will be fully replaced with a new dam that respects the historic look of the site and has a life expectancy of more than 80 years. The new dam will optimize hydraulic capacity, increase the safety of water management operations, and be constructed in a way that allows improved access for maintenance activities. In addition, the project will be the first step in creating a more public friendly lock site, with pedestrian access onto the dam itself restored. 

Why do we need the dam at Lock 19?

Scotts Mills Dam at Lock 19 plays an important role in the City of Peterborough, and is an integral part of the Trent-Severn system. The dam at Lock 19 is one link in a chain of  dams across Ontario that help Parks Canada to manage water, achieving a variety of objectives including navigation, mitigation of flooding, and the protection of the environment. Within Peterborough, the dam helps to regulate upstream and downstream water levels and creates Little Lake, serving the waterside economy and quality of life that Peterborough residents enjoy. 

What has been done to prepare for construction?

Parks Canada has completed significant preliminary assessment to ensure the most appropriate way forward for both the design of the new dam and the implementation of its construction. This has included examining various alternative dam styles, as well as completing investigations that provide the topography of the bed of the river, the depth of bedrock, and information about existing soil and concrete conditions. Significant environmental analysis has included three years of fish spawning and habitat surveys resulting in the completion of improved and expanded fish spawning habitat downstream for walleye and other fish species. This environmental work and subsequent recommendations will be reflected in a draft environmental Detailed Impact Analysis, which will soon be available for public review and comment.

How is this construction project unique? 

The replacement of the dam at Lock 19 holds logistical challenges due to its location in an urban area. To manage this challenge, Parks Canada purchased four properties adjacent to the dam on the west side to use for construction staging. During the project, this space may be used to store materials, manoeuvre machinery, and access the construction site.

Unique to many construction projects on the Trent-Severn Waterway, Parks Canada must maintain an ability to manage water through the dam during construction to mitigate the risk of flooding upstream and downstream of the dam, and within the City of Peterborough. For this reason, the dam will be constructed in phases, and construction will be scheduled to maximize flow capacity during the spring melt.

Parks Canada and our partners at Public Service and Procurement Canada have made every effort to plan a project that reduces impact on the neighbourhood, while balancing the logistic challenges of replacing this structure that is so essential for the protection of people and property. Residents can expect construction noise and increased construction traffic during the project. Parks Canada thanks you for your patience. 

Where can I find more information?

To find additional Questions & Answers and up-to-date news about this or other infrastructure projects in your area, please visit  

To enroll for email updates about the project to replace the dam, please contact us at and include “Scotts Mills Dam” in the subject heading. You will also receive an invitation to a public information session in the coming weeks.

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