Nassau Mills Dam Replacement, Trent-Severn Waterway – Public comments invited from May 19 2026 to June 18 2026  

May 19 2026 – Parks Canada  and Fisheries and Oceans Canada must decide whether the proposed project Nassau Mills Dam Replacement, located in Trent-Severn Waterway National Historic Site is likely to cause significant adverse environmental effects. Parks Canada  and Fisheries and Oceans Canada will be assessing this project using a Detailed Impact Assessment.

To help inform this decision, Parks Canada and Fisheries and Oceans Canada are issuing this notice of intent to make a determination and inviting comments from the public on the project's potential effects on the environment as the public consultation for this proposal. All comments received will be considered public. For more information on the public nature of your comments, individuals should consult the Privacy Notice on the Registry website.

In order to submit comments or request a copy of the draft Detailed Impact Assessment report, contact:

Trent-Severn Waterway National Historic Site

P.O. Box 567

Peterborough, Ontario K9J 6Z6

Email: trentsevern@pc.gc.ca

Comments must be submitted by June 18 2026.

Project Summary: The project is a complete replacement of the dam by a newly constructed sluiceway dam with an expected service life of 80 to 100 years. The scope of work includes phased reconstruction of the entire existing structure downstream of the existing dam. Project activities include, but are not limited to, constructing cofferdams, replacement of the dam, sluices, new stop logs, new decks, operator safety features, railing for public safety, new floating safety boom, landscape and embankment works, commissioning, demolition of the old dam and site restoration.

Scope of Assessment: The Detailed Impact Assessment will assess the impacts on fish and fish habitat, water quality, Species at Risk and Critical Habitat, vegetation, wildlife, Heritage Features, Archaeological Resources, and visitor experience. Through engagement, it will additionally assess potential impact to Indigenous treaty and/or Indigenous rights and interests.