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Construction on Timiskaming dam and bridge project begins in 2026

Deadline for public comments on environmental impacts is end of day May 3
(Government of Canada photo)

The federal government plans to replace the Quebec side of the Timiskaming dam and bridge and is taking comments from the public as part of an environmental assessment (EA).

The Impact Assessment Agency of Canada has a federal EA underway and is taking comments up until May 3.

The dam and bridge is situated on either side of Long Sault Island and spans the Ottawa River between Thorne, Ont. and Timiskaming, Que. 

The dam controls the water level in Lake Timiskaming, upstream, and the flow of the Ottawa River, downstream. The structure also controls the last major reservoir on the Ottawa River upstream of the St. Lawrence River at Montréal and provides water storage for hydroelectric generation downstream.

Ontario Highway 63 runs across it as well as a natural gas pipeline.

The original dam complex was built between 1909 and 1913. It's comprised of two structurally independent dams.

The Quebec side of the dam was rebuilt in the 1930s following a foundation failure. The government deems it’s still safe but it’s near the end of its operating life and needs to be replaced.

The Ontario side of the dam and bridge was completed for $32.9 million and opened for traffic in 2016. Now it’s time to replace the structure on the Quebec side of the river.

The government is calling on the public and Indigenous people to comment on any potential environmental impacts they see associated with this project. This EA process began in June 2018.

This is the third of four opportunities for the people to comment on the EA.

Public Services and Procurement Canada said the proposed new structure would include a two-lane roadway and a sidewalk and would regulate water levels on the river. It would be approximately 75 metres long, and have ten bays with vertical sluice gates. 

The construction would take place over 30 months.

In September 2016, the government awarded a $2.39 million engineering design contract to Tetra Tech QI Inc. for the replacement of the Quebec dam. The project’s status is that it’s currently in its design phase. The design work officially begins after the environmental process is done. Procurement Canada said it will then solicit bids for the construction work. 

Construction is expected to begin in 2026 and be completed in 2030.

Comments can be submitted online at the project home page on the Canadian Impact Assessment Registry (reference number 80151). 

Those who wish to provide their input in a different format can contact the agency by writing to

The deadline for comments is 11:59 p.m. on May 3. All comments received will be published online as part of the project file.

There will be virtual information session to learn more about this project and how the environmental assessment project works.

English Sessions:

  • April 19, 2023, from 2:00 p.m. to 3:30 p.m. ET

French Sessions:

  • April 18, 2023, from 6:30 p.m. to 8:00 p.m. ET

More information on how to attend the virtual information sessions is available by visiting the project homepage noted above or by emailing

Stay updated by following on Twitter: @IAAC_AEIC #TimiskamingDamBridge