Sustainable and reliable Hatch-designed Chaudière Dam officially opens
In 1998, Public Works and Government Services Canada (PWGSC) began the commissioning of physical investigative studies and engineering feasibility studies for the Big Chaudière Dam, one of the three dams located on the French River in Dokis, Ontario, Canada. The results from the studies, coupled with dam safety reviews performed in 2005 and 2011, led to the consensus that the dam needed to be replaced with a new structure immediately downstream of its existing location.
Originally built between 1910 and 1916, the Big Chaudière Dam consists of two separate water-retaining gated structures each located across one of two channels extending along the North and South sides of a rocky island. Both structures include steel gates that are approximately 12.2 meters wide, hoisted by means of a mechanism housed in a steel superstructure. The South channel structure included two concrete abutments and a single gate, whereas the North channel structure included a single pier and two gates.
“The major concerns with the prolonged use of the dam under its existing state were the aging equipment, the ongoing deterioration of the concrete abutments and sills, significant leakage under the South sill of the existing South dam, and uncertainties related to fatigue stress induced by gate vibrations and possible ice impacts,” explained Fadi Chidiac, Hatch’s project manager.
As a result, in June 2012, Hatch was retained by PWGSC to undertake the overall project development for the replacement of the Big Chaudière Dam. Hatch’s scope of work included design engineering, the completion of construction documents, contract administration, as well as supervision during the construction of the new dam—which was completed on time and budget. With the construction undertaken by EBC Inc., the replacement of the South channel dam began in the fall of 2014 and was completed in September of 2015, while the replacement of the North channel dam began in November of 2015 and was completed in October of 2016.
“We have much to be proud of. Through the implementation of modern public infrastructure, we were able to partner together to achieve common priorities—improving the environment, enhancing safety, and developing the economy—which will benefit future generations to come,” added Chidiac.
Fifteen Dokis First Nation members, as well as ten members from the local community were engaged in the project’s construction. On August 14, 2017 the Government of Canada officially opened the Big Chaudière Dam, where the operation of the new dam will also provide ongoing full-time employment to two members of the Dokis First Nation community.