H2O Power confirmed that a partial dam breach occurred at its 27.5 MW Twin Falls facility on the Abitibi River near Iroquois Falls, Ontario, Canada.
No injuries have occurred, and responders are onsite, the company said. “At this time, the risk to the town and surrounding community is low. However, this is a developing situation that we continue to monitor,” a release said.
The Twin Falls Generating Station is a five-unit hydroelectric station that was built in 1922. It serves as a peaking station and controls the discharge of Lake Abitibi. The site is restricted by a maximum water elevation due to flood constraints and a summer minimum elevation to respect navigational constraints. Operation of the station is coordinated with Iroquois Falls GS downstream, which is constrained by a 56.6 m3/s minimum flow limit.
H2O Power had initiated a planned project at the Twin Falls facility to complete concrete repairs for an existing leak in the facility. During the repair work on July 5, the leakage increased, prompting a response. Additional resources were deployed and are onsite actively evaluating and managing the developing incident, the company said.
As part of the response protocols, H2O Power is passing increased water through the Twin Falls facility. This has resulted in increased water levels and flows, similar to what is experienced during typical springtime conditions.
H2O has alerted public officials at the Township of Black River – Matheson and the Town of Iroquois Falls, as well as the Taykwa Tagamou Nation. H2O has also notified Ontario Power Generation and Liberty Power, two generators downstream of the Twin Falls Facility. And regulatory authorities have been notified, including the Ministry of Natural Resources and Forestry, Ontario Northland Railway, and the Independent Electricity System Operator.