Enhancing dam safety at Caribou Falls GS
Sitting in the far reaches of Ontario near the Manitoba border, Caribou Falls Generating Station (GS) has been producing clean, renewable hydroelectric power since 1958.
Now, the 92-megawatt station located 66 km northwest of Kenora is undergoing a major overhaul of one of its important block dams to correct erosion. The project is set to be completed this fall.
Caribou Falls’ Block Dam #2 (or “BD2”) forms the outlet of Umfreville Lake, the storage reservoir for the plant. “The purpose of a block dam is to block the water from travelling into other storage areas or old river systems,” said Kris Chartrand, a Project Leader in OPG’s Northwest Operations. “A block dam functions to block water from moving elsewhere for storage, and enables water to be diverted through the GS for power generation.”
In 2014, an irregular slump erosion occurred along the eastern section and upstream slope of the dam. The multi-year project to address this deterioration is tracking on time and on budget. The remediation will ensure BD2 meets all dam safety standards and long-term performance requirements.
Current work involves constructing a new embankment structure that will replace the original block dam. The old block dam will be regraded and covered in riprap, a type of loose stone, to mitigate erosion due to waves crashing into the shore.
“When it comes to the integrity and erosion of a dam, we have to act immediately and make it one of our highest priorities,” said Chartrand. “It's important to finish a project like this in a timely manner with a priority on safety.”