The St. Marys River hydroelectric plant is owned and operated by Cloverland Electric Cooperative. The project diverts approximately 30,000 cubic feet per second (cfs) from Lake Superior around the natural falls to the St. Marys River where it generates approximately 30 megawatts (MW) of hydroelectric power. The 11,200-foot-long power canal directs flow to a 1,350-foot-long masonry powerhouse with 74 turbine-generator units.
Barr performed a facility evaluation that included a comprehensive assessment of the facility’s civil, structural, and mechanical aspects (except for energy generation). The objective was to identify issues that could arise over the next 50 years and possibly impact plant operations or present undue risk to the public. We conducted a detailed visual inspection of the powerhouse foundations and superstructures, log boom system, canal walls, embankments, headgates, and gate and maintenance hoist systems. We also reviewed available project documentation and analyses and completed a comprehensive review of the project’s dam safety program. Based on our detailed review, we developed risk-based recommendations for repairs, upgrades, and improvements; detailed cost estimates; and time-based projections for addressing the recommendations.
Barr’s assessment included extensive review of available project documentation as well as in-person inspection of project features by civil, structural, geotechnical, and mechanical engineers. We used a GIS-based smartphone application to document and georegister our field inspection observations.
To safely and efficiently observe and evaluate difficult-to-access features, such as canal walls, elevated portions (e.g., roofing, windows, gate hoist superstructure), and shoreline areas, we used a drone to provide high-resolution video and photo images.
Our team included an architect with historic property expertise to make practical recommendations for maintaining historic structures, specifically the roof, eaves, windows, and doors. We also had a construction estimator with extensive hydropower expertise to help develop realistic cost estimates associated with our recommendations extending over a 50-year look-ahead.