At the time of its completion in 1931, Hardy Dam was the largest earthen dam east of the Mississippi. Still the highest dam in Michigan, its impoundment forms a lake with over 50 miles of shoreline, a big draw for tourists. Schnabel personnel began working at the site in 1992 on an embankment stability analysis that included a subsurface investigation and instrumentation installation program.

The semi-hydraulic fill embankment dam and hydroelectric power plant is located on the Muskegon River, about 40 miles north of Grand Rapids. The reservoir has a surface area of 4,000 acres and the power plant has an installed capacity of 31.5 megawatts. Since 2000, we’ve completed over 30 separate tasks at this site, which includes pre-2016 projects completed under the business name of AG&E.

Our tasks have ranged from studies – such as potential failure mode analysis, stability analysis, and FERC Part 12 inspections – to design and construction support for tipping wall replacement, repairs to the upstream sloping slab, development of an instrumentation monitoring system, and the historical review of boils and artesian conditions.

High artesian pressures are a common thread throughout the different projects, requiring subsurface investigations and drilling into the artesian aquifers, and subsequent analyses. Our staff has also completed underwater dive and remote-operated vehicle inspections, geophysical surveys, spill tube risk assessment, a rehabilitation plan for relief wells, and an options study for roadway crest repairs.