Significant Movements on Crumbling Michigan Hydro Dam

Three movement clusters identified on the 115-year-old Au Train hydroelectric dam, which is overdue for upgrades.

August 29, 2025

In late August, the AP reported on concerns regarding the poor condition of Au Train hydroelectric dam in Alger County, Michigan. For the past 15 years, regulators have expected upgrades to the dam’s structure to meet safety standards

The repairs have yet to take place, raising local concerns about livelihoods and safety. “The top of the dam is pockmarked, with chunks of missing concrete. Streaks of water leak through a seam in the dam,” the report described, adding that should a weather event overwhelm the dam’s capacity and it fail, the torrents of water would likely wash out M-94 highway, a main east-west artery just north of the dam.

This prompted ValueSpace to conduct a satellite-based movement analysis of the Au Train dam. The assessment, based on a 1.5-year data timeline, identified three significant movement clusters on the dam’s structure as shown in the image below:

Movement clusters on Au Train dam identified by ValueSpace’s satellite-based assessment.

  • Two movement clusters located east of the spillway extend across the entire dam structure up to the embankment of M-94 highway and one movement cluster is west of the spillway.

  • All three moving sections exhibit subsiding (downward) movement (indicated by red measurements) and are distinct from the rest of the structure, which remains generally stable (indicated by green measurements).

  • The two clusters east of the spillway exhibit velocities of up to 55 mm (2.1 in) per year. The western cluster has a velocity of up to 23 mm (0.9 in) per year.

Had this assessment been conducted for a client, considering the significant findings, ValueSpace would have recommended that on-site engineers verify the structural stability of the identified dam sections as soon as possible.

Learn more about how satellite-based monitoring and assessment can identify structural weaknesses in dams. Read our recent case study on the failure of the Waxhoma dam in Oklahoma.

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