Located on the Lake Michigan shoreline, the Ludington Pumped Storage Plant has been called one of the world’s biggest electric batteries. The 1,872-megawatt hydroelectric facility generates sustainable energy. Water pumped from the lake is stored in a manmade 842-acre upper reservoir and later released to generate electricity at peak load hours. The reservoir is enclosed by a 5.5-mile long, earthfill embankment.

Soon after initial operation, water leaking from the reservoir caused hydrostatic overpressures to develop beneath the asphalt liner, causing uplift, bulging, and deformation of the liner. The owner installed a wellpoint system to relieve the pressures and to pump water from beneath the asphalt liner. The portion of the wellpoint system above the liner was subject to ice damage and was not able to prevent additional deformation of the liner.

Schnabel began site investigations and engineering analyses to determine the location of the leak(s) and the mechanisms of the liner deformation. Our team designed a sub-liner trench drain with redundant pumps to replace the old wellpoint system and intercept leakage. We also designed a vibrating-wire piezometer monitoring system to monitor the effectiveness of the drainage system after construction. During construction, our personnel provided engineering oversight, full-time observation, quality assurance, and documentation of the work.