Rehabilitation of Five High-Hazard Dams

Various Locations, Pennsylvania

Michael Baker successfully brought five high-hazard dams into compliance with Pennsylvania Department of Environmental Protection safety regulations. Services included geotechnical investigation and design, instrumentation, seepage collection, drainage improvements, spillway replacement, articulated concrete block (ACB) and roller compacted concrete (RCC) embankment overtopping protection, as well as concrete dam stabilization.

To rehabilitate Dutch Fork Lake Dam, Michael Baker offered geotechnical design of a primary spillway and chute with passive anchorage dowels to replace a failed chute base slab breached during Hurricane Ivan. The dam required spillway replacement and overtopping protection given that the dam could not convey the design event.

Kyle Lake Dam was constructed in 1910 and creates Kyle Lake, a recreational facility. Michael Baker evaluated the dam's spillway capacity and overtopping protection during the design event and determined that an ACB protection system was most cost-effective.

The Canonsburg Lake Dam required installation of passive dowels and 24-strand post-tensioned anchors to improve the stability of an existing concrete gravity dam and lake dredging. The dam was built in 1943 to create a water supply for ALCOA's Canonsburg Forging Plant during World War II and is currently used recreationally. The Canonsburg Dam received the national 2012 Water Supply Project Merit Award by the Environmental Business Journal.

Donegal Lake Dam was constructed in 1967 and creates Donegal Lake. Michael Baker determined that an RCC protection system was required. The team developed options to replace the outlet works in the control tower, including the reuse of the structure while incorporating a dewatering valve and aluminum stop logs.

To rehabilitate Lake Somerset Dam, Michael Baker developed an innovative concept to partially reconstruct a 25-foot-high by 1,500-foot-long earthen embankment to use existing materials for internal dam drainage, reduce internal cracking, control exit gradients and manage underseepage from both a pervious alluvial foundation and dipping fractured sandstone formation.