Repairs to Whitehouse Lake Dam: Fid-Bau Portal

Repairs to Whitehouse Lake Dam

Gregory, Garry H. / Richards, Stephen R.

Whitehouse Lake Dam is a 15.2-m (50-ft) tall earth fill dam located in Smith County, Texas, near the small community of Whitehouse. The dam is owned by the nearby City of Tyler, Texas, and is a primary source of water supply for the city. The dam was constructed in 1948–1949. During a routine site visit in June 2012 to observe some undermining of the concrete spillway, significant seepage was observed on the downstream toe area of the dam, with indications of critical internal erosional piping that could potentially put the dam at risk of failure. A design team was quickly formed and began interactions with the Texas Commission on Environmental Quality–Dam Safety Program. An extensive site exploration was conducted, and instrumentation was installed and monitored frequently during the design of remedial measures. The site exploration and instrumentation confirmed the internal erosional piping. Extensive analyses were performed including finite element seepage analyses and 2D and 3D slope stability analyses. A soil-cement-bentonite (SCB) cutoff wall approximately 915 m (3,000 feet) long and up to 25 m (80 feet) deep was designed to reduce the seepage, along with repairs to the spillway and compaction grouting of critical areas. Construction was completed in early 2015 at a cost of approximately $8 million. The repairs resulted in a large reduction of the seepage to very acceptable levels. Continued monitoring of the instrumentation indicates that the safety issues related to the seepage have been fully remediated. The observational method was used throughout this project.