In 2023, Fairfax County completed the construction of improvements to aging toe drain infrastructure at Lake Barton, one of the County’s PL-566 state-regulated dams which was originally constructed in 1978. This presentation will provide an overview of the County’s state-regulated dams and PL-566 program, flood warning system, the design and construction lessons learned from the Lake Barton toe drain improvements project, and the County’s future plans for preventive improvement projects on other PL-566 dams. Fairfax County has the maintenance responsibility for 19 stated regulated dams which includes 6 PL-566 dams. The age of these dams ranges from ten to fifty years old which presents a wide variety of maintenance problems including pipe deterioration.
The Lake Barton Toe Drain Repair project began design in 2021 and completed construction in 2023. The plan included a geotechnical assessment of the dam to determine the presence of groundwater in the dam that could be contributing to elevated moisture levels or zones of saturation in the embankment. After the assessment was completed a construction plan was developed to replace the toe drains and piezometers located at this facility. Construction lasted 5 months and the entire rehab including design and construction was approximately $350,000.
