The dam was built in 1912 to support fire protection, drinking water and manufacturing needs. Its rehabilitation was necessitated by flood regulations requiring an exponential increase in the dam’s designed capacity. New flood regulations require the dam to pass a probable maximum flood of 107,000-plus cu ft per second—a huge hike in its capacity.

York Water seized the chance to improve other elements, including the original spillway’s lack of underdrainage, the core wall’s foundation on undisturbed earth rather than bedrock and an aging bridge and bascule gate system. A labyrinth spillway built on a roller-compacted concrete gravity section is founded on bedrock and designed to handle significantly higher discharge capacities than the original dam. Other enhancements included an outlet valve tower and advanced seepage- management features. These improvements respected the dam’s historical elements, including its original concrete core wall, which was excavated and confirmed to be intact and structurally sound.

The $40-million project was finished in 22 months, at budget and on schedule.