Searsburg Dam and Power Station

Many visitors to the valley, at least those who venture west of the light in Wilmington, have seen this pipeline snaking along the side of the mountains and wondered what it is and what runs through it. There may even be a few locals who aren't quite sure what the mysterious pipleline carries. Speculation on the contents of the pipeline runs from the town's drinking water to a fuel supply line.

The pipeline, or penstock, carries water used to operate a small hydroelectric station on the Wilmington/Searsburg town line. This type of system, in which the dam and generation facility are separately located, is known as a "divided fall facility."

The water is concentrated at small reservoir in Searsburg, located on the road to Somerset Reservoir.

Searsburg Reservoir and Dam

Adjacent to the dam is a small pump house that directs water into the penstock when the hydroelectric station is running.

Pump house

The system was originally built in the 1920s. The penstock is constructed of wood staves bound by metal hoops. The assembly is supported in a wooden cradle that rests on a bed of gravel. The penstock is 8-feet in diameter, and stretches 3.5 miles from the reservoir to its terminus above the power plant.

View showing staves, hoops, and cradle.

A bridge allows access to both sides of the penstock for maintenance

The penstock ends at a surge tank above the generation facility - visible from Route 9, near the Wilmington town line. The surge tank was new technology at the time the station was built. The tank acts like a shock absorber - equalizing the force of the incoming water and protecting the system from potential damage when the turbine gates were closed rapidly. A much larger surge tank is located at nearby Hariman Station.

The Searsburg Station is at the bottom of the photo. Above the station is the "surge tank."

Searsburg station is a 5 mega-watt facility, completed in 1922. When it was built, the facility was the largest fully-automated plant in the United States. It could be operated without an attendant thanks to a time clock that opened the turbine at a certain time, and shut itself down at a predetermined limit. It also was designed to operate based on water height at the reservoir, using an electric float switch.