Waterpower at Harpers Ferry

George Washington chose Harpers Ferry for a new national armory in 1794 because, he claimed, it possessed an "inexhaustible supply of water." Almost a century later, in 1885, government engineers still described the waterpower at Harpers Ferry in the highest terms, reporting that "there seems to be no reason why a large and fine power could not be utilized here. The site is probably the most favorable one on the river."

The natural descent of the Potomac River here – 22 feet in just over a mile – is considerable. Along the Shenandoah River, the waters tumble 14 feet in just under a mile. Sitting at the point where both rivers converge, Harpers Ferry commands a combined drainage area of 9,180 square miles, a potential maximum streamflow of 8,260 cubic feet per second, and access to 18,350 gross horsepower – enough to attract both millwrights and entrepreneurs for nearly two centuries.

Today, Harpers Ferry National Historical Park offers a unique place to explore the legacy of waterpower in America. Cradled between the free-flowing and often unpredictable waters of the Potomac and Shenandoah rivers, Harpers Ferry still demonstrates the important relationship between man and nature. Park Service archeologists have uncovered remnants of a once robust industrial community: iron gearing, leather belting, tin conveyor buckets, and miscellaneous parts of broken machinery. Armory records preserved by the National Archives are replete with detailed references to troublesome waterwheels, promising new turbine technologies, and the day-to-day particulars of running water-powered machinery. And because the landscape here has been so well preserved, substantial remains of 19th century water works are still visible: brick-lined culverts, extensive headraces, dam ruins, factory foundations, turbine pits, and even abandoned turbines – their wicket gates now closed for good.

Last updated: April 8, 2022

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Mailing Address:

Harpers Ferry National Historical Park
National Park Service
PO Box 65

Harpers Ferry, WV 25425


304 535-6029

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