Castle Gatehouse, Washington Aqueduct is a pumping station at the Georgetown Reservoir on the Washington Aqueduct in The Palisades neighborhood of Washington, D.C., United States. The building is on the National Register of Historic Places and contributes to the Washington Aqueduct National Historic Landmark.

History

In 1852 the United States Congress authorized the Army Corps of Engineers to construct a water supply for the city of Washington, using the Potomac River at Great Falls as its source. Construction of a 12-mile pipeline began in 1853, and portions of the system began operation in 1859. Little Falls Branch was used as an interim source until the pipeline was completed in 1864. The water was routed to Dalecarlia Reservoir, followed by Georgetown Reservoir.

Improvements to the water system in the late 19th century included the Castle Gatehouse. The gatehouse was constructed at the Georgetown Reservoir to pump water into the four-mile long Washington City Tunnel that led to McMillan Reservoir, completed in 1902. A filtration system was constructed at McMillan in 1905 and this system improved the quality of city water.

Construction of the gatehouse began in 1899. The design was intended to replicate the Corps of Engineers insignia. Portland cement plaster was used to replicate stonework and give the gatehouse an authentic castle appearance.

The gatehouse was added to the National Register of Historic Places on March 13, 1975. It is managed by the Army Corps of Engineers, Baltimore District.

https://en.wikipedia.org/

The castle gatehouse is a rare example of architecture based on a government logo, the so-called “Corps Castle” insignia.

The castle stands atop the entrance to a four-mile-long tunnel that connects with an early bit of public health infrastructure: a Slow Sand Filtration facility on the other side of Washington, D.C.

The castle and tunnel were built as a part of an effort to reduce annual typhoid epidemics that plagued Washington during summertime. Prior to their construction, all tap water in the city was unfiltered, muddy, and laced with bacteria.

Inside the castle, Aqueduct employees can monitor the stream in a little observation pool before it enters the tunnel. At this preliminary stage in the filtration process it’s not uncommon to see marine life like fish and even eels. There’s also a large iron sluice gate that can be dropped down to cut off the flow if maintenance is necessary.

The castle gatehouse is a local landmark that’s loved by locals, even if they aren’t privy to its technical purpose.

https://www.atlasobscura.com/

Free

- It is used as a reservoir

- No visiting