Originally appropriated by Congress in 1853, the conduit was built of brick, stone, and mortar and is 9 feet in diameter. It was the largest single structure involved in the construction of the Washington Aqueduct, directed by Corps of Engineers Lieutenant Montgomery C. Meigs, who also played a role in building a number of other well-known Washington landmarks including the Cabin John Bridge, Arlington National Cemetery and the extension and dome of the U.S. Capitol. The conduit design was based upon the early New York and Boston aqueducts, completed a decade earlier in the 1840’s.

Construction of the Washington Aqueduct. Library of Congress photo. 

Construction broke ground for the conduit in November 1853, with a force of 300 to 400 men at any given time. Labor was intensive but plentiful. The only machine available for construction purposes during that time was the steam-driven hoist. Aqueduct historical reports include mention of a steam-operated rock drill trial, which led to a determination that drilling by hand was far superior and faster.

Water from the Potomac River was first introduced into the conduit in December 1863. The conduit was placed in regular service in July 1864 and thanks to the qualified professionals that have overseen its operations and maintenance throughout the past 159 years, remains a vital component of ensuring that the approximately one million citizens living in, working in, or visiting the Nation’s capital can access safe water, a key component to public health and safety.