Potomac River Guide Home

Interactive Maps

The Lower Potomac

The Potomac Estuary

Mount Vernon to Anacostia River

Mall Area

Georgetown to Great Falls

Potomac Piedmont

Upper Potomac

The North Branch

Boat Ramps

Monitoring Sites

Bridges and Ferries

Cruises and Charters

Search Potomac Sites

Also Explore

The Hudson River GuideThe Delaware River Guide
NEW! The Connecticut River Guide

Washington Aqueduct

U.S. Army Site

blank dot

Great Falls is the original intake for the Washington Aqueduct, the supply division of the District of Columbia water system. The Aqueduct facilities, built and operated by the U.S. Army Corps of Engineers, bring about 200 million gallons a day out of the Potomac, divert it through two conduits under MacArthur Boulevard, and treat it at the Dalecarlia and McMillan Water Treatment Plants. The original Aqueduct was built in the early 1860s by the Corps, and is still operated by the Corps. The city of Washington was served by a number of wells and springs for the first several decades of its existence.

By 1802, the city was laying wooden pipes made of bored logs for supplying a few houses on Pennsylvania Avenue. But the main impetus for a reliable source of water for the city came from the need for adequate fire protection. Between 1832 and 1850, a number of studies for Congress indicated that springs and wells would not be adequate for the future growth and safety of the city. The British invasion of 1814 and burning of the White House had given evidence enough of that.

Today the Washington Aqueduct is a modern water treatment system suppling water to the District of Columbia and Arlington, Virginia.

Suggested Links

Click here for larger map and nearby sites.

Contact Information
U.S. Army Corps of Engineers
5900 MacArthur Blvd., N.W.
Washington DC 20016
202-764-2753
Website