Named for the Columbian Cannon Foundry, Foundry Branch is a tributary stream which begins in Tenleytown and goes through multiple DC neighborhoods before entering the Potomac. Ruins of the Foundry Branch Trolley Trestle, which was built in 1896 as part of the streetcar system that carried DC residents from Georgetown to Glen Echo, Maryland, can be seen nearby in Foundry Branch Valley Park. Only street parking is available.

**WARNING: SWIMMING IS PROHIBITED IN D.C. WATERS REGARDLESS OF THE CURRENT STATUS**

Despite its designation as a Class A Primary Contact waterway, the DC Department of Health (DOH) bans swimming in the Potomac River citing the risk of high bacteria levels after rainstorms as the only reason it is considered “unsafe” to swim. The activation of the Clean Rivers Project in DC is expected to reduce system wide combined sewage overflow by 96%, bringing the Potomac significantly closer to a swimmable river.

Water quality standards as well as the methods used to determine pass or fail status vary widely across jurisdictions and monitoring programs. We encourage users to explore the sample data in addition to checking the swim guide status. These data can be viewed through the Chesapeake Monitoring Collaborative Data Explorer, https://cmc.vims.edu/#/home

The description above was copied from or heavily based on Swim Guide, with permission.

More Information

• Swim Guide - Weather and water quality for Potomac River - Foundry Branch and 8,000 other beaches.