Map: The blue arrows represent the pedestrian detour. Motorists follow the yellow arrows. The bicycle trail remains open.

DC CLEAN RIVERS – POTOMAC RIVER TUNNEL PROJECT

Beginning on or about May 8, 2025, DC Water will begin work to locate and mark underground utilities on K Street Northwest between 29th and 30th streets Northwest. The work, which involves drilling small holes, will require temporary lane and parking closures and parking restrictions.  

This activity is a part of pre-construction work to build DC Water’s Potomac River Tunnel Project and will continue for approximately 2-3 weeks, weather permitting. The temporary closures are to direct pedestrians, cyclists, and motorists around the work zone during the investigation process. 

The contractor will drill a series of small holes, known as potholing, to investigate the locations of underground utilities such as water, gas, electrical, communication and fiber-optic lines. Detours will be in effect until the investigation work is finished, and the site restored.  

While the utility investigation is underway, motorists and pedestrians are encouraged to follow directional signage and detours.

 For additional details, please refer to the map above.  

K Street Northwest (Map)   

• Date: May 8 – May 21, 2025, weather permitting. 
• Time: Monday–Friday from 9:30 a.m. – 3:30 p.m.
• Location: 2900 block of K Street Northwest between 29th Street and 30th Street Northwest 
• Pedestrian Detours: The sidewalk on the north side of K Street will be temporarily closed. Please follow the detour signage. 
• The bicycle lanes will remain open. 

Important Information  

• Commuters and pedestrians will notice road signs and flagging personnel directing them through the temporary closures. 
• Please plan your travel routes accordingly and anticipate potential delays. Traffic control measures will be in place to guide motorists safely through the area. 

Project Details 

DC Water is constructing the Potomac River Tunnel and support structures to capture combined sewer overflows (CSOs), a mixture of sewage and stormwater, and redirect it to DC Water's Blue Plains Advanced Wastewater Treatment Plant. The tunnel will begin operating in 2030. At the K and 30th streets site, DC Water will construct an underground facility to connect to the sewer outfall and direct the overflows to the tunnel.  

The project is needed to reduce overflows polluting the Potomac River and, ultimately, Chesapeake Bay. The tunnel also ensures compliance with the 2005 Federal Consent Decree entered by DC Water, the District of Columbia, the US Environmental Protection Agency, and the US Department of Justice, as amended in January 2016. The tunnel will reduce the volume of these overflows to the Potomac River by 93% and reduce their frequency from approximately 74 events to four events in a year of average rainfall. 

Learn more at www.dcwater.com/prt. 

Contact Us 

Project Email: dcpotomacrivertunnel@dcwater.com  
Project Hotline: 202-972-1388  
DC Water 24-hour Emergency: 202-612-3400