DC CLEAN RIVERS – POTOMAC RIVER TUNNEL PROJECT  

DC Water is advising the public of construction impacts starting on or about the week of May 12, 2025, in the 3500 block of Water Street Northwest near the Capital Crescent Trail, weather permitting. Temporary traffic lane closures, trail detours, and parking restrictions will be in effect to allow construction at the site for a facility to capture and divert sewer overflows to the river. 

The work is part of the ongoing Potomac River Tunnel Project to redirect combined sewer and stormwater during heavy rains through the tunnel to the Blue Plains Advanced Wastewater Treatment Plant. Signage will be posted to detour pedestrians, cyclists, motorists, and workers around the construction area. The Capital Crescent Trail will remain accessible while work is underway.

During this initial mobilization phase, the contractor will construct the following:

• A new trail on the west side of the aqueduct to direct trail users around the construction site area.
• A path on the north side of Water Street to direct pedestrians and bicyclists under the aqueduct.
• Two lanes under the aqueduct: one for trail users and the Washington Canoe Club, and another for accessing the construction site. 

Water Street Northwest Work

• Start Date: Week of May 12, 2025, weather permitting.
• Time: Monday–Friday from 7:00 am – 7:00 pm
• Location: 3500 block of Water St NW
• Traffic Pattern Changes and Pedestrian/Bicycle Detours:
  • Temporary traffic lane closure during non-peak hours, between 9:30 a.m. and 3:30 p.m.
  • Parking restrictions will be implemented on the south side of Water Street, NW in front of the Potomac Boat Club
  • Pedestrian and Bicyclist Detours around the work zone. Flaggers will direct trail users. Please adhere to the flagger's directions and construction signage.
• See the map below for additional details.

Map: The traffic pattern changes begin near the Aqueduct. The Capital Crescent Trail will remain open to users. Parking restrictions will be in place in front of the Potomac Boat Club.

• Commuters and pedestrians are advised to follow signage and flagging personnel directing them through the temporary closures.
• Please plan your travel routes accordingly and anticipate short 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 Capital Crescent Trail site location, DC Water is constructing 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 their frequency from approximately 74 events to four events in a year of average rainfall.

Learn more at: dcwater.com/prt

Contact Us

Project Email: dcpotomacrivertunnel@dcwater.com

Project Hotline: 202-972-1388

DC Water 24-hour Emergency: 202-612-3400