Map showing the diversion facility in orange and yellow, connecting to the existing sewer system in green and the tunnel in blue.

Beginning on or about January 12, 2026, DC Water will begin the next phase of construction for the Potomac River Tunnel Project at the Georgetown University entrance site along the Canal Road NW. Construction activity will impact traffic entering the main campus, but is not expected to impact traffic on Canal Road as the site is located in the wooded area above Canal Road. 

Project Scope and Timeline

At this location, DC Water will construct a drop shaft and an underground facility that connect the existing sewer infrastructure to the Potomac River Tunnel to capture combined sewage and stormwater from overflowing into the river and divert it for treatment. 

Increased construction activity, equipment, and personnel in the area are expected for the duration of the project which is scheduled to be completed in 2030.

• Work hours: 7 a.m. to 7 p.m., Monday through Friday
• Lane Closures: 10 a.m. to 4 p.m., Monday through Friday
• Duration: Through early 2030

What to Expect: Site Mobilization and Preparation

The mobilization phase will last approximately three to four months and includes the following key activities:

• Installing fencing, signage, and safety barriers
• Clearing and securing the construction zone
• Relocation of temporary crosswalk and installation of ADA ramps
• Delivery and hauling of materials
• Protecting nearby buildings and infrastructure
• Installing underground utility protection
• Implementing traffic control measures for vehicles, pedestrians, and bicyclists
• Traffic lane closures and pedestrian/bicyclist detours

Traffic Impacts and Safety Measures

While the Canal Road NW entrance will remain open, traffic will be reduced to one lane in each direction starting the week of January 12, 2026. To ensure public safety and maintain access:

• The primary work zone will be in the wooded area adjacent to and above the University’s Canal Road NW entrance
• The site will be fully enclosed and restricted to the public
• Flaggers will assist in directing motorists, cyclists, and pedestrians
• Clear signage and physical barriers will guide all road users safely around the work zone
• The adjacent sidewalk on K Street NW will be temporarily closed during initial setup, with detour signage in place.

The initial traffic pattern change during mobilization includes sidewalk and lane closures near the entrance. Signs will direct the pedestrian detour and lane shifts. See the maps below of the alternating phases.

Stay Informed

Learn more about the project at dcwater.com/prt or contact our outreach team at dcpotomacrivertunnel@dcwater.com for additional information and to receive advance traffic advisories and the latest project updates. 

We thank you for your patience and cooperation as we work to build a cleaner, healthier future for the District.

Project Details

The Potomac River Tunnel is part of DC Water’s Clean Rivers Project, a long-term effort to reduce pollution in our waterways. Each year, about 650 million gallons of untreated sewer overflows enter the Potomac River and, ultimately, Chesapeake Bay, releasing trash and increasing bacteria levels harmful to aquatic life. The 5.5-mile tunnel system will help capture and redirect this overflow to the Blue Plains Advanced Wastewater Treatment Plant, reducing the volume of overflow by 93% and the number of times this occurs from 74 to 4 in a typical year. 

This work is being completed in compliance with a 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.