DC CLEAN RIVERS - POTOMAC RIVER TUNNEL PROJECT

Beginning the week of February 24, DC Water will implement temporary traffic changes, sidewalk closures, and parking restrictions in the 2900 block of K Street Northwest to locate and mark underground utilities for the Potomac River Tunnel (PRT) Project. Crews will dig a series of test holes, work that is expected to continue for approximately 4-6 weeks, pending inclement weather.

To minimize the disruption to traffic and the surrounding neighborhood, the excavation activity will take place during midday between the morning and evening rush hours. The process, known as potholing, involves creating a series of small holes to identify water, electrical, gas, fiber optics, and other underground utilities in preparation for construction.

DC Water’s contractor will be building a diversion facility at this site. The facility will be used to redirect wastewater from existing sewer lines to help manage high volume flows during heavy rains instead of sending the overflow of untreated wastewater into the Potomac. The underground facility includes a complex series of structures including a diversion chamber to hold the wastewater, an approach channel, and drop shaft.

The PRT is a 5.5 mile long, $819 million project as part of DC Water’s Clean Rivers initiative and will help improve the health and water quality of the Potomac, a critical natural resource.

While the utility investigation is underway, motorists and pedestrians are encouraged to follow directional signage and detours. The site will be restored once the work is completed. For additional details, please refer to the maps below.  

K Street, NW (Maps A, B, C, & D) 

• Date: February 24 – March 31, 2025, weather permitting.
• Time: Monday – Friday from 9:30 am – 3:30 pm, non-peak hours
• Location: K St, NW between 29^th St NW and 30^th St NW
• Traffic, pedestrian and bicyclist impacts include:
  • Phased lane closures.
  • Detours for pedestrians and bicyclists around the work zone.
  • Please adhere to construction signage and follow the instruction of flagging personnel.

Map A: K St, NW, temporary pedestrian path closure highlighted in blue

Map B: K St, NW, temporary pedestrian path closure highlighted in blue.

Map C: K St, NW, temporary lane closure highlighted in red.

Map D: K St, NW, temporary lane closure highlighted in red.

Important Information

• Be aware of road signs and flagging personnel directing traffic through the temporary closures.
• 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

The Potomac River Tunnel is the next major phase of the DC Clean Rivers Project. The project will capture wastewater from the existing combined sewer system and direct it to the Blue Plains Advanced Wastewater Treatment Plant. The project is needed to reduce sewer overflows into the river and to comply 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.

During heavy rains, the system may exceed capacity and release this untreated wastewater into the Potomac River, increasing water bacteria levels, harming aquatic life, and increasing trash in waterways. An estimated 654 million gallons of sewer outflows currently enter the Potomac in a year of average rainfall. The tunnel project is expected to reduce the amount of sewer outflows into the river by 93% and reduce the frequency from approximately 74 events to four events in a year of average rainfall.

For more information

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