Anacostia River Tunnel Construction Brings Closure to I-295 Southbound Onramp

September 15, 2016

(Washington, DC) – DC Water is performing construction activities as a part of the Anacostia River Tunnel Project.

Construction will consist of building six shafts along the tunnel to serve as access points for the tunnel and to assist in diverting Combined Sewer Overflows (CSOs) to the Anacostia River Tunnel.

Beginning Wednesday, September 14, 2016 through Monday, February 27, 2017, weather permitting; the I-295 Southbound entrance ramp at eastbound Suitland Parkway will be closed to all oncoming traffic between the hours of 7:00pm at night to 1:00pm the following day. It is advised that southbound South Capitol Street, SE to Overlook Avenue, SE be used as an alternative route for travel to I-295 southbound during the hours of closure.

Important Information:
All traffic lanes on the I-295 Southbound onramp at eastbound Suitland Parkway will be closed from 7:00pm at night to 1:00pm the following day. It is advised that southbound South Capitol Street, SE to Overlook Avenue, SE be used as an alternative route for travel to I-295 southbound.

The entrance ramp will be open only during rush hours daily from 1:00pm to 7:00 pm and closed at all other times.

Traffic will be diverted beginning September 14, 2016 and the ramp will remain closed through February 27, 2017, weather permitting.

Temporary traffic signs will be set up throughout the area to alert motorists of the upcoming closure.

Some traffic delays within the vicinity of the work zones are anticipated.

Noise levels will be closely monitored during construction.

Project Details:
DC Water is constructing the Anacostia River Tunnel, which consists of six shafts located along the tunnel to serve as access points for the tunnel and to assist in diverting Combined Sewer Overflows (CSOs) to the Anacostia River Tunnel. The project will also include diversion and order control structures at 5 locations along the tunnel alignment. This infrastructure improvement is a major component of the DC Clean Rivers Project that will reduce CSOs annually by 96 percent throughout the system and by 98 percent for the Anacostia River alone.

This portion of the project, which includes the I-295 Southbound entrance ramp at eastbound Suitland Parkway closure will allow for retrieval of the tunnel boring machine once it has completed mining the Anacostia River Tunnel and completion of the construction of the Poplar Point Junction Shaft.

###

For more information on the DC Clean Rivers Project, visit dcwater.com/cleanrivers.

Latest News

Tree and debris removal for environmental rehabilitation

Work is nearly complete on the downstream section of the Potomac Interceptor to reinforce the pipeline with geopolymer. The concrete-like material will strengthen and restore the structural integrity of the pipe. Completion of the geopolymer lining downstream is one of the final steps to restore flow to the interceptor and finish the emergency repair.

This comes one month since the last overflow reached the Potomac River.

geopolymer downstream

As emergency repairs continue, today marks 27 days, nearly one month, with no overflow reaching the Potomac River.

Crews are making significant progress to reinforce the downstream section of pipe from the collapse site and completed 240 linear feet of geopolymer overnight. Crews are working to apply another layer of geopolymer today. The material is similar in strength to concrete and when applied restores the structural integrity of the pipe.

photo inside tunnel with geopolymer

Reinforcement of the upstream section of the Potomac Interceptor has been completed, marking the halfway point in emergency repairs following the January 19 sewer line collapse. Crews continue to advance repairs on schedule, with full project completion expected by mid-March.

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Announcement

Map of lane closure
Traffic Advisory: Rock Creek and Potomac Parkway NW Lane Closure Beginning Jan 19

Beginning on or about January 19, 2026, weather permitting, DC Water will implement a temporary lane closure on Rock Creek and Potomac Parkway NW b

Latest Blog Post
A helicopter lowers a drill rig to workers on the Potomac River.
DC Water begins drilling in Potomac River to explore options to rehab underwater sewer line
When one of your major sewer lines runs through the Potomac River, a backhoe and trencher won't do. That's why we've got helicopters carrying a 14-ton drill and workers suspended midair over the Potomac.
Upcoming Meeting
Date
March 11, 2026
Wednesday, 9:30 AM

Upcoming Events

Customer Service Center Announcement

Payment Plan Incentive: provides a credit back of 50% of the last 3 payments made. Eligible participants are residential customers who have had an outstanding balance for 60 days or greater and with an outstanding balance of $500 or more.