Northbound Lanes of 14th Street NW Reopen Following Emergency Repairs to Abandoned Sewer Tunnel
Tonight, DC Water has reopened the northbound lanes of 14th Street NW between L Street and Thomas Circle, following the successful completion of emergency repairs to a century-old, abandoned sewer tunnel beneath the roadway. These repairs took place over the past week, ensuring the safety and stability of this critical thoroughfare.
The emergency work focused on filling and sealing an old, brick-lined sewer tunnel that was found to be compromised and at risk of collapse. To resolve this issue, DC Water crews used specialized flowable fill concrete material, which provides superior reinforcement and rapid stabilization. Crews carefully placed 200 cubic feet of concrete into the tunnel over several days, filling 600 linear feet of tunnel to reinforce and stabilize the area beneath the street.
A water main break repair had led to the discovery that the sewer tunnel was not properly filled and sealed when abandoned more than 50 years ago. That prompted DC Water to inspect the tunnel and assess the condition. Using CCTV cameras, the inspection found a 70-foot crack in the crown that compromised the structural integrity. Working in close coordination with the District Department of Transportation, emergency lane closures were implemented immediately out of an abundance of caution and to protect public safety.
DC Water crews worked through the week on a comprehensive stabilization effort and to get the road reopened as soon as safely possible. The repair process involved pouring concrete through existing manholes and creating additional access points to ensure the tunnel was completely filled and sealed. This method provided a reliable and lasting solution to eliminate the risk of collapse and restore the integrity of 14th Street.
We appreciate the patience and understanding of residents, commuters, and local businesses throughout this emergency work. Additional work will continue along 14th Street to address non-emergency work to complete the remaining length of the abandoned pipe but does not require full lane closures.
