Construction on a new tunnel has just finished in D.C., with the goal of alleviating dangerous flooding during major storms. D.C. Water says construction has been finished on the Northeast Boundary Tunnel. The tunnel has been in the works for six years. The purpose of the tunnel is to reduce water and sewer backups that can then cause major issues on area streets.

Late Breaking News! Commissioning of the Northeast Boundary Tunnel is complete as of today. The tunnel and all related diversion facilities are in service! We will celebrate with the community soon! pic.twitter.com/3iMBc2PuxN

— DC Water (@dcwater) September 15, 2023

The big goal is to prevent flooding on Rhode Island Avenue, where flash flooding in August killed 10 dogs at the now-closed pet day care center District Dogs. The tunnel runs under the street and will add 90 million gallons of storm water storage. D.C. Water says it is the largest component of the Clean Rivers Project. It starts south of RFK Stadium and runs north to Rhode Island Avenue and west to R Street Northwest. The tunnel cost $583 million to construct and runs over 27,000 feet long. According to D.C. Water, it will lead to a 98% reduction in overflow to the Anacostia River. According to D.C. Water, experts say the flooding issues were caused by population growth in the area.