Drill-and-blast excavation of Blackwater CSO Tunnel’s path is complete

On Saturday, July 11, the excavation of the underground Blackwater CSO Tunnel was completed with the final drill-and-blast clearing the final feet of the 4,744-foot tunnel path about 100 feet below the Blackwater Creek.

The tunnel’s excavated path now stretches from the project’s construction site at the bottom of 7th Street in Downtown Lynchburg to the CSO 52 site along the Point of Honor Trail just east of Hollins Mill Dam. Drill-and-blast excavation of the tunnel’s path began in March 2025.

The completion of excavation marks a significant milestone for the Blackwater CSO Tunnel project, which is the largest capital improvement project in Lynchburg’s history and the capstone project for Lynchburg’s 45-year CSO program, that will reduce the volume of combined wastewater/stormwater overflowing into Lynchburg’s waterways by 98% since its start.

Next, with partners Stantec and Atkinson Construction, crews will begin to line the interior of the tunnel in order to store up to 4.7 million gallons of excess wastewater/stormwater during heavy rainfalls. Crews are also continuing to construct above-ground facilities, including a diversion structure at the CSO 52 site and a pump station at the 7th Street construction site. The full project is expected to be completed in summer 2027.