The Cemetery Brook Drain Tunnel is the centerpiece of Phase II in Manchester's more than $338 million investment to address CSOs and improve Merrimack River water quality. The new drainage system will include a two-mile long, 12-foot inside diameter tunnel, constructed 30 to 80 feet below ground with seven drop shafts along its length to receive flows. The city will also leverage the project to upgrade utilities, rebuild roads, add curbing, sidewalks, crosswalks, bike lanes, and other amenities. About Parso ...