Barr has been assisting the RWMWD with repair and rehabilitation of the Beltline and Battle Creek stormwater tunnel systems for more than three decades. Constructed in 1925, the Beltline interceptor captures stormwater from two watersheds through a system of tunnels around 34,000 feet in total length. The Battle Creek system, built in 1982, conveys stormwater flow under the creek via 4,500 feet of tunnels.
Our inspectors, certified by the National Association of Sewer Service Companies (NASSCO), provide regular inspections of the tunnels. In 2015, we conducted a five-year inspection and condition assessment of the entire Beltline and Battle Creek storm tunnel systems. Using a NASSCO PACP inspection approach, we documented structural and operational/maintenance defects. We then used a coding system to assign numerical scores to condition defects based on their seriousness. Observations and defects were catalogued by location IDs linked to station numbers and clock position. Tunnel segments were then evaluated by condition ratings to identify and prioritize those most needing repair.
Barr then developed a rehabilitation design for approximately 16,000 feet of tunnel, including repair details and quantities. We also provided bidding and construction administration and full-time, on-site construction observation. Conducted in two phases over two years, the $4 million project was completed in 2018. The next five-year inspection is scheduled for 2020.