About 80 feet beneath downtown Minneapolis, the Central City Parallel Storm Tunnel adds a new route for stormwater to reach the Mississippi River. The roughly 4,200-foot tunnel runs alongside parts of the older system, increasing capacity and easing pressure on infrastructure that has served downtown for decades. The project has received a 2026 American Public Works Association Public Works Project of the Year Award in the Environment category for projects costing $25 million to $75 million.
Constructing a tunnel beneath active streets also required careful surface planning. Access points, utilities, trees, traffic, and restoration all had to be considered while the underground work moved forward.
Sambatek prepared the shaft siting study to identify three construction access points while limiting utility impacts. Our team also completed the portal site’s tree inventory and survey, developed surface removal and restoration plans, and served as CADD lead for the plan sheets. We finalized traffic control plans, collaborated on drainage junction structure designs, and performed traffic control and SWPPP inspections during construction.
Congratulations to the City of Minneapolis and the full team on this recognition. The completed tunnel strengthens a system that downtown residents, businesses, and visitors depend on during heavy rain.
Project Partners
- City Of Minneapolis | Managing Agency
- TKDA, (CNA Consulting Engineers) | Design & Engineering Consultant
- Hatch | Design &Engineering Consultant
- Sambatek | Design & Construction Support Consultant
- Pciroads | Contractor
