Central City Tunnel System Construction
The City is planning to construct a new stormwater tunnel in Downtown Minneapolis. The new tunnel will be parallel to the existing tunnel located under Washington Avenue between Nicollet Mall and Chicago Avenue and under Chicago Avenue between Washington Avenue and the Mississippi River. The new tunnel will increase stormwater capacity and will reduce possible safety hazards and failure of the existing stormwater tunnel.
The project is currently in the design phase and includes community outreach activities to inform the public on project schedule and staging. The final design for the parallel tunnel is anticipated to be completed in early 2021 and construction is tentatively scheduled to begin in late summer/early fall 2021.
Recommended design concept
The new tunnel will be constructed parallel to the existing tunnel 70 feet under Washington Avenue between Nicollet Mall and Chicago Avenue and under Chicago Avenue between Washington Avenue and the Mississippi River.
Two tunnel access points will be constructed for tunnel access and construction staging. The proposed access points are located at 2nd Avenue, north of Washington Avenue, and at Mill Ruins Park near the Mississippi River (see project map above).
Most of the tunnel work will occur underground and will have minimal impact on properties. Work around the tunnel access locations will have above ground impacts.
The current tunnel is unable to support the increasing volume of stormwater, functions under high pressure, and needs repair. A new stormwater tunnel will reduce pressure in the existing tunnel and provide capacity for future growth. The two tunnel access points will be constructed to provide access for workers and equipment to dig the new parallel stormwater tunnel.
Tunnel fractures caused by pressurized water in the tunnel
Ice buildup in the tunnel caused by groundwater leaking through cracks
Anticipated project schedule (subject to change):
- Spring 2019 - Early 2021: Design phase
- Late summer/Early fall 2021: Construction tentatively begins
Anticipated traffic impacts (subject to change): Construction of the new tunnel will occur underground, except at tunnel access locations. Traffic impacts will likely include closure of a parking and/or traffic lane in a one block area near each of the access points.
- July 21, 2020: A virtual open house was held to provide information, current status, and next steps of the project.
Joe Klejwa, Engineer; 612-673-5608 or [email protected]
- Project phone: 612-888-9418
- Project email: [email protected]
Last updated Aug 5, 2020