August 2023 Minneapolis Central City Tunnel Project Update

Via an August 7 e-announcement from the City of Minneapolis:

Project Overview

The City of Minneapolis Public Works Department is constructing a new parallel storm tunnel, enlarging a portion of the existing storm tunnel, and constructing a new tunnel access in Downtown Minneapolis.

The new tunnel is being constructed parallel to the existing tunnel located under Washington Ave S between Nicollet Mall and Chicago Ave. The existing tunnel under Chicago Ave between Washington Ave S and the Mississippi River is being expanded to handle the increased stormwater capacity. The purpose of this project is to reduce pressure in the existing tunnel, provide more room for future growth, and to reduce the need for future repairs and tunnel failures.

Project Map

Latest Project News

Mississippi River Portal

• Crews continue to work on lining the existing storm tunnel at the Mississippi River with concrete. Excavation will resume later this fall when they can access the storm flow again.

2nd Ave

• Crews continue to work on lining the new parallel storm tunnel under Washington Ave from the new tunnel access shaft in the southbound lanes of 2nd Ave S, just north of the Washington Ave intersection.

Portland Ave

• Crews continue to work on lining the new parallel storm tunnel under Washington Ave from the existing tunnel access shaft at the northeast corner of the Washington Ave and Portland Ave intersection.

Photos Uploaded to Website:

• Visit the project website to see photos of work inside the storm tunnel. https://www.minneapolismn.gov/government/projects/central-city-tunnel/

Tunneling Progress

The project has reached 97% completion with excavation. Crews have removed approximately 67,800 tons of material to date. As noted in the infographic above, this is equal to the weight of 6.7 Eiffel Towers. The final excavation will occur next winter. 

Lining progress

In July, crews continued to work on the concrete tunnel lining pouring about 1,000 cubic yards of concrete. To date, 6,800 cubic yards of concrete have been poured. As noted in the infographic to the left, this is just over two times the volume of an Olympic swimming pool. This process is approximately 41% complete.

Long-term closures/restrictions

• The north westbound lane, bike lane, and parking lane remains closed on Washington Ave between Portland Ave and Park Ave. These closures will remain in place until the project is completed.
  • During this closure, pedestrians can still use the sidewalks along Washington Ave.
  • Crosswalks across Washington Ave and Portland Ave will remain open.
  • Bicyclists will share the traffic lane.
  • The existing left turn lane on Washington Ave at the Portland Ave intersection will temporarily become a left turn and through lane.
• Northbound lane of Portland Ave will be periodically closed between Washington Ave and 2nd Closures will happen during the workday only.
  • Closure is for the placement of concrete into the tunnel.
  • East crosswalk across Washington and north crosswalk across Portland will be closed.
  • Sidewalks will remain open to businesses and residences.
• The north sidewalk along Washington Ave remains restricted between Hennepin Ave and Nicollet Mall.
  • During these restrictions, pedestrians share the bike lane on Washington Ave.
  • The crosswalks at the Washington Ave intersections of Nicollet Mall and Hennepin Ave remains open.

• The sidewalk on the east side of 4th Ave S remains restricted through the end of the project. The dewatering well and pumps are installed in this area.
  • Pedestrians can use the sidewalk on the west side of 4th Ave S.
  • The crosswalk at the Washington Ave and 4th Ave intersection remains open.
  • Access to driveways off 4th Ave S remains open.
• The west sidewalk of Portland Ave south of Washington Ave will remain restricted to pedestrians around the dewatering well and pumps until the project is completed.

• The parking lot and trail near Mill Runs Park has reopened.
  • During the summer, the trail will have flaggers to allow concrete trucks to pull into and out of the work site.
• 2nd Ave S remains a single lane in each direction using the northbound lanes between Washington Ave and 1st St S. Access will be restricted until the project is completed.
  • Access to driveways off 2nd Ave S remain open. There may be short-term access delays while crews move equipment and materials around.

Stay Connected

There are multiple ways to get information including email updates and ongoing stakeholder meetings. Visit the project website for more information and to sign up for project updates: https://www.minneapolismn.gov/government/projects/central-city-tunnel/

Email the project team: info@mplscentralcitytunnel.com

Contact the project hotline: 612-888-9418