Access Shaft Interior, I-35W Stormwater Storage Facility, Minneapolis
The I-35W Stormwater Storage Facility in Minneapolis is an underground concrete cistern built to hold runoff from the surrounding highway corridor before it's released into the municipal storm sewer system. Structures of this type are cylindrical, poured-in-place concrete chambers reinforced with steel rebar, designed to reduce peak flows during heavy rain and limit flooding downstream. Access shafts like this one allow crews to reach the interior for inspection and maintenance, with steel stair towers bolted in place to reach the working platforms below grade. MnDOT built the facility as part of broader stormwater management improvements tied to the I-35W corridor through Minneapolis.
Photo taken in February 2022.



