We’re constructing six HUGE underground water storage tanks on the east side I-35W.

On Monday, April 20, crews started pouring the concrete walls of the first drainage tank along I-35W north near 42nd Street in Minneapolis. Plans call for three wall panels to be poured each week until all 48 panels are poured on the six tanks. Crews should complete the walls by September.

Crews will work this year and in 2021 building the tanks. When finished, the six tanks will be able to hold 4.5 million gallons of water (about seven Olympic-sized swimming pools) to reduce flooding on I-35W during heavy rainstorms. During heavy rains, the tanks will capture rainwater, store it and slowly release it into drainage pipes. This will help reduce the chance and frequency of flooding on the freeway. It will also help with MnDOT’s overall goal of making a safer, more reliable and more resilient transportation system.

Crews started work Monday and poured the concrete walls on a storage tank.

Crews use machines the excavate and cut the ground the create space for the concrete walls.

A hydrofraise is a machine that uses rotating blades to cut the ground and remove material.

Rendering of the six water storage tanks that are being installed underground between 40th Street and 42nd Street on the east side of the freeway.