So, what purpose do these tubes located between 40th and 42nd Streets serve? Agility course for Clifford, the dangerously large red dog? Real-world, super-sized Super Mario level? Something else entirely?

Turns out it's the last one.

The tubes will aid in the construction of enormous underground tanks to house water after extreme rain, MnDOT spokesman Dave Aeikens tells us.

"They will hold a slurry that will be used to create the space for the outer walls of the tanks," he says. "The tanks are concrete and will be 80 feet deep and hold 4.5 million gallons."

In a word? Dang.

Work on the tanks will pick up in April, Aeikens says, with crews toiling 24 hours per day, five days per week. It'll be complete in three years. Above ground, things should return to normal along I-35W between downtown and crosstown late next year, thus completing the four-year construction adventure.

Take us out, Willie.

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