On this episode of Urban Spelunking, Bobby and I head deep beneath the surface of Lake Michigan to Milwaukee's Deep Tunnel pump room. Inside, three massive pumps move water through the 28-mile underground water-storage network, where it awaits treatment before being released back into Lake Michigan.
Access to the tunnel itself is restricted and rarely granted, with routine inspections happening roughly every decade or so. But Milwaukee Metropolitan Sewerage District (MMSD) crews visit the pump room daily to inspect the pumps and the rest of the operation, which is spread across multiple connected rooms.
To get to the pump room, we stepped into a small industrial elevator and descended 320 feet below the surface, a trip that took about three minutes. During our descent, we interviewed Bill Graffin and Dan Wittlieff of MMSD, as well as Andi Kneeland from subcontractor Veolia.