History:

Part of MMSD's $3 billion Water Pollution Abatement Program that began in 1977, the Deep Tunnel System emerged as the most cost effective solution to reducing overflows. It took two years to design the tunnels and nine years to build the 19.4-mile-long system. It went "on line" in late 1993 with 1994 being the first full year of operation.

McKinley Beach and Lake Shore

Cool Facts

Building phase one of the tunnel system required the removal of more than 250,000 truckloads of waste rock.

The excavated Rock was used for creating Summerfest Island in Milwaukee, reconstructing McKinley Beach, and shoreline protection along the lakefront.

Phase one of the tunnel system holds 405 million gallons. If you filled railroad tank cars with the same volume, it would take two trains stretching from Milwaukee to Chicago to contain all that water.

At the peak of phase one construction, 1,000 construction workers were employed. 600 engineering personnel worked during the peak of design.