MMSD offers look inside Milwaukee's deep tunnel system

MILWAUKEE (WITI) -- Since it was constructed nearly two decades ago, many of us have heard quite a bit about Greater Milwaukee's deep tunnel system. Wednesday, members of the media had an opportunity to see the deep tunnel system first hand.

After it flows, most of us never see where the water goes. Wednesday morning, folks with the Milwaukee Metropolitan Sewerage District and Veolia gathered for a tour of the deep tunnel system. "It's like going to the doctor for a checkup. You just want to make sure everything's working," MMSD Executive Director Kevin Shafer said.

It's a 300-foot descent via crane that takes about a minute and a half to get into the deep tunnel system.

Inside the tunnel, concrete sections, measuring up to 30 feet in diameter continue for 21 miles, through Greater Milwaukee. "We have the best record that I know of for controlling overflows with our tunnel system," Shafer said.

Shafer says prior to the deep tunnel's construction, the area suffered through 50 to 60 overflows every year. Shafer says since the tunnel was constructed, the yearly average is down to two. "We're still going to have overflows. I'm not going to tell you we're done, but the environment is much better. The rivers and the lake is much cleaner, and our drinking supply is protected much better," Shafer said.

The system's success, Shafer says, is not going unnoticed. "We all need to improve. We keep adding improvements to the system as it matures, but a lot of places in the country are trying to model after Milwaukee," Shafer said.

Shafer said during the massive flooding in July 2010, the tunnel was filled to the brim with 523 million gallons of water from the storm and sewers. Shafer says a system that could handle the flood's volume of water would be cost-prohibitive.