skip to nav skip to content


John Mercure: Mercurey Rising

Inside the Deep Tunnel

  • (1) | COMMENTS
  • Print

I had a very interesting morning. The photo above is MMSD Communication Director Bill Graffin and me outside the deep tunnel on Milwaukee's near north side.

For almost 20 years the Metropolitan Milwaukee Sewerage District has operated the controversial tunnnel below Milwaukee.  When it rains the tunnel collects overflow sewage and storm water form combined sanitary and storm sewers.  During torrential storms, if the deep tunnel fills up the wastewater is released into local rivers and Lake Michigan.  The Milwaukee Journal Sentinel reports that that were 51 storms last year and only once was the deep tunnel not able to handle the water.

The 28 mile long tunnel is 300 feet beneath the city. It is 32 feet tall and constructed of solid concrete.  It can hold 526 million gallons of wastewater.  It is huge.

Today for the first time since it was completed in 1994 journalists were allowed into the southern section of the deep tunnel.  Four at a time we were taken the 300 feet down to the bottom of the deep tunnel.  It was 80 degrees at the surface and 55 degrees on the tunnel floor.  There was about six inches of water in the tunnel.

Here are a couple of  pictures of us being taken into the tunnel.

This site uses Facebook comments to make it easier for you to contribute. If you see a comment you would like to flag for spam or abuse, click the "x" in the upper right of it. By posting, you agree to our Terms of Use.

Milwaukee, WI

Broken Clouds
Broken Clouds
SW at 13 mph

620 WTMJ