The boring of the 8 km (5 mile) Deep Rock Tunnel in Fort Wayne, IN concluded in July as the tunnel boring machine (TBM) named MamaJo broke through.

The Associated Press reported tunneling for the combined sewer overflow (CSO) tunnel began in February 2019.

The tunnel connects with 14 neighborhoods, storing and transporting sewage during heavy rain and reducing overflows into local rivers.
MamaJo’s tunnel has been the largest part of the project’s scope, Deputy Director of City Utilities Matthew Wirtz said. The 14-year construction endeavor has been decades in the making. The tunnel is slated to be fully operational by the end of 2023.

Once completed, the Deep Rock Tunnel will be able to handle 3.2 million liters (850 million gal) of combined sewage traveling through it each day, city officials said.

The increased sewer capacity is expected to result in cleaner rivers and protect about 45,000 residents and 15,000 properties from basement backups and street flooding. The $188 million investment is expected to serve the city for more than 100 years.

Fort Wayne Mayor Tom Henry talked to us about too much untreated sewage making its way into our rivers in days gone by.

“We all knew that was totally unacceptable, not only from a health perspective but environmentally as well. So we began to look at various initiatives, ultimately the deep rock tunnel was the option that we chose. It’s a very huge project, we knew it was going to take a while, but it was the right thing to do,” Henry said.

MamaJo’s name comes from the first two letters of each of Fort Wayne’s rivers: “Ma” from the St. Marys and the Maumee and “Jo” from the St. Joseph River.

The deep rock tunnel is the largest construction project in the city's history.

The $188-million investment is supposed to have a life expectancy of more than 100 years.