MamaJo finishes Fort Wayne’s deep rock tunnel

(Photo Supplied/City of Fort Wayne)

FORT WAYNE, Ind. (WOWO): It took over three years and involved boring through more than five miles of bedrock beneath the Summit City, and on Thursday morning, officials announced that the massive tunnel boring machine nicknamed “MamaJo” had reached her destination.

A 16 foot diameter tunnel that’s nearly five miles long, 220 feet below the surface was built to store and transport sewage during heavy rains, which will protect the three rivers from overflows, benefiting the entire community.

Boring began near Glasgow and Dwenger Avenue and proceeded underground across 14 neighborhoods on both sides of the river, ending at Foster Park.

“I’m encouraged and impressed by the work that’s being done to protect neighborhoods and preserve our rivers through the MamaJo investment,” said Mayor Henry. “Today’s deep rock tunnel accomplishment sends a strong message that Fort Wayne is committed to reducing combined sewer overflows. It’s also vital that we continue to be proactive and innovative in order to be a high-performing city that’s meeting the needs of residents, neighborhoods and businesses now and in the future.”

The Deep Rock Tunnel is the largest construction and public investment project in the City’s history.  The $188 million investment is designed with a life expectancy of  more than 100 years. World renowned construction contractors S.A. Healy/Lane Construction, and Salini Impregilo, partnered to construct the tunnel.  The companies have built deep-rock tunnels in more than 50 countries.

Quick Facts

  • 24,519 feet (nearly 5 miles) of tunnel stretching from Glasgow Ave. to Foster Park
  • 14 million tons (28 billion pounds) of material have been mined
  • When operational, the tunnel will reduce combined sewer overflows by 94 percent
  • The best mining day was January 19th, 2021, with 115 feet constructed
  • The tunnel is 220 feet below the earth’s surface
  • The interior tunnel diameter is 16 feet
  • The tunnel is made up of 4,878 rings; each is made up of six concrete segments
  • 850 million gallons of combined sewage can travel through the tunnel each day
  • MamaJo’s name was created with the first two letters from Fort Wayne’s three rivers: Ma from the St. Mary’s, Ma from the Maumee, and Jo from the St. Joseph


Projects to complete by 2023

  • Six Adits – Connections from the bottom of shaft to tunnel
  • Drop Shaft (DS) #5 (Thieme Drive) under construction completion in September 2021
  • Deep Dewatering Pump Station – Near Water Pollution Control Plant. Will lift flow from tunnel and send it to storage ponds or treatment plant. Construction begins summer of 2021.
  • Consolidation Sewer – Near-surface sewers constructed to collect sewage from several existing sewers to divert it from the rivers and convey it to the drop shaft and on to the tunnel.
    • Consolidation sewers under construction at DS9 – Headwater Park West, DS12 – East Central Park
    • Consolidation sewers in design at DS3 – Brown Street, DS6 – Camp Allen, DS7 – Guldlin Park
  • Restoration work throughout


Please enter your comment!
Please enter your name here