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The I-94 project to include a massive drainage tunnel on Detroit’s east side

Online Niel November 8, 2024

The I-94 upgrade project means rebuilding a roughly 7-mile section of the freeway through Detroit, but before more of the project can begin, the Michigan Department of Transportation plans to build a tunnel.

It’s not a tunnel for cars, trucks and SUVs, though.

No, this part of the project is about drainage.

Adam Wayne, MDOT’s I-94 senior project manager, called it one of the “critical pieces” that must be built before roadwork can begin in an upcoming phase from Burns (west of Gratiot) to Barrett Avenue ( east of Conner). Wayne, who has been with MDOT for about eight years, replaced longtime project manager Terry Stepanski, who retired.

MDOT plans to begin construction on a drainage tunnel in 2026 before moving on to road and bridge work on a roughly 2-mile stretch beginning in 2028 or 2029. MDOT, which has filed a series of lawsuits in the Circuit Court of of Wayne County in recent weeks, requesting temporary construction easements to access nearby properties for grading, scheduled an in-person community meeting to outline details and gather feedback. The meeting is set for 6-7:30 pm Thursday at the Wayne County Community College District Eastern Campus, 5901 Conner Ave.

The 14 ½-foot-diameter tunnel would be 50 to 80 feet underground. It will capture, retain and then discharge stormwater from service roads and highways to the Conner Creek Combined Sewer System, Wayne said, noting that the project was driven by the City of Detroit’s Stormwater Ordinance.

The road project itself would mean more stormwater runoff because of the additional impervious surfaces, but Wayne said the tunnel project is expected to reduce stormwater runoff into the combined sewer system by 82 percent.

This should reduce the risk of flooding not only on I-94, but also in some neighborhoods on the east side. Those areas and Detroit’s highways battled flooding during major storms in recent years. Wayne noted there are few “silver bullets” related to flooding, but described the tunnel as a significant investment.

MDOT spokesman Rob Morosi noted that originally the plan was to replace the sewer in the area with larger pipes, but “we were pretty sure that might not cut it to reduce the risk of flooding,” based on what we saw in recent years.

The proposed launch site for mining operations to build the tunnel would be in the area of Cadillac and I-94 to the west. It would be one of two drainage tunnels planned for the I-94 project, the other being built further west. MDOT pointed to a drainage tunnel being built along I-75 as part of that highway’s overhaul as an example of what is planned for I-94.

A video posted by department notes that the I-75 drainage tunnel, which runs 4 miles along the northbound service road between 8 Mile and 12 Mile Roads, can hold more than 25 million gallons of water. The tunnel’s ability to store a significant amount of stormwater during major rain events, giving other areas time to drain into the system, is what should help it mitigate potential flooding.

Wayne said if the combined sewer system is over capacity, the I-94 tunnel would not discharge into it until the water level recedes.

As mentioned, the Burns to Barrett section is only one piece of the overall project. Including the drainage tunnel, the cost of this section is estimated at 540-570 million USD. The total cost of the project, from east of the I-96/I-94 interchange to east of Conner, has been estimated at more than $3 billion, although officials say it’s difficult to put a total price because funding isn’t currently dedicated. to him. The time frame for the rest of the project is also unclear.

The overall project, which has been in some phase of discussion and planning for years and has seen the replacement of numerous bridges to date, has generated some controversy in the past over the width of the highway, which is set to increase from three to four . strips. However, the department opted to effectively maintain the current footprint, moving from sloped hills at the edges to retaining walls.

Although space for four lanes would be included in the Burns to Barrett section, they likely won’t be used until more of the highway is rebuilt to prevent congestion, Wayne and Morosi said.

The intention is to maintain two lanes of traffic in each direction during construction, with closures limited to specific cases, such as to accommodate utilities.

This portion of the project is also expected to have seven bridge reconstructions and a newly constructed non-motorized bridge near Conner for Iron Belle Trailaccording to Wayne. Previous bridge work for the I-94 project includes the Second Avenue Bridge, the first grid-tied arch bridge in the state, which was built off-site and moved into place. the current position across the highway in 2022.

Contact Eric D. Lawrence: [email protected]. Become a subscriber. Submit a letter to the editor at freep.com/letters.