ANN ARBOR – City officials and residents gathered Tuesday morning in the Amtrak Station parking lot on Depot St. to kick off the start of the longstanding Allen Creek Railroad Berm Project.
More than a dozen years in the making, construction on the $9.4 million project could start as early as next week, weather permitting, said construction manager Robb Welch.
The project was first pitched in 2006 as part of the city’s flood mitigation plans. The original goal of the project was to improve the water quality in the Allen Creek drainage area that flows into the Huron River.
“The railroad berm in this area is perpendicular to the overland flow of the floodwaters and that creates flood depths during heavy storm events of up to 10 feet,” said Welch, a senior civil engineer with consulting firm Fishbeck. “During flood events, the rainwater sweeps across the adjacent city streets and flushes into the Huron River contaminants from automobiles, heavy metals and other chemicals.”
Once the city learned it would be possible to ‘poke a hole’ in the railroad berm to convey floodwaters, it added the goal of creating a pedestrian tunnel that would connect the downtown area with the Border-to-Border Trail north of the tracks.
The current lack of access to the Border-to-Border Trail from the downtown area causes pedestrians to engage in dangerous trespassing behavior over the tracks, said Welch.
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Over the next several months, crews will be installing three separate culverts under the the railroad lines, two of which will convey floodwater and one of which will be the pedestrian tunnel.
“As part of the project we’ll also be installing a brand-new 48-inch sewer that will convey the water from Depot St. into the new wier that we will construct adjacent to the storm culverts,” said Welch. “This will convey all of the stormwater over the surface streets into the Huron River.”
Welch said in total, construction crews will excavate approximately 13,000 cubic yards under the tracks to install the culverts and utilize 214,000 pounds of steel to reinforce the culverts, retaining wells and pedestrian bridge.
If all goes to plan, the project will be completed in late September.
“This is an event that is a long time coming,” said Ann Arbor Mayor Christopher Taylor. “We are so grateful here in the city to have a visionary population, willing to look for projects that can be and having an outstanding staff up and down the line who are able to make it happen.”
Taylor said that the city is funding about 45% of the project, while 55% is coming from other sources, namely the Michigan Federal Emergency Management Agency, Michigan Department of Transportation, Southeast Michigan Council of Governments and the Michigan Department of Natural Resources.