Ann Arbor Celebrates Virtual Grand Opening of Allen Creek Berm Stormwater Mitigation Project 

​The City of Ann Arbor today debuted a new video featuring Mayor Christopher Taylor, as a virtual commemoration marking the official grand opening and completion of construction on the $9.4 million Allen Creek Berm Project, capping the largest stormwater management and flood mitigation project in city history.

“I’d like to welcome you to this virtual grand opening of our Stormwater Smart campaign’s Allen Creek Berm project,” Taylor says in the video.“This is an incredibly exciting municipal project, multimillion dollar, years in the making. It addresses two really important municipal goals: stormwater and flood protection mitigation as well as promotion of nonmotorized transportation,” the mayor adds.

The city produced the 90-second video instead of holding a traditional ceremony due to COVID-19 pandemic. The video includes aerial drone footage and additional video that highlight the project’s landscaping and safety improvements. For example, the Allen Creek Berm tunnel pedestrian pathway, in combination with new fencing, for the first time, provides nonmotorized users safe passage under the Amtrak railroad tracks.

“Residents, for years, have wanted to be able to get to Kerrytown and downtown via the amazing Border-to-Border Trail, in a way that’s awesome,” the mayor says.

In addition, the project’s massive new culverts — which measure roughly 200 feet long, 12 feet wide and 7 feet high — will eliminate or greatly reduce flooding risk for dozens of properties on or near Depot Street along the Huron River, said Brian Slizewski, the city engineer who oversaw the construction.

“We’re effectively lowering the floodplain from 10 feet to 3 1/2 feet, so depending on exactly where the property is, the chances of flooding will be reduced by at least 70%,” Slizewski said, adding that any flooding will also be less severe.

With the stormwater culverts complete, the city has submitted documentation to the Federal Emergency Management Agency (FEMA) requesting a change in the floodplain map in the Depot Street area. That process, which is expected to take at least two months, will remove several houses and businesses from the floodplain, eliminating their need to purchase flood insurance or potentially reducing their premiums because of the lowered flood risk.

Under the previous configuration, once the belowground Allen Creek drain reached its capacity, flooding resulted when the railroad berm would block overland flow from reaching the Huron River — a problem that was corrected with the culverts’ installation under the tracks.

Construction on the Allen Creek Railroad Berm project got underway in March, nearly 13 years after city officials proposed the project in the city’s flood mitigation plan.

Now it’s a highlight of the city’s new Stormwater Smart education campaign. The campaign supports Ann Arbor’s commitment to developing forward-thinking, data-driven strategies, embracing today’s advanced technology tools and celebrating the efforts of citizen-volunteers to ensure the city’s stormwater is managed effectively.

The project will also help the city meet the goal of its recently adopted A2 Zero initiative for achieving communitywide carbon neutrality by 2030.

The Allen Creek Berm project is funded with grants from FEMA, the Michigan Department of Transportation, SEMCOG and the Michigan Department of Natural Resources, to make this project possible.