A new underground stormwater infiltration system on the U-M campus will help protect university buildings from potential floods while benefiting the environment and city of Ann Arbor.
The system will be constructed under the lawn area between South State Street and Angell, Tisch and Alumni Memorial halls, where the painted steel sculpture “Orion” is currently displayed.
The infiltration system will reduce the likelihood of flooding at Tisch Hall and other university infrastructure beyond a 100-year, 24-hour storm event, will free up capacity in the university’s and city of Ann Arbor’s stormwater systems, will reduce flows to Allen Creek Drain, and will replenish groundwater.
Construction will begin after commencement and is scheduled to be completed this fall. The project is phased to avoid interference with the Ann Arbor Art Fair and minimize impacts on pedestrians and parking.
An east-west pedestrian route between the Diag and the front of the U-M Museum of Art will be maintained. The north-south pedestrian route along State Street will vary and on-street parking closures will be temporary. When completed, the project area will be restored and “Orion” will be reinstalled.
The project supports U-M’s sustainability goal to protect Huron River water quality by minimizing runoff from impervious surfaces.
“The new system will improve water quality by removing stormwater flows that may contain sediment and nutrients that would otherwise flow to the Huron River and ultimately Lake Erie,” said John Kosco, senior environment, health and safety professional with U-M’s Department of Environment, Health & Safety.
The infiltration system can accommodate approximately 750,000 gallons of water at a time, which equates to 1.75 feet of water covering a football field.
Water will flow through an underground chamber that is designed to remove sediment and other potential pollutants, which will help to protect groundwater and maintain the functionality of the system. The infiltration system consists of concrete arches with a hollow bottom atop a gravel base that allows water to soak into the ground.
This Central Campus stormwater system follows other stormwater-management initiatives that U-M has completed to benefit campus and the community, such as rain gardens, green roofs, porous surfaces, and infiltration or holding basins.
“This project aligns well with the university’s broader goal of sustainability,” said Branko Kerkez, assistant professor of civil and environmental engineering. “By proactively building stormwater solutions that reduce flooding and improve water quality, the university can play an important role in being a pivotal community member and watershed steward.”
The project is being managed by Facilities & Operations’ Architecture, Engineering and Construction. The estimated cost of the project is $4.5 million. Funding will be provided from Utilities resources and investment proceeds.