Low Impact Development Manual for Michigan - OSEH - University ...

Case Study: Ann Arbor District Library,
Mallets Creek Branch
One of the goals of this project was to design a development aesthetically
pleasing to both nearby residents and clients of the Mallets Creek Branch
Library in Ann Arbor, MI, while managing stormwater onsite to help protect
Mallets Creek. Bioswales were also installed in the Mallets Creek Library
parking lot to slow and filter stormwater and increase infiltration prior its
passage to the detention area. To help reach the library’s goal of zero stormwater
runoff, it shares its parking spaces with an adjacent public building to
reduce the amount of impervious surface.
Soil restoration at Mallets Creek Library to enhance vegetation
InSite Design Studios
The existing site consisted of clay soils with a sand seam four feet down.
The bioswales were designed to connect to the sand seam to help with the
infiltration of stormwater.
A mix of topsoil, compost, and sand were added to the bioswales while the
detention area had compost integrated into the parent soil. The bioswales
had a four foot section of the special mix and the detention area had three
inches of compost integrated into the top six inches of parent soil. Amending
the soil resulted in an increased long-term capacity for infiltration in
areas designed to handle stormwater runoff with a goal of zero runoff. In
addition, the amended soil has the ability to support healthy native vegetation
which helps to manage stormwater and reduce maintenance needs.
Case Study Site Considerations
Project Type Soil amendment, green roof, rain garden
Soil Conditions Clay soils with sand seam
Estimated Total
Project Cost
Maintenance
Responsibility
$70,000 (not including green roof)
Bioswale mix was $60/cubic yard
Mallets Creek Branch Library
Project Contact Andrea Kevrick, 734-995-4194
LID Manual for Michigan – Chapter 7 Page 282