City of Ann ArborThis map shows the amount of impervious area by parcel that is used to determine stormwater utility fees, as well as what stormwater rate credits a particular site currently qualifies for. Click on a polygon information to see more information. *If this map loads slowly or not at all, try zooming in.*stormwater-impervious-surfaces-and-credits-mapengAnn Arbor Data CatalogPublicEnvironmentStormwater Impervious Surfaces and CreditsDatasetsMichigan--Ann ArborMichiganLast Modified: 2025-09-24