City of Ann ArborThe City of Ann Arbor conducts annual fire hydrant flushing beginning every spring and continuing on a weekly basis through the fall. This preventative maintenance and inspection ensures the proper functioning of the water system. This map shows progress through the different districts of Ann Arbor.hydrant-flushing-mapengAnn Arbor Data CatalogPublicInfrastructureHydrant Flushing MapDatasetsMichigan--Ann ArborMichiganLast Modified: 2025-09-25