Ann Arbor Local Research

Three mechanisms, only one of them regulated

Floodplain management holds the parcel record and matters where structural work is extensive inside a mapped zone. The two physical mechanisms are separate: glacial clay holds water against foundations and swells, and frost heave adds a seasonal lifting force that southern markets simply do not have. A diagnosis that names only one of the three is incomplete.

Official sources

• Ann Arbor floodplain management
• Ann Arbor stormwater management

Establish the mechanism before choosing a repair

Citywide records cannot tell you your parcel's flood status, how deep your footings sit, or which mechanism is actually moving your foundation. Get the first from the city and the rest from an engineer with no stake in the repair.