Equalization/Property Description & Mapping


The Equalization Department ensures that the real and personal property has been uniformly assessed across townships and cities within the county. The County equalizes separately personal property, and agricultural, developmental, residential, commercial, industrial, and timber cutover real property. This is done by adding to or deducting from the valuation of personal property and each class of real property in each township and city an amount that will produce a sum, which represents 50% of true cash value.

Real Property

In the residential class, the department uses sales data from a one-year period. Staff directly compares it to assessments to determine whether the residential property class has been equally and uniformly assessed at 50% of true cash value. Appraisal studies are done in the other classes of real property where sufficient sales are not available. In these classes, a random sample is selected to be representative of the entire class of property. Professionals then draw up property record cards, collect the field data and determine the true cash value of each property selected. The studies are then subject to review, audit and change by the Michigan State Tax Commission. The Equalization Department does not determine individual assessments. Instead, the appraisals made by the equalization staff are used to determine the true cash value of an entire class of property.

Personal Property

An auditor conducts audits of a sample of the personal property in each township and city to determine whether the personal property in the respective townships and cities has been equally and uniformly assessed at 50% of true cash value.

Property Description and Mapping

Equalization maintains the parcel related layers in the County Geographic Information System for all parcels in Ottawa County. The staff assigns new parcel numbers, writes new tax descriptions and updates databases including the Property Search. The GIS Department offers standard and custom maps, aerial photos, Ottawa County Plat Books and more.

Other Duties

The department also calculates millage rollback fractions required by law (Headlee, Truth in Assessing, Truth in County Equalization and Truth in Taxation) and provides assistance to local assessing officers and other organizations when requested.