Open Space Valuation
In accordance with Section 10-155 of the Property Tax Code (35 ILCS 200/10-155), in all counties, in addition to valuation as otherwise permitted by law, land which is used for open space purposes and has been so used for the three years immediately preceding the year in which the assessment is made, upon application under Section 10-160, shall be valued on the basis of its fair cash value, estimated at the price it would bring at a fair, voluntary sale for use by the buyer for open space purposes.

Land is considered used for open space purposes if it is more than 10 acres in area and:

Is actually and exclusively used for maintaining or enhancing natural or scenic resources
Protects air or streams or water supplies
Promotes conservation of soil, wetlands, beaches, or marshes, including ground cover or planted perennial grasses, trees and shrubs and other natural perennial growth, and including any body of water, whether man-made or natural
Conserves landscaped acres, such as public or private golf courses
Enhances the value to the public of abutting or neighboring parks, forests, wildlife preserves, nature reservations, sanctuaries, or other open spaces, or preserves historic sites

Land is not considered used for open space purpose if it is used primarily for residential purposes.

Application Process

The person liable for taxes on land used for open space purposes must file a verified application requesting the additional open space valuation with the Chief County Assessment Officer by June 30th of each year for which that valuation is desired.
If the application is not filed by June 30th, the taxpayer waives the right to claim that additional valuation for that year.
The application shall be in the form prescribed by the county and contain information as may reasonably be required to determine whether the applicant meets the requirements of Section 10-155.
If the application shows the applicant is entitled to the valuation, the Chief County Assessment Officer shall approve it; otherwise, the application shall be rejected.
Applications can be filed through our Smartfile E-Filing Portal
How to file an open space application through Smartfile

When any portion of the land described on any application filed under Section 10-160 is no longer used for open space purposes, the person liable for taxes on that land must notify the chief county assessment officer, in writing.
The person shall pay to the county treasurer, by the following September 1st, the difference between the taxes paid in the three preceding years as based on a valuation under Section 10-155 and what the taxes for those years would have been when based on the valuation as otherwise permitted by law, together with five percent interest. If this difference is not paid by the following September 1, the amount of the difference shall be considered as delinquent taxes.