The Riley County Subdivision Regulations apply to the subdividing of property within the unincorporated portions of Riley County that are outside of the Urban Area Planning Board Boundary.  Property that is divided into smaller parcels (with the exception of agricultural exempt tracts or tracts larger than 20 acres) are subject to the regulations.  These regulations were originally adopted in 1974 and they were last amended in July of 2000.

Property located inside the Urban Area Planning Board Boundary falls under the jurisdiction of the Manhattan Urban Area Subdivision Regulations.

The Riley County Zoning Regulations govern the use of property in the unincorporated areas of Riley County. Agricultural uses of property, as determined by the Planning & Development Department, may be exempt from the regulations. The Board of County Commissioners, following the required public notice and hearings, originally adopted the current regulations in 1974. The regulations were last amended in June 2006.  Copies of the Zoning Regulations are also for sale in the Planning & Development office.