Ark. Code Ann. § 14-17-210

The county planning board shall have the exclusive zoning and planning jurisdiction over all unincorporated areas lying within a county and along a navigable stream notwithstanding the fact that such areas may be within five (5) miles of the corporate limits of a city having a planning commission if the unincorporated areas are lands upon which a new community has been or is being developed with funds guaranteed, in whole or in part, by the federal government under Title IV of the Housing and Urban Development Act of 1968 or under Title VII of the Housing and Urban Development Act of 1970.