A. A cluster development is any division of land that creates parcels containing less than thirty-five (35) acres each, for single-family residential purposes only, where the tract is being divided pursuant to a rural land use process and reserves at least two-thirds of the total area of the tract for preservation of open space. No rural land use process as authorized by this Section shall approve a cluster development that would exceed one (1)  residential unit for each seventeen and one-half (17 1/2) acre increment.

     B. As a condition of approving a cluster development, a rural land use process shall require that the cluster development plan to set aside land to preserve open space or to protect wildlife or critical areas not permit development of such land for perpetuity from the date the plan is approved.