Statement of Intent. This section of the Zoning Ordinance is intended to provide for areas within the city that may be used for agricultural purposes. The lands in the RR rural residential district are expected to be urbanized ultimately in accordance with the general plan. At present, however, these lands provide areas for part-time farming and the keeping of livestock. The minimum lot size is intended to preserve lots in sizes suitable for agricultural use and potential urban development. The following regulations, except to the extent that they may be modified by a combining district, shall apply to every lot and building in an RR rural residential district.