1.   Permitted Principal Uses.

      A.   Agriculture and agricultural buildings except as provided by paragraph 2(A) of this section and provided that livestock shall not be housed or fed within 2,640 feet from the runway centerline and runway thresholds associated with Runways 18/36 and 13/31.

      B.   Single-family detached dwellings on lots of 20 acres or more.

      C.   Essential services as defined in Section 165.01.

      D.   Transformer stations and booster or pressure regulating stations, without service yard or storage.

      E.   Publicly owned airports – Washington Municipal Airport.

   2.   When Authorized by Board of Adjustment.

      A.   Lots for confinement and feeding of livestock subject to controls of surface run-off and located as follows:

         (1)   The area under the Approach Surface extending beyond Runways 18 and 36: 2,640 feet.

         (2)   The area under the Approach Surface extending beyond Runways 13 and 31: 1,320 feet.

         (3)   The area under the Transitional, Horizontal or Conical Surface: 1,820 feet from the runway centerline associated with Runways 18 and 36; 1,570 feet from the runway center line associated with Runways 13 and 31.

      B.   Orchards, tree farms and vineyards.

      C.   Permanent ponds.

      D.   A single-family detached dwelling located on a lot or parcel which is less than 20 acres as long as the lot or parcel upon which said single-family detached dwelling will be constructed was:

         (1)   Part of an original lot or parcel that totals more than 40 acres; and

         (2)   The original lot or parcel was occupied by, and owned or beneficially controlled, by a lineal descendant or ancestor of the beneficial owner of the original lot or parcel as defined in Section 450.9 of the Code of Iowa.

   3.   Permitted Accessory Uses.

      A.   Buildings, structures, and uses accessory to agricultural uses including roadside stands, selling produce grown on the premises, provided such roadside stands are located not less than 20 feet from a street or highway right-of-way line.

      B.   Private garages or parking areas.

      C.   Living quarters of persons employed on the premises.

      D.   Home occupation as defined and regulated by Section 165.23.

      E.   Signs as regulated by Section 165.21.

   4.   Height Regulations. No principal structure shall exceed two and one-half stories or 30 feet in height, and no accessory structure shall exceed 15 feet in height, except as provided in Section 165.24.

   5.   Lot Area, Frontage and Yard Requirements. The following minimum requirements shall be observed subject to the additional requirements, exceptions and modifications in Section 165.24. Each lot shall contain a minimum area of 20 acres, except as allowed by the Board of Adjustment subject to paragraph 2(D) of this section.