Chapter 11.74
AIRPORT OVERLAY DISTRICT (AOD)
Sections:
11.74.040 Airport overlay districts established.
11.74.050 Development standards.
11.74.070 Application requirements.
11.74.010 Authority.
(1) This chapter is adopted pursuant to the requirements of RCW 36.70A.510 and 36.70.547 wherein counties within which general aviation airports are located and operated for the benefit of the general public, whether publicly owned or privately owned public use, shall through its comprehensive plan and development regulations, discourage the siting of incompatible uses adjacent to such airports.
(2) RCW 36.70A.200 identifies airports as essential public facilities and requires local jurisdictions to provide a process for identifying and siting essential public facilities. The Chelan County zoning maps identify the existing airports located within Chelan County. (Res. 2000-129 (part), 10/17/00).
11.74.020 Applicability.
(1) The provisions of this chapter apply to all lands and all zoning districts lying within the boundaries of the airport overlay districts as shown on the Chelan County zoning maps. Airport overlay districts in Chelan County include lands lying outside of existing city limits incorporating and adjacent to the Cashmere Dryden Airport, the Chelan Municipal Airport, the Lake Wenatchee State Airport, and the Stehekin Airfield.
(2) All land uses, buildings, structures, features, including vegetation, and lighting located within the airport overlay district are subject to the provisions of this chapter with the exceptions of those listed in Section 11.74.030. (Res. 2000-129 (part), 10/17/00).
11.74.030 Exemptions.
The following structures, uses or activities are exempt from the provisions of this chapter when permitted in the underlying zoning district:
(1) Necessary Aviation Facilities. Any aviation use or air navigation or landing facility or device approved by the Federal Aviation Administration (FAA).
(2) Shielded Objects. Any structure or object that is shielded by existing structures of a permanent and substantial character or by natural terrain of equal or greater height and located in an area of established development where the structure so shielded would not further adversely affect air navigation safety. A determination that a structure or object is shielded will be subject to approval of the administrator.
(3) Temporary Uses. Temporary, lawful uses, such as but not limited to carnivals, religious assembly, or outdoor entertainment, limited to a period of operation of five days.
(4) Existing Uses. Any existing use, lot, building, structure or feature, including vegetation, legally existing prior to the effective date of the resolution codified in this chapter shall be considered a legal nonconforming use. No such nonconforming use shall be changed, however, in any manner that would result in a greater degree of nonconformity with respect to this chapter.
(5) Agricultural Uses. Nonresidential agricultural uses, structures or buildings are allowed; provided, that they do not penetrate the airspace zones established herein or create other safety impacts.
(6) Other Uses. Other uses may be exempt when determined by the administrator to be minor or incidental in nature and do not compromise the intent of this chapter. (Res. 2000-129 (part), 10/17/00).
11.74.040 Airport overlay districts established.
(1) The airport overlay district (AOD) identifies a series of imaginary air surfaces and aircraft accident safety zones within the area influenced by airports and lying outside of incorporated city limits. The imaginary surfaces and safety zones are based upon Title 14 Code of Federal Regulations, Subchapter C, Part 77, Objects Affecting Navigable Airspace, and data from the National Transportation Safety Board (NTSB), analyses performed on the NTSB data, case law, other general resource areas, and an analysis of the existing land use patterns and land use designations established in the Chelan County comprehensive plan.
(2) The imaginary air surfaces are those air spaces above and around airports that require protection from potential obstructions that might interfere with airport traffic. The size of the imaginary surfaces is based upon the category of each runway. The outer limit of the imaginary surfaces included in the airport overlay district is shown on the Chelan County zoning maps. Imaginary surfaces include the following:
(A) Horizontal Surface. A horizontal plane one hundred fifty feet above the established airport elevation, the perimeter of which is constructed by swinging arcs of five thousand feet (for utility or visual runways) radii from the center of each end of the primary surface of each runway of each airport and connecting the adjacent arcs by lines tangent to those arcs.
(i) The established airport elevations for airports in Chelan County are as follows:
(a) Cashmere-Dryden Airport—eight hundred fifty-three feet above mean sea level.
(b) Chelan Municipal Airport—one thousand two hundred sixty-three feet above mean sea level.
(c) Lake Wenatchee State Airport—one thousand nine hundred thirty-six feet above mean sea level.
(d) Stehekin Airfield—one thousand two hundred thirty feet above mean sea level.
(B) Conical Surface. A surface extending outward and upward from the periphery of the horizontal surface at a slope of 20:1 for a horizontal distance of four thousand feet.
(C) Primary Surface. A two-hundred-fifty-foot-wide surface for utility runways having only visual approaches longitudinally centered on the runway. When the runway has a specially prepared hard surface, the primary surface extends two hundred feet beyond each end of that runway. When the runway has no specially prepared hard surface, or planned hard surface, the primary surface ends at each end of that runway. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline.
(D) Approach Surface. A surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface expanding uniformly to a width of one thousand two hundred fifty feet (for utility runways with only visual approaches). The approach surface extends for a horizontal distance of five thousand feet at a slope of 20:1 for all utility and visual runways.
(E) Transitional Surfaces. These surfaces extend outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of 7:1 from the sides of the primary surface and from the sides of the approach surfaces.
(3) The aircraft accident safety zone, as shown on the Chelan County zoning maps, includes areas surrounding airports that encompasses potential accident areas based upon analysis of accident locations near airports, historically. The aircraft accident safety zone includes the following:
(A) Runway Protection Zone 1. An area extending out from the end of the primary surface for one thousand feet with a width of four hundred fifty feet at the end away from the primary surface and centered on the extended runway centerline.
(B) Inner Safety Zone 2. An area adjacent to the end of the runway protection zone four hundred fifty feet wide and one thousand five hundred feet in length, centered on the extended runway centerline.
(C) Inner Turning Zone 3. An area composed of a sixty-degree sector centered on the end of the primary surface with an arc radius of two thousand five hundred feet.
(D) Outer Safety Zone 4. An area adjacent to the end of the inner safety zone four hundred fifty feet wide and two thousand five hundred feet in length, centered on the extended runway centerline.
(E) Sideline Safety Zone 5. An area adjacent to the primary surface extending five hundred feet perpendicular to the centerline of the runway and extending parallel to the primary surface and until the intersection with Runway Protection Zone 1 and Inner Turning Zone 3. (Res. 2000-129 (part), 10/17/00).
11.74.050 Development standards.
Except as noted in Section 11.74.030, the following standards shall be applied to all lands within the airport overlay district:
(1) With the exception of those necessary and incidental to airport operations, no uses shall be permitted that allow buildings, structures, vegetation or other development that penetrates the imaginary air surfaces described in Section 11.74.040(2).
(2) No uses shall be allowed that cause electrical interference with the operation of radio or electronic signals at the airport or between the airport and aircraft.
(3) No structure, device or other object shall be placed that makes it difficult for pilots to distinguish between airport lights and other lights, impairs visibility, or otherwise endangers the takeoff, landing or maneuvering of aircraft.
(4) No use, building or structure shall emit smoke, steam, ash, dust, vapor, gas or other emissions that may conflict with operations at the airports.
(5) No use shall be made of the land within Runway Protection Zone 1, Inner Safety Zone 2, Inner Turning Zone 3, Outer Safety Zone 4 or Sideline Safety Zone 5 that promotes areas of standing water one-half acre or larger in size.
(6) No use, building or structure shall be permitted within Runway Protection Zone 1, Inner Safety Zone 2, Inner Turning Zone 3, Outer Safety Zone 4 or Sideline Safety Zone 5 that promotes large concentrations or bulk storage of hazardous or flammable materials.
(7) Land uses that promote large assemblies of people such as multifamily housing, hospitals, churches, schools, etc., shall be prohibited within Runway Protection Zone 1, Inner Safety Zone 2, Inner Turning Zone 3, Outer Safety Zone 4 or Sideline Safety Zone 5.
(8) A note shall be recorded with the county auditor for each lot when subdivision, short subdivision, binding site plan, building permit or other development activity is located within the horizontal surface. Additionally the note shall specifically state when the properties are located within the approach surfaces of airport runways. The statement shall essentially read as follows:
The subject property is located within an Airport Overlay District (AOD) in which a variety of aviation activities occur. Such activities may include but are not limited to noise, vibration, chemicals, odors, hours of operation and other associated activities.
(Res. 2000-129 (part), 10/17/00).
11.74.060 Review procedures.
(1) All land use and building permit applications within any portion of the airport overlay district (AOD) shall be subject to the application and review procedures prescribed in Title 14, Development Permit Procedures and Administration, of the Chelan County Code.
(2) No use, building, structure, or development activity on lands within the AOD district shall be established, altered or relocated except as authorized by this chapter and shall be processed in accordance with the applicable provisions of the underlying zone. (Res. 2000-129 (part), 10/17/00).
11.74.070 Application requirements.
In addition to that information required pursuant to Title 14, Development Permit Procedures and Administration, Chelan County Code, all development applications within the AOD district shall provide information sufficient to determine the maximum finished elevation of all vegetation, buildings and structures relative to established airport elevations. Additionally, the review authority may require the applicant to submit either or both of the following:
(1) A certificate from a licensed engineer or registered land surveyor that clearly states that no airspace obstruction will result from the proposed use;
(2) The maximum elevation of proposed buildings, structures or vegetation based on the established airport elevation. Elevations shall be determined by an engineer or land surveyor. (Res. 2000-129 (part), 10/17/00).