Chapter 18.65


18.65.010    Purpose.

18.65.020    Statutory authority.

18.65.030    Applicability.

18.65.040    Exemptions.

18.65.050    Development standards.

18.65.060    General review procedures.

18.65.070    Site plan requirements.

18.65.080    Airspace surfaces.

18.65.010 Purpose.

The purpose of the airport overlay (AP-O) district is to protect the viability of the Pangborn Memorial Airport as a significant resource to the community by encouraging compatible land uses, densities and reducing hazards that may endanger the lives and property of the public and aviation users. The AP‑O classification identifies a series of imaginary surfaces and compatibility zones within the airport influence area that have historically been prone to hazards associated with aircraft and airports. This chapter is based on aircraft accident data from the WSDOT Aviation Land Use Compatibility, 2002 Caltrans Airport Land Use Compatibility Handbook, National Transportation Safety Board (NTSB) and the Federal Aviation Regulations (FAR) Part 77 Imaginary Surfaces. As the name implies, this classification is laid over the existing Douglas County zoning districts. Densities and land use requirements of the underlying zoning districts are consistent with the NTSB standards and provide for maximum protection to the public health, safety and general welfare of the community and for those citizens working and residing within the airport influence area. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.020 Statutory authority.

This chapter is adopted pursuant to Chapter 36.70 and 36.70A RCW, which require a county to enact development regulations within its jurisdiction to discourage the siting of incompatible land uses adjacent to general aviation airports for the purposes of promoting the public health, safety and general welfare of county residents and aviation users. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.030 Applicability.

The provisions of this chapter shall apply to all lands, buildings, structures, natural features or uses located within those areas that are defined by the AP-O airport overlay district designated on the official Douglas County zoning map. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.040 Exemptions.

The following structures, uses or other activities are exempt from the provisions of the AP-O district when permitted in the underlying zoning district:

A.    Height. Any structure or object that would be shielded by existing structures of a permanent and substantial character or by natural terrain or topographic features of equal or greater height and would be located in an area of established development where it is evident beyond all reasonable doubt that the structure so shielded will not adversely affect safety in air navigation or penetrate the FAR Part 77 surfaces;

B.    Necessary Aviation Facilities. Any air navigation facility, airport visual approach, or aircraft arresting device, or meteorological device, or a type of device approved by the FAA, the location and height of which is fixed by its functional purpose;

C.    Temporary Uses. Temporary uses including but not limited to: circus, carnival or other outdoor entertainment events and religious assembly, so long as the period of operation does not exceed five days, except as otherwise prohibited herein;

D.    Nonconforming Uses. A use, lot, building or structure which legally exists prior to the effective date of the ordinance codified in this chapter is considered nonconforming and therefore is exempt, except as may be compelled by state or federal regulations. The use, lot, building or structure must adhere to the regulations prescribed in DCC Chapter 18.82, Nonconforming Uses, and DCC Section 18.65.050(F); provided, that no building, structure or use shall be so changed as to result in a greater degree of nonconformity with respect to this chapter;

E.    Agricultural Uses. Nonresidential agricultural uses, structures and/or buildings; provided, that the use will not penetrate the airspace within the AP-O district safety zones, the FAR Part 77 surfaces or otherwise create a safety impact as determined by the review official;

F.    Other Uses. Other uses may be exempt when determined by the review authority to be minor or incidental in nature and within the intent of this chapter. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.050 Development standards.

The following criteria shall be applied within the boundaries of the AP-O district:

A.    No use shall be made of any land that will cause electrical interference with navigational signals or radio communications at the airport or with radio or electronic communications between the airport and aircraft.

B.    No use, building or structure shall emit emissions of fly ash, dust, vapor, gases or other forms of emissions that may conflict with any planned operations of the airport.

C.    No use shall be permitted that would foster an increase in bird population and thereby increase the likelihood of a bird-impact problem.

D.    No structure, device or other object shall be placed or erected that makes it difficult for pilots to distinguish between airport lights and other lights, results in glare in the eyes of pilots using the airports, impairs visibility in the vicinity of the airport, or otherwise endangers the landing, taking off or maneuvering of aircraft.

E.    Except as necessary and incidental to airport operations, no building, structure or object of natural growth shall be constructed, altered, maintained, or allowed to grow so as to project or otherwise penetrate the airspace surfaces.

F.    No use, building or structure shall be permitted within Zones 1, 2, and 3 that promotes large concentrations (six thousand gallons or more) of bulk storage of flammable substances or materials.

G.    The public assembly of people and other uses or activities that allow public concentration of people such as hospitals, nursing homes, schools, and large day care centers, etc., shall be prohibited within Zones 2 and 3.

H.    No use, building, or structure shall be permitted or constructed within Zone 1, except accessory activities such as off-street parking facilities; stormwater detention facilities; low growing landscaping; mini-storage; agricultural storage buildings and/or other similar activities as approved by the review authority.

I.    Family farm support divisions; Ag-to-Ag transfers having a remainder less than ten acres in size; or accessory agricultural housing shall be prohibited within Zones 1 and 2.

J.    Single-family dwellings lawfully permitted and established within the AP-O district prior to the adoption of this chapter may be maintained, repaired or reconstructed in accordance with the provisions of this chapter, provided the dwelling meets the applicable standards of the DCC. Permit applications under this subsection are not subject to the procedures of DCC Section 18.82.080.

K.    Other uses or activities determined to be incompatible with aviation and aviation safety as determined by the review authority shall be prohibited.

L.    A note shall be placed on a final plat, final short plat or final binding site plan and noted in the deed of record or on a notice to title for each lot when a subdivision, short subdivision, binding site plan or other development is located within the airport protection zones established pursuant to the Greater East Wenatchee Area (“GEWA”) Comprehensive Plan and this chapter. The property owner shall sign an affidavit acknowledging the following statement and shall record it with the county auditor for disclosure in the deed and mortgage records of the subject property. The statement shall read as follows:

The subject property is located within airport protection zones for Pangborn Memorial Airport (“PMA”) established pursuant to the Greater East Wenatchee Area (“GEWA”) Comprehensive Plan and DCC Chapter 18.65, AP-O Airport Overlay District that are routinely subject to overflights by aircraft using PMA and, as a result, residents of the subject property may experience inconvenience, annoyance, discomfort and loss of quiet enjoyment arising from the noise, fumes, illumination, smoke, vibration and hours of operation (collectively “Overflight Effects”) of such activities. Washington State law establishes that airports such as PMA are essential public facilities and need protection for the public interest of the people of the state of Washington. Residents of the subject property should be prepared to accept the inconvenience, annoyance, discomfort and loss of quiet enjoyment arising from the Overflight Effects, as well as normal aircraft and airport operations, which Overflight Effects, as well as the normal aircraft and airport operations shall not be subject to legal action as public nuisances, provided the Overflight Effects and the aircraft and airport operations are performed in accordance with county, state and/or federal law. Any subsequent deed conveying this parcel or subdivisions thereof shall contain a statement in substantially this form.

M.    Nonresidential Land Usage Intensity Standards.

1.    Nonresidential land uses shall not exceed the following intensity levels:

Zones 1 and 2:

0 – 5 people per acre

Zone 3:

25 people per acre

Zone 5:

50 people per acre

2.    Usage Intensity Data Sources. The usage intensity depends on the specifics of the proposed land use and its design. Where necessary to determine the acceptability of a particular proposal, the maximum number of people per acre can be calculated based on any of the following methods:

a.    Parking Requirements. The number of automobile parking spaces required on the site according to the latest edition of the International Transportation Engineers Parking Generation Manual.

b.    International Building Code (IBC) Occupancy Levels. The anticipated maximum number of people occupying indoor facilities on a site can be assumed to be no higher than the total floor area of the proposed use divided by the minimum square feet per occupant requirements listed in the IBC.

3.    Usage Intensity Calculation Factors. The maximum number of people permitted on a site shall be calculated based on the following factors:

a.    All people (e.g., employees, customers, visitors, etc.) who may be on the property are to be included in the calculations.

b.    The calculations must reflect the total number of people on the site at any time, except temporary special events.

c.    All usage intensities are calculated on a gross acreage basis, including the use’s share of adjacent roads and permanently open lands.

N.    Structures shall be located away from the extended centerline of the runway to the greatest extent practicable. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.060 General review procedures.

No use, building, structure or development activity shall be established, altered or relocated by any person, firm or corporation, except as otherwise authorized by this chapter and shall be processed in accordance with applicable provisions of the underlying zone, and the following:

A.    Land use applications within any portion of the AP-O district shall be subject to the prescribed review of DCC Title 14.

B.    The review authority may require the applicant to submit either or both of the following:

1.    A certificate from an engineer or land surveyor that clearly states that no airspace obstruction will result from the proposed use;

2.    The maximum elevation of proposed buildings or structures based on the established airport elevation and NAVD 1988 reference datum. Elevations shall be determined by an engineer or a land surveyor. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.070 Site plan requirements.

An application for a building, structure, use, subdivision, short subdivision, binding site plan or other development activity shall submit the following information in addition to application materials required as set forth in the DCC.

A.    The site plan shall clearly delineate the location of the project in relation to the compatibility zones.

B.    The location and height of all proposed buildings, structures and natural vegetation as measured from the airport surface and when located within the following:

1.    Airport Compatibility Zones 1, 2, 3 and 5;

2.    Horizontal, transitional, approach, and conical surfaces identified as a natural obstruction; and

3.    Building or structures that exceed a height of thirty-five feet when located in any other compatibility zone or FAR Part 77 imaginary surfaces not described in subsections A and B of this section. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))

18.65.080 Airspace surfaces.

In order to carry out the purpose and intent of the AP-O district as set forth herein, and also to restrict those uses that may be hazardous to the operational safety of aircraft operating within the airport influence area, there are created and established air space and land use compatibility surfaces for runways 12-30 and 7-25 and are depicted on the official zoning map of Douglas County.

A.    Federal Aviation Regulations (FAR) Part 77 Imaginary Surfaces.

1.    Primary approach/departure surface: The approach area is all that land which lies directly under an imaginary approach surface longitudinally centered on the runway, extending two hundred feet beyond the paved threshold of the runway in each direction.

a.    Precision instrument runway 12-30: Runway 12-30’s primary surface measures one thousand feet across because it is a precision instrument runway.

b.    Visual approach runway 7-25: Runway 7-25’s primary surface measures two hundred fifty feet across because it is a visual approach runway.

2.    Approach surface: Inclined planes extending upward and outward from the ends of this primary surface.

a.    Precision instrument runway 12-30: The precision approach is a fifty-thousand-foot-long trapezoid that is one thousand feet wide at the point where it meets the primary surface. It has a fifty to one slope for the first ten thousand feet and a slope of forty to one for the remaining forty thousand feet. The approach surface is sixteen thousand feet wide at the outermost point.

b.    Visual approach runway 7-25: The approach surfaces are two hundred fifty feet wide at the intersection with the primary surface. It extends outward for a distance of one thousand feet at a twenty to one slope and is seven hundred fifty feet wide at the outermost point.

3.    Horizontal surface: A horizontal surface is one hundred fifty feet above the established airport elevation and begins by swinging arcs of five thousand feet from the center-end of the primary surface creating an elongated oval above the runway. The precision instrument runway 12-30 extends to a maximum length of ten thousand feet.

4.    Transitional surface: The transitional surface begins on either side of the primary surface and slopes upward and outward at a seven to one slope meeting the horizontal surface at one hundred fifty feet above the elevation of the airport. This surface is also connected to the approach surface at both ends of the runway at a slope of seven to one.

5.    Conical surface: The conical surface begins at the edge of the horizontal surface and extends upward and outward for a distance of four thousand feet at a slope of twenty to one with an initial elevation of one hundred fifty feet above the airport elevation. (Res. TLS 07-9B (part): Ord. TLS 00-05-38 Exh. B (part))