Chapter 18.125


18.125.010    Administration.

18.125.020    Definitions.

18.125.030    General requirements.

18.125.040    Prohibitions.

18.125.050    Permanent exemptions.

18.125.060    Procedures for code compliance.

18.125.070    Temporary exemptions.

18.125.080    Penalties.

18.125.010 Administration.

A. Purpose. This code is intended to restrict the permitted use of outdoor artificial illuminating devices emitting undesirable rays into the night sky which have a detrimental effect on astronomical observations.

B. Conformance with Applicable Codes. All outdoor artificial illuminating devices shall be installed in conformance with the provisions of the code, the town zoning regulations, and any building codes which may hereafter be enacted, as applicable. Where any provisions of any of the Arizona state statutes, or any of the federal law, or any companion town code comparatively conflicts with the regulations of this light pollution code, the most restrictive shall govern.

C. Approved Material and Methods of Installation. The provisions of this code are not intended to prevent the use of any material or method of installation not specifically prescribed by this code, provided any such alternate has been approved. The town building inspector may approve any such alternate provided he finds that the proposed design, material or method:

1. Provides approximate equivalence to those specific requirements of this code; or

2. Is otherwise satisfactory and complies with the intent of the code. (Ord. 06-10, 2006; prior code § 17-26-1)

18.125.020 Definitions.

“Individual” means any private individual, tenant, lessee, owner, or any commercial entity including but not limited to companies, partnerships, joint ventures or corporations.

“Installed” means the initial installation of outdoor light fixtures defined herein, following the effective date of this code but shall not apply to those outdoor light fixtures installed prior to such date.

“Outdoor light fixtures” means outdoor artificial illuminating devices, outdoor fixtures, lamps and other devices, permanent or portable, used for illumination or advertisement. Such devices shall include, but are not limited to, search, spot, or flood lights for: buildings and structures, recreational areas, parking lot lighting, landscape lighting, billboards and other signage (advertising or others), and street lighting. (Ord. 06-10, 2006; prior code § 17-26-2)

18.125.030 General requirements.

A. Shielding. All exterior illuminating devices, except those exempt from this code and those regulated by Section 18.125.040(C), shall be fully or partially shielded as required in subsection C of this section.

1. “Fully shielded” shall mean that those fixtures shall be shielded in such a manner that light rays emitted by the fixture, either directly from the lamp or indirectly from the fixture, are projected below a horizontal plane running through the lowest point on the fixture where light is emitted.

2. “Partially shielded” shall mean that those fixtures shall be shielded in such a manner that the bottom edge of the shield is below the plane centerline of the light source (lamp), minimizing light above the horizontal.

B. Filtration.

1. Those outdoor light fixtures requiring a filter in subsection C of this section shall be equipped with a filter whose transmission is less than five percent total emergent flux at wavelengths less than 3,900 angstroms. Total emergent flux is defined as that between 3,000 and 7,000 angstrom units.

2. It is recommended that existing mercury vapor fixtures shall be equipped with a filter whose transmission is less than 10 percent total emergent flux at wavelengths less than 4,400 angstroms. Total emergent flux is defined as that between 3,000 and 7,000 angstrom units.

3. Low pressure sodium lamps are the preferred lamps for minimizing adverse effects on astronomical observations.

C. Requirements for Shielding and Filtering. The requirements for shielding and filtering light emissions from outdoor light fixtures shall be as set forth in the following table:



Fixture Lamp Type



Low pressure sodium1



High pressure sodium



Metal halide6









Incandescent greater than 150 W



Incandescent 150 W or less



Mercury vapor



Fossil fuel



Glass tubes filled with neon, argon, krypton



Other sources

As approved by the town building inspector


1.    This is the preferred light source to minimize undesirable light into the night sky affecting astronomical observations.

2.    Warm white and natural lamps are preferred to minimize detrimental effects.

3.    For the purposes of this code, quartz lamps shall not be considered an incandescent light source.

4.    Most glass, acrylic, or translucent enclosures satisfy these filter requirements.

5.    Outdoor advertising signs of the type constructed of translucent materials and wholly illuminated from within do not require shielding.

6.    Metal halide display lighting shall not be used for security lighting after 11:00 p.m. (or after closing hours if before 11:00 p.m.) unless fully shielded. Metal halide lamps shall be in enclosed luminaries.

7.    Recommended for existing fixtures. The installation of mercury vapor fixtures is prohibited effective 90 days after the date of adoption of this code.

(Ord. 06-10, 2006; prior code § 17-26-3)

18.125.040 Prohibitions.

A. Searchlights. The operation of searchlights for advertising purposes is prohibited.

B. Recreational Facility. No outdoor recreational facility, public or private, shall be illuminated by nonconforming means after 11:00 p.m. except to conclude a specific recreational or sporting event or any other activity conducted at a ball park, outdoor amphitheater, arena, or similar facility in progress prior to 11:00 p.m.

C. Outdoor Building or Landscaping Illumination. The unshielded outdoor illumination of any building, landscaping, signing or other purpose, is prohibited except with incandescent fixtures less than 150 watts.

D. Mercury Vapor. The installation of mercury vapor fixtures is prohibited effective 90 days after the date of adoption of this code. (Ord. 06-10, 2006; prior code § 17-26-4)

18.125.050 Permanent exemptions.

A. Nonconforming Fixtures. All outdoor light fixtures existing and fully installed prior to the effective date of the code may remain “nonconforming” indefinitely; provided, however, that no change in use, replacement, structural alteration, or restoration after abandonment of outdoor light fixtures shall be made unless it thereafter conforms to the provisions of these regulations.

B. Fossil Fuel Light. Light produced directly or indirectly by the combustion of natural gas or other utility-type fossil fuels.

C. Federal and State Facilities. Those facilities and lands owned, operated and protected by the U.S. federal government or the state of Arizona are exempted by law from all requirements of this code. Voluntary compliance with the intent of this code at those facilities is encouraged.

D. Special Exemption. The building inspector may grant a special exemption to the requirements of Section 18.125.030(C) only upon a written finding that there are extreme geographic or geometric conditions warranting the exemption and that there are no conforming fixtures that would suffice. (Ord. 06-10, 2006; prior code § 17-26-5)

18.125.060 Procedures for code compliance.

A. Applications.

1. Any individual applying for a building or use permit under the town zoning regulations intending to install outdoor lighting fixtures shall as a part of said application submit evidence that the proposed work will comply with this code.

2. All other individuals intending to install outdoor lighting fixtures shall submit an application to the building inspector providing evidence that the proposed work will comply with this code.

3. Utility companies entering into a duly approved contract with the town in which they agree to comply with the provisions of these regulations shall be exempt from applying for and obtaining a permit for the installation of outdoor light fixtures, including residential security lighting.

B. Contents of Application or Submission. The submission shall contain but shall not necessarily be limited to the following, all or part of which may be part of or in addition to the information required elsewhere in the town zoning regulations upon application for the required permit:

1. Plans indicating the location on the premises, and the type of illuminating devices, fixtures, lamps, supports, other devices, etc.

2. Description of the illuminating devices, fixtures, lamps, supports and other devices, etc. This description may include but is not limited to manufacturers catalog cuts, and drawings (including sections where required).

The above required plans and description shall be sufficiently complete to enable the town building inspector to readily determine whether compliance with the requirements of this code will be secured. If such plans and descriptions cannot enable this ready determination, by reason of the nature or configuration of the devices, fixtures or lamps proposed, the applicant shall submit evidence of compliance by certified test reports as performed by a recognized testing lab.

C. Issuance of Permit. Upon compliance with the requirements of this code, the town building inspector shall issue a permit for installation of the outdoor lighting fixtures, to be installed as in the approved application. In the event the application is part of the building permit application under the zoning regulations, the issuance of the building permit will be made if the applicant is in compliance with this code as well as the other requirements for issuance under the zoning regulations. Appeal procedures of the zoning regulations for decisions of the town building inspector shall apply.

D. Amendment to Permit. Should the applicant desire to substitute outdoor light fixtures or lamps after a permit has been issued, the applicant must submit all changes to the town building inspector for approval, with adequate information to assure compliance with this code. (Ord. 06-10, 2006; prior code § 17-26-6)

18.125.070 Temporary exemptions.

A. Request for Temporary Exemptions. Any individual as defined herein may submit a written request on a form prepared by the planning and zoning commission to the town building inspector for a temporary exemption to the requirements of this code, such exemption to be valid for 30 days, renewable at the discretion of the town building inspector.

The request for temporary exemption shall contain minimally the following listed information:

1. Specific exemptions requested.

2. Type and use of exterior light involved.

3. Duration of time for requested exemption.

4. Type of lamp and calculated lumens.

5. Total wattage of lamp or lamps.

6. Proposed location of exterior light.

7. Previous temporary exemptions, if any.

8. Physical size of exterior light and type of shielding provided.

In addition to the above data, the town building inspector may request any additional information that would enable him to make a reasonable evaluation of the request for temporary exemption.

B. Appeal for Temporary Exemption. The town building inspector, within five days from the date of the properly completed request for temporary exemption, shall approve or reject in writing the request. If rejected, the individual making the request shall have the right of appeal to the appropriate board of adjustment for review pursuant to the procedures applicable to any other appeal of a decision of the town building inspector. (Ord. 06-10, 2006; prior code § 17-26-7)

18.125.080 Penalties.

Any person violating any of the provisions of this code shall be deemed guilty of a class two misdemeanor, and each such person shall be deemed guilty of a separate offense for each and every day or portion thereof during which a violation of any of the provisions of this code is committed, continued or permitted and upon conviction thereof. (Ord. 06-10, 2006; prior code § 17-26-8)