Chapter 17.23
NIGHT SKY PRESERVATION

Sections:

17.23.010    Purpose.

17.23.020    Definitions.

17.23.030    Application requirements.

17.23.040    Operational standards.

17.23.050    New development standards.

17.23.060    Temporary lighting.

17.23.070    Nonconforming fixtures.

17.23.080    Exemptions.

17.23.010 Purpose.

To establish outdoor lighting regulations that encourage lighting practices and systems that will:

A. Permit reasonable uses of outdoor lighting for nighttime safety, utility, security and enjoyment while preserving the ambience of night;

B. Curtail and reverse any degradation of the nighttime visual environment and the night sky;

C. Minimize glare and obtrusive light by limiting outdoor lighting that is misdirected, excessive, or unnecessary;

D. Help protect the natural environment from the damaging effects of night lighting;

E. Meet the minimum requirements of the California Code of Regulations for Outdoor Lighting and Signs (Title 24, Chapter 6).

Other laws or ordinances may require minimum illumination levels for specific applications and may conflict with these regulations. In such cases, those laws or ordinances shall govern. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.020 Definitions.

“Footcandle” is a unit of measure of the intensity of light falling on a surface, equal to one lumen per square foot or the intensity of light from a standardized candle burning at one foot from a given surface.

“Light pollution” means the night sky glow caused by the scattering of artificial light in the atmosphere.

“Low-intensity” means lighting designed to accent architectural features or signs that does not produce glare, such as tubular neon or LED rope lighting. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.030 Application requirements.

Whenever a person is required to obtain a building permit, electrical permit for outdoor lighting or signage, and/or approval of any development project, the applicant shall, as a part of said application, submit sufficient information to enable the community development department to determine whether the proposed lighting will comply with the provisions of this chapter. The application shall include the following:

A. A site plan indicating the proposed location of all outdoor lighting fixtures that are not exempted by Section 17.23.080.

B. A description of each illuminating device, fixture, lamp, support and shield. This description may include, but is not limited to, manufacturer’s catalog cuts and drawings (including sections where required), lamp types and lumen outputs.

C. Photometric plans depicting the location of all light poles and building-mounted lighting fixtures and a maximum ten-foot by ten-foot grid of both the initial and maintained lighting levels on the site.

D. The project lighting plan shall be coordinated with any associated landscaping plan to prevent site planning conflicts.

E. Any other information the community development director may determine is necessary to ensure compliance with the provisions of this chapter.

The director may waive any or all of these requirements if compliance can be determined based on available information. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.040 Operational standards.

Outdoor lighting shall be designed, installed and maintained to prevent nighttime sky light pollution, preserve and enhance visibility of stars and use energy efficiently by lighting only those areas or objects necessary for safety and security. All outdoor lighting shall conform to the following regulations:

A. Outdoor lighting shall be directed downward and away from adjacent properties and public rights-of-way.

B. No lighting on private property shall produce an illumination level greater than two maintained horizontal footcandles at grade on any property within a residential zoning district except on the site of the light source.

C. The maximum light intensity on a residential site shall not exceed a maintained value of ten footcandles, when measured at finished grade.

D. The maximum light intensity on a nonresidential site, except auto sales lots and sports fields, shall not exceed a maintained value of ten footcandles, when measured at finished grade.

E. The maximum light intensity on an auto sales lot shall not exceed a maintained value of forty footcandles, when measured at finished grade.

F. The maximum light intensity on a sports field shall not exceed a maintained value of fifty footcandles when measured three feet above grade. Baseball field lighting and lighting for other recreational uses may be increased to a maintained value of one hundred footcandles with approval of the community development director.

G. Outdoor lighting shall be completely turned off or significantly dimmed at the close of business hours unless lighting is essential for security or safety (e.g., illumination of parking areas and plazas).

H. Outdoor lighting shall not blink, flash, or rotate.

I. Outdoor flood light projection above the horizontal plane is prohibited, unless exempted by Section 17.23.080.

J. All upward directed sign lighting, including illumination of billboards, is prohibited, unless exempted by Section 17.23.080.

K. Outdoor sports fields shall not be illuminated after eleven p.m. except to conclude a scheduled recreational or sporting event in progress prior to eleven p.m. (Ord. 1553 § 19, 2010; Ord. 1527 § 2 Ex. A (part), 2009)

17.23.050 New development standards.

In addition to required operational standards, new development projects shall incorporate the following regulations:

A. Outdoor lighting fixtures, including lighting for outdoor recreational facilities, shall be cutoff fixtures designed and installed so that no emitted light will break a horizontal plane passing through the lowest point of the fixture (see Figure 10). Cutoff fixtures must be installed using a horizontal lamp position. Lighting fixtures should be of a design that complements building design and landscaping, and may require architectural review.

B. Outdoor lighting shall be fully shielded or recessed (see Figure 11).

1 Figures shown are examples for the public and staff to use in meeting the intent of this chapter. The city of San Luis Obispo does not endorse or discriminate against any manufacturer that may be shown or mentioned as examples.

C. Lighting fixtures shall be appropriate in height, intensity, and scale to the use they are serving. Parking lot lights shall not exceed a height of twenty-one feet, and wall-mounted lights shall not exceed a height of fifteen feet, from the adjacent grade to the bottom of the fixture. The architectural review commission can approve an exception to these height standards based on specific extenuating circumstances.

D. All luminaries mounted on the under surface of service station canopies shall be fully shielded and utilize flush-mounted canopy fixtures with flat lenses.

E. Search lights, laser source lights, or any similar high-intensity light shall be prohibited, except, in emergencies, by police and/or fire personnel, or at their direction, or for purposes of gathering meteorological data. Exceptions may be granted in conjunction with approved temporary lighting. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.060 Temporary lighting.

The community development director may approve temporary lighting that is an exception to the regulations contained in this chapter. The director must make the following findings:

A. The purpose for which the lighting is proposed is not intended to extend beyond thirty days; and

B. The proposed lighting is designed in such a manner as to minimize light pollution and trespass as much as feasible. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.070 Nonconforming fixtures.

No outdoor lighting fixture which was installed prior to the enactment of this chapter, and was consistent with zoning regulations at the time of installation, shall be required to be removed or modified. However, no modification or replacement shall be made to a nonconforming fixture unless the fixture thereafter conforms to the provisions of this chapter. (Ord. 1527 § 2 Ex. A (part), 2009)

17.23.080 Exemptions.

The following lighting fixtures are exempt from the requirements of this chapter:

A. Neon and other low intensity outdoor lighting fixtures used for signage or architectural decoration that are approved through architectural review.

B. Outdoor lighting fixtures on public rights-of-way; provided, that measures have been taken to mitigate impacts on surrounding properties and the night sky.

C. Emergency lighting operated by public agencies or for the purpose of aviation safety.

D. All temporary lighting used for the construction or repair of roadways, utilities, and other public infrastructure.

E. Nonelectric lighting such as gas lamps or kerosene lanterns.

F. Temporary lighting equipment and seasonal lighting equipment; provided, that individual lamps are ten watts or less.

G. Accent lighting for architectural features, national flags, statues, public art, signage or other objects of interest provided the fixture emits a very narrow cone of light for the purpose of confining the light to the object of interest and minimizing spill-light and glare. Accent lighting is subject to the director’s approval.

H. Upgrades to existing lighting fixtures on outdoor advertising signs (billboards) that reduce light pollution, provided the level of illumination is not increased and subject to the director’s approval. (Ord. 1527 § 2 Ex. A (part), 2009)