This article shall be known and cited as the "dark sky ordinance."
(Ordinance 714 adopted 12/13/2022)
The purpose of this article is:
(1) 
To reduce glare and improve nighttime visibility which contributes to safer, more secure, and attractive outdoor living spaces;
(2) 
To encourage efficient, controlled lighting that conserves energy;
(3) 
To make our community a better place to live and work;
(4) 
To protect properties from light trespass;
(5) 
To restore and preserve our heritage of a clear, dark night sky;
(6) 
To position the city to apply for the designation of International Dark Sky Community;
(7) 
To have lights at night that are directed where light is wanted, are a warm color, and the appropriate amount of light;
(8) 
To prevent light at night from being wasted off-site, off-property, or into the night sky;
(9) 
To prevent training exercises and other operations on military facilities from being compromised by light pollution.
(Ordinance 714 adopted 12/13/2022)
(a) 
Applicability.
This article applies to all property within the city limits. Additionally, the provisions of this article pertaining to signs apply in the city's extraterritorial jurisdiction. The city limits and ETJ are those existing at the time this article is adopted and as may be modified from time-to-time.
(b) 
No limitation.
Nothing herein shall be construed as preventing or limiting the city from applying this article within the surrounding areas where the city asserts powers of extraterritorial jurisdiction through agreements with property owners, or as a term affixed to a conditional approval (such as a variance) or if authorized by the state.
(Ordinance 714 adopted 12/13/2022)
(a) 
Generally.
As used in this article, the words and phrases defined in this section have that meaning ascribed to them in this section. Words and phrases not otherwise defined have their common, ordinary meaning. The text of this section controls over any diagrams, drawings, or other images. Words used in the singular include the plural, and vice versa, as required by context. Words used in any tense include any other tense. Headings and captions are for reference purposes only.
(b) 
Definitions.
In this article, the following terms have that meaning ascribed to them below:
Adaptive controls.
Mechanical or electronic devices, when used in the context of outdoor lighting systems, intended to actively regulate the switching, duration, or intensity of light emitted by the outdoor lighting system. Examples of adaptive controls include timers, dimmers, and motion-sensing switches.
Beam of a light fixture.
The spatial distribution of the emitted light.
City limits.
The corporate boundaries of the city.
Correlated Color Temperature (CCT).
A measure of the color properties of light, being equal to the temperature, expressed in Kelvins (K).
ETJ.
The extraterritorial jurisdiction of the city pursuant to Texas Local Government Code § 42.021.
Existing light fixtures.
Those outdoor light fixtures already installed at the time this article is adopted.
Fully shielded.
All of the light emitted from a light fixture is projected below the horizontal plane passing through the lowest light-emitting part of the fixture.
Glare.
Visual discomfort or impairment caused by a bright source of light in a direction near one's line of sight.
Government-owned streetlight.
A streetlight owned, operated, or maintained by the city or other unit of state, local, or federal government that illuminates a public right-of-way or other governmental or public property. The term does not include lighting at public or private outdoor sports facilities.
Greenhouse.
Any building that is constructed of glass, plastic, or other transparent material in which plants are grown under climate-controlled conditions and includes hoop houses and other similar structures.
Illuminance.
The intensity of light in a specified direction measured at a specific point.
Light pollution.
The unintended, adverse, or obtrusive effect of the use of outdoor light at night, including but not limited to sky glow, light trespass, and glare.
Light source.
A light emitting portion of the luminaire and any diffusing elements and surfaces intended to reflect or refract light emitted from the lamp individually or collectively, such as a lamp, bulb, lens, highly reflective surface, or frosted glass.
Light trespass.
Light emitted in a manner that causes light to:
(1) 
Fall on a property other than the one where the light is installed and that unreasonably disturbs a person of normal sensitivities;
(2) 
Shine in the eyes of the operator of a motor vehicle on a public street; or
(3) 
Upwards toward the sky.
Lumen.
The unit of measurement established by the American National Standards Institute to quantify the amount of light produced or emitted. For the purposes of this article, unless otherwise stated, the lumen output values shall be the initial lumen output ratings as defined by the manufacturer of the relevant light source, multiplied by the lamp efficiency. Lamp efficiency of 95% shall be used for all solid-state lamps and 80% for all other lamps, unless an alternate efficiency rating is supplied by the manufacturer.
Lumens per acre.
The total number of lumens produced by all lamps utilized in outdoor lighting on a property divided by the number of acres, or part of an acre, with outdoor lighting on the property.
Luminaire.
A complete lighting assembly or lighting fixture, consisting of a lamp, housing, optic(s), and other structural elements, but not including any mounting pole or surface.
Luminance.
A measure of light emitted by or from a surface.
Nit.
The standard unit of measure of luminance used for internally illuminated signs, digital signs, or electronic message displays and is equal to one candela per square meter.
Nonresidential.
Zoned for uses other than residential use or associated with property that is zoned for uses other than residential use.
Outdoor lighting.
Lighting that is installed, located, or used in such a manner to cause light rays to shine outdoors. Nonresidential fixtures that are installed indoors that cause light rays to shine outside are considered outdoor lighting for the intent of this article. See exhibit 1 of section 3.09.063 for an illustration of this type of situation. Residential fixtures installed indoors generating more than 3,800 lumens that cause light to shine outside are also considered outdoor lighting for the intent of this article. All of the lighting that illuminates the translucent portion of a greenhouse or solarium, including roofing material, is considered outdoor lighting for the intent of this article.
Residential.
Zoned for residential uses or associated with property zoned for residential uses.
Sag-lens fixture.
A fixture, typically seen on older streetlights or parking lot lights, where the lens extends below the lowest opaque part of the fixture such that light is scattered above the horizontal plane.
Searchlight.
A light fixture having a narrow beam intended to be seen in the sky.
Spotlight.
A light fixture having a narrow beam.
Temporary lighting.
Nonpermanent lighting installations installed and operated for a duration not to exceed thirty (30) days.
Total outdoor light output.
The total amount of light, measured in lumens, from all outdoor light fixtures within the illuminated area of a property. The lumen value to be used in the calculation is the lumen value as defined in this article. To compute the total, add the lumen outputs attributed to each light fixture together.
(Ordinance 714 adopted 12/13/2022)