(A) Purpose and findings. These provisions are intended to control the use of outdoor, artificial illuminating devices emitting rays into the night sky that have a detrimental effect on the rural atmosphere and astronomical observations and that create glare. It is the intention of this section to:
(1) Encourage good lighting practices such that lighting systems are designed to conserve energy and money;
(2) Minimize glare;
(3) Protect the use and enjoyment of surrounding property; and
(4) Increase nighttime safety, utility, security and productivity.
(B) Applicability.
(1) Generally.
(a) All outdoor, artificial illuminating devices shall be installed in conformance with the provisions of this section and the Building Code of the city.
(b) This section does not prevent the use of any material or method of installation not specifically addressed. In considering any variance from the provisions of this section, the Board of Adjustment shall take into consideration any state-of-the-art technology that is consistent with the intent of this section as new lighting technology develops that is useful in reducing light above the horizontal plane.
(2) Exceptions. The following types of light fixtures shall be exempt from the provisions of this section.
(a) Low-intensity luminaires. Any luminaire with a lamp or lamps rated at a total of 1,800 lumens or less, and all flood or spot luminaires with a lamp or lamps rated at 900 lumens or less, may be used without restriction to light distribution or mounting height; except that, if any spot or flood luminaire rated 900 lumens or less is aimed, directed or focused to cause direct light from the luminaire to be directed toward residential buildings on adjacent or nearby land, or to create glare perceptible to persons operating motor vehicles on public ways, the luminaire shall be redirected or its light output controlled as necessary to eliminate such conditions.
(b) Public street luminaires. Luminaires used for public street illumination may be installed at a maximum height of 25 feet and may be positioned at that height up to the edge of any bordering property.
(c) Emergency lighting. All temporary emergency lighting needed by the Police Department, the Fire Department or other emergency services, as well as all vehicular luminaires, shall be exempt from the requirements of this section.
(d) Non-conforming fixtures. All outdoor light fixtures installed prior to the adoption of the UDC and those equipped with a permanent automatic shut-off device may remain unchanged; except that, the subject light fixtures shall not be operated between the hours of 11:00 p.m. and sunrise.
(e) Fossil-fuel light. This type of light is produced directly or indirectly by the combustion of natural gas or other utility-type fossil fuels.
(f) Low-intensity fixtures. Any outdoor lighting fixture that has a maximum candle power of less than 1,000 candelas is exempt from these provisions, if equipped with an automatic device that shuts off the fixture between the hours of 11:00 p.m. and sunrise.
(C) Shielding and filtration.
(1) All non-exempt outdoor lighting fixtures shall be limited to the types of fixtures specified in Table 153.1001(A) below and shall have shielding and filtration as required by Table 153.1001(A) below.
Fixture-Lamp Type | Shielded | Filtered |
Fluorescent | Fullyc,e | Yes |
Fossil fuel | None | None |
Glass tubes filled with neon, argon and krypton | None | None |
High-pressure sodium | Fully | None |
Incandescent, 150 watts or less | None | None |
Incandescent, greater than 150 watts | Fully | None |
Low-pressure sodiuma | No | None |
Metal halide | Fullyb,f | Yes |
Quartzd | Fully | No |
NOTES TO TABLE: a Preferred light source to minimize undesirable light emission into the night sky affecting astronomical observations. b Metal halide lighting used primarily for display purposes shall not be used for security lighting after 11:00 p.m. Metal halide lamps shall be installed only in enclosed luminaries. c Outdoor advertising signs of the type constructed of translucent materials and wholly illuminated from within do not require shielding. Dark backgrounds with light lettering or symbols are preferred to minimize detrimental effects. d For the purposes of the Unified Development Code, quartz lamps shall not be considered an incandescent light source. e Warm white and natural lamps are preferred to minimize detrimental effects. f Metal halide fixture-lamp types shall be filtered. “Filtered” means any outdoor light fixture that has a glass, acrylic or translucent enclosure of the light source (quartz glass does not meet this requirement). | ||
(2) Light source locations shall be chosen to minimize the hazards of glare. The ratio of spacing to mounting height shall not exceed a 4:1 ratio.
(3) All poles or standards used to support outdoor lighting fixtures shall be anodized or otherwise coated to minimize glare from the light source.
(D) Illumination. In order to minimize glare and hazardous conditions, illumination levels shall not exceed the levels set forth in Table 153.1001(B) below for any use permitted by this section. The maximum illumination shall be measured at grade at the property line of the site in accordance with subsection (I) below. (See Figure 153.1001(A) below.)
Area/Activity | Lux | Foot Candles |
NON-RESIDENTIAL ZONING DISTRICTS | ||
Adjoining another non-residential zoning district along an arterial | 20 | 2.0 |
Adjoining residential zoning district along arterial | 10 | 1.0 |
Adjoining another non-residential zoning district along arterial or collector street | 13 | 1.2 |
Adjoining residential zoning district along arterial or collector street | 6 | 0.6 |
Adjoining another non-residential zoning district along local street | 10 | 0.9 |
Adjoining residential zoning district along local street | 4 | 0.4 |
Adjoining another non-residential zoning district along property line | 10 | 0.9 |
Adjoining residential zoning district along property line | 2 | 0.2 |
OUTDOOR EVENTS | ||
Adjoining non-residential zoning district | 1,000 | 100 |
Adjoining or within 1,000 feet of residential zoning district | 100 | 10 |
RESIDENTIAL ZONING DISTRICTS | ||
Building exterior | 50 | 5.0 |
Front, side or rear yard (at property line) | 10 | 1.0 |
(E) Control of glare; luminaire design factors.
(1) Any luminaire with a lamp or lamps rated at a total of more than 1,800 lumens, and all flood or spot luminaires with a lamp or lamps rated at a total of more than 900 lumens, shall not emit any direct light above a horizontal plane through the lowest direct light emitting part of the luminaire.
(2) Any luminaire with a lamp or lamps rated at a total of more than 1,800 lumens, and all flood or spot luminaires with a lamp or lamps rated at a total of more than 900 lumens, shall be mounted at a height not exceeding the value 3 + (D.3), where “D” is the distance in feet to the nearest property boundary. The maximum height of the luminaire shall not exceed 25 feet.
(F) Prohibitions.
(1) Mercury-vapor fixtures and lamps. The installation of any mercury-vapor fixture or lamp for use as outdoor lighting is prohibited.
(2) Certain other fixtures and lamps. The installation of any low-pressure sodium, high-pressure sodium, metal halide, fluorescent, quartz or incandescent outdoor lighting fixture or lamp is prohibited unless it complies with the shielding and illumination standards (subsections (C) and (D) below) of this chapter.
(3) Laser source light. The use of laser source light or any similar high-intensity light for outdoor advertising, when projected above the horizontal, is prohibited.
(4) Searchlights. The operation of searchlights for advertising purposes is prohibited between the hours of 11:00 p.m. and sunrise.
(5) Recreational facilities. No outdoor recreational facility, public or private, shall be illuminated by non-conforming means after 11:00 p.m., unless otherwise permitted pursuant to a CUP, except to conclude specific recreational or sporting events or any other activity conducted at a ball park, outdoor amphitheater, arena or similar facility in progress prior to 11:00 p.m. All recreational outdoor lighting shall comply with height restrictions as specified in the Building Code. Outdoor lighting for open air arenas primarily used for rodeo and roping activities shall be permitted to a maximum height of 30 feet; provided that, shielding and filtration requirements (subsections (C) and (D) above) are met.
(6) Outdoor building or landscaping illumination. The unshielded outdoor illumination of any building, landscaping, signing or other purpose is prohibited, except with incandescent fixtures of 150 watts or less, or low-pressure sodium fixtures.
(G) Recreational facilities. Any light source permitted by this section may be used for lighting of outdoor recreational facilities (public or private), such as, but not limited to, football fields, soccer fields, baseball fields, softball fields, tennis courts, auto racetracks, horse racetracks or show arenas, consistent with the illumination standards specified in Table 153.1001(B) above; provided that, all of the following conditions are met:
(1) All fixtures used for event lighting shall be fully shielded, or shall be designed or provided with sharp cut-off capability, in order to minimize up light, spill light and glare; and
(2) All events shall be scheduled in order to complete all activity before or as near to 10:30 p.m. as practical, but under no circumstances shall any illumination of the playing field, court, or track be permitted after 11:00 p.m., except to conclude a scheduled event that was in progress before 11:00 p.m. and circumstances prevented concluding before 11:00 p.m.
(H) Outdoor display lots. Any light source permitted by this section may be used for lighting of outdoor display lots, such as, but not limited to, automobile sales or rental, recreational vehicle sales or building material sales; provided that, all of the following conditions are met:
(1) All fixtures used for display lighting shall be fully shielded or be designed or provided with sharp cut-off capability, in order to minimize up light, spill light and glare; and
(2) Display lot lighting shall be turned off within 30 minutes after the closing of business. The full illumination of the lot may be permitted after 11:00 p.m. pursuant to a temporary use permit. Any lighting used after that time shall be used as security lighting.
(I) Measurement.
(1) Metering equipment.
(a) Lighting levels are to be measured in foot candles with a direct reading, portable light meter.
(b) The meter typically has a color and cosine-corrected sensor with multiple scales and shall read within an accuracy of plus or minus 5%.
(c) It shall have been tested, calibrated and certified by an independent, commercial photometric laboratory or the manufacturer within one year of its use.
(2) Method of measurement.
(a) The meter sensor shall be mounted not more than six inches above ground level in a horizontal position. Readings are taken by qualified personnel only after the cell has been exposed long enough to provide a constant reading. Measurements are made after dark with the light sources in question on, then with the same sources off. The difference between the two readings shall be compared to the maximum permitted illumination and property line at ground level.
(b) This procedure eliminates the effects of moonlight and other ambient light sources.
(c) Where light patterns overlap, their total intensity shall be the sum of their individual intensities.
(Ord. 3020, passed 9-10-2013, § 5.15)