Dark Sky Ordinances By Buck Abbey, ASLA and Robert Reich School of Landscape Architecture Louisiana State University In November 2011, the Arizona Court of Appeals ruled electronic billboards along state and federal highways violate the Arizona Highway Beautification Act's ban on intermittent light. The Arizona State Legislature, however, is moving to legalize electronic billboards along the interstate (HB 2757), which obviously would increase light pollution. The establishment of the act, however, would not prevent a city or county from enforcing or enacting an ordinance regulating billboards, including the lighting of billboards.
?EUR??,,????'?????< ?EUR??,,????'?????< |
|
|
Lighting Ordinances and Green Laws If you have ever camped on the southeast rim of the High Chisos Trail near the impressive Toll Mountain in Big Bend National Park you know the dazzling spectacle of the night sky in all of its majestic sparkling beauty. Stretching from the northern aurora borealis to views of the Southern Cross, the Milky Way Galaxy presents a nighttime show to campers that humbles the human spirit and reminds us that we are but a speck in the natural world. In our cities this view of nature is disappearing.Communities across the country are concerned about the disappearing night sky and the loss of a resource that has amazed, fascinated and bewildered mankind since the dawn of civilization. If you live in New York, Chicago or San Francisco the nighttime sky is a hazy hue of yellow and the only evidence of the nighttime sky is the rising moon. Even those who live in a small town or rural community may have their night view disrupted by an inconsiderate neighbor.
 The Model Lighting Ordinance (MLO) is a joint venture of the International Dark-Skies Association (IDA) and the Illuminating Engineering Society (IES). MLO is an outdoor lighting template designed to help municipalities develop outdoor lighting standards that reduce glare, light trespass and sky glow. Image: IDA
Night Lighting Design Winter Haven does this by setting standards to control illuminance, footcandle (fc) intensities and color rating index (CRI) for each lighting purpose. Standards are based upon Illuminating Engineering Society of North America (IESNA) recommendations to focus lighting only where it is needed, and limit it beyond the fixture radius that is equivalent to the fixture height. Standard fc ratings in the code range from .05 to 20 fc. Pole and fixture heights are limited to 16 feet for most exterior areas, with the exception of parking lots, which may have 30-foot heights. Specific standards are mentioned in the code for parking areas, walkways, bikeways, drive-through service areas, dealerships, fire lanes, backlit awnings, store fronts and wall mounted fixtures. Residential areas are not required to comply with these standards. The use of cutoff lenses, hoods, visors and time controls are encouraged, while sag lenses, convex lenses and drop lenses are prohibited. Lighting plans and specifications for poles, fixtures, lenses and lamps are required to be prepared by an engineer, landscape architect or architect. Dark Skies Model Code The MLO was created to assist communities in setting responsible outdoor light level standards. The use of these special lighting criteria will reduce costs, save energy and cut back on greenhouse emissions. Together they will reduce the overuse of excessive foot-candle lumens, which are largely responsible for light pollution. Among the standards set forth in the MLO are five light-intensity zones, lumen (power) allowances for various type of land uses and IES?EUR??,,????'?????< You can find more technical information, including the MLO and a lighting code handbook, at www.darksky.org. |
|
