Maintain Original Intent
The proposed ordinances seek to maintain the general intent of the current lighting ordinance. That general intent is specified in the following introduction in the current lighting ordinance:
“This chapter 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, or which would otherwise be offensive to neighboring and nearby properties.”
Address New Technologies
New lighting options, particularly LEDs, produce more light at lower wattage and lower cost than ever before. Using watts to define brightness, as is done in the current lighting ordinance, is no longer relevant. Rather, definitions using Initial Lumens must be adopted.
Furthermore, LEDs can produce a bright white glare that is not only annoying to neighbors, but can also be a hazard to nighttime driving. People who have seen oncoming cars with bright white xenon headlights understand the kind of glare that bright white LEDs produce. A new technical term, Correlated Color Temperature (CCT), is needed to adequately control the type of light emitted by LEDs.
A second emerging technology is electronic message boards. Each year, they are becoming more affordable and the current ordinances have no guidelines for brightness and inadequate guidelines relating to usage. Here again, a new technical term, Nits, is needed so that maximum brightness of a flat panel display can be specified.
Note: The definitions of Initial Lumens, Correlated Color Temperature (CCT) and Nits are given on the first page of the Outdoor Lighting Zoning Code Amendments.
While the current lighting ordinance has guidelines related to shielding and light output per fixture, there is no guideline for how many fixtures can be installed on a given property (thus no limit on the total light output in a given area). For that reason, a lumen density cap per acre is needed for commercial and multi-family residential areas.