Dobbins JLUS IMP Public Draft Light Pollution Study | Page 110

W hat is a lumens cap and how does it work?
The majority of issues associated with overlighting can be addressed effectively by an overall
cap on the amount of light permitted, scaled to the area to be developed - lumens per acre
caps. (Lumens are a measure of light output as seen by the human eye and can be found on
every lamp package and catalog description.)
Lumens per acre is a simple calculation that does not require specialized technical training.
Newer versions of Outdoor Lighting Codes include a lumens cap. The lumens cap provides
maximum flexibility for the lighting designer to work within an overall "lumen budget" in order
to creatively achieve the goals presented by clients. Professional quality designs can achieve
the goals and solve the problems, if any, of each lighting situation by trading off amounts of
decorative and general illumination, areas to be illuminated, illumination levels and
uniformities, types of luminaire optical design, and other factors to achieve quality lighting
without the code specifying permitted or prohibited lighting uses, or illuminance levels for each
situation.
What about holiday lighting?
Seasonal decorative lighting is usually exempt from Outdoor Lighting Codes and is exempt
from the POLC during the holiday season.
What are Lighting Zones?
Lighting zones were first developed in Arizona lighting codes beginning in the 1980s, and were
designed to help protect astronomical observatories from the growth of light pollution. Since
then the concept has been expanded by the International Lighting Commission (CIE) and the
Illuminating Engineering Society of North America (IESNA) to address other environmental
concerns, such as energy conservation, glare, and light trespass. Environmental zone ratings
(Lighting Zones) help ensure that the lighting goals of an environment are appropriately
defined and met, but not exceeded. Simply put, the amount of light allowed in a given zone is
tailored to the density of development, activity levels and sensitivity of the zone or nearby
areas affected by lighting in the zone to off-site impacts of lighting (e.g. glare and sky glow).
For example, a densely developed commercial district would have a higher lighting allowance
than an agricultural area; areas near observatories or natural areas may have tighter limits than
areas located far from such sensitive areas.
What is the impact on planning and code enforcement staff in terms of administering an
outdoor lighting code?
Outdoor lighting codes have been in place in various Arizona communities since the 1970s
and have not been shown to create an unusual administrative load. At a MAG DSSG meeting,
the jurisdictions of Buckeye, Fountain Hills, Gilbert, Maricopa County and Mesa commented
that the code would not have a significant workload impact for them.
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Some jurisdictions have web-fillable or downloadable forms for the Existing Lighting Inventory
and Lumen Output Calculation Sheets as well as examples of properly prepared applications.
Nonetheless, as with any code, implementation and enforcement of a lighting code will impact
the planning and code enforcement staff. In addition to the time required to review materials
related to lighting, and on site follow-up to verify compliance, the staff will need to develop
some familiarity with lighting terms such as lumens, and how to reliably evaluate the shielding
characteristic of luminaires. Further, enforcement of any code includes not only the assurance
that plans and construction conform to the standards of the code when the building or lighting
permit is issued and when the project is completed, but also monitoring of continuing
compliance after the project is completed.
Can MAG adopt the POLC?
MAG is not an enforcement agency, as such, the POLC is not for adoption by MAG. It is
anticipated that MAG member agencies may consider adoption of the POLC either in whole
or in part as necessary for their jurisdiction.
Have crime, safety and Crime Prevention Through Environmental Design (CPTED) been
addressed in the POLC?
The pu