Implementing the full “Flagstaff Solution” for dark sky protection/restoration cannot be done all at once. While most communities naturally start by drafting a lighting code, this code cannot be developed or function in a vacuum. The lighting code is a regulatory tool designed to enforce the broader, long-term goals established in a city’s Comprehensive or Regional Plan. Because these two elements depend on each other, communities should develop their overarching plans and their specific lighting codes at the same time. This section focuses specifically on the lighting code.

Do Not Build Your Own

Unlike standard construction codes (such as plumbing or electrical) that come from established professional sources, dark sky protection lacks a universally recognized authority. Consequently, many communities take flawed models and try to customize them to fit local “values.” This customization relies on a false assumption: that protecting the night sky requires sacrificing practical human lighting needs. Ultimately, this tailoring process produces legally weak, technically flawed codes that fail to protect dark skies.

The published evidence of relentless night sky deterioration over the last 20 to 30 years shows the result [Footnote: Kyba et al., Guardian, etc.].

Flagstaff’s lighting code successfully protects dark skies, ensures legal clarity, and is consistent with effective outdoor lighting. Adopted in 1989 and regularly updated since, it has a proven record of practicality and effectiveness. The Flagstaff Dark Skies Coalition (FDSC) strongly recommends that other communities adopt this exact code rather than using alternative templates or attempting to customize it.

Customizing this code is both unnecessary and harmful. First, the goal of protecting the night sky and the needs for effective outdoor lighting are the same in all communities; dark sky protections do not require sacrificing visibility, safety, or utility provided by outdoor lighting. Second, altering the text almost always compromises critical wording, making the code less effective and often legally unenforceable.

FLAGSTAFF LIGHTING CODES AND OTHER STANDARDS

The Lighting Code

The Flagstaff lighting code is built around three principal strategies: From most to least important (with indicated approximate skyglow reductions)…

1. Use amber lighting (S/P less than 0.5) for general illumination (roadways, parking lots, etc.) – 70% reduction in artificial sky brightness
2. Use only fully shielded lighting – 50% reduction (amber + shielding cumulative 85% reduction)
3. Limit lighting on nonresidential properties to 35,000 lm per acre – 25% reduction (amber + shielding + amount cumulative 89% reduction)

(The skyglow reductions listed above and used to rank the importance of the strategies are based on published research and generally apply to observation locations near the lighting sources or within urban areas. The reduction amounts at greater distances vary, though in general the benefits of amber spectrum decrease and the benefits of shielding increase with distance from the light source.)

Flagstaff Lighting Code 11-15-22 – with Definitions

Flagstaff Lighting Code with Explanatory Material

Other Codes and Standards

Not all outdoor lighting is subject to the standards contained in the zoning code.

• Signs

In Flagstaff, lighting for signage is largely regulated through a separate section of the zoning code:

Flagstaff Sign Code 06-21-16

• Roadways

Municipal roadway lighting is governed through the city’s Engineering and Design Standards.

Flagstaff Engineering and Design Standards 09-15-20

State roadway lighting is governed by the Arizona Department of Transportation.

ADOT F0623 standard

• Lighting at Northern Arizona University is specified by Design Guidelines and Technical Standards

Northern Arizona University Design Guidelines and Technical Standards Division-26 01.08.21