IDA International Dark-Sky City
Award Criteria

Goals

• To identify towns and cities with exceptional commitment to and success in implementing the ideals of dark sky preservation and their promotion through quality outdoor lighting;
• To provide international recognition for such communities;
• To promote the ideals of the IDA by encouraging communities to identify dark skies as a valuable community asset and goal.

Process

• Nomination by IDA member in good standing, with supporting signatures of at least three IDA members, two from outside the community receiving the nomination;
• Official support for nomination from mayor and/or council of the municipality (This assures a level of education in the community such that they are aware of the IDA, the IDA IDSC program, its goals and requirements);
• Approval of nomination by the IDA Board of Directors by a majority vote.

Minimum requirements

• A quality comprehensive lighting code, in place for at least three years, with the following minimum standards;
• Full shielding or full cutoff standard for all fixtures over 3000 lumens initial lamp output;
• Effective restrictions on total amount of unshielded lighting, such as a limit on lumens per acre or total site lumens in unshielded fixtures;
• Method to address overlighting, such as lumens/acre or illuminance specifications;
• Application of all relevant lighting code standards to public sector lighting as well as private or commercial lighting;
• City government commitment to Dark Skies and Quality Lighting, as shown by City-owned lighting conforming or committed to becoming conforming with LC;
• Public support of dark skies and good lighting as indicated through city publications, flyers, PSAs, LC updates, etc.;
• Broad support for Dark Skies from community organizations (e.g. Chamber of Commerce, local electrical utility);
• Success in LP control: at least one of the following conditions must be demonstrated:
  • DMSP image of community must be at least 15% fainter than the mean for communities of similar size in the region;
  • Measurement of zenith sky brightness increase over natural condition must be at least 15% below composite BV prediction based on “standard” Garstang model (DUSTPOL9 analysis with 15% ground reflectance, 10% direct uplight, and standard ratio of B to V photons produced by artificial lighting). This measure should be made from a sufficient distance from the community that local effects (i.e. nearby lighting) are minimal.

Designation is permanent, but subject to review and possible revocation upon request of any IDA Board member. Designation as an IDA IDSC entitles the City to display of the IDA IDSC logo in official municipal publications and promotions, and use of this logo by commercial or other groups within the community when identifying the city itself (i.e. an organization can say “located in Star City, an IDA IDSC” or other words to the same effect). IDA will maintain a web page identifying and describing all IDSCs.

For more information, contact IDA in Tucson at IDA@darksky.org.