July 29, 2004


Planning & Zoning Commission

c/o Mr. John Neunuebel

Planning Director

Town of Sahuarita

850 W. Sahuarita Road -- B

Sahuarita, AZ   85729


Dear Commissioners:


We respectfully request that the Planning and Zoning Commission of the Town of Sahuarita deny the variance to the Outdoor Lighting Code requested by Diamond Ventures for Madera Marketplace.   We do not see that the applicant has shown an overriding need to use more than twice the amount of light allowed under the existing Sahuarita Code.


Please recall that the Observatory supported the proposal to double the amount of light permitted under the Sahuarita OLC just a few months ago as a compromise for uniformity and ease of compliance.  The developers now have the same lumens cap as the surrounding county land.  To ask for another doubling seems unreasonable.


We take exception to the applicant’s statement, “More importantly, the total number of lumens does not have an adverse effect on the Mount Hopkins Observatory’s light gathering capabilities due to the use of full-cutoff low pressure sodium fixtures.”


Light in the night sky harms astronomy in two ways:  Light, from whatever source (including LPS), escaping into the night sky overwhelms the light of stars and other fainter sources, making them hard or impossible to measure at all.  In addition, astronomers who study the individual colors of star light find the colors of Metal Halide, High Pressure Sodium and LPS lamp-light overlaying and hiding the star light colors.  LPS is the least harmful because it only has one color, but it is not harmless.


The total number of lumens has a tremendous effect.   From even the best outdoor lighting systems, an average of 15% of the light reflects off of the ground and into the night sky.  So any increase in lighting directly increases the amount of light in the sky.


The applicant expresses concern about criminal activity and liability resulting from following the current Code.  The City of Flagstaff Outdoor Lighting Code has had similar lighting limits since 1989.  (Please see attachment).  Any serious liability and criminal activity problems should have surfaced by now.





We are concerned about the precedent that would be set by granting this variance.  Diamond Ventures has assured us that this would not be precedent-setting since the Town would individually review every such application, yet they cite the precedents of the light levels of other commercial installations in their own application.  (These other installations were not built under the present code and don’t seem relevant.)


Hyman Kaplan, Chair of the Pima County Outdoor Lighting Code Committee, has commented on the design aspects of the application.  From his remarks, it seems the technical arguments for a variance are wanting.  The lighting allowances under the Sahuarita Code meet or exceed the Illuminating Engineering Society recommendations in a properly designed application.


Please remember that the Outdoor Lighting Code is not only for the benefit of astronomical science.  It encourages good lighting practice to save energy, prevent light trespass, and provide safe use of the night.


Thank you.








Dan Brocious

Public Information

Whipple Observatory