10-19-2015 Planning Commission Packet

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FILE#15-3784 19 October 2015 Page 2 of 3 bedrooms, etc. Solution: The most common, non-regulatory solution is for the property owner to willingly adjust or shield lights so that does not impact a neighbor. For situations where that does not occur,the proposed regulatory solution establishes measurable (1.0 fc) lighting at the property line as a nuisance and may be corrected through means offered in the code, including citations and mitigation. The proposed ordinance also alters the existing text regarding "Glare or Heat" to a more specific "Lighting", and offers a definition and general requirements for the use of lighting. The ordinance also requires light fixtures in the lake yard to be fully shielded, which is a new defined term. A full moon on a cloudless night is approximately .03 foot candles, based on internet studies,though that measure can vary based on several factors, including elevation. The standard for variance (1.0 fc) is purposely higher than the design standard for new fixtures. We recognize that existing lights provide light higher than 0.4 foot candles at the property line, but those lights would be allowed to remain as a permitted non-conforming improvement. Staff performed a real world test from a single light source in a residential neighborhood on a clear night with a crescent moon 2% illuminated. Results are tabled below. Topography, vegetation and competing light sources prevented full measurements. 60w clear bulb, Distance clear 60w frosted 150w flood Excel energy from source enclosure enclosure light street light @5 feet 0.34 @10 feet 1.73 0.9 12.5 0.46 @15 feet 0.4 0.34 @20 feet 0.22 @25 feet 0.22 3.3 @30 feet 0.12 0.13 @50 feet 0.07 0.06 All measurements are taken in footcandles Previous versions of the ordinance included a time limit. Upon further analysis,the time limit was removed, due to behavior modifications (a neighbor could simply turn off the light once every 2 hours or 2 minutes) and the expense of an officer or staff staying on the site for an extended period of time to verify that the light(s) never turned off. Options considered: Early drafts of the ordinance proposed regulating lighting in the zoning ordinance only, but were discarded because existing lights that shine on neighboring properties would be considered legal non-conforming,and allowed to continue in perpetuity. The city should be cautious about over regulating lights, recognizing that lights are very important features,often directly linked to safety and security. Enforcement: The enforcement of this code may be challenging,and will likely require equipment not currently owned by the city. Due to the nature of the potential violation, enforcement will most likely be completed by Police officers.