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