This section provides standards for outdoor lighting in the mountain and desert regions of the County.
(a) Shielding Required. All outdoor light fixtures shall be fully shielded, installed and maintained in such a manner that the shielding does not permit light trespass in excess of amounts set forth in subdivision (f).
(b) Light Pollution Standards. Light pollution and trespass shall be minimized through the use of directional lighting, fixture location, height and the use of shielding and/or motion sensors and timers in such a manner that the light source does not permit light trespass in excess of amounts set forth in subdivision (f).
(c) Automated Controls. Automated control systems, such as motion sensors and timers, shall be used to meet curfew requirements set forth in subdivision (d). Photocells or photo controls shall be used to extinguish all outdoor lighting automatically when sufficient daylight is available. Automated controls should be fully programmable and supported by battery or similar backup.
(d) Dark Sky Curfew. All outdoor lighting shall be extinguished by 11:00 p.m., close of business, or when people are no longer present in exterior areas, whichever is later, except for the following:
(1) Lighting used for entry and exit points of a structure, parking areas, driveways and driveway ingress/egress points; or
(2) Lighting activated by a motion sensor that extinguishes no later than five minutes after activation.
(e) Lighting Color. The correlated color temperature of all outdoor lighting shall be 3,000 Kelvin or less except for seasonal lighting.
(f) Allowable Light Trespass. Outdoor lighting shall not cause light trespass exceeding one-tenths foot-candles measured with a light meter oriented vertically or horizontally either at the property line of the adjacent property or measured from some other point on the property where light trespass may be reasonably determined to occur due to differences in property or improvement elevations.
(g) Blinking, Flashing, or High Intensity Lighting. Permanently installed lighting that blinks, flashes or is of high intensity or brightness that causes a light trespass is prohibited.
(h) Residential String Lights. Notwithstanding anything to the contrary, string lights may be allowed in outside dining areas, entertainment areas or used as landscape lighting in connection with a residential dwelling or use provided that all of the following conditions are met:
(1) The correlated color temperature of the light sources does not exceed 3,000 Kelvin; and
(2) The emission of no individual lamp in the string exceeds forty initial lumens, and the aggregate total of lumen output of such string lights used as outdoor light fixtures does not exceed 4,000 lumens.
(Ord. 4419, passed - -2021)