HomeMy WebLinkAboutA002 - Council Action Form dated July 14, 1998 ITEM # 374
DATE 07/14/98
COUNCIL ACTION FORM
SUBJECT: DISCUSSION OF ISSUES TO BE ADDRESSED IN A LIGHTING
ORDINANCE FOR PRIVATE PROPERTY AND MOTION TO DIRECT THE CITY
ATTORNEY TO PREPARE A DRAFT ORDINANCE.
ACTION FORM SUMMARY: This is a discussion of lighting issues proposed by the
Lighting Task Force and City staff preliminary to preparation of a Lighting Ordinance for the
City of Ames.
Approval of the lighting issues as recommended and direction should be given to the City
Attorney and staff to prepare a Lighting Ordinance.
BACKGROUND:
The City Council directed City staff to research and identify lighting standards for the
purpose of preparing a lighting ordinance for private property for the City of Ames. Staff
researched the literature available on outdoor lighting, and acquired model lighting
ordinances and several adopted lighting ordinances from around the country.
A Lighting Task Force also was formed to review some of the outdoor lighting literature,
the model ordinances and the existing ordinances. The members of the Lighting Task
Force were Royce Bitzer, Bill Lee, Dave Oesper, and Rick Thompson. Eden Schmitt
served as the staff member who worked with the task force. The task force met six times.
At these meetings they reviewed the available lighting material; made an outdoor lighting
tour, visiting several sites in the community to measure the level of lighting at night; and
came to a consensus about the lighting issues that they felt should be included in a lighting
ordinance for the City of Ames. The group developed a statement of need and purpose,
goals to be accomplished with a lighting ordinance and a list of items that should be
addressed in a lighting ordinance.
A compilation of those issues is attached to this Council Action Form. The title of that
attachment is "Outline of Issues to be Addressed in a Lighting Ordinance for the City of
Ames". Also attached is information from the outdoor lighting tour, including the locations
visited, light level readings at the various sites, and general observations. The third
attachment to this Council Action form is an information sheet called "Recommended
Lighting Levels for Exterior Lighting". The lighting levels given on this information sheet
come from the recommended levels in the IESNA Lighting Handbook (IESNA is the
Illuminating Engineering Society of North America). The Lighting Task Force has
suggested that any established lighting levels be based on these IESNA Standards
(see Attachment II). Their recommendation is to not exceed twice the "initial" IESNA
recommended levels. These lighting levels also can be compared to the readings that
the task force made at the various locations around the City.
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Staff would like to discuss with the City Council the lighting issues that were identified by
staff and the Lighting Task Force. If the City Council concurs with these recommendations
then the Council should direct the City Attorney and staff to prepare a Lighting Ordinance
for the City of Ames.
ALTERNATIVES:
1. The City Council can direct the City Attorney and staff to prepare a Lighting
Ordinance for the City of Ames that is consistent with the lighting issues addressed
by the Lighting Task Force.
2. The City Council can make modifications to the lighting issues addressed by the
Lighting Task Force and direct the City Attorney and staff to prepare a Lighting
Ordinance for the City of Ames.
3. The City Council can decide not to proceed with a Lighting Ordinance.
4. The City Council can refer the lighting issues back to City staff for additional
information.
MANAGER'S RECOMMENDED ACTION:
It is the recommendation of the City Manager that the City Council adopt Alternative #1.
COUNCIL ACTION:
Attachment
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Attachment 1
OUTLINE OF ISSUES TO BE ADDRESSED IN A LIGHTING ORDINANCE
FOR THE CITY OFAMES
STATEMENT OF NEED AND PURPOSE: Good lighting at night benefits everyone in the
community. It increases safety, security, and visibility, allows for the enjoyment of the night sky,
and enhances the nighttime character of the city. New lighting technologies have produced
lighting that is extremely powerful, and this type of lighting may be improperly installed so as to
create problems with excessive glare, light trespass, and high energy use. Excessive glare can
cause discomfort, impair visibility, and may cause safety problems. Light trespass onto adjacent
and surrounding property reduces privacy and interferes with the enjoyment of one's property.
Excessive energy use is wasteful. There is a need for a lighting ordinance that recognizes the
benefits of outdoor lighting and provides clear guidelines for its installation so that it will
enhance and compliment the City's character. Appropriately regulated, and properly installed
outdoor lighting will contribute to the safety and welfare of all the residents and visitors to the
City of Ames.
The GOALS of this lighting ordinance are as follows:
• To control or minimize glare;
• To minimize up light;
• To limit hours when light is on, as appropriate;
• To minimize or eliminate light trespass;
• To require cut-off light fixtures;
• To provide variable standards for different types of uses;
• To maintain safety, security and visibility;
• To allow lighting as an aesthetic feature or design element; and
• To establish maximum light levels for different purposes and uses.
The following items and issues should be addressed or included in the lighting ordinance:
1. Historic lighting may be exempted from the full cut off requirement and considered
on its own merits.
2. Any lighting source producing less than 1800 lumens shall be exempt from the
regulation. A 100 watt incandescent light bulb produces about 1700 lumens.
3. Full cut-off lighting fixtures shall be required. The definition for full cut-off lighting
that no light shall extend above the horizon. The purpose for full cut-off devices is to
control glare by directing light well below the horizon. The intent is to shield the light
source from the viewer's direct. line of sight and to illuminate only the area where the
light is needed. Installation of full cut-off lighting should be done in a manner so that it
will continue to meet the full cut-off definition.
4. Developers shall submit lighting plans for all exterior lighting as part of site plan
approval or before they decide to change the lighting on their site. The lighting plans
shall be approved by the City prior to the installation of the lighting. These lighting
plans should show the type and location of pole mounted fixtures and/or building
mounted fixtures and a photometric report, which could be a light level grid or
Iso-Illuminance circles. The photometric report will indicate minimum, maximum, and
average footcandle levels and the distribution of lighting within the lighted area on the
site. The photometric report will also include the amount of light in the uplight zone (90
to 180 degrees above nadir) and the glare zone (75 to 90 degrees above nadir) for each
luminaire in its installed position. This type of report may be prepared at no cost by the
luminaire manufacturer or by an electrical engineer, who is designing the lighting for a
large project.
5. Standards shall be provided to address all nonexempt outdoor lighting fixtures to
prevent light trespass onto adjacent and nearby property. These standards
(maximum lighting levels at the lot line) may vary by the zoning and/or the use of
adjacent property.
6. All existing lighting may remain and would be "grandfathered", however, if the
existing lighting is removed and replaced with new luminaires, it would have to meet the
lighting ordinance requirements.
7. Light color should not be addressed in the ordinance. Although some lighting
ordinances address light color,the Lighting Task force felt this would be too restrictive.
8. Height limitations for lighting fixtures and light poles should not be necessary, if
other lighting standards are in place that address maximum light levels, the prevention of
glare and standards for light trespass.
9. Nuisance lighting should be prohibited. This type of lighting might include: laser
source light or similar high intensity light for outdoor advertising or entertainment, when
projected above the horizontal; searchlights for advertising purposes; and other similar
type lighting.
10. The lighting ordinance shall include a provision that nonessential outdoor lighting
fixtures shall be turned off within apartment, commercial, industrial zones between
certain hours — e.g. between 11:00 p.m. and sunrise with certain exceptions such as:
commercial and industrial uses where the use continues after 11:00 p.m., security and
safety purposes, and recreational uses that continue after 11:00 p.m.
11. Lighting for outdoor advertising should include a requirement that lighting fixtures
shall. be mounted on the top of the sign structure and that bottom mounted lighting
shall not be used. Outdoor advertising signs that are internally lighted should have a dark
background or conform to a minimum lamp wattage to minimize the detrimental effects.
Illumination of outdoor advertising for businesses or facilities that are not open
shall be turned off between 11:00 p.m. and sunrise.
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12. Maximum lighting levels should be established for various types of uses and
locations including: parking lots, building exteriors, loading and unloading areas,
storage yards, outdoor retail areas, and service stations/convenience stores. These
maximum lighting levels should be based on illuminance levels established in the IESNA
Lighting Handbook. The Lighting Task Force suggested that they not exceed twice the
initial IESNA recommended levels.
13. Lighting on towers shall be prohibited except as required by the F.A.A.
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Attachment II
Information Sheet Number 77 (October 1996)
International Dark-Sky Association
3545 N.Stewart,Tucson,AZ 85716-1241 USA
SaveOurSky@aol.com http://www.darksky.org
Recommended Lighting Levels for Exterior Lighting
The Illuminating.Engineering Society of North America (IESNA, or IES) gives in current IES
publications quite a number of recommended illumination levels for outdoor lighting. We
summarize some of these recommendations below, and in some cases the original tables have
been simplified. Some of these illumination levels are currently under discussion by IES
technical committees. It is important to note that these values are recommendations, not
standards. Standards are set at the federal, state, county, or community level. The IES does not
set standards, though IES recommendations are often used by those who set standards.
In fact, recommended illuminance levels are to some degree arbitrary. On p. 93 of the 1993
edition of the IESNA Lighting Handbook, it states that
It remains to be determined whether the added accuracy in predicting visual performance
will be utilized in the illuminance selection procedure. A model of visual performance,
no matter how accurate, is only part of illuminance selection. The cost of equipment and
energy will always be an important part of the Society's decision. If electric energy
prices were to double, recommended illuminance levels would certainly become lower.
Further, there are other, perhaps more important, lighting design factors that the
practicing illuminating engineer must consider in setting illuminance levels.
In all outdoor lighting applications, many factors come into play and should be considered:
minimizing glare, mounting height and spacing, lighting system depreciation and life-cycle cost,
conflict areas (such as between vehicles or between vehicles and pedestrians), access control and
vandalism prevention, as well as the mix of commercial, industrial, and residential properties
near the area to be illuminated. For example, in the presence of glare, one needs more
illumination to try to overcome the adverse impact of the glare; without glare, lower illumination
levels are possible, with an actual improvement in visibility. The key is that all outdoor lighting
should be carefully done, with consideration given to all the relevant factors.
We give below a summary of the lighting illuminance levels in footcandles, as that is the most
common unit used in the United States. However, lux is the preferred international unit, and the
IES does officially recommend its use in the United States. A level of ten lux is about one
footcandle (10.76 Ix = 1 fc, exactly).
Roadway Lighting (for asphalt pavement; levels should be about one-third lower for
concrete)
Average Maintained Uniformity Expressway: Major divided highway.
Illuminance (fc) (Avg/Min)
Expressway 1.1 3/1 Major: Principal network for through traffic. Arterial.
Major road 1.2 3/1 Collector: The streets between Major and Local.
Collector road 0.8 4/1
Local road 0.4 6/1 Local: Access roads to residential properties.
Parking Lots
Horizontal Illuminance
Level of Activity: (Footcandles) Uniformity
Avg Min Ratio
High Major League Athletic Events 3.6 0.9 4/1
Major Cultural or Civic Events
Regional Shopping Centers
Fast Food Facilities
Medium Community Shopping Centers 2.4 0.6 4/1
Cultural, Civic, or Recreational Events
Office Parking
Airports, Commuter Lots, etc.
Residential Complex Parking
Hospital Parking
Low Neighborhood Shopping 0.8 0.2 4/1
Industrial Employee Parking
Educational Facilities
Churches
IES also states that the "Low" values are appropriate wherever there is a requirement to maintain
security at any time in areas where there is a low level of nighttime activity.
Recommendations for other outdoor lighting levels (footcandles)
Building exteriors
Entrances
Active (pedestrian and/or conveyance) 5
Inactive (normally locked, infrequently used) 1
Vital locations or structures 5
Building surrounds 1
Floodlit Buildings and Monuments Dark surroundings Bright surroundings
Light surfaces 5 15
Medium light surfaces 10 20
Medium dark surfaces 15 30
Dark surfaces 20 50
Loading and Unloading Platforms 20
Service Stations
Approach 1.5 3
Driveway 1.5 5
Pump Island 20 30
Service Areas 3 7
Storage Yards
Active 20
Inactive 1
Retail Outdoor Lighting Illumination Level of Surrounding Area
High Medium Low
Seasonal Circulation 10 7 5
Marketing area 30 20 10
Feature display 60 40 20
Auto Lots Circulation 10 7 5
Merchandise 50 30 20
Feature display 75 50 35
IES states that the illuminance in exterior retail selling areas should not exceed 10 times that of
the surrounding area. Measurements should be referenced from the roadway.
Information Sheet Number 77 (October 1996),p.2
Attachment III
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Outdoor Lighting Tour NOTE: f.c. is an abreviation
February 19, 1998 for footcandles
1.) Location
2.) Light level readings
3.) General comments on brightness, security,unusual features, etc.
City Hall parking lot
Beneath pole(max.): 4.2 f.c.
Between two poles: 1.9 f.c.
At center of 4 poles (min.): 1.9 f.c.
One fixture is cycling on and'off.
Light level is adequate. Seems well-lighted.
Apartment house, 705 Clark Ave.
Ca. 12 wall-mounted fixtures on garage and 3 sides of house
Considerable light trespass on surrounding properties
Harsh glare; the excessive light on the sides of the house make its front facade seem too
dark
Inappropriate lighting for a residential neighborhood. Lighting design inappropriate for a
historical area.
Apartment house, 9th St. and Kellogg Ave.
Good wall-mounted fixture designs--low glare, still some light trespass on neighboring
property to the south.
Mary Greeley Hospital parking lot
Beneath pole (max.): 8.6 f.c.
At center of 4 poles (min.): 3.6 f.c.
Amoco, 13th St. and Grand Ave. Pump island with 4 luminaires
22 f.c. in center of island, 28 directly beneath one luminaire
Light level under island seems adequate. North side of lot may seem dark because the
light above the north entrance to the lot is out.
Light level is low enough so that it is easy to see objects beyond the pump island when
one is standing beneath it.
Church of Jesus Christ of Latter-Day Saints parking lot, 2524 Hoover Ave.
Center line of lot: 0.7 f.c.
Beneath pole (max.): 8.2 f.c.
Floodlights to south may make south side of lot seem too dark. Also recheck when
pavement is dry.
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Cub Foods parking lot
Beneath pole (max.): 7.5 f.c.
At center of 4 poles (min.): 2.1 f.c.
Light level seems adequate, but may be some contrast effect due to white metal-halide
parking lot lights in the adjacent Wal-Mart parking lot.
Wal-Mart parking lot
Beneath pole (max.): 3.7 f.c.
At center of 4 poles (min.): 1.2 f.c.
Although the Wal-Mart parking lot is only half as bright as the Cub Foods lot, it actually
seems brighter!
Unity Christian Reformed Church, 3626 Ontario St., parking lot and building
Oversized ornamental fixtures on wall near door
Sidewalk 12 ft. from door: Horizontal illuminance, 6.4 f.c., vertical, 11.E f.c.
Parking lot
Between 2 poles, at east edge of center median: 3.7 f.c.
East edge of lot: Horizontal illuminance, 0.4 f.c., vertical, 1.1 f.c.
Considerable glare and light trespass on neighboring homes. Lighting is inappropriate for
a residential neighborhood.
Department of Transportation, east parking lot
Beneath pole (max.): 0.8 f.c.
At center of 3 poles (min.) 0.5 f.c.
Very high poles keep light levels almost uniform across the entire lot. Light levels are
adequate for a parking lot with this function.
Casey's, Lincoln Way and Clark Ave., pump island with ca. 20 luminaires
Beneath canopy: 55 f.c.
Light brighter than necessary. Sidewise glare is distracting and may make it hard for
passing motorists to see clearly.
When one is standing beneath the canopy and looking outward, it is hard to see some
objects beyond the canopy.
Ron Willey Ford, display lot
Beneath pole (max.): 61 f.c. (= illumination at sunrise or sunset on a clear day!)
At center of 4 poles (min.): 3.9 f.c.
Illuminance looks surprisingly uniform, considering the max.: min. ratio is over 15 : I!
Considerable reflected light shining up into the sky creates local airglow. Is this metal
halide lighting bright enough to create an ultraviolet:hazard to someone standing beneath
it and looking up into the fixtures?
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Lowe's Hardware Superstore,parking lot
Beneath 2-luminaire pole(secondary maximum): 15.1 f.c.
At center of 4 poles (2 with 2 luminaires, 2 with 3 Luminaires): 4.0 f.c.
Illuminance at north edge of sidewalk in front of building: ca. 12 f.c.
Maximum illuminance, from a 3-luminaire pole with attached floodlight shining toward
front of building: 40 f.c. From this spot,the fixtures at the top of the pole are at an
! altitude of 65 degrees.
€ Intense glare makes it difficult to see across the parking lot.
Swift Stop, 1100 block of South Duff Ave.,pump island with multiple luminaires
Beneath center of canopy: 76 - 80 f.c. Area seems overlit. Somewhat difficult to see
objects beyond canopy.
Front of store: 8 f.c. Light level seems adequate here.