Rob Roush, the developer of the Red Desert subdivision in Ivins, contacted us last month because he was interested in making his development next to Red Mountain as dark sky friendly as possible. He also helped us on our first nighttime outing to measure the color temperature of lights in the City.
Over the past month or so, we exchanged a number of emails and discussed outdoor lighting issues he was dealing with in drafting his CC&Rs. Rob recently filed CC&Rs and sent us a copy. Rob had clearly done a lot of homework.
Red Desert’s CC&Rs are more restrictive than out current outdoor lighting ordinance. And they are more restrictive than the International Dark Sky Association (IDA) requires for communities seeking certification as Dark Sky Communities.
For example, our current ordinance allows the color temperature of outdoor lighting to be has high as 4,000 degrees kelvin. That’s too high and the City has plans to reduce that requirement to 3,000k or lower. IDA requires a maximum of 3,000k. Rob’s CC&Rs requires a range between 2,200k and 3,000k with a target of 2,700k.
Red Mountain as seen in unusual February snow from the Red Desert development site
IDA also requires properties limit the total amount of outdoor lighting. Our existing ordinance doesn’t really address that, it’s a newer concept in outdoor lighting circles. Red Desert’s CC&Rs not only address overall limits, they also set a maximum amount of lumens for each type of outdoor lighting use. And Rob’s CC&Rs are not only more protective about shielding lights than our current ordinance, they are more protective than IDA requires.
Thank you Rob for taking the efforts of our Ivins Night Sky Initiative to heart.
For more information about night sky friendly lighting, projects we are working on, upcoming events, or inquiring about getting involved, Contact Us.
The color temperature of outdoor lighting has become a big deal in the past few years. LED technology has given us incredible energy efficiency. But more and more we are learning that this benefit comes at a cost: Too much glare, too bright, to much harmful blue wavelength emissions, and more. The old technology these LEDs are replacing, low- and high-pressure sodium lights, don’t have any of those problems.
The current outdoor lighting ordinance in Ivins sets a maximum color temperature of 4,000 degrees kelvin. Our ordinance is very dark sky friendly, and at the time it was implemented in 2007 it was probably a model of dark sky friendliness.
But time moves on. The “gold standard” today is to install lighting with a color temperature no more than 3,000 degrees kelvin. That is the requirement for designation as a Dark Sky Community by the International Dark Sky Association (IDA).
But some argue that 3,000k is still too high. For more information, see articles by Christian Luginbuhl, a retired scientist from the United States Naval Observatory in Flagstaff at the Flagstaff Dark Skies Coalition.
So, last night we went out to measure the color temperature of some outdoor lighting in Ivins. We were accompanied by Rob Roush of Red Earth Development. He is developing the Red Desert subdivision in Ivins next to the Reserve. He contacted us last month because he wants to maximize the dark sky friendliness of his project and has been searching for answers about appropriate color temperatures for his development’s outdoor lighting.
Technological improvements are great, but they can create more work, especially for those who pay attention. Color temperature is something nobody ever had to pay much attention to.
First, a disclaimer. Our outing last night is just a preliminary step. We need to do a lot more research, especially since the results we got raised some questions. But it was eye-opening.
We used a high-end spectrometer, the AsenseTek Lighting Passport. It’s an expensive little device that costs about $2,000. It communicates with an app on your cellphone. We were fortunate to be able to borrow it from IDA.
We measured some of the bollards on the west side of Rocky Vista University on 200 N. The spectrometer reading as under 1,600k for these. We’ll have to doublecheck with the City, but we believe the light source is an LED rated at well over 2000k.
City staff told us they added a “lens” to these lights that seems to lower the color temperature. But that’s still a big difference. It may be caused by the light source bouncing off a bowl shaped dome, and the dome’s color lowering the color temperature. Well, there’s some homework.
The color temperature of one of the city’s cobra lights was 1,851k. The light source in cobras is typically high pressure sodium. But they are slowly being replaced by LEDs.
We measured a number of other lights and got similarly low color temperature readings. Maybe the app we downloaded didn’t like our android phone. So Rob downloaded the app on his iPhone. He got the same readings.
For example, the newer post top lantern lights the City is installing were around 1,800k using both phones. We were expecting higher readings.
Maybe the AsenseTek spectrometer was giving us incorrect readings. That seemed unlikely. It’s an expensive, professional device.
But we were still concerned. Maybe we were measuring incorrectly. We tested that by taking a meter reading right next to the light source and a reading a number of feet away from the light source. We got the same result. That’s how it should be. We are measuring the color temperature of the light, not the amount of light, or illumination.
So we continued. The Veterans Center has parking lot lights that read just over 1,700k. These appear to be sodium lights. And it looks like a few were fluorescent, which came in at close to 3,000k. These readings made sense.
Similarly, the parking lot lights at Rocky Vista University registered around 4,000k. That also made sense. These are LED lights and our current ordinance allows lighting up to 4,000k. We found other parking lot lighting that had even higher kelvin readings, some close to 5,000k and some even higher. These were probably installations that predated our current ordinance.
Why go to all this effort? If we are going to recommend changes to the city’s outdoor lighting ordinance, we need to understand what lighting in the city might look like in the future.
This was a first step, and it certainly wasn’t a giant leap for Ivinkind, but at least it’s a start. We have some homework to do with IDA, AsenseTek, and the City.
If you have any expertise in lighting issues, we would value your input. Let us know if you are willing to help by emailing us from the Contact us page.
We completed a first draft of a revised outdoor lighting ordinance today that meets the requirements of the International Dark Sky Association (IDA) and distributed the draft to the Mayor and City staff for their review and comment.
In addition to recommending changes to comply with IDA requirements, we identified issues where we believe the City should do some research before committing to certain changes. Here are two examples:
(1) IDA requires communities to set a limit on the total amount of lumens generated by outdoor lighting on a property. IDA does not set what that limit should be. We listed limits other communities have adopted. However, we recommended researching a sample of existing properties in the City to find out their total lumen output and use that as a guide for setting limits.
(2) IDA requires that city-owned lighting be brought into compliance with its new regulations within five years. For some time now, Ivins has had a plan of replacing poor city-owned outdoor lighting. However, we recommended continuing the research we began this past week, the City-Owned Street Lighting Study: Part 1, where we inventoried all existing outdoor city-owned lighting. The next step should be to determine which lights would need to be replaced or retrofitted to meet IDA requirements and determine the cost for that work. That way, the City will be able to determine if it can realistically budget for those changes within the 5-year limit.
During December we completed a review of ordinances from nine communities that meet the requirements of the IDA. The ordinances contained a number of good ideas, separate from IDA requirements, that we recommend the City consider including in its ordinance as well. However, that should be “step 2.” Step 1 is reaching conclusions on the IDA requirements that were incorporated into the draft ordinance submitted today.
