April 26, 2023 618 PM
PRESIDIO — At last week’s meeting, Presidio ISD leadership made the case to City Council that they should be exempt from the city’s dark sky ordinance. Ruben Armendariz, the district’s facilities and operations director, cited safety concerns as he respectfully pushed back against the call to replace outdoor lighting at the Presidio High School campus with lower-intensity bulbs.
Back in 2021, Presidio City Council approved an ordinance that would overhaul the city’s municipal lighting — and offer incentives to homeowners to switch out their lighting — in order to preserve Presidio’s pristine night skies. Experts and city leaders stressed that the change in lighting wouldn’t sacrifice safety, but would instead have a multitude of benefits for local wildlife as well as their human counterparts.
The initiative came just a few months before the region was designated the largest International Dark Sky Reserve in the world. The local tourism industry is built, in part, on the Big Bend’s spectacular stars. Even in the heart of the city, Presidians can still see the Milky Way — unlike 80% of Americans, whose night skies are polluted by light.
But Armendariz argued last week that the new lights simply weren’t enough to keep kids safe at the high school. The school’s outdoor lighting is currently running at 5000 Kelvins — a scale that measures the color, or temperature, of light — while the new dark sky-friendly municipal lights are 2200 Kelvins.
“We feel it won’t be enough for our parking lot, where we have incidents with immigrants, animals and so forth,” said Armendariz, who did not respond to inquiries from The Big Bend Sentinel about the alleged incidents.
PISD School Board President Ethel Barriga and Superintendent Ray Vasquez also attended the meeting to show their support, explaining that the high school campus is adjacent to a series of fields that run all the way to the river — prompting the concerns about human and animal traffic in the dark. PISD students involved in extracurriculars sometimes get back into town in the middle of the night, making it difficult to schedule lighting in advance. “We’re not trying to be uncooperative, but our number one priority is the safety of our kids,” Vasquez said.
Upgrading the Presidio High School parking lot has been a hot topic among district officials for awhile — at a February school board meeting, Armendariz and Vasquez weighed several options for making the campus safer, including fencing around the back of the school and more extensive lighting and surveillance. “Lighting is — for me — a priority,” Vasquez said.
McDonald Observatory Dark Skies Specialist Stephen Hummel attended the meeting alongside Big Bend Conservation Alliance Executive Director Shelley Bernstein. “We want to do what’s right for the school and I hope we can find a compromise,” Bernstein said.
Hummel gave a brief presentation from his work as a dark sky expert and educator to address some of the district’s concerns. He explained that state health and safety standards surrounding security lighting are based on research by the Illuminating Engineering Society of North America (IES).
The IES uses a unit of measurement called a “lux” to quantify how to best illuminate outdoor spaces weighing both safety and light pollution. A “lux” is one lumen per square meter, measuring how intense the human eye perceives light on an illuminated surface.
IES recommendations cap parking lot illumination between 5 and 10 lux — up to 30 can be used in “high security” contexts. The Presidio High School parking lot is currently estimated to measure 100 lux, which is approximately the level of illumination outdoors on a cloudy day.
Those standards come down to biology — contrary to popular belief, brighter lights at night actually make it harder to see in the dark because our eyes automatically make up the difference. Bright lights cast a glare that makes it more difficult to see beyond an illuminated area. “Dimmer light than you would expect allows you to see in the shadows,” Hummel explained.
The IES also recommends that the emphasis of lighting design be on the uniformity of light — in other words, consistent spacing around a particular lot or building — not necessarily on brightness or color. “Uniformity provides greater leverage in promoting the perception of safety,” reads a 2020 report from the Rensselaer Polytechnic Institute. “Designing for uniformity presents a strategy with great leverage for saving energy.”
Hummel previously worked with Alpine ISD to design dark sky-friendly security lighting for their parking lot, which rings in at 10 lux and currently uses a third of the electricity that Presidio ISD’s lighting does. Alpine ISD also reported no complaints from students, parents and staff. “Parking lot lighting is the kind of thing nobody notices when it is good — plenty complain when it is bad, so I view the lack of negative feedback as a good sign,” he said.
Superintendent Vasquez, however, argued that Hummel’s research does not apply to Presidio. “We’re totally different communities, and deal with different safety concerns than folks up north,” he said. “They’re not apples to apples.”
Councilmember Arian Velázquez-Ornelas also brought up the fact that the district’s current lights not only violate the dark skies ordinance, but also violate the State Health and Safety Code. “The majority of [state-funded] entities have to abide by this legislation,” she explained.
The Health and Safety Code statute she cited requires state-funded entities to balance “minimum illuminance adequate for the intended purpose” and to give “full consideration … to energy conservation, reducing glare, minimizing light pollution, and preserving the natural night environment.”
Council ultimately decided to take no action. All parties involved in the discussion could agree that Presidio High School needs new parking lot lighting, but exactly what that will look like is yet to be determined. “Even if Council were to grant an exemption, we’d still have to do something about the lighting,” Hummel said.