At Monday night’s City Council meeting, Presidio’s dark skies ordinance survived a challenge from Councilmember Fernando Juarez mostly intact—meaning that the greater Big Bend region’s claim to fame as the world’s largest International Dark Sky Reserve lives on too.
The city plans to move forward with a plan hatched in late fall of last year to experiment with new lighting downtown after a number of accidents and close calls on O’Reilly Street. “None of us are really satisfied with what we have right now,” Councilmember Juarez explained.
Communities around the Big Bend have adopted dark sky ordinances in phases since 1976, when the first local ordinance of its kind was passed in Jeff Davis County. The goal is to reduce light pollution around the McDonald Observatory so that the facility’s equipment can work under optimal conditions. The observatory’s campus in the Davis Mountains is home to some of the largest telescopes in the world, leading cutting edge research into the existence of life outside Earth and of more abstract concepts like dark energy.
In 2011, Gov. Rick Perry signed a bill into law requiring all communities around the McDonald Observatory to adopt dark sky-friendly lighting. Presidio was the last of the pack to pass an ordinance that round, but bounced back in 2021 to be the first to embrace a new series of restrictions.
“Dark sky-friendly” describes lighting that’s thoughtfully placed to reduce light pollution. Typically these lights are warmer in temperature and lower-intensity, and are both pointed at the ground and shielded from the sky above. The ordinance caps any lights installed at 2700 Kelvins, which is a scale that measures the color temperature of light.
Public education has been a huge part of the push against light pollution, as they challenge folks’ assumptions about how light works—for example, that brighter lights at night are automatically “safer.” As anyone who’s driven on Highway 67 at night can attest, super bright, cool temperature LED bulbs can be blinding, affecting your ability to see into the shadows.
As McDonald Observatory Dark Sky Specialist Stephen Hummel explained to Monday night’s crowd, “More lighting with less thought is less safe.” Over the years, he’s worked with companies like Apache Energy and Exxon—and other companies in the energy sector—to install workplace lighting that cuts down on light pollution and costs for employers.
After the latest ordinance was passed in 2021, the city made progress on updating lighting around town with help from the Big Bend Conservation Alliance. While many folks were happy with the lighting installed at their homes, the general consensus was that the City of Presidio needed more lighting infrastructure to close dark gaps around town. Councilmember Juarez pointed out that 1992 was the last time new lights were installed in town. “It’s definitely overdue for us to add additional streetlights,” he said.
One of Juarez’s proposals was to nix language in the ordinance limiting lighting to 2700 Kelvin and instead increase that number to 6000 Kelvin to allow for greater selection from AEP, which will ultimately order and install the new lights. Some folks in the audience worried that removing the limit as written in 2021 would jeopardize Presidio’s participation in the Dark Sky Reserve. That status has Brewster County officials seeing dollar signs—astrotourism is a booming industry and has come out on top as the No. 1 reason visitors choose Big Bend for their vacations. “We have to think of the greater context,” said Amber Harrison of Dark Sky International. “You stand to lose that certification for everybody in the tri-county.”
Other council members pushed back, and the ordinance was officially adopted with the 2700 Kelvin limit.