Presidio leads the pack among Big Bend communities implementing dark sky lighting ordinances

A slide from Bill Wren’s dark skies presentation delivered to Marfa City Council in July 2021, featuring an illustration by Rémi Boucher of the Mont-Mégantic International Dark Sky Reserve.

PRESIDIO — The stars over Presidio at night may soon get even more spectacular as the city works with the Big Bend Conservation Alliance to replace streetlights with dark sky friendly fixtures. 

In December, city council ended the year on a high note by passing the latest round of ordinances, which help solidify the Big Bend region’s place as the largest international dark sky reserve in the world, according to the International Dark Sky Association. The ordinances have rolled out around the region in stages, allowing each municipality five years to catch up with the latest changes. 

“When we passed our first ordinance in 2014, we were the last city to get on board, but this time around, we’re the first,” said Mayor John Ferguson. The city will work with the Big Bend Conservation Alliance to replace the city’s streetlights with LED fixtures that will reduce light pollution and enhance nighttime visibility. Bill Wren, a former dark skies specialist at the McDonald Observatory, toured regional city councils over the summer to defuse common misconceptions about the recommended updates. “Dark skies, not dark ground” was the slogan used to assure the public that reducing light pollution doesn’t mean that every town in the Big Bend will go pitch black after sunset. 

Current McDonald Observatory dark skies specialist Stephen Hummel explained that the ordinances have been gradually rolling out in the region since the 1970s, when a team of professional and amateur astronomers approached local leadership Fort Davis about protecting the observatory’s view of the stars by making changes to their streetlights. The ordinances have been updated over the years to keep pace with the latest technology. “Things have changed a lot since the 1970s — the language in the ordinances back then really doesn’t really work with modern LEDs,” Hummel explained. 

In 2011, Governor Rick Perry signed a bill into law that required all communities around the McDonald Observatory to switch over to dark sky friendly lighting. Towns around the Big Bend that hadn’t yet passed ordinances started thinking about how to transition. To make lighting “dark sky compliant,” lights must be shielded and pointed down, preventing light pollution from blotting out the stars. Warmer, lower-intensity bulbs on timers are the ideal dark sky streetlights, but communities can make a lot of headway just by shielding their bulbs. 

Dark skies are judged against a metric called the Bortle scale, which assigns a number from 1 to 9 based on the number and quality of celestial bodies that are visible to the naked eye. The night sky in New York City scores a 9 on the Bortle scale, while the view from the front steps of Presidio City Hall is considered a 4, typical of “rural/suburban transition.” The rodeo grounds in Redford earn a Class 2 Bortle ranking, and deep in the heart of the Solitario in Big Bend Ranch State Park, you can enjoy pristine Class 1 skies, the highest classification available. 

Over the summer of 2021, the Big Bend Conservation Alliance, with help from local painter Julie Speed, raised $46,000 for dark sky compliant lighting in the region. “Some of these municipalities have money to do the swap, and some of them don’t,” explained Shelley Bernstein of the Big Bend Conservation Alliance. “We’re trying to figure out how we can get this done for the ones that don’t.” The City of Presidio, a lower-income city recovering from years of financial turmoil at the municipal level, is one such example. City officials met with Blake Burchard and Bart Rosenquist of AEP to discuss the logistics of switching the city’s 103 streetlights to dark sky friendly and energy efficient LED bulbs. 

Presidio’s much larger sister city, Ojinaga, made the swap in 2015. The transition to LED came mostly from a cost-saving perspective, but as word about the push for dark sky protections made its way across the river, Mexican officials voiced their support. “I am supportive of efforts to use outdoor lighting in a responsible, cost-effective manner that helps protect our shared night skies,” Luis Ernesto López Echavarria, technical secretary for the Council for the Economic Development of the State of Chihuahua, wrote in a letter to the International Dark Sky Association. “The designation as an international dark sky reserve for this region has many positive impacts, including ecological, human health, and increased tourism, as well as protecting professional and amateur astronomy for the future.” 

Presidio officials are pitching the plan to the public as a boon to tourism and as a cost-saving measure. The light fixtures suggested by AEP would save the average homeowner $3 or more a month. The streetlights can be rolled out by the city relatively quickly — Burchard estimated that each municipal light will take his crew about 30 minutes each to replace. The big hang-up is waiting for the new LED fixtures to arrive, victims of the shipping bottlenecks consumers around the world have been facing during the COVID-19 pandemic. “It’s a supply chain issue for sure,” he explained. 

A second phase of the project will be convincing homeowners to replace their guard lights. There are 68 non dark sky compliant guard lights in Presidio, but it’ll be up to each individual to make the swap. The Big Bend Conservation Alliance plans to go door-to-door, educating the public about the environmental and cost-saving benefits of upgrading their outdoor fixtures. Local homeowners will be given a few options that will meet their aesthetic and security needs. 

A large part of Wren’s original outreach work for the observatory explained that diffuse, unshielded security lights can actually inhibit your night vision, making them less safe than using shielded bulbs that point toward the ground. “If we continue to spread awareness for the safety aspect of it, especially now with some of the turmoil that’s happening with migrants and things like that, I think people will say, ‘Okay, well, it definitely looks like it’s safer, I’m saving money’,” said City Councilmember Arian Velazquez-Ornelas over Zoom. 

For City Administrator Brad Newton, the push for dark sky friendly lighting is a personal crusade. “I’m a licensed master electrician in the state of Texas,” he said. “I’ve put up a lot of dark sky unfriendly guard lights in my career, and now I’m trying to right my wrongs. Our challenges here in Presidio are achievable goals.” 

For Mayor John Ferguson, it’s a way to protect some of the things that make Presidio special. “I grew up in the Dallas area and my parents are still there. Having lived out here for all these years, when I go back to Dallas and look at the night sky, I can only see a glow,” he said. “We have a chance right now in Presidio to do the right thing.”