As San Antonio readies for another scorching summer, the city’s Office of Sustainability announced Thursday it will use new data to help battle the heat island effect in the inner city.
Using information collected in partnership with UTSA, the city has launched a cool neighborhood pilot program following in the footsteps of its year-old cool pavement program, which is being expanded.
The two programs will utilize dollars from the city’s relatively new Resiliency, Energy Efficiency and Sustainability (REES) fund, which was created with the adoption of the city’s 2023 budget at the request of then-Councilwoman Ana Sandoval. It comes from an allocated portion of the money the city receives every year from CPS Energy and is earmarked specifically for green initiatives. As a municipally owned utility, CPS Energy contributes roughly 14% of its gross revenues to the city every year, making up about a third of the city’s General Fund.
The data-directed projects are aimed at helping mitigate urban heat islands in San Antonio — areas where heat becomes even more extreme after a city replaces natural land cover with pavement, buildings and other surfaces that retain heat, said Doug Melnick, the City of San Antonio’s chief sustainability officer.
“Summers in San Antonio are only getting hotter — and for longer periods of time,” Melnick said. “Some parts of the city can get hotter than others, and certain residents are more vulnerable to the rising heat. It’s critical that we direct resources to those most in need of relief.”
The newly released data, which the city has shared publicly, shows that downtown and areas close to downtown — especially those within Districts 3, 4 and 5, are especially affected by urban heat islands, city officials told council.
The cool neighborhood pilot program will utilize existing city programs such as the Casa Verde program, Under 1 roof program, EquiTree program and approved bond projects to help mitigate heat in four neighborhood sites — one in District 2, one in District 3 and two in District 5 — selected for the pilot.
“Working across departments and with UTSA, we’re trying to figure out how do we leverage the existing resources that we have within the organization … to come up with a multiyear mitigation strategy?” Melnick told council members. “We’ve started community engagement in these neighborhoods. We want to understand how do they experience heat.”
The REES fund has allotted $1 million in the upcoming annual budget toward increased weatherization efforts, Melnick said, which can be used to help this pilot program.
The city also plans to take the data gathered during its cool pavement pilot project last year to expand areas that are paved with “cool pavement,” Melnick said. These pavement sections received a reflective coating to help them absorb less radiant heat from the sun, helping keep the surrounding air cooler.
Among the products tested in the 2023 cool pavement pilot, SealMaster demonstrated the most consistent and significant reduction in surface temperatures, with an average decrease of 3.58 degrees, the city said in a press release about the expansion of the project.
SealMaster’s maximum surface temperature reduction relative to fresh asphalt was 18 degrees.
“These findings provide concrete evidence of the effectiveness of cool pavement in reducing surface temperatures,” the city stated.
The results will support the planning and implementation of coordinated heat mitigation measures such as green infrastructure, shade structures, water features, energy efficiency and cool materials, Melnick said.
“The real thing that we’re hearing is it’s about concentrating; it’s not enough to just to put a block here or there but once you really start getting a neighborhood saturated [with cool pavement], you can start seeing more significant benefit,” he said.
The locations for the cool pavement project expansion are still being decided, he noted.
The City Council voiced support for the direction of these projects and the collected data.
Councilman Marc Whyte (D10) said he’s glad to see the city is following a data-driven approach to tackling urban heat islands. Councilwoman Teri Castillo (D5) said she’s especially glad to see work being done in her district.
“I’m really excited to see this response evolve, particularly around infrastructure, because our community, as cited in your presentation, there’s a higher need — a high heat island effect and impact, and communities often ask me how can we activate many of these city-owned vacant properties?” she said.
Mayor Ron Nirenberg called the presentation extremely insightful, saying it presented “a very clear case” for concentrating REES funds in lower-income areas.
“The urban heat island is very well correlated in terms of geography with the areas of lowest income in our community,” he said.
