The convergence of dialogue, data, and disaster have sparked a more serious look at regulations that impact water management and development in San Antonio, Mayor Ron Nirenberg said Monday.

Revisions to the City’s impervious cover policies will likely add to the longstanding contention between developers and environmentalists. That fight is a political “Pandora’s box,” he added, but it’s time to stop ignoring the “seriousness of the situation.”

Hurricane Harvey, which claimed 77 lives, helped expose that situation, the mayor said. New data-driven analyses of how a storm of that magnitude could impact San Antonio combined with local and statewide conversations about resiliency and preparedness have provided city leaders with a “moment in time” to rethink development patterns and practices, he added.

In that vein, the San Antonio River Authority is working with the City’s Office of Sustainability and  Transportation and Capital Improvements (TCI) on a timeline for an official review of impervious cover regulations, Nirenberg said. He expects to see a draft timeline by next week.

Nirenberg spoke Monday at a water forum at the Witte Museum, which was hosted by the River Authority and moderated by Rivard Report Publisher Robert Rivard. Water experts and elected officials discussed the San Antonio River’s challenges and triumphs, including recently released models that show the city’s vulnerabilities to flooding.

Impervious cover refers to surfaces – buildings, streets, and other structures – that interfere with rainwater’s ability to reach the ground. The further water has to travel to get to the ground or a stream, the more likely it is to pick up contaminants. Restrictions on impervious cover are especially strict over the Edwards Aquifer recharge zone, so as to ensure that water can be filtered by soil and pool in the aquifer. While some argue that those restrictions should be implemented citywide, others say they would make development cost-prohibitive and impede the growth needed to accommodate the additional 1 million people expected to live in the area by 2040.

“The stormwater threat that we have is very real, and we need to see what we can do to ensure that our river is protected,” Suzanne Scott, River Authority general manager, told the audience of more than 550. But the City can “balance development with protection,” she added.

Language regarding impervious cover policy goals was weakened in the Sustainability Plan included in SA Tomorrow, the City’s comprehensive growth plan, before it was approved last year.

“We basically said, ‘Some conversations are off limits,’” Nirenberg explained. “Discussion and data is what we lacked.”

The City’s Planning Commission removed altogether the provision to “develop and implement effective impervious surface standards for new development and redevelopment projects.” City Council later reached a compromise, changing the strategy to: “Through a representative stakeholder process, [the City will] conduct a science-based assessment of the impact of increased impervious cover and determine if development standards are needed to address flooding, water quality, and urban heat islands.”

That stakeholder process will soon be initiated, Nefi Garza, assistant director of TCI, told the Rivard Report after the water forum. The City and River Authority already are looking into more “science-based assessments” of impervious cover.

“There certainly is an impact [of impervious cover],” Garza said. “But we’re trying to understand what it is.”

The City and River Authority essentially are taking an inventory of existing regulations and rules that have to do with impervious cover, from the tree ordinance to impact fees.

“There [are] a lot of things in play now that I think need to be included in the equation when we’re talking about revamping or restructuring the policies,” Garza said.

The City doesn’t require low-impact development features that manage the quantity and quality of stormwater. Instead, such features are incentivized and encouraged.

“And that doesn’t work,” Garza said. “We’re also looking at that. We’re working with the River Authority to define what low-impact development means to us.”

Soil type is part of the stormwater runoff equation, Garza said. “Are clay soils – about 60% of our city – also contributing to the flooding?”

The River Authority is currently researching that theory and others. Resulting information could impact where certain regulations are implemented and, therefore, how the city grows.

This review process has been in the works for years, Garza said, but Harvey “put things into focus.”

Meanwhile, the City is working with the University of Texas at San Antonio on a climate action plan – even more data – that will dovetail into policies on impervious cover.

This summer, CPS Energy contributed $500,000 toward the research that will lead to the City’s first plan to improve air quality and reduce greenhouse gas emissions.

Senior Reporter Iris Dimmick covers public policy pertaining to social issues, ranging from affordable housing and economic disparity to policing reform and mental health. She was the San Antonio Report's...