Following a groundbreaking ceremony last month for the expansion of Loop 1604, San Antonio residents and environmental groups are voicing concerns about the project.

While Texas Department of Transportation officials and local leaders such as state Sens. Donna Campbell, José Menéndez, and Roland Gutierrez have voiced support for the project, members of the Greater Edwards Aquifer Authority, the Sierra Club Alamo Group, and other San Antonians are worried the highway’s expansion won’t relieve traffic and may cause environmental concerns.

The $1 billion project will expand Loop 1604 from four to 10 lanes, including a high-occupancy-vehicle lane in each direction, and will replace the existing connections with streamlined ones. The project will be done in segments and is expected to be completed by 2027. 

The expansion of Loop 1604 is overdue, said Isidro Martinez, director of the Alamo Area Metropolitan Planning Organization (AAMPO). Discussions about the highway’s expansion began in the early 2000s, and since then congestion has become a major issue, he said.

Annalisa Peace, executive director of the Greater Edwards Aquifer Alliance, said the project won’t really address traffic congestion, but it will threaten San Antonio’s primary drinking source: the Edwards Aquifer.

The project will expand impervious cover — the amount of land that can’t soak up rainwater — over the aquifer’s recharge zone, which will increase temperatures in the area from climate change both directly and indirectly, Peace said.

According to the environmental impact study filed by TxDOT, rainwater that lands on the expanded roadways will still runoff onto rechargeable land within the zone. “Although runoff increases due to impervious cover, the recharge water is not lost, because it may be redistributed to other areas where it can recharge,” the study states.

It states that adding 198 acres of impervious cover may divert 109 acre-feet of potential recharge water as runoff each year, “which is insignificant.” But the expansion won’t affect the aquifer’s ability to recharge, according to the study.

GEAA is also concerned about the quality of the water seeping back into the aquifer and has been actively expressing its concerns to TxDOT since the project’s first public meeting in 2017, Peace said.

“The environmental impact study didn’t really address our concerns about the recharge zone,” Peace told the San Antonio Report. In the study, four major concerns from the GEAA are listed with rebuttals addressing each. These concerns include using 1604 to transport hazardous materials and chemicals over the recharge zone, increased runoff, the coverage of a monitoring well, and an increase in potential sewage waste leaks.

The project will be “implemented, operated, and maintained in a manner that complies with the Edwards Aquifer rules and any applicable [Texas Commission on Environmental Quality] guidance documents,” TxDOT states in the study. TxDOT has “obtained coverage under all applicable environmental permits for construction based on the final design.”

The Sierra Club Alamo Group has similar concerns about the project, said Alan Montemayor, a Sierra Club member. Montemayor said he and other members are concerned an expanded highway system will result in more traffic, which could also lead to increased air quality concerns.

“By building more roads, basically you’re just encouraging people to drive more, and we need to incentivize people to drive less,” Montemayor said.

Citing Stuck in Traffic by Anthony Downs, Montemayor said he believes rush hour will still result in slow-moving traffic, but more cars will be contributing an increased amount of exhaust into the air. The city and state should instead be encouraging ridesharing and taking the bus, as well as other more environmentally friendly solutions, Montemayor said.

David Schrank disagrees. The Texas Transportation Institute senior research scientist
of mobility analysis said highways that flow well tend to have fewer air pollutants, and widening highways in other areas of Texas has improved traffic flow.

Schrank said when Interstate 10 was widened in Katy in 2008, studies showed traffic flowed better. However, the Houston-Katy area has grown by another million people making it seem just as congested. If the highway hadn’t been widened, that congestion would have been even worse, he said.

Schrank and Montemayor agreed, however, that Texas needs to invest in solutions that help get people off of roads. The pandemic has shown companies that their employees don’t have to drive to work to be productive, Montemayor said, which he hopes accelerates the work-from-home movement. Even then, infrastructure needs to be able to support a city and its people, he said.

“Even if we drive 10% less than we used to, but our population doubles, we’re still going to need transportation facilities,” Schrank said.

Lindsey Carnett covers the environment, science and utilities for the San Antonio Report. A native San Antonian, she graduated from Texas A&M University in 2016 with a degree in telecommunication media...