The stretch of Central Texas between San Antonio and Austin — once separated by 80 miles of farmland and Spanish oak-covered hills — is rapidly transforming into one continuous metroplex.
From the booming suburbs of New Braunfels and San Marcos to smaller towns like Kyle and Buda, growth along the crowded Interstate 35 corridor is rewriting the economy of Texas.
The U.S. Census Bureau lists both Austin and San Antonio among the nation’s fastest-growing large cities.
New Braunfels has grown by more than 50 percent since 2010, while Hays County has doubled in population. Economists predict that by 2040, the two metro areas will effectively merge into a “San-Austin Corridor"—home to more than six million people.
But this rapid expansion is straining the region’s infrastructure and natural resources. Water scarcity is one of the most pressing concerns.
Both cities depend on the Edwards Aquifer and a patchwork of regional water projects to meet future demand. Environmental groups warn that unchecked development threatens recharge zones and springs that sustain local rivers and endangered species. Meanwhile, traffic congestion has become a daily ordeal, with I-35 ranked among the most gridlocked highways in the country.
Critics say poor regional planning and political rivalry are partly to blame. Austin’s progressive city government and San Antonio’s more pragmatic approach often clash over transportation priorities, housing, and economic development incentives. Local governments compete for business relocations rather than coordinate land use, resulting in sprawl that consumes farmland and increases flood risk.
Yet the challenges come with enormous opportunity. If the two metros can cooperate, experts say the corridor could become an engine of innovation and prosperity. Joint investment in mass transit, regional water systems, and affordable housing could create a model for sustainable urban growth.
Tech companies from Austin’s Silicon Hills are already expanding south, while San Antonio’s universities and military medical centers provide a growing talent base.
Guest:
Henry Cisneros is a former mayor of San Antonio and U.S. Secretary of Housing and Urban Development who has been a prominent advocate for coordinating the growing Austin-San Antonio mega-metro, often discussing the region's potential to become a global economic powerhouse. He co-authored "The Texas Triangle" and "The Austin-San Antonio Megaregion" to explore the rapid growth and challenges of the area between Austin and San Antonio.
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This interview will be recorded live Tuesday, October 7, 2025, at 12:30 p.m.
