The Texas Department of Transportation (TxDOT) is reconstructing and lowering Interstate 35 as part of its I-35 Capital Express Central project.

Work on the $1.1 billion project began in May 2025, with completion anticipated in 2029.

The planned improvements will require effective flood and stormwater management.

This segment will construct 6.5 mi. of 22-ft.-diameter drainage tunnels between Airport Boulevard and Holly Street; and along Cesar Chavez Street, from I-35 to U.S. 183. Access shafts will be added along I-35 to ensure proper maintenance and operational access to the new infrastructure.

The segment also includes the construction of a pump station to improve stormwater management along the corridor.

The contractor for the drainage tunnel is SAK/Shea JV, and the pump station contractor is Webber LLC.

Work on the project is taking place in four phases:

• Utility relocation and site work at Airport Boulevard, 15th Street, Brushy Street and River Street drop shafts and the Cesar Chavez/I-35 intersection; excavate at the Airport Boulevard and 11th Street drop shafts and CC/I-35 intersection; install geotechnical monitoring equipment.

• Excavate 15th Street, Cesar Chavez Street and River Street drop shafts.

• Relocate utilities at Hancock Center, Edgewood Avenue and 11th Street drop shafts; launch tunnel boring machines; excavate the Hancock Center, Edgewood Avenue and Brushy Street drop shafts.

• Establish tunnel connections from drop shafts; restore drop shaft sites; install final tunnel lining.

Construction is funded by TxDOT and the Capital Area Metropolitan Planning Organization (CAMPO).