Williamson County To Seal Underground Cambria Drive Cave

WILLIAMSON COUNTY, TX — State environmental regulators have approved county officials' plans to close the Cambria Drive cave.

The plan meets both objectives by Texas Commission on Environmental Quality (TCEQ) regulators to protect the water quality and keep the cave hydraulically connected to the aquifer and the county’s objective to reopen the road with a minimum impact to the neighborhood, county officials said in a press advisory.

A portion of Cambria Drive collapsed on Feb. 8 at around 3 a.m. near the Woods of Brushy Creek neighborhood situated between Highway 183 and Cedar Park on the west and Interstate 35 and Round Rock to the east. The street collapse revealed the presence of an underground cave below the asphalt.

The county’s first steps will be to remove the material that fell into the cave when the roof collapsed and evaluate the void that was discovered during core sampling, officials said. Williamson County will fill its portion of the cave under its right-of-way, officials added.

The process will start with approximately six feet of free draining gravel material, according to the advisory. A filter fabric will be placed over the granular material, then filled with high-strength concrete in 18-inch layers, using geogrid and wire retaining forms to contain the concrete, officials explained. Finally, utilities will be reestablished, and the road will be reconstructed, officials said.

The county will receive bids for the work over the next few weeks, with officials anticipating being able to begin repairs in approximately one month. The bids will contain the amount of time needed for the work; however, the county is committed to completing the work as quickly as possible, officials said.

During construction, officials added, additional security measures will be in place to provide safety.

>>> Photos of underground cave at Cambria Drive courtesy of Williamson County