4th Chamber Found At Williamson County Cave

WILLIAMSON COUNTY, TX — The underground cave in Williamson County that gave way last week — taking a big chunk of roadway along with it — is even bigger than previously thought: On Monday, officials disclosed the discovery of a fourth subterranean chamber.

The additional chamber of the cave underneath Cambria Drive was discovered by county environmental consultants, officials said in a press advisory. The newly discovered chamber is about 30 feet long, bringing the total length of the cave to approximately 200 feet.

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 previously unknown presence of the cave trail under the road surface. Residents reported hearing a loud sound akin to thunder during the collapse that left a gaping 20-foot-deep sinkhole where asphalt once stood.

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Officials revealed at the time that a leaking water pipe slowly chipped away at the subterranean cave's roof until it gave way, essentially swallowing up part of the street as it crumbled inward. No injuries were reported, but about a dozen households were left without tap water for some time before service was restored.

County Engineer Terron Evertson holds a speleothem that was dislodged when the cave roof fell.

Just three feet high, the additional chamber is not as tall as the other three — dwarfed by the tallest chamber standing at a height of 22 feet, officials said. Williamson County structural engineering consultants Dunaway Associates visited the site on Monday to analyze its structural characteristics toward evaluating street repair options, officials said. They're expected to finalize their report in the next 30 days, county officials added.

Engineers and environmental consultants view the cave to determine repair options

For the time being, Cambria Drive will remain closed for several weeks while county officials work with the Texas Commission on Environmental Quality (TCEQ) on remediation efforts.

Williamson County officials previously released photos of the cave shortly after its discovery following the street collapse:

>>> Uppermost image: Fourth cave chamber, all photos courtesy of Williamson County