The Texas Historical Association claims that Texas has at least 3,000 caves. Make that at least 3,001.
A cave—first incorrectly called a sinkhole—was discovered underneath Cambria Drive in the Woods of Brushy Creek neighborhood on Feb. 8, 2018.
While it was reported initially that a broken water pipe contributed to the collapse of the cave roof, there is no evidence of that. There was, however, a relatively thin cave roof under Cambria Drive where the water line trench had been dug.
Caves can be fun and mysterious, but they can be a bit disturbing when they’re right smack in the middle of a subdivision and reach underneath the yards of three homes.
Chief Appraiser of the Williamson Central Appraisal District (not part of county government) Alvin Lankford said the homes’ values will be impacted, but we may not know how much until and if the homes are sold.
Mr. Lankford worked mightily helping these homeowners by discussing their valuations over the past several months. His decisions on values are restricted by the property tax code.
Cambria Cave was thought to consist of four chambers, but in early August, when the cave floor was cleared of debris, a fifth chamber extending into Ephraim Drive was discovered.
Cambrian Environmental (company name coincidental) geoscientists mapped the cave in February and measured it as approximately 230 feet long by 40 feet wide, with a maximum floor-to-ceiling height of about 23 feet in the largest chamber.
Only about 10 percent of the cave was affected by the collapse that occurred in the early morning hours. Neighbors said it sounded like a bomb blast.
Cave experts said that the closed cave is prehistoric, close to 40 million years old. When authorized personnel entered the cave, they found no evidence of previous human entry. They were the first!
The Texas State Historical Association reports that caves and sinkholes are distributed in karst areas covering about 20 percent of the state. Karst is terrain formed by the dissolution of bedrock.
After county and outside experts started entering the cave, sections of asphalt roadway and concrete curb on Cambria Drive began moving downward, and the sides to the entrance of the cave began crumbling. The Texas Commission on Environmental Quality approved a request from the county to allow our contractors to open the cave entrance 20 feet longer, making the entrance more stable for workers going inside.
The neighborhood where the cave is located was developed between 1986 and 1990, and there are other caves in this area. In 1986, during development of Ephraim Drive, which runs perpendicular to Cambria Drive, a cave was discovered but at the time, TCEQ didn’t exist and the developer just dynamited and filled the void, and then completed the road.
However, no previous knowledge of a cave at the Cambria location was known until now.
It required five months to conduct evaluations and pass TCEQ approvals to fill the cave per the designed plan. We now know about preservation of cave critters and water flow to the Edwards Aquifer – gone are the days of bomb-fill-go.<