On Feb. 8 residents of the 8400 block of Cambria Drive in Round Rock reported a water outage. Responding Brushy Creek Municipal Utility District utility workers discovered the cause of the outage was a collapse of the water line into a relatively large cave. Since the discovery of the cave, Williamson County officials have closed off a portion of Cambria, and engineers have started work to determine the stability of what is now known as the Cambria Cave. “It’s a typical cave; it just happens to be a little bit larger than normal, and it was found in an unusual way,” said Gary Boyd, environmental programs director with the Williamson County Conservation Foundation. Boyd said that the collapse was likely the result of utility work in the area in the early 1980s. When workers dug a trench for water and gas supply for the area, they probably dug very close to the cave. As rainwater has drained through the trench over the years, it weakened the roof of the cave, eventually causing it to collapse. Connie Odom, Williamson County public affairs manager, said the county’s primary concern is public safety and determining the stability of the cave so the road can be reopened. Once the stability of the cave is determined, officials will begin to investigate the presence of endangered species. There are two endangered species found in caves in Round Rock—the bone cave harvestman and the coffin cave mold beetle. The bone cave harvestman is the most common of the two in Round Rock, found in at least 70 caves in the city, according to Boyd. The harvestman is similar to a daddy longlegs spider, but much smaller and without eyes. It has been found as far south as Travis County and a some have been found in Bell County, but the species are unique to Central Texas. Boyd said that if a developer participates in the county’s habitat conservation plan and he or she encounters a cave while developing a portion of land, officials will determine if any endangered species inhabit the cave. If they do, the next step is to determine the underground footprint of the cave. A perimeter of 345 feet is then drawn around the cave, and the developer has the option of developing around that perimeter or paying a fee to develop within it. If the developer chooses to come within 50 feet of the cave, he or she must pay a fee to “take” that cave, which essentially allows a developer to destroy it. To ensure that the species are conserved, Boyd said that the WCCF maintains preserve areas known as Karst Fauna Areas. Its goal is to establish nine total KFAs, three in the north of the county, three in the central area and three in the south. “If a cave has a surface expression or means of transporting nutrients down into the cave, such as tree roots, then it’s fairly common to find [an endangered species],” Boyd said. The two preserves nearest to Round Rock—Beck Preserve, near the intersection of Great Oaks Drive and RM 620, and the Chaos Preserve, south of RM 620 and north of SH 45 N—both house bone cave harvestmen. Boyd said it is not unusual to find caves in the area as much of it exists in a Karst Zone, meaning the topography is made up of soluble stone. In Central Texas that stone is limestone—which is porous and conducive to the formation of caves. “If you’re operating in the Karst Zones of the county, you have a really high potential of hitting a void,” Boyd said. Boyd said there are well over 700 caves in Williamson County alone. If no endangered species are found in the cave and it is determined to be structurally sound, officials will determine the best way to seal it. The Cambria Cave is currently covered by a temporary cover which was put in place Feb. 20. The cover is designed to stay in place for several weeks while officials determine the best way to move forward.