Karst

Caves of the Village of Western Oaks Karst Preserve

The Village of Western Oaks Karst Preserve is an 18 acre preserve is South Austin just off Davis Lane west of Mopac. The preserve was established through a joint effort by the developer, the Texas Cave Management Association and the City of Austin to protect several caves and the cave adapted animals that inhabit them. There are five caves and a sinkhole in the VWO Karst Preserve.

The largest cave in the preserve is Get Down Cave that was discovered by surveyors during the early development and named after their rock-and-roll band. This cave is the home of two types of cave adapted animals, a small blind beetle that looks like a large red ant, and a pure white millipede with long legs. These animals live only in southern Travis and northern Hays Counties. They are listed by the U.S. Fish and Wildlife Service as "Species of Concern" because houses and streets will soon cover their entire range. This surface disturbance threatens the existence of the animals and the VWO Preserve will provide a small undisturbed area that will insure that at least some of the cave animals will have a chance to survive.

Get Down Cave opens into an entrance room that ends in a rocky pit that descends to the main level of the cave where the cave adapted animals live. This area has a constant 100 percent humidity and total darkness. The entrance passage extends through an area of stalactites and flowstone to a low wide passage that extends to the south. The entrance area of Get Down cave has recently been restored to its natural state and a new gate installed.

To the east of Get Down Cave are Live Oak Cave and Senatorial Sink. The sink, named for the impressive live oak trees, was formed by the collapse of what was once a much larger cave. This collapse was many thousand years ago and now dirt has collected in the sink and large trees established. Live Oak Cave is a small part of the original larger cave that did not collapse, and now consists of a passage that opens into a low room beside the sink.

In the drainage beside Senatorial Sink is Equinox Cave a small but important cave that may in the future used to recharge the Edwards Aquifer. The plan is to remove the cover over the cave as soon as the wet pond is effective and there is good quality water flowing over Equinox Cave. This cave extends below Senatorial Sink and likely forms a direct connection to the aquifer. [It will be a major accomplishment if the storm runoff from a subdivision can be purified enough to be used to supply the Aquifer that feeds Barton Springs]

Millennium Cave was discovered during excavations for the water quality pond. It was a surprise to the contractor when the bottom of the pond fell away to reveal a large cave. Cave experts were called and recommended that the pond not be built over the cave, so the section of the pond over the cave was filled and a large pipe placed over the entrance to provide access. This cave is a relatively large, well-decorated room that had no natural entrance. So far no cave animals have been found in this cave.

The smallest cave in the preserve is Survey Line Cave located near the southwest entrance. This cave consists of a small low room. The caves in the preserve are located in one small area due to favorable geologic conditions, but the entire Village of Western Oaks area is in the Recharge Zone of the Edwards Aquifer. Homeowners should be careful in their use of chemicals for fertilizer and weed control, as many of these substances are toxic to animals that live in the caves and in the Edwards Aquifer.