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Western Oaks Karst Preserve Austin Cave Festival - Saturday, October 27, 2007 Each year, The Barton Springs/ Edwards Aquifer Conservation District and the Texas Cave Management Association hold an event at the Village of Western Oaks Karst Preserve to educate visitors about the importance and sensitivity of the aquifer and its recharge features. The day’s events feature informational booths from local organizations, activities for children, and short adventures into the Preserve’s Live Oak Cave and Get Down Caves. This year's Cave Festival will be held on Saturday, October 27, 2007 from 9am to 4pm and admission is FREE. The Karst Preserve is located at La Cresada and Davis Lane just west of Mopac. For more information on this year's event, click here. For directions to the Preserve, click here. History of the Preserve Annexation of the Village at Western Oaks and subsequent zoning in 1997, afforded the City of Austin, in cooperation with Lumbermen's Investment Corporation, Inc., an opportunity to establish protective measures for Get Down Cave and associated karst features located in what is now this karst preserve. It is also an opportunity to educate about the importance of caves and karst features found in the Edwards Aquifer Recharge Zone. Get Down Cave, discovered in 1985, contains two "Species of Concern" and is identified as a cave requiring protection within the City of Austin and Travis County's Balcones Canyonlands Preserve Endangered Species Permit. What is a Karst Preserve? A Karst Preserve is a tract of land, small or large, that has been protected from development because it includes features such as sinkholes and caves. These features often function as drains, down into the aquifer. Filling them in or developing over them could impact or stop their ability to recharge, or fill up, the aquifer below. Karst describes a landscape of limestone that contains sinkholes and caves. It originates from a German term for the Slavic “kras” meaning bleak, waterless place. Sinkholes or Sinks are depressions in the ground which funnel water underground. Sometimes they are helped along by the collapse of a cave ceiling. Sinking streams are creeks in which some or all of the flow sinks below ground. Some may have cave openings which create whirlpools where the water leaves the surface and enters a cave. Springs are exit points for groundwater. Springs in karst landscapes, such as Barton Springs, commonly have very high volume flow. Window Into the Aquifer Is there a connection to Barton Springs from the Western Oaks Karst Preserve? Quite possibly. A dye tracing study conducted in the Barton Springs Edwards Aquifer from 1996 to 2000 revealed connections between nearby recharge features and flow emerging at Barton Springs pool. Flow in the small creek that runs through the preserve probably recharges the aquifer through Equinox Cave. Activities within this watershed could impact the habitat of Barton Springs Salamander and the pool’s water quality. Species of Concern Despite their tiny size, cave invertebrates play important roles in the ecology of a cave. Several species are referred to as "Species of Concern" because they are cave-adapted animals with a limited distrubution and a highly specialized niche that in some cases are not yet fully understood. There are two species of concern found in Get Down Cave in this preserve. They are the ground beetle Rhadine [rä-di-nee] austinica, which is 8mm long and pictured at left, and a new species of millipede Speodesmus [spee-o-des-mus]. Both are found primarily south of the Colorado River in Travis County and a bit south into northern Hays County. Caves as Habitats When you think of caves, the first word that comes to mind might be dark, wet, or even scary, but probably not the word ‘habitat’. As inhospitable as a cave might seem to humans, numerous species of animals use caves for one or more of their four basic needs--food, water, shelter, and adequate space. Cave ecosystems have very few food resources, requiring cave dwellers to adapt physically for survival. Cave dwelling animals are traditionally divided into three categories--troglophiles, trogloxenes, and troglobites--according to their degree of adaptation to the cave environment. Some of Austin's rarest animal species are cave dwellers. Austin is home to six federally listed endangered karst invertebrates. There are also 25 karst invertebrates, classified as “species of concern” that could be listed in the future if not enough of their habitat is protected. The Western Oaks Karst Preserve is home to three of these "species of concern"; a ground beetle (Rhadine austinica), cave millipede, (Speodesmus spp.), and a harvestman, (Texella malaiki). Ancestors of these animals entered the caves when the Ice Age ended and the land warmed and became drier, about one million years ago. These rare karst invertebrates face two serious threats to their continued survival. Urban sprawl directly threatens caves by filling in or paving over caves, and cutting off necessary sources of nutrients for its inhabitants. Contaminated runoff from gas stations, leaking gas lines, leaking sewer lines, and pesticide runoff from nearby homes endanger these rare karst invertebrates. The red-imported fire ants (Solenopsis wagneri) is a recent and major threat to cave fauna because they compete for food and predate on our rare cave fauna. Visiting the Western Oaks Karst Preserve The public is welcome to walk through the preserve's trail system, to view outstanding examples of karstic features such as sinkholes and caves. When at the preserve, please observe the following rule since they were adopted to protect the threatened species located within the preserve's boundaries.
City of Austin - Watershed Protection (512) 499-2550 http://www.ci.austin.tx.us/watershed City of Austin - PARD Balcones Canyonlands Preserve 512) 402-0781 http://www.ci.austin.tx.us/preserves Texas Cave Management Association 512) 453-4774 http://www.cavetexas.org/tcma/home.htm |
