Cave Restorations on the Urban Frontier

Leader: Drew Thompson, Biologist, Austin Water Balcones Canyonland Preserve Program

Synopsis: See the City of Austin’s cave restoration and stabilization projects of the past decade in South Austin. Our urban karst landscapes have taken many hardships throughout its recent history from deforestation and overgrazing to the purposeful filling in of caves and sprawling urban expansion. Witness firsthand the City of Austin’s efforts to reopen and restore our valuable resources increasing clean water recharge, healthy biological habitat, and creating a safe environment to educate the public about the benefits of caves and their contribution to the Edwards Aquifer.  

Logistics:  Group size will be limited to 30 people. We will depart promptly at 9:00AM from the San Marcos Activity Center, returning at 5:00PM. Lunch will be provided so packing one’s own is not required. All lights, helmets, and pads will be provided for those who would like to enter the caves. Personal cave gear will not be allowed to enter the cave in efforts to reduce the chance of cross contamination and possible transfer of WNS. All sites require a short to moderate walk on easy terrain. Comfortable hiking shoes, a reusable water bottle, (drinking water will be provided), and sun protection are highly suggested. Details are preliminary and subject to change.

Details: The caves of South Austin are plentiful and contribute directly to the Barton Springs segment of the Edwards Aquifer. They are very rich in biodiversity being home to numerous karst obligate species and resident troglophiles. Once often seen as unwanted and unnecessary burdens in the past by landowners and developers, the City of Austin has gone to great lengths to correct the negative effects by restoring these important ecosystems and recharge features to a healthy and manageable state. By means of excavation, stabilization, and revegetation, these neglected treasures now have a second chance. On this fieldtrip we will visit 11 major sinkhole/cave restorations conducted by City of Austin staff under the supervision of Dr. Nico Hauwert. Sites will include a visit to the William H Russell Karst Preserve, (a 200 acre plot previously known as the Blowing Sink Research Management Area), where we will visit the stabilized entrances of Sinky Dinky, William’s Well, Wyoaka, Brownlee, Winter Woods, and Blowing Sink Caves. We will then visit the Goat Cave Karst Preserve to see Wade and Hideout Caves. From there we will take a trip into the entrance portion of Grassy Cove Cave (an easy hands and knees crawl through a nicely decorated passage). We’ll then make our way to the Lady Bird Johnson Wildflower Center to visit the entrance portions of Wildflower Cave (a decently sized room used as underground Classroom) and LaCrosse Cave (a multi-level room used as an underground classroom). During the fieldtrip we will go over site history, biology, geology, excavation methods and techniques, and the obstacles that we overcame to achieve our goals. 

Preliminary schedule:

Wednesday November 3, 2021