New Wells in Austin to Monitor Oxygen Levels for Endangered Salamanders

A dry Barton Creek in December (Photo by John Anderson)

Despite a rainy start to the week, Central Texas’ historic drought is not turning around anytime soon. The Barton Springs/Edwards Aquifer Conservation District declared a Stage 4 Exceptional Drought for the first time in its 36-year history in December, after its Lovelady monitoring well measured alarmingly low water levels – and forecasters are expecting another hot, dry summer. Diminished flows in the Edwards Aquifer don’t only affect human permit holders; they cause dissolved oxygen levels in the water to go down, making it harder for the endangered Barton Springs and Austin blind salamanders to breathe.

To better understand what’s affecting the salamanders, the aquifer district is installing two new, permanent monitoring wells this month which will collect data on flow, oxygen levels, and other features of groundwater. The district already gathers data from more than 40 wells in the Edwards and Trinity aquifers, but “most of our monitoring wells are residential, being used domestically, and the property owners have given us access,” explains Jeff Watson, a hydrogeologist with the district. “So these are special in that they’re owned and operated by the district, and specially constructed with monitoring in mind.”

The two new wells – one in Zilker Park and one in Garrison Park – are years in the making and were included in the District's 2013 Habitat Conservation Plan for the salamanders. Data from the wells will also tell the district how feasible it is to deploy a strategy that might make the salamanders’ lives more comfortable: manually injecting oxygen into the aquifer.

“A key question would be: Where in the aquifer do we want to inject it?” Watson said. “Because we’re talking about a package of rock three to four hundred feet thick, so you’ve got a lot of options.” The Zilker well by Barton Springs will gather data throughout the whole aquifer instead of at a single water level, allowing geologists to observe “from top to bottom.” The Garrison Park well sits along a known flow path that feeds Barton Springs, which makes it an ideal location for monitoring for things like water quality and contaminants, Watson said. Plus, biologists would have access to deploy salamander traps in the deeper part of the aquifer.

Construction is starting this month and is expected to finish before the end of March, and the district expects to publish preliminary findings sometime this year. But the wells are permanent, and Watson said. “It’s really with many years of data collection that we develop more interesting datasets for analysis.”

Editor' Note Tuesday, February 6, 2:50pm: A previous version of this story the story wrongly referred to a City of Austin Habitat Conservation Plan from 2013, which is not related to the Zilker monitoring well. The right Habitat Conservation Plan is from the Barton Springs/Edwards Aquifer Conservation District and was done in 2018. The Chronicle regrets the error.