Officials at Big Bend National Park are weighing the impacts climate change could have on the sole source of water for the Chisos Basin lodge and camping area — one of the most popular visitor destinations within the expansive desert park.
Since the 1950s, Big Bend National Park has pumped water from the nearby Oak Spring into the Chisos Basin. But the old, leaking pipeline system used to transport the water is in need of at least $8 million worth of repairs. Before the park made the investment, however, NPS officials wanted to better understand what a changing climate would mean for the future of the water source.
“Before we want to move ahead on a big project like this — improving those lines, spending a lot of money — we just want to make sure that water source is reliable and would provide enough water for this operation into the future,” said BBNP’s Tom VandenBerg.
To understand the potential changes, officials at the West Texas park reached out to climate-change ecologists with the National Park Service Climate Change Response Program to study Oak Spring.
Using a number of global climate models, the report’s authors, Amber Runyon and Dave Lawrence, looked at the best and worst case climate scenarios for the Chisos Basin.
“In this area, basically all of the models consistently project increasing temperature,” said Lawrence. “So they all agree that things are going to get warmer.”
Keeping a warming climate in mind, the pair of NPS scientists then set out to determine how much precipitation the area could see.
The best scenario shows the climate becoming warmer and wetter, leading to a roughly 25% increase in precipitation. The worst case predicts the West Texas climate will become hotter and drier; under this projection, annual rainfall in this corner of the park drops by nearly 30%.
When considering the potential future impacts of climate change, looking at the area’s projected levels of precipitation was key for the study’s two authors because area rainfall directly correlates to the spring’s flow.
“Our analysis of ten years of data suggests flows from Oak Spring are sensitive to contemporary changes in precipitation,” reads the report.
Any changes in precipitation would impact the flow rate from Oak Spring, which Big Bend officials say needs to be at 20 gallons per minute. Anything below that would be insufficient and could trigger conservation efforts in this area of the park.
The Climate Change Response Program used this rate of 20 gpm as a benchmark when looking at the Oak Spring’s projected flow at the end of the century. Under a warmer and wetter climate, Oak Spring will continue to produce water at the same rate as in the past. A hotter and drier climate in the Big Bend would see significant declines in the spring’s flow.
The various climate models and their predicted impacts on Oak Spring provided Big Bend officials with enough scenarios to make an informed decision, said Amber Runyon, one of the study’s authors.
“The use of scenarios helps to stress test those decisions and make decisions that are robust to whatever the future looks like,” said Runyon.
With the best case scenario showing Oak Springs will maintain a reliable flow in the decades to come, park leadership believes it makes economic sense to go forward with the multimillion dollar repairs to the Oak Spring pipeline system.
“Using the results of this study, coupled with the high cost and uncertain reliability of any alternative water sources, we’re confident that we can recommit to Oak Spring,” said Superintendent Krumenaker in a press release.
Krumenaker wants the park to move toward “significantly increasing” the water storage in the Chisos Basin and to eventually install water-efficient infrastructure.
A team of contractors are set to visit Big Bend this year to further evaluate the repair costs to the Oak Spring pipeline.
