Nestled among the arid hills of central Terrell County, an area practically devoid of human life, the Caroline Spring gushes from the rocks at up to 5,000 gallons per minute. Also known as the T5, which was the name of the ranch encompassing the spring that the Hicks family operated for most of the 20th century, the Caroline Spring fills a series of man-made tanks created by another former owner, including a 3-acre upper lake and an 11-acre lower lake. Since 2000, the spring has been protected as part of a 20,000-acre conservation area known as the Independence Creek Preserve owned by the Nature Conservancy (TNC).
Perhaps the first sensation one feels when initially beholding Caroline Spring is astonishment. How could something that prolific exist in such a harsh, arid environment? When asked where so much water could be coming from, Ryan Smith, director of water and science at TNC, responded that “there is confidence that the springs originate from the Edwards-Trinity Aquifer, and there is some information [indicating] that flow to the springs seems to come from the west and west/northwest somewhat following the surface watershed of Independence Creek.” These flows could “possibly also come from the north/northwest.” Based on the available data, the “recharge to the flowpaths contributing to the springs likely goes well into eastern and southeastern Pecos County and maybe as far as the area south of Fort Stockton,” according to Smith. As these flows reach Caroline Spring and Independence Creek, they issue forth through “vertical fractures in the Edwards Limestone formation with the water upwelling from the deeper Trinity Sands formation under artesian pressure,” according to other literature by TNC. Located about 5 miles above the confluence of Independence Creek with the lower Pecos River, Caroline Spring and the creek itself increase the Pecos River’s water volume by about 42% and reduce the total dissolved solids in the river by up to 50%. This significantly alters the otherwise alkaline condition of the Pecos and greatly improves water quality in the Amistad Reservoir and the Rio Grande River further downstream.
The importance of the contribution of Caroline Spring to the health of the region’s rivers cannot be overstated. According to a 2016 report by a team of scientists from Southwest Research Institute led by Dr. Ron Green titled “Modeling Groundwater Flow to Understand the Water Resources of the Lower Pecos River Watershed,” a significant portion of water that flows from the upper reaches of the Pecos River watershed to the lower Pecos River is intercepted by groundwater extraction near Roswell and Carlsbad in New Mexico, and in the vicinity of Fort Stockton in Texas. “As a consequence, discharge of the Pecos River to the Amistad Reservoir is derived mostly from the main tributary watersheds in the lower Pecos River watershed,” including Independence Creek. The authors warn, however, that “the amount of groundwater flow” into the lower Pecos River watershed “is not accurately known.” As with so many of our water resources in Texas, there are major gaps in the data and our understanding is limited.
This could change now that the area has recently been declared a National Natural Landmark by the National Park Service (NPS). According to the NPS brief explaining the importance of the Caroline Spring/Independence Creek Preserve, “The presence of a sustained, aquifer-supplied water source in a desert environment makes the creek a key habitat for three vulnerable native fish species: the Proserpine shiner (Cyprinella proserpina), the Rio Grande Darter (Etheostoma grahami), and the Headwater catfish (Ictalurus lupus).” Caroline Spring is also home to several never-before-seen species of aquatic invertebrates, including snails, beetles and flatworms.
The area’s importance is further supported based on its location within a transition zone between three ecoregions: Chihuahuan Desert, Edwards Plateau and Tamaulipan Thornscrub, with “significant relict stands of large Texas live oak (also called plateau live oak, Quercus fusiformis) … at the western extreme of their range in Texas,” according to NPS.
While this unique natural wonder has remained closed to the public since the pandemic, West Texas Preserves Manager Ryan Thornton would like to see that change eventually. In addition to more “community outreach and education,” increasing “volunteer involvement with a number of wildlife and habitat management projects” and facilitating “scientific research on the property,” he would like to reimplement “open days at the preserve” to get “the public back out during select time periods to experience this amazing place.” According to Thornton, who recently began working at Independence Creek Preserve, “I really look forward to carrying the torch of stewardship that has been passed on to me. Also, a big thank you to the members and donors who make my work, and the work of all TNC employees, a possibility.”
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Trey Gerfers serves as general manager of the Presidio County Underground Water Conservation District. A San Antonio native, he has lived in Marfa since 2013 and can be reached at tgerfers@pcuwcd.org.