The Davis Mountains Streams NFCA includes the Balmorhea Springs Complex and streams in the Davis Mountains. The Balmorhea Springs Complex is considered one of the largest and most important of the remaining desert spring systems in West Texas (Karges 2014b). The main springs include Phantom Lake, San Solomon, Giffin, Saragosa, Toyah Creek, East Sandia and West Sandia springs. This was once a massive, interconnected network of ciénegas fed by cumulative spring discharges of approximately 130,000,000 liters per day (White et al. 1941). Groundwater pumping and draining ciénegas for agriculture has reduced flow and disconnected the ciénega network. All that remains for aquatic habitat are artificial refuge ciénegas and irrigation canals (Garrett 2003).

In addition to the focal fish species, other aquatic species of concern include the Diminutive Amphipod Gammarus hyalleloides, Phantom Cave Snail Pyrgulopsis texana, Phantom Springsnail Tryonia cheatumi, Rio Grande cooter Pseudemys gorzugi, and Pecos sunflower Helianthus paradoxus. Areas being actively managed for conservation include Davis Mountains State Park, Balmorhea State Park, and the Nature Conservancy’s Sandia Springs Preserve.

The Davis Mountains Streams NFCA also includes Comanche, Leon, and Diamond-Y springs. Comanche Springs no longer flow and as Gunnar Brune (1981) noted “failure of Comanche Springs was probably the most spectacular example in Texas of man’s abuse of nature.” Flowing at 1,200 – 1,900 L/s, this spring was one of the largest in Texas, but flow completely ceased in 1962 due to aquifer pumping for irrigation from a well field up-gradient of the springs during the drought of the 1950s (Mace 2001). The outflow from the springs, Comanche Creek, supported a vast ciénega of approximately 25 km in length. The drying of the springs was not only an ecological disaster, but also had severe impacts on the more than 100 farmers who had, since the 1860s, depended on waters flowing from Comanche Springs and the ciénega for irrigation of approximately 2,500 ha of cropland (Brune 1981).

Leon Springs, up-gradient and in the same aquifer as Comanche Springs, were also modified to provide irrigation for farming. Originally the springs were deep and up to 30 m in diameter and supported a large ciénega that extended for many kilometers downstream (Brune 1981). During the 1920s, a stone and earth dam created Lake Leon (Scudday 2003) that backed water up to, or over, Leon Springs. Unfortunately, this modification likely led to the extirpation of both Pecos Gambusia Gambusia nobilis and Leon Springs Pupfish Cyprinodon bovinus as none were collected by Carl Hubbs in his 1938 survey of this type locality for the Leon Springs Pupfish (Hubbs 1980, Minckley et al. 1991). The same groundwater pumping that led to the demise of Comanche Springs also dried Leon Springs in 1958 (Brune 1981).

Although Diamond-Y Springs were not as large as Comanche and Leon springs, they continue to flow and provide habitat for the federally endangered Pecos Gambusia and Leon Springs Pupfish as well as several other species; however, the flow is greatly reduced from historical levels (Scuddy 2003). Fortunately, the Diamond-Y Springs ecosystem does not derive its flow from the same aquifer as Comanche and Leon springs. Other rare species in this system include federally endangered invertebrates: Diamond Tryonia Pseudotryonia adamantina, Gonzales Tryonia Tryonia circumstriata, Pecos Amphipod Gammarus pecos, and Pecos Assiminea Assiminea pecos, and the federally threatened Pecos Sunflower. Some degree of protection is afforded the inhabitants of the ciénega at Diamond-Y Springs in that The Nature Conservancy owns 1,600 ha that encompass it and is committed to its maintenance and perpetuation.

In the Guadalupe Mountains Streams NFCA, McKittrick Creek is unique in that it supports a population of introduced Rainbow Trout Oncorhynchus mykiss and likely had a native population of Rio Grande Cutthroat Trout O. clarkii virginalis (Garrett and Matlock 1991; Petersen 2002). The stream could provide a viable option for creating sustainable populations of Rio Grande Cutthroat Trout and/or Rio Grande Chub Gila pandora.

Agricultural and municipal water diversions have greatly diminished water quantity in the upper part of the Pecos River NFCA and increased salinity to near that of seawater. High salinity has resulted in the loss of many fish species and the repeated occurrence of a toxic golden alga Prymnesium parvum bloom. Inputs from Independence Creek and other springs greatly improve water quality and quantity in the lower segment. Other threats include groundwater extraction, oil and gas development and invasive species. In addition to the focal fish species, other aquatic species of concern include the Rio Grande Cooter Pseudemys gorzugi, American Beaver Castor canadensis, and Pecos River Muskrat Ondatra zibethicus ripensis. An 8,000-ha preserve along Independence Creek is owned by The Nature Conservancy with an adjacent 280 ha under conservation easement (Karges 2014a).

Sources

Brune, G. 1981. Springs of Texas. Vol. I. Fort Worth: Branch-Smith.

Garrett, G. P. 2003. Innovative approaches to recover endangered species. Pages 151-160 in G. P. Garrett and N. L. Allan, editors. Aquatic Fauna of the Northern Chihuahuan Desert. Museum of Texas Tech University, Special Publications 46.

Garrett, G. P., and G. C. Matlock. 1991. Rio Grande cutthroat trout in Texas. Texas Journal of Science 43:405-410.

Hubbs, C. 1980. Solution to the C. bovinus problem: eradication of a pupfish genome. Proceedings of the Desert Fishes Council 10:9-18.

Karges, J. 2014a. Pecos River. Pages 32-33 in M. D. Wesson, C. Hallmich, J. Bennett, C. Sifuentes Lugo, A. Garcia, A. M. Roberson, J. Karges, and G. P. Garrett, editors. Conservation Assessment for the Big Bend-Río Bravo Region: A Binational Collaborative Approach to Conservation. Montreal QC: Commission for Environmental Cooperation.

Karges, J. 2014b. Balmorhea Springs Complex. Pages 34-35 in M. D. Wesson, C. Hallmich, J. Bennett, C. Sifuentes Lugo, A. Garcia, A. M. Roberson, J. Karges, and G. P. Garrett, editors. Conservation Assessment for the Big Bend-Río Bravo Region: A Binational Collaborative Approach to Conservation. Montreal QC: Commission for Environmental Cooperation.

Mace, R. E. 2001. Aquifers of West Texas: an overview. Pages 1-16 in R. E. Mace, W. F. Mullican III and E. S. Angle, editors. Aquifers of West Texas. Texas Water Development Board Report 356.

Minckley, W. L., G. K. Meffe, and D. L. Soltz. 1991. Conservation and management of short-lived fishes: The cyprinodontoids. Pages 247-282 in W. L. Minckley and J. E. Deacon, editors. Battle Against Extinction. Tucson: The University of Arizona Press.

Petersen, A. M. 2002. The ecology of fishes in McKittrick Creek, Guadalupe Mountains National Park, Texas. Master’s thesis. Colorado State University.

Scudday, J. F. 2003. My favorite old fishing holes in West Texas: where did they go? Pages 135-140 in G. P. Garrett and N. L. Allan, editors. Aquatic Fauna of the Northern Chihuahuan Desert. Museum of Texas Tech University, Special Publications 46.

White, W. N., H. S. Gale, and S. S. Nye. 1941. Geology and ground-water resources of the Balmorhea area, Western Texas. Water-Supply Paper 849-C. U.S. Department of the Interior.