Amistad National Recreation Area, Texas, protects many archeological sites in the Lower Pecos Canyonlands region of southwest Texas. Sites are affected by lake level fluctuations related to climate change impacts including precipitation, storms, and changes in agricultural water use. Park managers are documenting the impact of changing water levels on the cultural resources in the park.
The reservoir that is the centerpiece of Amistad National Recreation Area was created when the Rio Grande, Pecos, and Devils Rivers were dammed in 1969. The reservoir provides flood control, water for agriculture, and recreational opportunities for visitors. In addition to having more than 129 km (80 mi) of international border with Mexico along the Rio Grande, the park is located at the intersection of several distinct physiographic, biological, and climatic regions and is characterized by variable and unpredictable weather. The park’s location at the intersection of the arid west, the humid east, the seasonal latitudes to the north, and the tropical climates to the south contributes to exceptionally unpredictable precipitation patterns. The park is also periodically impacted by tropical storms and hurricanes coming off the Gulf of Mexico, resulting in massive flash flooding. As the climate changes, it is likely that weather patterns will become increasingly erratic, and that greater outputs from the reservoir will be required to satisfy agricultural water needs. Fluctuating water levels in the lake, caused by both variability in precipitation and by outflow from the dam, expose cultural resources to a variety of physical, human, and biological threats.
Park personnel are currently spending as much time in the field as possible to revisit known sites and to do condition assessments and improve documentation on recently exposed sites. Additionally, the park has recently completed a cutting-edge LiDAR and photo documentation project at Panther Cave in cooperation with the Texas Parks and Wildlife Department and local nonprofit rock art research and education center, Shumla.
The park is presently studying impacts to natural and cultural resources from illicit cross-border traffic and associated law enforcement activities—another human threat to cultural resources that is not yet well understood at the park. The fieldwork for this project allows park personnel to revisit sites and to complete more condition assessments and documentation than would be possible otherwise. Unsurprisingly, these assessments routinely show impacts to sites caused by threats associated with changing lake levels. One very successful measure the park has taken is that all new law enforcement rangers receive a three-day, intensive cultural resources orientation from the park archeologist. This increases their awareness of and enthusiasm for park resources and resource issues, and builds rapport between law enforcement and resources staff. Their informed observations while on patrol and timely communication with resources staff have proven very helpful.
The park also collaborates with Texas Parks and Wildlife Department and Shumla on outdoor experiential learning programs for local and area schools. These programs introduce elementary students to the cultural and natural resources of the area, and use these resources as a lens through which to teach and reinforce science and math concepts from the classroom that students will later be responsible for on standardized tests. Moreover, these programs work to instill an enjoyment of the natural and cultural landscape and appreciation of and respect for the resources, as well as to foster a sense of responsibility and stewardship.
Johnson, J.G., and B.K. Todd. (2015). Reservoir Water Level Change Impacts on Cultural Resources, Amistad National Recreation Area, Texas [Case study on a project of the Amistad National Recreation Area]. Excerpted from Schupp, C.A., R.L. Beavers, and M.A. Caffrey [eds.]. 2015. Coastal Adaptation Strategies: Case Studies. NPS 999/129700. National Park Service, Fort Collins, Colorado. Retrieved from CAKE: www.cakex.org/case-studies/reservoir-water-level-change-impacts-cultural-resources-amistad-national-recreation (Last updated November 2015)