HYDROLOGIC, GEOMORPHOLOGIC AND GIS ANALYSIS AND DEVELOPMENT OF AN INTERFACED SEDIMENT/DISCHARGE SAMPLING STATION AS A MEANS TO QUANTIFYING A SEDIMENT BUDGET FOR THE UPPER TERLINGUA CREEK WATERSHED

Terlingua Creek is a major tributary of the Rio Grande in the Big Bend region of Texas. It enters the Rio Grande near the mouth of Santa Elena canyon in Big Bend National Park. The Terlingua Creek watershed is 2,851 square kilometers (704,500 acres) and is located in Brewster and Presidio counties. The creek is a major contributor of both water and sediment to the Rio Grande. The general condition of the watershed is degraded due to land use practices and recent restoration projects have been initiated on privately held land in the upper portion of the watershed.

This study is designed to evaluate and monitor the hydrology, sediment load characteristics and general watershed condition of the watershed and to create a baseline data set to assess sediment mobility and the effects of the restoration projects. The study includes the integration of three interdependent components. Component one entails the compilation of a GIS data set which includes soil, geology, hydrology, topography, imagery, aquifers and well data. Component two is a detailed topographic study of selected areas in the upper portion of the watershed using RTK GPS and Total Station laser survey equipment in order to create a baseline dataset for future monitoring of changes that may occur as a result of restoration efforts and climatic events. The third component involves the installation of a permanent sediment/discharge sampling station consisting of an unmanned cableway and an automated pump sampler. The results of this project will be beneficial in our understanding of sediment transport to the Rio Grande and in our understanding of the positive effects of local restoration projects.