MONITORING THE TRINITY AQUIFER IN MCLENNAN COUNTY, TEXAS: AN ASSESSMENT AND STRATEGY FOR THE SOUTHERN TRINITY GROUNDWATER CONSERVATION DISTRICT

Groundwater is an important water source in the State of Texas and the rapidly developing I-35 corridor. Understanding aquifer water level trends is helpful to groundwater management and conservation efforts. A major responsibility of Groundwater Conservation Districts (GCDs) in Texas is to monitor aquifer levels. Many GCDs measure monitor wells annually, quarterly, or monthly to study seasonal or multi-year trends. Groundwater levels can fluctuate for a variety of reasons and are often difficult to interpret. Groundwater managers need to understand the effects of stressors and delineate those effects in different datasets. Technological advances allow groundwater managers to capture much more data on aquifer levels than previously possible. These data can reveal more aquifer responses to natural or human events than before. However, the density of the more detailed data make interpretation difficult, especially when trying to relate cause and effect. This study provides an assessment and strategy for the Southern Trinity Groundwater Conservation District (STGCD) to improve data collection methods and aid interpretations for the confined portion of the Trinity aquifer. The STGCD has gathered hourly, monthly, and yearly water level data from monitoring wells using a combination of pressure transducers and sonic data loggers, telemetry, and manual water level measurements. In this study, a dense data set from nine monitoring wells over a five-year period is used to create visual representations of various water level trends in the confined Trinity aquifer. Correlating aquifer responses to meteorological and production data will allow the STGCD to improve their monitoring techniques. This will help groundwater managers understand how the groundwater is being used in municipal and industrial circumstances and guide future monitoring strategies for the Trinity aquifer in McLennan County, Texas.