The Edwards Aquifer in central Texas is a complex underground system made of limestone and dolomite. Scientists have used groundwater models and dye tracing to study how water flows through the aquifer. While models help understand water movement and pumping effects, dye tracing is better for measuring flow rates. Models are good at predicting spring water levels but struggle in areas with strong underground channels. Dye tracing is best for tracking water movement but doesn't help with water levels or budgets. Overall, models are useful for understanding water flow and budgets, while dye tracing is better for measuring flow rates in karst aquifers.