The scientists improved a computer model called SWAT+ by adding MODFLOW to better simulate how groundwater moves and interacts with surface water in a Texas watershed. They tested the model on the Middle Bosque River Watershed and found that it accurately predicted water flow patterns. The model showed that groundwater discharge rates increased by 50% compared to the original model, with the timing of groundwater flow being influenced by the rise and fall of water levels near streams rather than just by rainfall.