Scientists tested a method to estimate water flow in rocky underground areas. They used maps and data to predict how water moves through the ground. By comparing different models, they found that the method using regional data was accurate in predicting water flow. The models also showed that water moves differently in areas with fractured rocks compared to weathered rocks. The models were mostly accurate in predicting how much water flows into streams, but some areas were overestimated due to underground drains not being considered.