Groundwater recharge from river leakage in a karst canyon area was studied in a lead-zinc mining region in southwestern China. By monitoring water levels and conducting tests, researchers found that river water contributes to the mining area's groundwater. Pore groundwater moves quickly horizontally and can supply karst groundwater vertically, but at a slower rate. The injected tracer took over seven months to dissipate, indicating slow movement in the karst aquifer. Despite intensive mine dewatering, the mining area is not at risk from river leakage, and the river ecosystem is not greatly affected by the interaction between surface water and groundwater.