Based on hydrogeological surveys, drilling campaigns, and long-term monitoring of surface and groundwater levels in Jiuxian groundwater source field in Tai′an, a regional-scale numerical groundwater model was established to quantitatively analyze the dynamic variation in water exchange between Mouwen River and the complex aquifer during typical hydrological years. Mouwen River was divided into four reaches from upstream to downstream, and the water exchange volumes between different impounded reaches and the unconfined and confined aquifers were calculated separately. The results show that river impoundment by rubber dams altered the recharge relationship between Mouwen River and groundwater:groundwater discharged into Reach 4 without rubber dams, whereas Reach 4 recharged groundwater after dam construction. Significant differences were observed in the water exchange fluxes of different reaches; under the influence of rubber dams, the order of river recharge fluxes to groundwater from the smallest to the largest was Reach 2, Reach 1, Reach 4, and Reach 3. With rubber dams in place, the annual recharge volumes from the entire river to the unconfined aquifer increased by 7.4924 million m³,7.4437 million m³, and 7.7310 million m³ during dry, normal, and wet years, respectively, while the annual recharge volumes to the confined aquifer increased by 1.3321 million m³,1.4083 million m³, and 1.6474 million m³, respectively. River impoundment thus significantly enhanced Mouwen River recharge to groundwater.