Abstract: Annual precipitation in Taiwan is approximately 2,500 mm. Although the mean annual precipitation is relatively high, the erratic pattern of precipitation in time and space, as well as the mountainous nature of the island, restricts the efficient use of the water resource and renders the existence of reservoirs for storage mandatory. During a precipitation event, a portion of rainwater infiltrates the soil and contributes to groundwater recharge. However, when rainfall intensity surpasses the soil’s infiltration capacity, excess water becomes surface runoff that drains into nearby rivers. This study concentrates on the development and validation of an in-situ monitoring method for characterizing soil-based groundwater recharge in a watershed. Utilizing a real-time monitoring system based on the concept of Internet of Things (IoT), the paper quantifies important hydrological parameters such as rainfall, infiltration capacity, and soil moisture retention. Soil moisture is continuously monitored at several shallow depths and additional rain gauges are placed close by to maximize spatial representation of the precipitation measurements. These monitoring data allow us to analyse vertical infiltration behaviour on sloping lands when the rainfall intensity is high. Additionally, hydrological parameters such as the Curve Number (CN) and soil water storage potential (SWSP) are computed to assist in the analysis. The results provide valuable knowledge for the management and evaluation of groundwater recharge performance in reservoir-impacted catchment areas.