AbstractIn recent years, climate change has caused extreme weather all over the world, including in Taiwan. Rainfall in Taiwan is distributed unevenly in both time and space, leading to a shortage of water resources which has become a pressing issue for the island. Groundwater plays a vital role as a backup and supplementary water resource. This study proposes a method that combines the seepage theorem, field observations, and a numerical simulation to identify high-potential groundwater resource regions to meet the demand for water supplies in future development. The Taichung Chingshui Coastal Plain (TCCP) was selected as a study area for testing the method. Two new wells were drilled in the area to obtain additional information to supplement the analysis of groundwater levels (GLs). Results indicate that the hydrological and hydrogeological parameters (e.g., Manning’s coefficients, hydraulic conductivity, and formation thickness) can be obtained reasonably by comparing the numerical simulation with the observed GLs. It was found that the Dadu, Waipu, and Qingshui districts are the top three areas with higher potential groundwater resources in the TCCP. Data from the observations wells and in situ pumping stations verified our simulation results, which showed that our proposed methodology is advantageous. The research results can help improve the effective use of existing groundwater resources and assist with water resource development and sustainable usage.