Abstract: In order to investigate the influence of terrain on the division of zonal metering areas (DMAs) of urban water supply pipe networks, a DMA design and optimization method for urban water supply pipe networks adapted to the terrain is proposed based on the hydrological analysis-based D8 algorithm, mathematical morphology methods and marker control methods by using the GDEM data with 30 m spatial resolution. The influence of topography and existing water supply pipe networks data on DMA design is analyzed from the perspective of DEM data optimization. The study shows that: ① The hydrological analysis method based on DEM data can quickly realize the division of DMAs, and the area similarity ratios compared with the actual engineering results are 0.84 to 1.11, which indicates that the method is feasible to a certain extent. ② The use of mathematical morphology methods and existing water supply networks data to optimize the DEM data can optimize the distribution of sub-basins in the study area, and the area similarity ratios with the actual engineering results are 0.95 to 1.08, with the degree of similarity close to 1, which are more in line with the engineering practice. ③ The optimization of terrain data using mathematical morphology methods and marker control methods can improve the design results and effectively improve the result accuracy. The research results can provide a terrain data optimization method for similar engineering design in the future.