The three rivers in the east of the High-tech district of Weifang City, Dongpusha River, Xipusha River, and Dongzhuo River, are the research objects. Based on landscape information modeling (LIM), the digital terrain model and hydrodynamic numerical simulation of the watersheds of these three adjacent revers are conducted to explore the spatial characteristics of a drainage system and the temporal and spatial variation of hydrology. The simulation results are applied to the landscape planning in this region. Thus, the problems of discontinuous river flow and the impact on water quality caused by the weak hydrodynamic performance are studied and responded to. This research adopts the research approach that integrates engineering project implementation, technological experiments, and scientific exploration in the planning and design process. It integrates 3D digital model construction and numerical simulation, The digital terrain model (DTM) for the research object is conducted to represent its spatial characteristics accurately. The digital water systems and their watersheds distribution characteristics are analyzed. Numerical simulation is carried out to reveal and predict river hydrological processes. The outcome of the LIM model and numerical hydrodynamics simulation are applied for planning decision-making. The results are as follows: (1) The form and distribution of the natural catchment basins of the three rivers in the east of the Weifang High-tech district are revealed, and the flowing process in the three watercourses is explained. (2) The hydrodynamic characteristics of the three rivers are revealed through hydrodynamic numerical simulation. (3) It verifies the credibility and effectiveness of the application of digital water systems in planning and application and improves the ability of overall management of hydrological water systems in planning.