As a significant part of water informatization, the efficiency and effect of GIS development is closely related to the performance of the water information system. The framework of WaterMap, as proposed in this paper, is built on the basis of OpenLayers catering to the necessity of water informatization. Besides, certain breakthrough is made on the aspects of precipitation display, spatial data model, and data visualization. Thus, it can be repetitively applied in different scenarios, help improve the efficiency of GIS development, and greatly improve the flexibility and variability of map operation. The framework is verified to be useful with the experiment of application in Dynamic Monitoring System for Water Projects. With the fast accumulation of spatial data and ever-increasing necessity of data visualization, it is suggested that the framework can be further applied.