Abstract: Accelerating the construction of an intelligent water systems with four functions (forecasting, early-warning, drill and emergency plan, FEDE) is a clear requirement of national intelligent water works of China. The data baseboard is the necessary support of the four functions of FEDE system. Several cases of intelligent water works and digital twin river basins in China have been tested first, and their respective data and technical advantages have been brought into play to complete the construction of corresponding levels of data base plates, providing support for the application of four function of FEDE for digital twin basins and flood defense. On the basis of combing the relevant technologies of data baseboard and the experience of pilot work, the construction framework and main technical route of data baseboard for flood management is put forward, including data collection and integration, multi-source heterogeneous data aggregation, multi-dimensional and multi-scale data fusion, business information resource database, baseboard thematic map, data standardization for hydrological numerical model, data sharing management platform and visualization technology. Lastly the shortcomings and expectations of data baseboard construction are discussed in order to provide reference for the construction of digital twin river basins for flood management with four functions of FEDE.