Flood control and flood plain management investigations using spatial data management techniques are increasing in the Corps of Engineers. Pilot studies initiated in the mid-1970's were successful in consolidating analysis concepts, fostering the development of spatial data file creation and management technology and enhancing the consideration of existing and alternative future development patterns in Corps' planning studies. Over 30 studies using HEC-SAM, the Corps' spatial data management system, are now completed or underway. HEC-SAM was created through selective acquisition of commercial software, adaption of academic research products, and development by researchers at the Corps' Hydrologic Engineering Center (HEC). The HEC role continues to be that of system developer and technology transfer agent. The evolution, present capabilities, and applications of HEC-SAM are described. Observations are offered on spatial technology development, implementation, and servicing. (Author).

This paper describes the new version of the HEC-1 Flood Hydrograph Package - a comprehensive simulation model computer program. The many hydrologic and hydraulic simulation capabilities of the model are described. Special emphasis is given to analysis of dam safety and dam failure flood damage studies, and urban hydrology. The general applicability and usage of the model are described. (Author).