Developing a New HEC-1 Model

About the Tutorial

This tutorial includes important guides in the use of Drainage Design Management System for Windows (DDMSW) software such as accessing helpful document from the Help menu, setting and updating project defaults, setting the paths where model input and output files are saved, and how model data are created and established.

Data Sets

Model development involves the establishment of the following data sets which are entered manually:
  • Diversions
  • Flow Data
  • Land Use
  • Rainfall
  • Routing Reaches
  • Soils
  • Storage Facilities
  • Sub-Basins


The procedure also includes the development of the model network that defines the relationship of the different hydrologic elements (including sub-basins, routing reaches, diversions, storage facilities, and direct flow data) in the model.

DDMSW builds the HEC-1 models for the six standard return periods hard-coded in the program (2-year, 5-year, 10-year, 25-year, 50-year, and 100-year) and generates the flow hydrographs and peak flows associated with those return periods.