This document, which is available by clicking on the link below, explains the procedures to follow in performing a floodway analysis using the U.S. Environmental Protection Agency Storm Water Management Model (SWMM). SWMM is an unsteady-flow model that has been accepted by the Federal Emergency Management Agency (FEMA) for use for National Flood Insurance Program (NFIP) purposes.
Resources related to the Floodway Analysis Using SWMM can be downloaded through the link below. These resources and an array of other useful FEMA, NFIP, and Risk MAP resources are located in the FEMA Library.
View the complete listing of Numerical Models Accepted by FEMA for NFIP Usage.