Book Description

This document illustrates how computer program HEC-2 can be used to develop a designated floodway as required for Type 15 flood insurance studies. It was assumed that the reader has a knowledge of the basic input requirements. The computer procedure for delineating a floodway includes: (1) the development of water surface profiles under natural conditions (i.e., prior to encroachment) and (2) the delineation of a designated floodway that meets certain requirements. The procedure in the HEC-2 encroachment routines allows a program user to make the preliminary estimate of a designated floodway in one operation of the program. Additional computer runs may be made to improve the acceptability of the floodway. The computerized procedure was discussed and illustrated in an example problem. Appendixes contain a hand calculation example to illustrate the procedure, and first and second trials of a simple problem using the HEC-2 program. The Users Manual, available from The Hydrologic Engineering Center, provides the input specifications. (Author).