1.   Purpose and objectives

     DAMBRK develops an outflow discharge hydrograph due to spillway and/or dam-failure flows. This hydrograph is routed through the downstream river-valley. Peak water surface profiles, maximum discharge profiles, and their time of occurrence are computed.

2.   Description

     The DAMBRK model develops an outflow discharge hydrograph due to head-dependent flow through spillways, over the dam crest, and through a time-dependent, variable-geometry, dynamic breach. The breach characteristics are specified by the model user. The effects of reservoir inflows are considered along with the storage characteristics of the reservoir via a choice of either storage or dynamic-wave routing within the reservoir. Capabilities for generating a wave due to landslides are also available in DAMBRK. The outflow hydrograph is stored internally and then routed through the downstream valley via a dynamic wave routing technique in which the St. Venant equations are solved by an implicit 4-pt weighted finite difference technique using variable time and distance steps.

3.   Input

     Card input. Data requirements include: breach width, time of duration of failure, reservoir inflow time series, spillway characteristics, reservoir storage characteristics, starting reservoir pool elevation, 
cross-section geometry in the form of channel widths vs. elevation table, Manning n coefficients, expansion-contraction coefficients, and location of cross-sections and downstream dams or bridges.

4.   Output

     Printed output in form of tables and line-printer plots.

5.   Operational requirements and restrictions

     a) Users should have knowledge and experience in unsteady open-channel flow.
     b) Three to five day training seminar recommended.
     c) The program was written in FORTRAN IV for use on the IBM 360/195, but has been used on a         wide variety of main frame, mini, and microcomputers with little or no modifications.
     d) Maximum array sizes are for 200 cross-sections, 700 time steps, 6 plots, 8 channel widths, 10         lateral inflows, 10 multiple dams. 
     e) Program limitations: the model considers the unsteady flow to be one-dimensional. The program         is applicable on single river problems only.
     f) Typical CPU requirements (IBM compatible PC - 133 mhz Pentium) are less than 30 seconds and         storage requirements are less than 1 MB of storage space

6.   Form of presentation

     3/5" floppy diskette, and written documentation; program also available over the Internet. The Internet address is http://nws.noaa.gov/oh/hrl/rvrmech/rvrmain.htm

7.   Operational experience

     Hundreds of applications throughout North America and Europe.

8.   Originator and technical support

     Dr. D.L. Fread - Office of Hydrology (Originator),  
     Mrs. J.M. Sylvestre - Hydrologic Research Laboratory (Support).

9.   Availability

     HOMS National Reference Centre for USA.

10.  Conditions on use

     A standard handling fee is charged for the diskette and documentation.