The River Mechanics models and tools were originally developed by Dr. Danny Fread and Janice Sylvestre at the National Weather Service (NWS) from 1974 through 2005.  Although they are no longer supported by NWS, the RiverMechanics Group is committed to enhancing and maintaining the following: BREACH, SMPDBK, FLDWAV, FLDAT, and FLDVIEW.

Featured Application:   SDB-J

SDB, an enhanced version of the NWS SMPDBK application, is a simplified procedure for predicting downstream flooding produced by a dam failure.  It produces information needed for delineating areas endangered by dam-break floodwaters while substantially reducing the amount of time, data, and technical expertise required in employing more highly sophisticated unsteady flow routing models such as the FLDWAVE model. With a minimal amount of data, SDB can be used to predict the dam-break flood wave peak flows, peak flood elevations, and peak travel times at selected downstream points. This capacity for providing results quickly and efficiently makes the SDB a useful forecasting tool in a dam failure emergency when warning response time is short and data are sparse.  SDB is also useful for pre-event dam failure analysis by emergency management personnel engaged in preparing disaster contingency plans when the use of other flood routing models is precluded by limited resources.  Peak flows calculated with the more complete FLDWAVE model and those calculated with SDB are often within 10 percent of each other.

SDB does not account for backwater effects caused by natural or man-made channel constrictions, the presence of which can substantially reduce the model's accuracy.

The original FORTRAN code (NWS SMPDBK) was developed in 1983 and revised in 1991. The current Java GUI (SDB-J) replaces the awkward Fortran-based GUI while continuing to use the original FORTRAN calculations portion of NWS SMPDBK.  SDB-J  is used to create or read in an input data file, run it through the SDB application, and display the peak conditions graphically. Enhancements to SDB-J include error checking, a metric option, and the ability to export a FLDWAVE file.  The current version (2019) is not affiliated with NWS.

An example of the SDB-J input and output is shown below.




   is not affiliated with the National Weather Service

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