[JTardiff]

I am working to correct a few technical issues for a DAMBRK project tentatively completed back in 2004. I was able to resolve several of the issues using the DAMBRK manual, troubleshooting guides, and online forum postings. I still require assistance to explain or correct one remaining issue involving unrealistic downstream breach condition elevations exceeding the defined dam breach crest elevation. In other words, the elevation of the water is mathematically showing a “jump” in elevation immediately downstream of the dam following breach initiation.

My scenario comprises of a simple 20-foot-high concrete dam and fixed spillway with a reservoir storage area of approximately 60 acres. The user defined 8 downstream cross sections vary in width and elevation over a several mile long alignment, however no other major features have been included in the model (i.e. dams, bridges). The downstream cross sections were modeled using the method incorporating elevations, channel widths, storage widths and associated Manning’s Coefficients for each cross section. Boss DAMBRK Option #1 was used for defining the model alignment.