HEC-RAS Dam Break

[DSI50]

Hi All,

It's my first time working with unsteady flow. I'm using a FEMA RAS model in order to determine the hazard classification of an existing dam.
The reach from the dam to the mouth is 2 miles long and includes numerous crossings.
Hydrographs at the dam (before breach) developed with WinTR-20 are available.
I already looked in the HEC-RAS User's Manual Chapter 16, Chapter 8 Performing an Unstedy Flow Analysis and Example 17 Unsteady Flow Application. I feel that I need extra help and/or access to additional literature describing a step by step procedure using HEC-RAS Dam Break.
I'm not sure exactely what boundary conditions (U/S, D/S and initial) to use. Could be the existing hydrograph before the breach the U/S boundary condition? D/S and initial? What are they exactly in the unsteady flow?
Also I'm having problems finding the RAS window for the control of the dam gate in the unsteady flow data.
I'm looking to get water depths and velocities and using some available charts to determine the hazard classification.
As you can see, I'm strugggling with this very interesting exercise. Please help.

 

[chicopee]

The noted "Francesca" will tell you to spend some quality time with the Hydraulic Refernce Manual.

 

[francesca]

I may or may not have typed that very response in last night, only to change my mind about posting it, only because I wasn't sure if HEC-RAS was even the right application for a dam break analysis. Certainly in my hydrology class we used WMS, but then WMS is just a very nice GIS wrapper for a lot of HEC programs anyway.