Calculating the volume of a dam sight

[JaromHlebasko]

Hello, any input to what I am trying to do would greatly help my workflow. I have a proposed dam site that needs to be 20 feet in width at the top of the dam and then from there on both sides, I need to calculate the volume on a 3 (horizontal) to 1 (vertical) slope until it touches the existing surface. Any thoughts? I know how to calculate volume at a specific elevation but when the 3:1 needs to go off both sides of the top of the dam, I am stumped.

Any suggestions would be greatly appreciated!

Jarom

[GerryGabrisch]

If you know the elevation of the 20 foot section of the top of the dam and its location, then create a polygon of the 20 foot piece.  Create buffers at 3 meter intervals to this polygon.  Populate the attribute table of the buffer rings with the appropriate descending values.  Convert the buffers to a raster using the descending elevation values. 

Use the con function to alter your new damn model. If the dam pixel is higher in elevation than the surface model then keep it, otherwise replace the pixel with NoData.  The result should be a model of your dam.