I have a question that has been around the forums before but I haven�??t seen it solved fully yet, I now actually have to do this myself for a project so I was hoping we could once and for all sort this out!
The problem is this; - I have a DEM. - I also have a known volume of water that will be released onto the DEM. - I need to know the height of the water level once it has flowed out over the DEM. - I need to take into account that the water can be released in any position on the DEM.
My problem is that I need to model this taking into account the fact that water behaves like a liquid, i.e. it will flow to the lowest point in the DEM, start filling up from there and then continue to cover further areas until no more water is released. In other words the resulting surface will be flat, as opposed to just raising the level of the DEM by a uniform height.
The closest to a solution I could find were these posts by Bill Huber: http://forums.esri.com/Thread.asp?c=93&f=995&t=235957&mc=7#msgid718242 . But as far as I can tell, this just distributes a known volume evenly across a surface. The question in the above thread concerned soil, which does not behave like a liquid obviously.
Maybe this Python script will help. You could use it to calculate the volumes above your dem at graduated levels. Then, check the volumes at each graduation to find the level that equals your input volume of water. You now have the elevation that equals your input volume!
