Hey all! I have a technical question regarding some spatial analysis. It may be easy asnwer but for whatever reason I can't think of a solution. So I have a ditch system (water canal that drains from fields). I need to be able to measure the depth of ditch, depth of water, and volume of sediment underneath. Basically they are going to redo the entire ditch and construction needs to know if I can estimate the volume of dirt and sediment that will need to be moved.

Any answers, short or long would be much appreciated. Thank you.

So Map Algebra (see: A quick tour of using Map Algebra—ArcGIS Help | ArcGIS Desktop ) con be used to mimic the behavior of the Cut/fill tool.

If you have a DEM that represents the situation without the dirt sediment and another one that includes the sediment, calculating the difference between the two (and mask them for the ditch area) can be used to sum the data and calculate the volume. This will require enough your DEMs to have sufficient precision in order to get a good estimate.

What is the spatial resolution of you DEM? How wide are the ditches? Can the "rough construction measurements" be used to create a 3D representation of the ditch without sediment? Is your DEM (with sediment) based on recent data (situation might have changed if data is not recent)?

Can you share a part of your data to see what you have and if it is possible to get the results you're after?