Surface Depth Area

[erwebsite]

For a surface: I would like to a boudare above a inlet point that is 3" deep.

I would like something like catchment area but the ability to specify a depth distance. Or specify a depth in the water shed anaylisis in the surface properties.

The only way I know to do what I want is user defined contours for each elevation.

Is there a better way to do get a specific shed area for a depth?

Thanks

-John

[DaveM]

I have never attempted this, but it seems like it would work. Create a catchment area using a 3d polyline. Convert this polyline into a surface. Create a comparison surface between that surface and the original. Creat a user contour at 3" or .25'. Thoughts?