In Feature Analyst, the Flat Feature analysis function allows the user to test that the delta Z (MaxZ – MinZ) for all vertices of a feature is less than the specified Z tolerance range. By default the value is 0, but the user can specify the tolerance value when activating this function in the Feature Analyst Options dialog. This is useful for quickly determining whether a feature, such as a water body, is flat with no variations in elevation anywhere in the feature or no variations that exceed the specified tolerance, defaulted to zero.
Once setup, a column will appear that, once analysis is run, will show a green check if the feature passes the tolerance range and a red x if the feature does not pass. A question mark shows the analysis has not been run. This test is pass/fail for an entire feature. To pass, the difference between the Min and Max vertex z-values must fit within the specified tolerance.
If a feature fails, check the vertices of the feature in the vertices tab to find and drive to the offending vertices.