In using the Annotate Cross Section command to display the elevation of a ditch, the feature for the ditch bottom must be displayed in the cross section set and then apply the Annotate Cross Section command.
Select Evaluation>Cross Section>Update Cross Section and select the cross section set that contains the ditch to be annotated. Ensure the Mode is set to Display On and select the Projected Features leaf, and then select the surface that contains the ditch to be annotated. The last step in displaying features in cross sections is to select the ditch bottom feature and then Apply.
Select Evaluation>Cross Section>Annotate Cross Section and select the cross section set that contains the ditch to be annotated and the surface that contains the point to be annotated. Select the Features leaf, and check Include (top of dialog), now select Features and Elevation. Select Annotate (within Features Leaf), select the feature to be annotated and then apply.