The Cross section Editor (accessible via Edit » Link Cross Sections... and shown in Figure 1) allows you to specify the physical cross-section of a river. This can then be used to generate a rating curve.

Note the following about cross sections:

Cross sections are defined at the scenario level and are available at a global scale. They can be created manually (by entering the value directly in the Editor) or exported;
A single rating curve is created for each Z-point;
A single cross section can be referenced by multiple rating curves;
A given rating curve can refer to one of the globally defined cross sections; and
A rating curve can be manually edited after being loaded from a cross section.

Figure 1. Cross Section Editor

Browser not supported