Cross section data should be entered into HEC-RAS from left to right when looking downstream. This is the assumed direction for all of the cross sections and other structure data. If you have data that has not been entered from left to right while looking downstream, this editor will allow you to reverse the data to the assumed direction. To bring up this editor, select Reverse Station Data from the GIS Tools menu of the geometric data editor. When this option is selected a window will appear as shown in Figure 5-86.

Figure 5 86. Reverse Cross Section Stationing Editor

As shown in Figure 5-86, you first select the river and reach which contains the data to be reversed. Then select the particular river stations of the data that is not in the correct format (left to right looking downstream). Add those locations to the box on the right side of the editor, by pressing the arrow button in the middle of the editor. Continue to do this until you have all of the cross section that you want to reverse the stationing for. Finally, press the OK button and the data will be reversed.