Display surface contours in the drawing to define the basin from a surface or surface contours. This is a prerequisite if you want to use the Define From Entities option in the Stage Storage dialog box. 
- Open a drawing that contains a basin you would like to study. 
 
- To view surface contours, right-click on the surface, and click Edit Surface Style. 
 
- In the Surface Style dialog box, on the Display tab: 
- Set Major Contours and Minor Contours to be visible. 
 
- Optionally, set User Contours and Watersheds to be visible. 
 
- Click OK.