2.0

Calculating the Runoff from Watershed Areas
553
To select and edit the runoff curve numbers for different soil groups and cover
types
1 From the Hydrology menu, choose Runoff ä SCS Curve Number Editor to
display the Runoff Curve Number Editor dialog box.
The dialog box lists curve numbers for surface cover and conditions for soils
types A, B, C, and D. These curve numbers are also provided in the TR-55
manual, Table 2-2.
NOTE
Do not edit the surface cover and conditions descriptions or the curve
number values unless you use non-standard curve numbers for your project
area.
2 You can select and edit the CN values by using the following guidelines:
If you want to} Then}
locate a CN value use the navigation buttons. For more information,
see Hydrology-Navigation in this chapter.
select a CN value double-click in the cell and click OK.
insert a row of CN values for a cover
type
place your cursor in the row you want to insert
the row above, and click Insert.
delete a row of information place your cursor in the row to delete and click
Delete.
3 Click OK.