Product(s): |
StormCAD, CivilStorm, SewerGEMS |

Version(s): |
CONNECT Edition, V8i |

Area: |
Modeling |

# Problem

Is it possible to change or adjust the IDF Curve Equation or the IDF Table Equation used in the Storm Events dialog?

# Solution

It is not possible to make a change the IDF curve equation or table equation, as they are hard-coded into the program.

If you have a different equation, it is recommended to use Excel to calculate the intensity values, and then use those values to create a User Defined IDF Table.

Here are two ways this can be done.

**Option 1**

1. Use Excel to calculate the intensity values.

2. Copy the values from Excel.

3. Paste them into the User Defined IDF Table in the Storm Data dialog.

**Option 2**

Excel files can be saved in a .txt or .csv format, which can be imported into the IDF table using the steps in the following link: What is the expected text file format for IDF import?

# See Also

IDF Equation Coefficients: E, B, D vs A, B, N

Import IDF Equation Storm Data