You can assign model-specific rainfall content data for more accurate drainage design. You can use customizable, sample data formulas, or import data to create a rainfall IDF curve. Analysis tools then use the curve you specify to generate more accurate results for specific situations.

See To manage rainfall content for step-wise instructions.

The three sample formulas provided are:

• FHWA BDE Equation
• ANZ 6-degree polynomial (used widely in Australia and New Zealand)
• A Tabular sample

You can modify these formulas, rename them as needed, as well as import rainfall data and create your own rainfall curve.

You can import rainfall data in the these formats:

• Australian Rainfall & Runoff 6-degree polynomial data (.csv)
• NOAA PFCD (.csv)
• Hydraflow (.idf) or (.stm)

You can export rainfall data to Microsoft Excel, edit it and use it in a different model

Rainfall Content and IDF Rainfall Panels

The rainfall content manager opens initially as a tab, along with the Model Explorer. You can move it to display the panel in its own window.

• You can use standard interface controls to Add, Delete, Import or Export rain content data files, create a copy of the currently selected rainfall content sample formula, or open it in the IDF Rainfall panel.
• You can also double-click to open a sample in the IDF Rainfall window. The panel graphs the IDF rainfall curve for each of the AEP conditions you select. You can rename a sample or name a new one, describe it and state its equation. Note that you can set current formula as the default.

The panel also shows these data in tabular form. The fields change to reflect the sample formula you are working with. You can work with the tabular data to specify the most accurate curve for your design.