Creating rainfall data in the UK for FSR

Step-by-step:

Once you have decided on which rainfall methodology will work for your site, you can begin to create the drainage network in your model, starting with the no-surcharge state.

This model already has catchment areas set up, with a manhole in each and pipes connecting the manholes. The flow arrows between the pipes designate the flow direction. The next step is to create rainfall data to be used in the Network Design Wizard.

IMPORTANT: The rainfall method you use is dependent on your local standards. This example is in the UK and uses the FSR data.

1. On the ribbon, Rainfall/Pollutants tab, Rainfall panel, click Rainfall Manager.
2. In the Rainfall Manager Tree View, expand the Design Storms node and select FSR.
3. In the toolbar, click Add.
   
4. Click the Parameters tab.
5. In the Label type box, name the test “Rain 1”.
6. Under the Parameters, enable both Summer and Winter.
7. Keep the England and Wales region active.
8. For the M5-60 (mm) type box, enter 20.0.
9. For the Ratio R value, enter 0.400.
   
10. Click the Return Periods tab.
11. Enable the Use
12. Under Return Period (years), enter 2.
    
13. Click the Storm Durations

Here, you choose the storm durations you want to include in your design. (It is not necessary to choose them all.) When you click Default, a nice range of storm durations are chosen for you, from only 15 minutes, up to a whole day. Note that some catchments are susceptible to short storms and others longer events, so it is important to select a range of storm durations.

14. Select Default.
    
15. In the Toolbar, click Save.

InfoDrainage has the ability to save the rainfall separately from the catchment data. The advantage is, you can create a rainfall event here and then use that same rainfall data across different studies.

16. The Rainfall Manager file dialog box opens. Browse to the folder where you want to save the rainfall study, name the file “design rainfall”, and click Save.
    
17. In the Rainfall Manager, click OK to finish creating the rainfall data.