Weather Underground to SWMM 5 Rainfall Time Series

Weather Underground is a site that provides excellent local weather information in the form of graphs, tables and csv files. You can use the data very easily in SWMM 5 by copying from Excel to a time series in SWMM 5.  Here is the rainfall for a storm event in Tampa, Florida in September, 2010

Export from WeatherUnderground using the CSV File Export Option

The data imported from the csv file to Excel and after the text to columns tool is used looks like this in Excel. The data is now ready to be imported into SWMM 5 after the time column is adjusted to fall on even 5 minute intervals. In Excel you can use the formula @ROUND((B2)/"0:05:00",0)*"0:05:00" to round all of the time values to 5 minutes. If you do not do this step then you will have problems in SWMM 5 due to the rainfall interval not being equal to the defined raingage interval.

You will need to format the new rounded time as a time format for import into SWMM 5

Open up and make a new time series in SWMM 5 and then copy and paste the date, rounded time column and rainfall column into the SWMM 5 time series columns.


DWF Scale Factor in SWMM 5 for entering Population Data

I (and a few others) think a welcome change to the DWF dialog in SWMM 5 would be the addition of another scale factor to modify the average flow field.  The purpose of the scale factor would be to allow the users to enter the DWF contributing population * the various DWF patterns * the scale factor (in units of cfs/person or l/s/person) in the Inflows dialog.  Some users of SWMM 5 prefer to use population directly in the GUI rather than doing this calculation externally and entering either the flow in cfs or l/s.  An example of why this would be useful is a future conditions model in which the population either increases or decreased in the catchment.

InfoSewer Node Surcharge Depth New Output Variable

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New Table Output and Display of Node Surcharge Depth. 

A positive Surcharge Depth means the node water surface elevation is above the highest pipe crown, a negative depth means that the node depth is below the highest pipe crown.



Storage Unit Infiltration Behaviour - Initial Soil Moisture Deficit

If you have IMD of zero then the IMDMax is 0 and the Green Ampt solution may not be the most robust.  I need to add some graphics to see what is going on.

 Maybe this helps – you see that with a non zero IMD the initial infiltration is greater than with a zero value of IMD.  This makes the peak depth smaller and the peak volume much smaller.