How to Make a Trapezoidal Inflow Time Series in InfoSWMM

You can make a Trapezoidal shaped Time Series in InfoSWMM by using the following steps:

Use the Inflow Icon at a Node in the Attribute Browser
Use either an Inflow Time series with date/time/value or
A baseline flow value with a pattern
The time series comprise a Date that matches your simulation time period
A hour:minute:second Time value in the Time Series Table
A flow unit with the units used in the General Tab of Run Manager
This time series is entered in the Attribute Browser under Time Series in the Operation Tab
You can also have more complicated inflow time series or the time series can be a combination of dry weather flow + wet weather flow so you don’t need rainfall or Subcatchments but simply a inflow time series into a node
Due to Windows limitations you can only have 512 time series per model in SWMM5.

How to Make An Inflow Time Series at a Node in InfoSWMM

ICM SWMM & ICM InfoWorks, SWMM5 & SWMM5+