What is the purpose the Rainfall File, Runoff File, and RDII File in the Calculations Options? Why are the files not being created?
The Rainfall File, Runoff File, and RDII File are primarily used with the Long Term Continuous Simulation workflow. LTCS allows a user to run a long simulation to see the impact of a system, taking into account a lot of different factors. Information on LTCS can be found in the link in the See Also section below.
The Rainfall File, Runoff File, and RDII File are created to aid in the calculation of this type of simulation. In order for these to be created, you must used an external Rain File. This is one of the storm types available in the Storm Data dialog.
Rain Files contain gage data that can be applied to a system. These are typically .TXT or .DAT files. These are explained in further detail in the link related to Long Term Continuous Similar below. The Rainfall File and Runoff File will not be created if you are using a different storm data type, like
Rainfall Files are binary files that can be saved and reused from one analysis to the next. The rainfall interface file collates a series of separate rain gage files into a single rainfall data file. Normally a temporary file of this type is created for every SWMM analysis that uses external rainfall data files and is then deleted after the analysis is completed. However, if the same rainfall data are being used with many different analyses, requesting SWMM to save the rainfall interface file after the first run and then reusing this file in subsequent runs can save computation time.
To create and save a Rainfall File, open the properties for the Calculation Options and set the value for Rainfall File Mode to "Save". Click the dropdown menu for the the property Rainfall File and clicked the ellipsis (...) button. Give the file a name or select an existing file. When you compute the model, a Rainfall File will be created or saved. When you want to use this file, set Rainfall File Mode to "Use". The following file modes are available:
None -When this option is selected, no Rainfall File will be used or saved.Use -When this option is selected, the Rainfall File field will become available, allowing you to select the rainfall file to use. Save -When this option is selected, the Rainfall File field will become available, allowing you to specify the name and location for the rainfall file to be saved.
Runoff Files can be used to save the runoff results generated from a simulation run. If runoff is not affected in future runs, the user can request that SWMM use this interface file to supply runoff results without having to repeat the runoff calculations again. Note that the Runoff File will only be created if you are using the EPA-SWMM runoff method in the model's catchments. The steps to create, save, or use this file are as found in the steps for the Rainfall Files above.
RDII Files are a text file that contains a time series of rainfall-dependent infiltration/inflow flows for a specified set of drainage system nodes. This file can be generated from a previous SWMM run when Unit Hydrographs and nodal RDII inflow data have been defined for the project, or it can be created outside of SWMM using some other source of RDII data (e.g., through measurements or output from a different computer program). The manholes in the model need to be have the properties setup like the screenshot below:
The steps to create, save, or use this file are as found in the steps for the Rainfall Files above.
Running a Long Term Continuous Simulation
Error 318 appears when computing model using the SWMM solver