i_SWAT is a model control system for the SWAT river basin model developed by the Grassland, Soil & Water Research Laboratory, USDA-ARS, in Temple, Texas.  It stores SWAT input data in an Access database, feeds that data to SWAT, runs SWAT, and reads and stores the results.

SWAT Home Page at Blacklands Research Center.

For further information see the i_SWAT description on pages 229-234 of the 2nd International SWAT Conference Proceedings at www.brc.tamus.edu/swat/2ndswatconf/2ndswatconfproceeding.pdf.

Draft SWAT literature database.

Operation Diagram: i_SWAT.gif (20856 bytes)

Table Structures:

[Control Records]
   [Lake Water Quality]
   [Point Sources]
   [Point Sources Monthly]
   [Point Sources Daily]
   [Point Sources APEX]
   [Potential Evapotranspiration]
    [Stream Water Quality]
    [Water Use]
    [Soil Layers]
[Weather Stations]
    [Weather Historical]
    [Weather by Month]
[Watershed Water Quality]
[Septic Water Quality]
[Output HSL]
[Output HRU Annual]
[Output HRU Monthly]
[Output Reach Annual]
[Output Reach Monthly]
[Output Reach Daily]
[Output Sub-Basin Annual]
[Output Sub-Basin Monthly]
[Temporal Conservation Practices]


Download i_SWAT.exe 2015-01-28
Download vcredist_x86.exe, which installs system DLLs required by the Visual Studio 2013 compiler used to create i_SWAT. Install if you get the message "application failed to start because application configuration is incorrect".
Download i_SWAT Help file (read by the program to show variable descriptions)
Download i_SWAT Output Variable Descriptions file
Download empty database 2015-01-28
List of SWAT version changes
SWATDiff - a utility to compare two SWAT runs for differences.

Installation: drop the above files into a directory containing Swat.exe. Open i_SWAT, select "File" | "Configuration", click change button under "Location of SWAT Executable", browse to swat.exe. Then select "File" | "Open" and browse to empty.mdb.

Use "File" | "Import" | "Import CIO File" to read an existing set.

If applicable, copy any daily record files indicated by routing (.FIG) file to the SWAT2000.exe run directory.

Changes since previous version: 

2015-12-14: New output reach table variables.
New fields "Chlorophyll-a Out" (CHLA_OUT), "CBOD Out" (CBOD_OUT), "Dissolved Oxygen Out" (DISOX_OUT) added to both [Output Reach Annual] and [Output Reach Monthly].

2015-01-28: Many updates for newer SWAT versions & revisions.
New revision number entry in "File" | "Configure" to enable code to more closely follow SWAT changes since 2010-04-16. New function check_extract throws error if "Nan" appears in output.hru, output.rch or output.sub. New fields "Lateral Discharge" (LAT Q), "Lateral NO3" (LATNO3) and "Groundwater NO3" (GWNO3) added to both tables [Output Subbasin Annual] and [Output Subbasin Monthly]. New fields "Initial Operation Year" (isep_iyr), "Operation" (isep_opt), "Capacity" (sep_cap), "FailureDuration" (isep_tfail), "StreamDistance" (sep_strm_dist), "Density" (sep_den), "PSorptionDistribution" (coeff_pdistrb), "PSorptionCapacity" (coeff_psorpmax), "SolublePSlope" (coeff_solpslp), "SolublePIntercept" (coeff_solpintc) in table [Septic]. For revision 503, New tables [Detention Pond], [Weir Stage], [Wet Pond], [Retention Irrigation Basin] and [Sedimentation Filtration Basin]. New field "Urban BMP Runoff" in table [Urban].
New fields in [Control Records]: "SoilPhosphorusMethod" (SOL_P_MODEL), "ImperviousCoverAbstraction" (IABSTR), "BaseflowDistributionFactor" (BFLO_DIST), "UnitHydrographMethod" (IUH), "HydrographGammaAlpha" (UHALPHA), "ErosionCoefficientSplash" (EROS_SPL), "ErosionCoefficientRill" (RILL_MULT), "ErosionOverlandFlow" (EROS_EXPO), "InstreamSedimentModel" (SUB_CHSED), "CFactorScaling" (C_FACTOR), "ParticleSizeMedian" (CH_D50), "ParticleSizeSTD" (SIG_G), "Atmospheric Deposition Monthly" (IATMODEP), "Stations Per File PCP" (NRGFIL), "Stations Per File TMP" (NTGFIL), "Curve Number Retention" (R2ADJ), "Static Max Depressional Storage" (SSTMAXD_BSN), "Max Depressional Storage Flag" (ISMAX). New fields "Root Shoot Ratio Initial" (rsr1c) and "Root Shoot Ratio Final" (rsr2c) added to table [Crops].
Many fields renamed to avoid Firebird's 31-character name limit. See the list here. Table [HRU] field "Area" changed from single to double. New field "Static Max Depressional Storage" (SSTMAXD) added.

Use TableCheck program to convert existing databases.
New column added to "iSWATOutput.csv" for swat2009 output.sub variables.

Developer's Page