The Soil and Water Assessment Tool (SWAT) is a public domain model, which is a small watershed to river basin-scale model to simulate the quality and quantity of surface and ground water and predict the environmental impact of land use, land management practices, and climate change. SWAT is widely used in assessing soil erosion prevention and control, non-point source pollution control and regional management in watersheds.

The ArcSWAT ArcGIS extension is a graphical user interface for the SWAT (Soil and Water Assessment Tool) model (Arnold et al., 1998). The model is physically based and computationally efficient, uses readily available inputs and enables users to study long-term impacts. For a detailed description of SWAT, see Soil and Water Assessment Tool input/Output and Theoretical Documentation, Version 2012 (Arnold et al., 2012a; 2012b), published by the Agricultural Research Service and the Texas Agricultural Experiment Station, Temple Texas. ArcSWAT extension of ArcGIS creates an ArcMap project file that contains links to your retrieved data and incorporates all customized GIS functions into your ArcMap project file. The project file contains a customized ArcMap Graphical User Interface (GUI) including menus, buttons, and tools.

SWAT and the ArcSWAT interface are public domain software. Support is provided through the SWAT user website and several user groups and discussion forums. The following are links to SWAT related user support sites.

SWAT user web site:

SWAT forums and user groups:

ArcSWAT user web site:

ArcSWAT Google user group:


(1) SWAT and ArcSWAT is public software, free of charge, but with the research standard and scientific merit. They are widely applied for PhD water studies around the world.

(2) ArcSWAT provides friendly Graphic User Interface (GUI) to prepare SWAT input data and visual the output, once the data are prepared.

(3) SWAT can run without using ArcGIS, this provides the flexibility for non ArcGIS users.

(4) From SWAT and ArcSWAT user group one can get most the question answered.

Data availability

Most of the input data required by SWAT are public available, including DEM, soil land use/cover data wind 1km resolution should be enough for national level assessment. 

SWAT can be applied in monthly steps, monthly precipitation and temperature data can be obtained from varies sources, including local station observations and international data. Other required variable also could be calculated.

CLIMsystems can assist clients with the preparation of data for use with SWAT either off-line or through SImCLIM 4.0 for Desktop. Contact for more information.