WaterBase is a project of the United Nations University. Its aim is to advance the practice of Integrated Water
Resources Management (IWRM) in developing countries, by providing (a) free, open source tools for modeling and decision
support (b) a collection of IWRM resources: web sites, tools, literature, training material, etc. and (c) a community of
partners who can provide advice, support, contribute to tools and resources. A first step in the project is a tool to provide
Geographic Information System (GIS) support and a setup interface for the Soil and Water Assessment Tool (SWAT).
This paper describes the design of this tool, called Map Window SWAT (MWSWAT).