Land and Water are the two major resources that the entire life system is depending upon. So optimum utilization of land and water requires an effective management of them. An effective management of land and water can only be achieved through a complete understanding of their characteristics. Hydrological modelling of such resources by the latest techniques will be more helpful for that purpose. This study involved hydrological modelling of Poondi sub-watershed by using Soil and Water Assessment Tool (SWAT). SWAT was used to generate valuable information for decision making by providing maps with model output. SWAT requires various input data such as land cover/land use data, weather data, etc. Remote sensing techniques were used to create land cover/land use data and soil cover data. The output was used to estimate the flow and its variation over the basin. Spatial distribution of annual rainfall, evapotranspiration, sediment yield and water yield was also estimated. These results were represented in the form of graphs and maps.