Catchment scale modelling is an invaluable tool to determine the impact of policies and, legislation on the catchment outcomes. However, Australia is relatively poor in catchment level, modelling which takes into account the spatial variability of natural resources in the catchment., Current models generally do not take into account all variability. In the United States a GIS, (geographical information systems) based model called AVSWAT has been developed. At each, point in the landscape AVSWAT uses a similar approach to runoff modelling as, PERFECT/HOWLeaky, Professor David E. Radcliffe from the Department of Crop and Soil Sciences at the University of, Georgia visited Australia on a scientific exchange grant from the Australian Cotton CRC. The, aims of the visit were to:, ?? Explore the model AVSWAT and discuss the possibilities for using this model as a, catchment management tool in Australia., ?? Explore uncertainty and how uncertainty could be dealt with using AVSWAT