This paper describes the use of Esri software to process airborne SAR data for a GIS flood model of a major UK river catchment. The model is used for insurance and reinsurance business purposes. The paper describes the background to the project, introduces the SAR product, and describes the ARC GRID and ARC TIN processes and the ERDAS techniques involved. The paper will include examples of the ArcView GIS front end produced for user operation. The paper concludes with an analysis of the experimental project and an analysis of the suitability of Esri software and SAR data for insurance flood modeling.