Inundation mapping for Indus River and its tributaries is a large as well as complex task to undertake. GIS and remote sensing technologies enable us to handle the complexity involved in the development and maintenance of such large systems. The main feature of such systems is the easy incorporation of changes to system. The influence of a revision in methodology at any stage of the system development lifecycle does not propagate to every other stage of the system thus allowing for incremental development. Moreover, the savings in time and project cost cannot be stressed more as use of satellite technology complements conventional engineering techniques for data gathering and lead to more information rich systems.