Entire Catchment Flood Modelling as a Planning Tool – River Trent Case Study

Two-dimensional (2D) flood modelling techniques have been used on floodplain management investigations for some years now. Often these models would have only been applied to a section of an urban or rural catchment, and would not have covered the entire floodplain within the catchment of interest. With advances in computer hardware and modelling software; including the introduction of multiple 2D domain modelling, much larger flood models can be built and used. These advances in technology have meant that entire river catchments, included major and minor tributaries, can be modelled as part of a single overall model. This paper will discuss these software advances and their implications for flood modelling. Catchment flood models can be used to determine the impact of localised changes in land use or management on the entire river catchment and not just discrete sections of the waterway. Large scale developments; changes to planning schemes; changes to land management; flood mitigation works; river works, and the effects of climate change can all be assessed at this broad scale to determine the impacts not only from a flooding perspective, but also from a planning perspective. In the United Kingdom, the Environment Agency (EA) uses a strategic planning tool known as a Catchment Flood Management Plan (CFMP). The CFMP is used to identify broad policies fo