It could help save thousands of homes from the devastation of flooding and prevent hundreds of millions of pounds worth of damage.

A new visualisation tool to predict the maximum cost of coastal flooding to communities around estuaries, such as Southampton, has been developed by city scientists at the National Oceanography Centre (NOC).

Developed along with the University of Liverpool the tool works by combining high impact flooding scenarios with land use maps.

It comes as residents in Southampton were given an insight into a multi-million pound coastal defence scheme to protect homes along the River Itchen for the next 70 years.

Researchers used the latest method to find that the economic damage of coastal flooding increased much more than expected with the size of the flood.

Combining a model for flood inundation with one that simulates the effect of waves means that it is possible to estimate how likely it is that sea defences will be ‘over-topped’ in a changing climate.

This threshold is based on a plausible amount of sea-level rise by 2100.

The highest recorded river level was also added to this model to give an overall ‘worst-case scenario’ of flooding for communities around estuaries.

A new tool then relates the model output in terms of how many brick layers the flood water will reach, this can then be easily related to possible mitigation options for the different water levels.

An estimate of the economic damage of the flood is obtained by relating the water depth predicted by this method with the land use maps.

This information is then fed into ‘depth-damage curves’, which are used to give a value for the economic damage of flooding for a given water depth and land use type. For example, arable land under five meters of water or residential property under three meters.

Dr Jenny Brown, co-author of this study from the NOC, said “This research is an example of the NOC’s commitment to developing transferable science that benefits coastal communities through the provision of evidence in support of flood risk management.

“This new visual representation of flood hazard identifies areas at risk, allowing improved adaptive management - increasing community resilience to climate change and rising sea levels. This work leverages the expertise in marine hazards from across NOC, and our external collaborators, to assess flood risk to a coastal community from extreme waves, water levels and projected rises in sea level.”

Currently more than 400 homes in Northam, St Mary's and Chapel are at risk of flooding and Southampton City Council is considering two different plans which could involve more than £40 million spent on the banks of the River Itchen.

It is estimated that due to the rising sea level, 1,150 homes could be at risk by 2085, and that £800m of damage could be caused over the next seventy years if no defences are built.

And members of the public got a chance to see the detail of the proposed projects at the Northam Community Centre, with further events to come at the Matthew Le Tissier suite at St Mary’s Stadium from noon to 6.30pm on September 8, and the Southampton Water Activity Centre on September 23 from noon to 8pm.