Little Blakenham’s Flood Risk Modelling

We’ve recently commissioned detailed flood risk modelling for the surface water catchment of Little Blakenham to better understand how rainwater moves across the landscape and where it might cause problems.

Using specialist software, a model was created that shows how water flows over the ground and through local streams and drains.

To make sure the model is accurate, new river survey data was collected, topographic LiDAR data was used to map the shape of the land and local rainfall data was included to simulate different storm events.

This modelling helps us see where flooding could happen, how deep it might be, and which areas are most at risk. It also shows how water interacts with the natural and man-made drainage systems.

Different scenarios are tested to understand how changes in rainfall or land conditions might affect flooding. This helps us plan for uncertainty and make informed decisions.

The modelling helps us to:

• identify area’s most at risk of surface water flooding

• Explore ways to reduce flood risk for the community

• Look at opportunities to capture and reuse rainwater

We have included one of the maps produced from this modelling work. The one below shows the predicted flood depths for a 1% AEP (Annual Exceedance Probability) event lasting 3 hours.

This means it represents a severe storm with a 1 in 100 chance of occurring in any given year. While an event on this scale is rare, understanding this scenario helps us plan for more extreme weather and better understand how to reduce flood risk more effectively.