Mapping by Mott MacDonald helps Lincs manage tidal flood risks

Mott MacDonald is working with the Environment Agency (EA) to highlight the risk of flooding to communities along the Lincolnshire coast, as part of its appointment to the nationwide Strategic Flood Risk Management (SFRM) framework.

The consultancy is providing flood risk mapping for the Lincolnshire coast and the Wash using two-dimensional hydraulic models that will anticipate the effect of water breaching and overtopping the region’s coastal flood defences.

Sun Yan Evans, Mott MacDonald’s project manager for the scheme, said: “Breaching of the flood defences may be triggered by a large storm such as a spring tide with a large surge component, similar to the devastating floods that occurred along the east coast of England in 1953, affecting communities like those at Mablethorpe and Skegness in Lincolnshire.

“To improve the understanding of tidal flood risks and effectively manage them using a risk-based approach, the project is mapping the extent of flooding from overtopping or breaching of the sea defences, depicting hazard ratings and potential depth and velocities for use by the local authorities and emergency services in the case of an evacuation due to flooding.

She continued: “The flooding maps are critical, as they allow the authorities to know which access routes, for example, are likely to become inundated during a flood. The maps are also used in planning, enabling the EA to support or object to the development of property on the grounds of predicted flood risk.”

EA Flood Risk Mapping & Data Management team leader John Ray explained that the work would “help us fully understand the potential flood risk in the area, and how this may be affected by climate change. This information will help us, our professional partners and the communities at risk to be better prepared for a major tidal surge”.

A significant part of the project is to predict the extent of future breach flooding for extreme events, such as a 0.1% chance flood, over a 100-year horizon. To do this, Mott MacDonald’s team is taking into account the impact of climate, as sea levels are expected to rise.

The project is expected to be completed this October.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie