Thanet District Council
Following on from the successful submission of the Project Appraisal Report (PAR), which resulted £6.2M of Capital Grant Aid funding being awarded to Thanet District Council, Herrington Consulting were again commissioned by the Council, this time to undertake the detailed wave modelling to inform the detailed design stage of the Margate flood and coast protection scheme.
A large number of wave models; testing a series of wave and water level combinations for a range of extreme events with different return periods, were run to identify the design conditions along the Margate frontage, for the current day scenario and taking the impacts of climate change in to account. The outcome of this process, along with comprehensive consultations was a recommendation for a stepped concrete revetment. The results of the numerical modelling were subsequently tested and validated using a physical wave model.
To allow the nearshore wave climate within the harbour to be fully understood under extreme storm conditions, a Boussinesq numerical wave model was used. This allowed the complex processes of wave refraction, diffraction and reflection to be accurately simulated. In addition, a combination of wave overtopping and 2D hydrodynamic flood flow routing models were used to determine flow paths, velocities and depths. This data was used to inform the design of a new automated flood gate..
As the project moved into its detailed design phase, the numerical modelling was validated using scaled physical models, which showed very good correlation. The detailed design of the stepped revetment was then incorporated within the overall scheme package. The construction of the scheme was completed in 2012, ensuring the protection of Margate from a storm event with a 1 in 200 year return period, including for the impacts of climate change in to the future.