Portchester Castle to Emsworth Strategy

This Strategy considers the section of mainland coastline between Portchester Castle and Emsworth.

The Portchester Castle to Emsworth Coastal Flood and Erosion Risk Management Strategy has been developed by the Environment Agency, working in partnership with Havant Borough, Portsmouth City, Fareham Borough, and Chichester District Councils. The Strategy identifies the best way of managing coastal flood and erosion risk over the next 100 years.

The estimated whole life cost to implement the recommendations in the strategy is £113 million (excluding inflation). These funds would need to be pursued through Flood Defence Grant in Aid from the Environment Agency and a partnership funding  approach seeking contributions from local, public and private sources.

The key benefits of delivering the preferred options are:

a) Reduced flood risk to 901 residential and 178 commercial properties for 2020, increasing to 4,257 residential and 433 commercial properties by 2110 across the whole Strategy area;

b) Reduced flood risk from typically a 5% annual exceedance probability (aep) (1 in 20yr event) to a 1.33% aep (1 in 75yr event), sustained for 100 years;

c) Improved flood risk and erosion protection to M27, A3(M), the South Coast Rail Link;

d) Improved flood risk protection for numerous heritage and recreation sites and features such as Portchester Castle;

e) Farlington Marshes, South Moor, Warblington and Conigar Point - maintain existing defences for the next 20 years. This will provide sufficient time to develop the long-term management options for the sites and establish compensatory habitat as required. The selection of a preferred long-term option requires further detailed studies which will be completed over the next 3-5 years. The information from these studies will confirm the best way to balance habitat requirements across the estuary, support the designated features and species and plan how to establish compensatory habitat. This work will inform the next SMP and Strategy review in approximately 10 years’ time. Maintenance of defences in the interim at Farlington Marshes will be through Environment Agency revenue budgets subject to availability of resources and approval of funds. Any recommendations from these studies will need to take account of the views of the Farlington Marshes Management Committee and other advisory bodies.