Through the Coastal Partners, Portsmouth City Council has led on the Portsea Island Coastal Strategy Study (PICSS), which was developed in partnership with the Environment Agency. The strategy, in combination with the Portchester Castle to Emsworth Coastal Flood and Erosion Risk Management Strategy (2013), completes the long-term strategic approach to Portsmouth's entire coastline. The strategy builds on policies set in the North Solent SMP and helps to decide how the coastline surrounding Portsea Island, Portsmouth, Hampshire will be managed for the next 100 years.
PICSS identified that Portsea Island consists of 7 independent flood cells. This means that if one cell was to flood (or breach) from the sea, the flood water would not flood a neighbouring flood cell.
PICSS identifies that Flood Cell 1 – Southsea and Flood Cell 4 – North Portsea Island are both priority frontages and recommends that coastal flood and erosion risk management solutions are prepared at the earliest opportunity to manage the risks of flooding from the sea to the existing communities and infrastructure on the Island. The Eastern Solent Coastal Partnership has started the development of options for these frontages.
PICSS concluded that a 'Hold the line' policy to Portsea Island is imperative in order to protect the population of the city and its infrastructure from the risk of flooding from the sea. It also recognises that in some areas, Capital Grant funding from the Government is not justifiable and recommends that developers and other beneficiaries should contribute to the upkeep of their own coastal defences.