A delegation from the Environment Agency (EA) and Portsmouth City Council has given the seal of approval to a scheme that will provide protection against flooding for residents of North Portsea Island.
The party came to inspect progress at Anchorage Park, a £6m flood protection scheme being delivered by Mackley working as part of Team Van Oord*.
Portsea Island is a small, low-lying island which contains a large proportion of the city of Portsmouth. It is the third largest (by population) of any island in the British Isles after the mainlands of Great Britain and Ireland, and has the highest population density.
The scheme, which will reduce the risk of coastal flooding and erosion to the area over the next 100 years, was commissioned by the Eastern Solent Coastal Partnership and made possible through funding awarded to Portsmouth City Council by the EA.
It involves the construction of 1.4km of coastal defences along the north of Portsea Island between Ports Creek Railway Bridge and Kendall’s Wharf.
Visitors to the Anchorage Park site 12 November included John Curtin, the EA’s new Director of FCERM who sent a series of tweets during the visit, Ian Hodge, the EA’s Deputy Director of Delivery and Assurance, and several members of the EA area team and Portsmouth City Council senior management.
1.4km of new embankment has been constructed using 42,000 tonnes of earth – sufficient to fill 8 Olympic size swimming pools. Rocks were then placed over the top of the embankment to protect it from erosion. Imported from Norway, the rock was specially selected due to its strength, weather resistance and durability.
On the eastern side of the site a wall has been created from gabions (stone filled wire baskets) to support the new embankment.
A new flood wall has also been constructed around a bridge to reduce the risk of Eastern Road becoming a flood route. A new foundation has been created for the wall by driving more than 400 steel sheet piles into the ground, and the sheet piles have also been extended up and around the electricity substation in the vicinity.
Construction works began in May 2015 and are now substantially complete.
Praise from local residents
The scheme was also praised by many local residents who attended a drop-in exhibition on 7 September, which provided an opportunity for local people to find out more about the construction work, and meet and chat to the project team.
Comments on the day included a “fantastic effort”, “first class job” and “well thought out and effective”.
Tony Battrick, Works Manager for Anchorage Park, said: “Although access to the site was through a densely populated housing estate, we managed to complete the works with very little disruption to the community.
“One way we achieved this was to use 1,200 French Oak timber mats to create an access track that carried all the deliveries to the work area.”
The wider scheme
Anchorage Park is the first stage of a wider scheme which will reduce the risk of flooding and erosion from the sea to 4,200 homes, 500 businesses and critical infrastructure, over the next 100 years.
The design of the defences incorporates ideas from local residents, offered during consultation events.
Once the defences are built, the area will be enhanced through an extensive replanting programme. This will increase the diversity of plants in the area, improving the current ecosystems and habitats for wildlife. Paths along the coast will be improved as part of the scheme.
*Team Van Oord
Team Van Oord is a Joint Venture partnership between Van Oord, Kier Group, Mackley and Royal HaskoningDHV who between them have a combined turnover in excess of £1.8bn.