Flood risk on the Thames Estuary is increasing. Climate change is causing increases in sea level and river flows, and new development is taking place on the floodplain. In addition, the major flood management system for the tidal Thames is deteriorating. Many of the defences were built following the 1953 floods, and will reach the end of their design lives during the next 50 years.
The system includes the Thames Barrier, over 300 km of fixed defences and numerous smaller structures.
In order to plan for the expected future changes in flood risk and the need to upgrade the flood management system, the Environment Agency has undertaken the Thames Estuary 2100 project (TE2100) in which a plan was developed for managing flood risk on the Thames estuary over the next 100 years.
Pressures on land use combined with rising sea levels mean that flood risk is increasing (Due to isostatic rebound – after the melting of the ice cap following the last ice age land in the south of Britain is sinking by about 1-2mm a year).
This, with the addition of the uncertain contribution in sea levels resulting from climate change, means that processes of protection against flooding can never be static.
A programme of studies was developed to assess the feasibility of the options in which the Thames flood risk could be managed. Studies undertaken included flood modelling to determine flood defence levels, design of habitat creation areas, outline designs of potential new barriers and barrages, and predictions of morphological change in the estuary. Results were used to develop options for appraisal.
The selected TE2100 option is a combination of improvements to the existing flood management system followed by a major improvement to the system later in the twenty-first century.
It is now known where important estuary habitats will be lost through rising sea levels and what is needed to do to replace them. These habitats are vital to a rich biodiversity and commercial fishery in the estuary.
A minimum of 1,200 hectares will need to be replaced by the end of the century.
The TE2100 plan recommends options for creating new inter-tidal habitat through re-aligning the current flood defences around areas of former estuary marshland.
The plan indicated an option for Canvey Island for the creation of a space for flood water and a re-alignment of the sea defences along Roscommon Road, Canvey Road and Canvey Way.
Sea level rise will likely cause harm to the imporant habitat area of Benfleet Creek. Returning Canvey West Marsh to a wet land may compensate and provide one of the flood water storage areas that are required.
The last two winters have highlighted the folly of high density housing development in flood risk areas. Not only can we expect issues with house insurance but also the funding of sea defence improvements.
The Canvey Island sea defences allow for an almost 1 in 1000 year event. Improvements are necessary, however the funding is not assured.
Government advisors expect the number of homes at risk of flooding to quadruple in the next 20years. More and more sea and river defence schemes will appear.
Paul Leinster, chief executive of the Environment Agency, which delivers flood defences “There will always be more schemes proposed than funds available and no one can prevent flooding entirely.”
Whilst we must hope that sea defence schemes for Canvey Island are delivered in a timely fashion in the future, we should also be aware of how a realignment of the sea wall at West Canvey will reduce our green spaces.
To plan, as Castle Point Council are, to allow development at the Dutch Village and the old Castle View School site will not only cause the loss of Green Belt but important amenity space and areas that importantly offer space for flood water dispersment.
By actively promoting development in these two particular areas relieves any pressure to kick start the Town Centre regeneration plan and the regeneration of the previously developed areas in need of updating.
The Castle Point Local Plan indicates the need to respond to flood risk, but appears to have no substantiated plans or regard over how Canvey Island will be impacted upon should the plans eventually be implemented.