Facing up to rising sea levels
To defend is to ensure the sea water does not enter the existing built environment. This will require built defences to ensure the standard of protection will be met in the distant future as sea-levels rise. Although it is currently an expensive policy to adopt, can the defences themselves be designed in a way to make them economically and commercially viable?
Many of the hard engineered defences of the 20th century have been criticised for being unsustainable, reducing access to water, damaging to coastal habitats and costly to maintain and improve. However, they have provided protection and reduced risk from flooding, allowing activities to go on uninterrupted in the built environment. But what if the defences themselves served a dual function? For instance, could the defence structure be a part of a commercial development allowing for the developer to benefit from the proximity to water? Alternatively, there are several land uses suitable to locate within the inter-tidal zone that could be incorporated into a sustainable response to rising sea-levels, including public recreational space.
By choosing to defend, the existing built infrastructure of a city is protected from floods and does not need to be relocated to higher ground or rebuilt after flooding. However, as mentioned above flood defence is an extremely costly endeavour.
Currently, defensive practice is conducted in a piecemeal fashion, owing to the number of bodies involved and funding available. Could a citywide defence schemne be implemented and creatively financed, protecting the city from any severe tidal flood? The proposed line of defence is able to ‘hold’, ‘advance’, or ‘retreat’ the existing line of defence where necessary to accommodate the future needs of the city.