Coastal cities around the UK need to devise aggressive and proactive strategies to avoid devastation from rising sea levels, engineers and architects have warned.
The ICE and the Royal Institute of British Architects (RIBA) think tank Building Futures have teamed up to offer local authorities three bold approaches to mitigating the threat of rising sea levels by the year 2100: Retreat, Defend and Attack.
The report comes as local authorities approach a March deadline for completing the second generation of Shoreline Management Plans (SMP2s). SMP2s will provide road maps for local authorities to address coastal flooding risks.
Portsmouth and Kingston upon Hull − chosen as typical coastal cities for the study − will have to retreat inland, create inhabitable defence structures or build out into the sea, the report claims.
The Retreat scenario sees lines of defence moving inland, allowing water to occupy previously protected city areas.
“It is seen as a controversial, negative approach, almost giving up. But it needn’t be,” said report co-author and Halcrow maritime project director Ben Hamer.
Architects say it is crucial to take a positive, opportunistic perspective to rising sea levels.
Defend sees flood defence systems made commercially viable to attract private investment. This could mean inhabitable space on top of defence walls or reservoirs used for water sports.
The Attack option has cities building out into the water via stilted and floating structures, alleviating pressure from a growing population for living space and employment.
Architect Studio Egret West partner David West said it is crucial to take a positive, opportunistic perspective to find solutions to rising sea levels.
Attack-style measures are happening in Dubai and the Netherlands and are likely to enter common parlance in the UK within the next 20 years, he said.
Such structures could also make cities more attractive, West said.
The report Facing up to Rising Sea Levels: Retreat, Defend, Attack? was approached idealistically as if there were no financial or bureaucratic limitations. Solutions included inhabited piers in Portsmouth with lower tiers for traffic and upper tiers with pedestrianised streetscapes.
The team for Hull’s Retreat scenario hope the end result will be something similar to Venice, with the historic centre defended as an island
For Hull’s Retreat scenario the team envisaged “something similar to Venice”, with the historic centre defended as an island and the surrounding area flooded. “I think it could create a fantastic potential destination,” said Arup rivers and coastal director David Wilkes.
The full project will be exhibited at the Building Centre, London until 29 January, before travelling to Portsmouth from 15 to 27 February and then Kingston upon Hull from 15 to 28 April.
See the full Building Futures report online
- For more on rising sea levels and the ICE/Building Futures report, see NCE’s flooding special next week.