British coastal cities threatened by rising sea 'must transform themselves'

Hull and Portsmouth could be dramatically remodelled, suggests report
Robert Booth, guardian.co.uk 15 Jan 10;

Hull could be transformed into a Venice-like waterworld and Portsmouth into a south coast version of Amalfi, engineers and architects have claimed in a study of options for developing Britain's coastal cities in the face of rising sea levels.

The Institution of Civil Engineers and the Royal Institute of British Architects yesterday warned the future of cities including London, Bristol and Liverpool was at risk from seas which the Environment Agency predict could rise by as much as 1.9m by 2095 in the event of a dramatic melting of the Greenland ice sheet.

The report, Facing up to Rising Sea Levels. Retreat? Defence? Attack?, suggests swaths of Hull and Portsmouth's city centres could be allowed to flood over the next 100 years and large parts of the populations moved out.

In a model that explores managed retreat from the coast in some areas, Hull's historic city centre would be limited to an island reached by bridges and Venetian-style water taxis, while in Portsmouth large parts of Portsea island would be given back to the sea while new "hillside living" developments would be built on densely packed hillside terraces, akin to the towns of Italy's Amalfi coast. "The scenarios we have created are extreme, but it is an extreme threat we are facing," said Ruth Reed, Riba president. "Approximately 10 million people live in flood-risk areas in England and Wales, with 2.6m properties directly at risk of flooding."

Other options include building out into rising waters using piers and platforms to create new habitable space – a strategy known as "attack". In Hull this could involve floating disused oil rigs up the Humber and reusing them for offices, homes and university buildings, while in Portsmouth two-storey piers could be built with the lower tier used for traffic and the top tier used for pedestrian space.

Architect David West, one of the report's author's, admitted the proposals were "blue sky thinking" and uncosted, but said they had the potential to relieve pressure for housing on inland sites. "I think the concept of arriving at Hull as if you were arriving at Venice airport and taking a boat into the city is really exciting."

The proposals were met with scepticism in Portsmouth. "A retreating coastline in this area would have a significant detrimental impact on the internationally designated harbours," said Bret Davies, a coastal strategy manager at Portsmouth city council.

The Environment Agency's coastal policy adviser, Nick Hardiman, warned that extending into the sea was likely to be too expensive and structures were not likely to be sustainable.In the next financial year the Environment Agency will spend £570m on building and maintaining flood defences.

Radical sea defence rethink urged in the UK
BBC News 15 Jan 10;

Rising sea levels and more storms could mean that parts of at-risk cities will need to be surrendered to protect homes and businesses, a report warns.

The authors say that "radical thinking" is needed to develop sea defences that can cope with the future threats.

About 10 million people in England and Wales live in flood risk areas.

The project, launched on Friday, is a joint venture between the Institution of Civil Engineers (Ice) and the Royal Institute of British Architects (Riba).

The report, Facing up to Rising Sea Levels, urges the government, planning authorities and the public, to act sooner rather than later.

"If we act now, we can adapt in such a way that will prevent mass disruption and allow coastal communities to continue to prosper," said Riba president Ruth Reed.

"But the key word is 'now'," she added.

The study warns that rising sea levels, an increase in the frequency of storms and sinking landmasses could leave many UK coastal areas vulnerable to extreme flooding.

Facing the future

The project focuses on Kingston-upon-Hull and Portsmouth, two cities deemed among the most at-risk areas in the UK, and presents a series of six scenarios set up to 90 years in the future.

The scenarios are based on three themes:

• Retreat - moving "critical infrastructure" and housing to safer ground, allowing the water into parts of the city

• Defend - building city-wide sea defences to ensure water does not enter the existing urban area

• Attack - extending the existing coastline and building out on to the water (using stilts, floating structures and/or land reclamation)

The scenarios were developed by a group of experts, including architects, civil engineers, city designers, developers and policymakers.

Their ideas also had to take into account a number of constraints, including a lack of funding to protect the entire coastline of the UK, which stretches for more than 12,500km (7,700 miles).

"The scenarios we have created are extreme, but it is an extreme threat we are facing," observed Ms Reed.

The authors decided to focus on Kingston-upon-Hull and Portsmouth because the two cities displayed many of the characteristics of flood-prone areas.

They said that Kingston-upon-Hull was a low-lying city that has to be constantly drained by pumps, the River Hull - which runs through the middle of the area - is liable to flooding, and the port is of national strategic importance.

Portsmouth was also vulnerable, they added, because most of the city is located on an island that was no more than 3m (10ft) above sea level, and was densely populated.

Ben Hamer, chairman of the Ice steering group, said that government, public officials and businesses needed to work together in order to halt the "water invasion".

"Some very difficult decisions need to be made in the future, and to do this we need integrated thinking," he said.

"The UK must urgently change the way it plans, builds and designs at-risk communities."

The project's findings, which include sketches and details of the proposed "new cities", will be presented in a exhibition that will visit London, Portsmouth and Kingston-upon-Hull.