While increasing resistance against storms and drought is now a national priority, new economic and environmental resilience is also being built on rising waters further downstream where the Thames meets the sea and the UK’s modern trading links to the world. Jon Herbert looks at developments.
Whatever the proven links with global warming, the prediction that there will almost certainly be greater variations in extreme rainfall levels, floods, droughts and storm-battered coasts is prompting a wide range of innovative responses both large and small.
Small can be beautiful. One of the latest truly grass-roots tools in the Government’s armoury against devastating flood damage is the development of a natural hybrid grass. This has very long roots and is reported to be able to soak up twice the volume of water that ordinary grasses do. Tests in fields planted with the strain being developed by Aberystwyth University have indicated that water run-off can be halved.
Leaves and roots count when they form an army of millions. Many areas of urban Rotterdam are below sea level. Part of the Dutch genuinely green solution is to encourage the use of vegetation in roofing to lock-up rainfall where it falls before it can flood rivers and surface run-off systems to sewers.
However, a full UK strategic solution is likely to be focused on a combination of technology and management planning. The Netherlands has set a precedent by planning for the much more onerous once-in-1000-years flood event rather than the more tame 100-year events considered by the UK.
In learning to live with water rather than fighting against it, the Dutch want to make impermeable driveways and hard-standing areas such as car parks a thing of the past. Instead, their strategy is to hold back heavy run-off by making sure that the ground can store water temporarily and quickly until better weather arrives.
The Dutch experience is also that houses can be built successfully on flood plains if the appropriate mitigating measures are taken. They have little choice! In the UK, it is estimated that more than 200,000 new houses were built on flood plain land in the decade up to 2011. In the worst case scenario, a large part of the UK is theoretically open to flooding, albeit not all at once; this is also land that is very conveniently close to economic infrastructure and communication links.
Another part of the Dutch sustainable solution is to make individual properties more resilient through many small measures that pose both challenges and opportunities to the building industry and white-goods manufacturers.
Ahead of this, the Government and/or local authorities might be expected to put strategic components into place. These could include offshore reefs to break the power of waves, new sea-defences and returning land to absorb the power of the sea. Inland, better drainage and improved maintenance of ponds and reservoirs can optimise storage. New river flood walls can be covered with grass to soften their impact on built-up areas. This can be combined with the installation of artificial barriers that rise and lock into place to protect local communities.
Water-resistant plasters and transparent wall sealants may be used to protect individual properties. Some homes could be built on stilts or allowed to rise with water levels, with ground floors left open and used for car parking. Flood guards can be fitted to doors and windows, air bricks covered at peak times and tiled floors laid. Non-return valves can be fitted to both washing machines and sewerage pipes. Pumping systems can be embedded to remove any water that does enter.
Nevertheless, major decisions are still to be taken over which specific areas of the UK to protect with dredging, gates and barriers, and which to relinquish to changing weather patterns.
More importantly perhaps will be a complete revision of who is responsible for local flood defence and emergency response. Funding levels and the most appropriate use of available finance in flood defence will be overhauled to safeguard not only properties but also vital road and rail links.
There will also be a much stronger emphasis on helping natural systems to store more upstream water and a review of modern farming and crop practices to prevent unprotected open soil from being washed away as silt.
Rising tides lift all import and export boats
So much for unpredictable rainfall! Sea levels are rising too; driven by storms and tidal surges, they are causing immense damage to the coastline.
A Met Office sponsored assessment released in February notes the worrying fact that mean sea level rises along the English Channel have risen by some 12cm in the last 100 years.
More shockingly, it adds in the context of climate change that with “the warming we are already committed to over the next four decades, a further 11–16cm of sea level rise is likely by 2030”. That equates to a total sea level rise of 23–27cm since 1900. This is difficult news for the capital city; at least 15 other UK cities have also developed on or near the coast to make the most of international trade and the sea.
London has flooded before. On 7 January 1928, 14 people were drowned in basement dwellings when a sudden thaw sent a surge of snow melt water from the Cotswolds, compounded by heavy rain, rushing down the Thames. Simultaneously, a spring tide and strong North Sea storm surge moved up the estuary. As a result, water levels in central London were reported to be 18 feet and 3 inches above datum as the river flowed over the Embankment and flooded Westminster Hall and the House of Commons. Many thousands were made homeless.
However, there is good news on the full-flood too.
London Gateway is part of the enormous investment that is making the capital an ultra-modern city on a par with the great emerging global centres of world trade. A £1.5 billion deep-water port development, 20 miles to the east of the City of London at a former oil refinery site on the Thames’ northern bank in Essex, it will have a major knock-on effect for UK transport with significant environmental benefits.
With finance from Dubai, the facility has been designed as one of some 60 similar deep-water terminuses around the world to accommodate the world’s largest ships serviced by the biggest cranes and supported by a massive logistics park that is expected to alter the strategic pattern of UK goods distribution and storage.
Importantly, for the developers and UK businesses, it has the potential to link millions of UK-based exporters and importers with their global counterparts. The less positive news to date is that the UK’s economic recovery seems to be based largely on consumption — some 50% of departing vessels leave with empty containers.
Building London Gateway has involved the removal of an estimated 28 million m3 of river silt which has been used to recover a reach of the river that has been turned into 1.7 miles of deep-water quayside. The whole design is future-proofed.
The bigger, the better
In shipping, big is beautiful and very economic. In January, rough weather forced the Gudrun Maersk to divert from Felixstowe to London Gateway. The 1200-foot-long vessel, able to carry up to 8500 containers, was the largest to date to move up the Thames; but still larger craft are anticipated.
The port’s operators, DP World, expect giant vessels, such as the Maersk 1300-foot-long triple-E class to berth at the purpose-built facility. These are capable of carrying up to 18,000 containers.
When complete, the port will handle some 3.5 million containers representing world trade annually.
The ethos of the project has been to build logistics capacity ahead of and ready for the future, rather than waiting, in a traditional British way, until the present infrastructure is straining at full capacity.
The futuristic strategy of the port and planned nine million square feet neighbouring logistics park is that human beings have been replaced by automation. Driverless cranes transport containers back and forth at high speed; individual loads are identified electronically. Lorry drivers simply drop off and pick up their containers using a scan-card system.
The environmental advantages come in better use of the road and rail infrastructure; eventually, 30% of the park’s cargo will be moved by rail. As it is, containers are optimised by computer for their onward journeys. This cuts emissions.
At present, many UK goods are stored at a line of distribution hubs along the M1. It is estimated that the changing transport patterns resulting from London Gateway will take some 2000 trucks and their emissions off the highway every day.
Marks & Spencer will have a £200-million distribution centre at the park, which it will use to optimise some 110 existing smaller warehouses.
One giant vessel a week currently uses the new port; this is expected to rise to more than 20 per month when a second berth is built. A third berth is due to open at the end of 2014. If figures then support further expansion, three more berths could be built.
Plentiful water is making sure that change is taking hold at a very grass-roots level.
Last updated on 02/04/2014
First published by Croner-i on 19 March 2014