The Start of a "Win Win Win" Scenario

Andrea Klettner writing in Construction News reports that the Olympic Delivery Authority (ODA) has began remedial works on the waterways running through the Olympic Park

There are 8.35km of waterways in and around the Park. The Lea Valley waterways primarily run north to south through the heart of the Park and ultimately connect with the Thames. The River Lea runs through the centre of the Park and is joined in the northern part of the Park by the Channelsea River, Henniker’s Ditch and two main areas of wetlands. In the south, the waterways include the Waterworks River, City Mill River, Bow Back River and the Old River Lea. The Park’s western-most boundary is the Lea Navigation – a historically important canal that links London from east to west.

A 60-tonne craft has started dredging a 2.2km stretch of water from Bow Locks on Bow Creek to the Waterworks River, adjacent to the site of the Aquatics Centre.

The craft is expected to remove 30,000 tonnes of silt, gravel and rubble as well as tyres, shopping trolleys, timber (and apparently at least one motor car).

ODA environment manager Richard Jackson said: “The park is characterised by a series of waterways which act as green corridors running through the heart of the site. Currently, they are polluted, neglected and under-used, and have been treated as a dumping ground for everything from shopping trolleys to cars.
“This dredging programme is an important step in regenerating the waterways and will help improve water quality, creating better habitats for wildlife and plants.
The clearing and cleaning of the waterways will enable freight barges to carry construction materials in, and waste out, of the Park during the construction phase. A wharf is being constructed on the Waterworks River near the Aquatics Centre and will be used to receive freight loads for the Olympic Park contractors. Work began on the upper levels of the wharf this week and is due to be completed at the start of June.

British Waterways, Defra, the Department for Transport, the London Thames Gateway Development Corporation, the Olympic Delivery Authority and Transport for London fund the Three Mills Lock and Water Control Structure at Prescott Channel. It will re-establish full navigation on the Bow Back Rivers for the first time in decades. Barges will then be able to travel into the Park by water via the new lock and water control structure, Three Mills Lock, at Prescott Channel. The £20m structure comprises twin water control gates, a 62m-long tidal lock, footbridge, lock control building, fish pass and fixed weir.

Richard Jackson added: 'This is a crucial part of our logistics strategy as we plan to use the waterways for the transport of construction materials into the Olympic Park, cutting down on the amount of lorries travelling on the roads.'

Richard Rutter, Regeneration Manager, British Waterways said: 'Dredging the waterways of the silt and rubbish built up over the years in and around the Olympic Park is an essential part of the rejuvenation of east London’s rivers. The dredged aggregates will be recycled and reused in construction works in the Olympic Park.

'These dredging works will help us to realise our dream of seeing both commercial freight barges and leisure boats taking to the water once again in east London.'

The restored waterways will form a key part of the Olympics legacy and will almost immediately after the Games be put to good use facilitating synergy between two major projects - the building of Crossrail and Europe’s largest conservation project.


The River Lee runs just to the west of the Pudding Mill Lane Portal of Crossrail. The initial phases of construction at the portal involve the building of a reinforced concrete box to channel the river over Crossrail, but under the GEML. The area’s restored waterways will then be used to carry the clay, chalk and gravel generated by Crossrail’s Tunnel Boring Machines down the Thames to Wallasea Island where the Royal Society for the Protection of Birds (RSPB) is attempting a landmark conservation and engineering project for the 21st Century on a scale never before attempted in the UK, and the largest of its type in Europe.

The RSPB, Britain's largest mass membership organisation, is well known in political circles as a powerful lobbyist for its espoused campaigns. They plans to puncture the sea defences around Wallasea Island, situated just to the west of Foulness in the River Crouch between Southend and Burnham on Crouch, and turn 728 hectares (1,800 acres) of farmland into a mosaic of saltmarsh, creeks and mudflats. These will be criss-crossed by bunds along which visitors will be able to access much of the reserve. Conservation experts are hoping to reverse five centuries of British history by deliberately allowing rising sea levels to flood a huge stretch of reclaimed Essex coastline. Generations of farmers have worked the land on Wallasea for 500 years, since Dutch settlers first built a wall around the remote strip of coast once claimed by King Canute; the RSPB wants to transform the area into a wildlife reserve. As the sea returns, so should otters, wild plants, fish and birds, some species of which have not nested in the UK for more than 400 years.

Speaking to the Guardian in 2007, Graham Wynne, RSPB chief executive, said: "Wallasea will become a wonderful coastal wetland full of wildlife in a unique and special landscape. We will be restoring habitats that were lost more than 400 years ago and preparing the land for sea level rise. This is land that was borrowed from the sea that now the sea is reclaiming."

As mentioned, the £12m scheme is the largest of its type in Europe. It will see a series of low-lying walls built across the flat arable farmland, followed by a gradual reintroduction of limited amounts of sea water.

Mark Dixon, the RSPB’s project manager, said at the time: "We will have a landscape of marshes, islands, lagoons and creeks, little more than 20 inches deep at high tide. Wallasea is one island now but was once five separate pieces of land. We will restore these ancient divisions and each new island will have its own tidal control." The full force of the uncontrolled high tide would wash much of the restored landscape away, because the land inside the existing sea wall has been gradually lowered since it was reclaimed. He went on to say, "Many birds will starve to death if we don't restore Wallasea. Fish are under incredible pressure too, not just because of overfishing but because of the loss of their saltmarsh nurseries." The RSPB hopes the wetland will attract spoonbills, which have not nested in Britain since the 1600s, Kentish plovers, absent for 50 years, and black-winged stilts, which have only bred in Britain three times. Mark Avery, RSPB conservation director, said: "Our plans for Wallasea reflect the great difficulties climate change will cause, but also the RSPB's determination to find ways of combating them. "

The RSPB secured an option to buy the land and start the restoration and is raising funds. Wetland restoration schemes that allow seawater to reclaim protected land can be controversial. Local opposition forced at least one scheme in Essex to be scrapped, although a major scheme on the Ribble estuary just north of Southport went ahead in 2008. The Wallasea project borders a similar, smaller scale, saltmarsh restoration project carried out by Defra, the environment department.300 metres of the sea wall was bulldozed and the tide allowed to wash in. The region is already transformed, and saltwater plants and wildlife have moved in. Similar projects are under way in Germany, the United States, Denmark and Holland. Of 30,000 hectares (74,000 acres) of intertidal saltmarsh that surrounded the Essex coast 400 years ago, only 2,500 hectares remain, and 100 hectares more are destroyed across England each year. This rate of loss is expected to accelerate with climate change, as rising sea levels and more severe storms help them to erode. In turn, the loss of such saltmarsh could make Britain more vulnerable to the effects of global warming, because they buffer the force of the tides.

The dredging operation marks the start of what could be a significant tripartite “Win Win Win” situation for the Olympics, for Crossrail and for our fellow supporters of the Anorak industry – bird watchers. Don’t you just love it when a plan comes together.

Our thanks to the Olympic Delivery Authority for the images, Andrea Klettner of Construction News and David Adam of the Guardian.