Anyone who has visited London recently and seen the River Thames would understandably turn their nose up at the prospect of going for a swim in the murky waters.
Yet London architects Studio Octopi, in collaboration with Jonathan Cook Landscape Architects and Civic Engineers, have proposed a new vision for the famous river, which could see that become an appealing prospect once more.
The idea is a result of the collaborative London As It Could Be Now project, developed by The Architecture Foundation with Rogers Stirk Harbour + Partners and the Royal Academy. The project called on new visions for the Thames that encouraged increased interaction with the waterways and raised awareness of this vital artery running through the Capital.
In 1865, Sir Joseph Bazalgette’s London sewage system was opened. Nearly 150 years later, the sewers are at the limits of their capacity. In 2012, 57 combined sewer overflows discharged 39 million tonnes of sewage into the River Thames.
To address the rising problem of river contamination, Thames Water is planning the Thames Tideway Tunnel, or ‘Super Sewer’, for completion in 2023. This tunnel will remove 96 per cent of the sewage currently entering the river. Instead of a weekly discharge into the river, the Super Sewer will overflow a maximum of four times a year.
When Sir Joseph Baselgette’s sewer system was finally completed in 1875, swimming in the River became a common occurrence.
In the same year a floating swimming baths opened on the foreshore at Charing Cross. Heated river water was pumped around an iron and glass structure. Then in 1878 Agnes Beckwith, the 'greatest lady swimmer in the world’ safely swam 20 miles from Richmond to Westminster and back again.
Improvements in water quality open the possibility for once again swimming in the tidal Thames.
Studio Octopi’s proposals are focused on two of the Super Sewer construction sites: Blackfriars Bridge Foreshore and King Edward Memorial Park Foreshore. These sites were chosen for their contrasting London contexts.
“As well as creating a community resource and tourist attraction, these floating and fixed aquatic landscapes would also continue to improve the ecology of the River Thames,” said Chris Romer-Lee, principal of Studio Octopi. “Growing from planted rock cages (gabions) an array of native planting creates enclosure and frames views to the surrounding city.”
“The fixed pools, lifted high on timber and steel piles, are replenished at high tide like coastal rockpools,” he explained. “They rise and fall with the tide offering a unique experience with the river. The sunken structure protects the swimmers from currents, whilst the planting offers tantalising views to the city beyond.”
The fixed structure consists of a randomly ordered grillage of small sectioned steel channels founded in the river bed and extending to a height just below the high water mark. Embedded within the frame will be non-structural timber members. As these weather, they will be colonised by algae, ferns and saline plants such as sea beet and sea aster.
The fixed pools are split across two levels and sit on a concrete slab suspended on the steel frame. The second adjoining floating structure, which Romer-Lee explained will be free to rise and fall with the tide, is restrained by a series of substantial fixed posts.
Surrounding the pools, a concrete deck with cast-in air pockets counterbalances the weight of the planted rock gabion cages. The concrete deck can be precast off site and floated up the river into position.
The flooded pool will feature salt marsh species such as rushes and water plantains, while the wharf edge planting will be a relaxed mix of colourful perennials (red valerian) and ferns. All planted areas will soon be accompanied by naturally colonising plants, some native, others typical of London’s introduced alien flora.
“There are river pools in Berlin, Paris (Josephine Baker Piscine) and New York is also giving it a whirl,” said Romer-Lee. “But ours is different for its engagement with landscape. It is not just a floating pontoon. It was critical for us to get people swimming in river water not a chlorinated substitute.”
The design in New York filters river water through the pool's walls. The concentric layers of filtration materials that make up the sides of the pool are designed to remove bacteria, contaminants and odours, leaving only safe and hygienic water that meets city, state and federal standards of quality.
The New York pool also has a Kickstarter investment campaign running, which is one option for the vision for London.