So many office blocks, luxury flats and private leisure complexes have been built by the river in the last five years that the London Rivers Association - a watchdog bringing together councillors and environmentalists - fears that they are ruining the riverside and stopping the public from gaining access to it. Some structures being built rise to 22 storeys, casting huge shadows across the water.
A Blue Belt would work on the same principle as a Green Belt, taking in both the Thames and its riverside environment, and would limit development to buildings that are "sensitive and in keeping with the river's tradition", says the LRA.
The LRA says too much consideration has been given to views of the river as opposed to views from the river. Among the buildings which the organisation cites as particularly detrimental is the vast MI6 building on the south bank at Vauxhall.
Other large-scale developments which the LRA has identified include:
a 17-storey office development at the Effra Site, Vauxhall Bridge, which the LRA says raises concern about bulk and scale;
a 440-flat development at Smugglers Way in Wandsworth, which the LRA says provides no affordable housing and restricts access to the foreshore;
the 22-storey Canary Riverside development in Docklands;
a 12-storey residential and retail development in Lambeth which the LRA says is out of keeping with neighbouring Lambeth Palace and provides no public facilities;
the 20-storey Montevetro project at Wandsworth;
a 20-acre scheme for 650 residential flats and houses in Greenwich. The LRA says it is unhappy with the design, height and layout of the building.
LRA officer Rose Jaijee said: "The River Thames is all about strategic thinking. We're still getting developments that local authorities, local communities and environmentalists are very unhappy with. It became very fashionable and trendy to be on the waterfront."
The LRA is concerned that the Government's call for housebuilders to utilise old industrial sites - "brownfield land" - in preference to greenfield sites may actually have a negative impact on rivers. Many such sites in London are located on the Thames foreshore, where in the past it was easy for industries to discharge waste.
"The riverside shouldn't be regarded as a brownfield site," said Ms Jaijee. "A Blue Belt would tell developers that special conditions apply and that they must pay special regard to the location. The Thames is a vibrant eco-system that needs to be respected so the whole of the city benefits. You can't treat it as just another site for redevelopment.
"The very minimum is being done to ensure that buildings are sensitively designed. Developers put up these prestigious buildings but it's questionable what they contribute to the river. Their priority is to maximise their profits. All they want to do is sell the view from the building."
A document outlining broad planning guidance for the Thames was published in 1997 which said "development should take full account of its local context" but also told developers there was a place for "challenging" designs.
"This document is not enough. There's nobody to implement it," said Ms Jaijee.
But developer St George, which has projects for 4,000 homes and a million square feet of commercial property along the Thames, believes present guidance is sufficient.
"It's nonsense to suggest things are rubber stamped with no co-ordination," said managing director, Tony Carey. "Planning permission requires a long process and talks with some 30 bodies. We don't need another tier of subjectivity."
Developers were keen to include local communities in projects, he said.
"We are opening up derelict industrial sites that have been shut off to the public for hundreds of years. In some places affordable housing is appropriate. In others it isn't."Reuse content