A huge wall could be built across the middle of Preston Dock in a bid to make a new housing and watersports centre reality, the Evening Post can reveal.
Consultants have identified a plan to create a "mudcrete" wall by mixing silt in the water with cement as one way of controlling blue/green algae in the Ribble.
It means the water in front of the wall would be "bathing quality," enabling watersports events to be held.
The Great Wall of Preston, demonstrated in the Evening Post's mock-up, above, is one of several options being considered in a feasibility study on Preston Council's Quayside Project.
Other options include a full floating village complete with GP surgery, homes and a hotel on the dock, as first revealed by the Evening Post last year.
The wall option at the dock, which would then also see some floating homes built, would cost around £35m, council leader Ken Hudson said.
He added: "In very basic terms, the bottom of the dock is concrete and what they are talking about doing is building a wall right down the middle of the dock and lifting all the silt from one side of the dock and setting it at the back of the wall so you fill the dock with its own sludge."
The study, by British Waterways and consultants Arup, has been completed and will be presented to councillors in February or March.
It is understood members of the council have reservations about both options.
Building the wall might affect boat movements in the 20-30ft deep dock area, while building a floating development would not address the silt in the water.
Mike Brogan, assistant director of city projects at the council, said: "It is something that has been developed in New Zealand for treating contaminated silt which is the problem we have.
"One way of treating it is taking the silt and mixing it with cement. It is an option which has been put forward. It has not been presented to councillors because we want more information."
It is unlikely work on any scheme would begin until after the completion of the Tithebarn regeneration.
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