THE cost of putting locks on the River Hull has risen to a staggering £195m, the Yorkshire Post can reveal.
That figure is more than seven times higher than figures quoted in 1995, the last time costs for the proposals were estimated.
Creating a permanently fixed level has been an aspiration of city planners for years – it was discussed when the Abercrombie plan for rebuilding Hull after Second World War bombing was formulated.
Now a confidential report says constructing a barrage across the river would cost an estimated 46m, with another 43m on enabling works and 18m mitigation works. It could cost 560,000 a year to operate.
A feasibility study commissioned by urban regeneration body Citybuild has already cost the taxpayer 276,000 – and it will cost another 246,000 to be completed, the report says.
Locks on the river would mean mudflats being covered at all states of the tide, which could make the banks of the river far more attractive to developers.
The report suggests the project is economically viable. But it warns that "significant environmental issues" remain, and that the case for impoundment to improve flood risk management is "marginal."
Some councillors want more evidence before more money is spent on it.
Tory Group leader John Fareham said: "I'd like to see the economic case proven first – let's find out whether or not there's a demand for it."
Coun Andy Sloan, a member of the Citybuild board, said: "Are we going to get 200m benefit out of it? That's the big question. What else could we do for 200m and where do we find the 200m, given the other priorities?"
Council leader Carl Minns – also a member of the board – said he didn't want to comment on leaked figures. But he added: "I think what we have to measure off is the cost benefit analysis – will any potential cost be outweighed by the amount of jobs and investment that are brought in and that's something that's too early to say one way or another."
Jo Barnes, economic development director at Citybuild, said: "It has always been the intention of the study to look at the potential economic and environmental benefits that any feasible impoundment option would bring.
"Early analysis shows that the value of these potential benefits vastly outweighs the estimated initial financial investment required, however it should be stressed that this by no means guarantees that the impoundment of the River Hull will go ahead."
Stage two of the study showed significant potential economic benefits could include savings on flood risk management; commercial and residential development along the River Hull corridor; and the value of new retail spending in Hull city centre, Beverley, Driffield and surrounding areas.
The report said the issues were complex and required detailed consideration from the board.
In the past officials have said putting locks on the river could offer "unprecedented recreational, leisure and transport opportunities" as well as paving the way for changes to its use throughout the East Riding.
Similar projects have been carried out on the River Tees and Cardiff Bay, apparently with great success. The Cardiff Bay Barrage was one of the largest civil engineering projects in Europe during construction in the 1990s.
Opposition to the project came from many quarters but it has boosted regeneration with shopping and watersports drawn to the waterfront.