At least £1 billion a year needs to be spent on traditional flood and coastal defences in the face of climate change, the Environment Agency has said.
But Environment Agency chairwoman Emma Howard Boyd warned “we cannot win a war against water” by building ever-higher flood defences, and raised the prospect of communities having “to move out of harm’s way”in situations where threat levels are too high.
It came after the agency released its long-term strategy which plans for the potential of up to 4C of warming, well beyond the 1.5C or 2C limits agreed internationally.
The EA also predicts that climate change and population growth are set to double the number of properties built on the flood plain over the next 50 years.
Millions of pounds has been pledged towards the protection of homes and businesses, three years on from Boxing Day floods that caused an estimated £150 million worth of damage in the area.
Funding was approved to progress work on £60m of defence schemes to protect some of Calderdale’s worst flooding blackspots in January.
Councillors have approved £2.7m for schemes at Hebden Bridge, Mytholmroyd and Brighouse in Calderdale.
When complete, the schemes for Mytholmroyd, which will cost about £32m, another at Hebden Bridge, which is costed at £20m, and a third project at Brighouse, that will need £10m in funding, will represent more than £60m of investment in protecting Calderdale from flooding.
The estimated cost for the Hebden Bridge flood alleviation scheme Main Works has been updated after detailed design work and is estimated at £20.4m. The board agreed to increase its funding to the scheme from £10.9m to £13.3m, a rise of £2.4m.
The board also increased funding for the Brighouse scheme – up £179,000 to £1.45m. It is planned to deliver the Brighouse scheme in phases, the first element to tackle flooding from the River Calder and lower Clifton Beck and the second to create storage for flood water.
The reservoir work would also mean Yorkshire Water leaving extra capacity at reservoirs above the Calder Valley. Yorkshire Water representatives said although the water level was currently low, they could rise quickly up to between 60 to 65 per cent from 44 per cent in just three weeks.
The Calder Valley was among the worst hit parts of the region during the Boxing Day floods of 2015 which devastated communities across the North of England. A report by the University of Leeds published in 2016 estimated that the flooding had cost the Calderdale and Kirklees economy as much as £170m.