A tidal barrier “four times as big” as London’s £500m River Thames defences could be needed to protect Hull if sea levels rise as predicted.
Environment Agency regional boss Philip Winn said local authorities around the estuary were trying to agree on a plan to protect the region for decades to come.
Mr Winn said in 2013, when the area was hit by a tidal surge, the Humber region was just centimetres away from suffering the most catastrophic flooding since 1953.
His stark words, spoken at a recent Hull & Humber Chamber of Commerce meeting, came just days after severe flooding hit parts of Yorkshire and Lincolnshire.
Dr Ian Kelly, chief executive at the Chamber, said: “The scale of the flooding challenge facing the Humber was the biggest in the UK outside London.
“Innovative ideas and proposals are now coming forward to defend our area in the face of high tides and flash flooding, but we suspect much more than £150m for each six year planning period will be needed in the future. That is aside from the costs associated with decarbonising the Humber economy itself.
“We are doing great work in offshore wind development thanks to Ørsted, Siemens and ABP, but much more urgency will be required by the next Government to tackle the wider climate change crisis we now face.”
Mr Winn said if sea levels rise as predicted, a tidal barrier which would dwarf the one built across the River Thames in 1984 may eventually be needed to protect the Humber region.
The cost of such a barrier could cost billions of pounds, Mr Winn warned, and could be “decades away.”
Mr Winn also said the Environment Agency and all 12 local authorities around the Humber Estuary were currently trying to find an approach towards an agreed 25-year plan.
With the River Humber draining one-fifth of England with its tributary rivers including the Hull, Ouse, Trent and Derwent all feeding into it, atmospheric pressure and tidal changes together can mean the water level rises by up to two metres at peak times of the year.
Mr Winn was joined at the Chamber meeting by Environment Agency colleague Lucy Marshall.
Ms Marshall said the Environment Agency was also looking at how the region can best “Live with Water” and was engaging with key stakeholders, landowners and the NFU, as farmers increasingly need to be compensated if their land is deliberately flooded as part of wider flood prevention schemes.
