He says the project – which could cost up to £30 million but protect property worth £2 billion– is the keystone in plans for preventing a repeat of the disastrous floods on the Somerset Levels in the spring of 2014.
Some engineering works have already been carried out to defend vulnerable communities, including raising road levels, improving drainage channels and installing flood-proof bunds.
But, said Mr Liddell-Grainger, Conservative member for Bridgwater and West Somerset, there were some areas which only a barrage – which could be closed to stop the incoming tide preventing floodwater from draining – could protect.
Management of Somerset’s rivers has now been transferred from the Environment Agency to a newly-created local rivers authority, which is to have its future operations funded through a levy on local authorities.
Mr Liddell-Grainger said with climate change predicted to bring increased rainfall it was vital to have an integrated flood management plan for the entire county.
“The problems on the Levels are different from those around the Exmoor fringes and different again from the situation in South Somerset,” he said.
“But at the end of the day there is a common risk: flooding. We must have a strategic plan in place to mitigate its effects where possible and deal with it quickly and efficiently when it happens.
“But for the most vulnerable areas on the Levels clearly the Parrett barrage has to become a top priority. Nothing less will do the job.”