Work to build great sea walls along the Severn estuary will likely begin in summer.

The £100million flood defence scheme for the Avonmouth Severnside Enterprise Area is going ahead despite objections from Bristol Port and residents.

Critics claim flaws in the design will put lives at risk in Avonmouth, create too much environmental damage in Severnside and is based on out-of-date climate change data.

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But the project got the green light last week when the Tory administration in South Gloucestershire authorised final agreement of the “detailed design and build phase”.

Reinforced concrete sea walls up to 2.4-metres high and raised earth embankments will be built along 17km of the coast from Avonmouth to Severnside.

New wetlands for wading birds are also part of the plans for the coastline from the Lamplighter’s pub in Shirehampton to the M48 Severn Bridge.

A spokesman for the project said work will “most likely” begin in summer 2019 once a contractor has been appointed and more detailed design work has been completed.

“The construction work will be phased over a period of four to six years to be agreed with the preferred contractor,” he said.

The local authorities in Bristol and South Gloucestershire have already given their consent for the plans which they put together with the help of the Environment Agency.

They say the scheme will protect 2,500 homes and businesses for the next 60 years, create up to 12,000 new jobs and add £2.9billion to the economy.

Bristol and South Gloucestershire councils will each contribute £30million to the £100million scheme and the Environment Agency will contribute the remaining £40million.

Severn Beach residents Jackie Latham and Ian Roberts expressed their concerns about the scheme just before cabinet members gave it the final go-ahead on March 7.

They said the plans were drawn up using out-of-date climate change information and “phenomenal savings” could be made by reducing the size of a sea embankment planned for north of the M4.

Campaigners have complained the embankment for New Passage to Aust is “excessive” and will result in the unnecessary destruction of 500 Poplar trees and 4,000 metres of hedgerow.

Latham said: “We don’t want to see our homes flooded but we want to see this done in the best possible way to protect the ecology and get the best value for taxpayers.”

A spokesman for the Environment Agency said the earth embankment north of New Passage is the weakest point along this area of coastline even without consideration for sea level rise.

A controversial 100-metre gap in the sea wall around the aging lock-gates at the entrance to Avonmouth Docks has also come in for criticism.

Bristol City Council has said the plan is to close the gap before the next big flood, but Bristol Port Company maintains the “miscalculation” puts lives at risk.

Their experts disagree over whether the next big flood will be in 2076 or as early as 2026.

Conservative councillor for Pilning and Severn Beach Robert Griffin told South Gloucestershire cabinet members he remembered the great flood of June 1968 and it was “quite a traumatic experience”.

The Great Flood of 1968 was cause by large amounts of rain saw more than 14,000 properties flooded.

Amanda Cameron is a local democracy reporter for Bristol

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