A report has laid bare the consequences of climate change for thousands of homes and businesses if sea defences are not improved in a Kent coastal town.

Engineers hoping to secure millions of pounds for future prevention work warn inaction in the coming decades would see flooding devastate large parts of Whitstable in 100 years.

Schools, health centres and electricity sub-stations would also be among the buildings destroyed, causing more than half-a-billion pounds worth of damage.

But local officials say residents have nothing to fear as they are confident of winning funding to implement their plan to protect the town for generations.

Details of the intervention needed – and the dangers of doing nothing – are set out in a document shared with KentOnline called the Whitstable Assets and Adaptation Plan, which has been approved by the Environment Agency.

In it, Canterbury City Council’s revered engineers say the town’s sea walls need to be raised by up to 1.1 metres by 2121 and dozens of coastal defences must be replaced to prevent disaster if Whitstable is hit by a one-in-200-year “flood event”.

The town is currently well equipped to cope with such an eventuality, but experts say without major improvements over the next century it will be left at the mercy of rising sea levels.

Presenting a worst-case scenario, the report states: “A total of 2,155 ground floor residential properties and 493 ground floor non-residential properties would be damaged by the 0.5% annual event probability (one in 200 years) flood event, accounting for 100 years of climate change.

“A further 470 upper-storey residential and 40 upper-storey non-residential properties would be written off or otherwise impacted by flooding within the 100-year appraisal period.

“These include eleven electricity sub-stations, a pumping station, seven health facilities and eight educational facilities.

“The present value damages for the do-nothing option over the 100-year appraisal period are £594.5 million.

“This includes residential and non-residential property damage, property insurance write-off, mental health costs, intangible health costs, vehicle damages, evacuation costs and emergency response costs.”

The schools within the flood impact zone include Whitstable Juniors, St Alphege Infants and Whitstable and Seasalter Endowed, while homes and businesses in Harbour Street, Cromwell Road, Woodlawn Street and the town’s High Street are among those that would be at risk.

How to protect the town

Seven options to manage the flood risk were shortlisted by the city council, with one called ‘Adapt B’ the preferred choice and costing £19.5 million to implement.

This year alone the authority’s engineering team has successfully bid for £327,000 of Environment Agency funding to upgrade floodgates and recently submitted a business case for £1,597,000 to replace a section of the harbour quay.

Short-term works required include replacing 29 floodgates, replenishing the beach with extra shingle, raising seawalls across the seafront and replacing some harbour quay walls, the report states.

Any failure of the harbour quay as a frontline defence could eventually lead to the landmark’s perimeter walls being “lost to the sea”, allowing flood water to “flow unchecked into the flood basin and causing unprecedented flooding”, it adds.

In the long term, sea walls and groynes should be raised every 10 to 20 years, with some structures being increased in height by up to 1.1 metres by 2121.

Is flooding a concern?

While the council is confident of taking adequate measures to protect the town for the next century and beyond, the fear of flooding remains for many.

Just 11 years ago dozens of homes were evacuated in nearby Seasalter and Faversham as the Environment Agency predicted the most serious tidal surge for 30 years.

Emergency rest centres were set up and people in 70 homes along Faversham Road in Seasalter were advised to leave their homes as the sea rose close to record levels.

The water came over the top of the quay’s edge in Whitstable Harbour, flooding the harbour village - a group of local firms operating out of beach huts.

But fortunately, the impact on homes was not as bad as feared.

“I said ‘should we move everything upstairs?’,” remembers 51-year-old Claire Triggs, who lives a stone’s throw from the the harbour in Woodlawn Street.

“And I sometimes think ‘should we move and buy a house on a hill?’

“In terms of climate change, everything is a worry. But the sea defences are a saviour.”

Sarah Dunn’s house in Cromwell Road was hit by the North Sea flood of 1953 - a heavy storm surge that left hundreds trapped either upstairs or on the roofs of their homes, with 2,000 people eventually made homeless.

“We still get salt damage coming from the brickwork and it comes out through the plaster and paintwork,” the artist said.

“We still have problems now from the 1950s, which is frustrating.

“Damp-proofing specialists are kept quite busy in this area.”

Ms Dunn is one of several residents paying a higher home insurance premium because they live in a flood zone.

She also owns a business in the harbour village, which she says makes flooding “concerning” as it “wouldn’t take much” to devastate the area.

“The Gorrell Tank is an overflow for the harbour so when it floods it can make its way up the road,” the 41-year-old said.

“I have seen the water not far from my house before.”

Alice Carlill lives in Woodlawn Street and says if the flood risk increases in the area she would consider moving.

“I would not rent or purchase a house closer to the sea – some of them really overlook it,” the 31-year-old said.

“I’m not sure what the typography of the land is in terms of our risk but if it exacerbates over the next few years, we will have to reevaluate.

“We had looked at different locations around the UK and decided not to go for them; Norfolk for example, as they were too low-lying, so we chose here as a comparatively safe alternative.

“But that is not to say in the future it might not be a higher risk.”

Ms Carlill, who is studying the impact of climate change on mental health for her PhD, says the effect of any flood damage would go beyond that caused to properties.

“We can be fairly sure it is likely to increase anxiety and produce PTSD in the aftermath,” she added.

“But we are also seeing in populations like ours, which have not experienced the worst impacts of climate change, anticipatory conditions like anxiety, fear and depression.

“If a flooding event were to occur in Whitstable, I have no doubt it would cause wider strain on the NHS.”

John Butterworth has lived off Harbour Street in Whitstable for about 30 years and says he is worried about climate change.

“Ice caps are melting, and we should be concerned as a world about environmental issues,” said the 62-year-old.

“If you were a doom-monger, you would think, ‘I’m not moving to Whitstable’.”

Jonathan Hollow, of Woodlawn Street, says if the water had risen above the sea wall in 2013 it would have been “pretty catastrophic for where I live”.

But he has every confidence in the current defences keeping his property safe for the next 20 years.

“You have to rely on the [city council] to be there at the right time to put the floodgate in place,” he added.

“I am sure they would be as it is a key part of its job, and it is a key part of the defence of where I live.”

‘People can sleep well’

Whitstable Harbour Board chair Chris Cornell says the report shows the council has a “robust plan” to deal with flooding.

“We are well prepared and understand how our defences need to evolve as water levels rise,” he said.

“We are prepared for up to a one-in-200-year flood event - twice what many other towns are - and are extremely likely to see the cost of this work funded entirely by central government.

“Our engineers have calculated costs could rise tenfold and we would still be eligible for funding.

“A lot has changed since 1953 - the town is well prepared for flooding and people can sleep well knowing we are well prepared for the challenges to come.”

Kent county councillor Neil Baker, who represents the east of Whitstable, says he has more confidence in the city council’s engineering team than “almost any other group of people on the planet”.

He also believes the report – which he says makes “interesting reading” – sets out the “best way forward” and should help reassure residents.

“While it’s no secret Whitstable, or at least parts of the town, are vulnerable to flooding, the preferred approach outlined, which is based on incremental raising of the groynes and seawall and work at the harbour, does appear to be the best way to minimise risk during the next century,” the Conservative said.

“I appreciate residents may feel a little nervous when reading the report, especially as some of the implications of doing nothing, or doing a minimal amount of work, are highlighted.

“But such projections and comparisons are needed to determine the best way forward.

“I’m not a hydrologist, but the conclusions of this report seem positive and should offer townsfolk reassurance going forward.”

Green councillor Clare Turnbull says it is important to secure funding for the measures outlined in the document and to fully implement the improvements listed.

“The report underlines the serious danger climate change now presents to homes, businesses and people’s lives in coastal towns like Whitstable,” she said.

“The impact of climate change is now right on our doorstep and we need to be doing much more to reduce CO2 emissions locally.

“It is good the report lays out the risks of flooding and the actions that need to be taken to deal with these risks.

“It will need funding of course, but the cost benefits mean it should be feasible to obtain national funding for this vital work to strengthen our coastal defences.”