Anxious residents fear falling water quality will "kill" their coastal town if people are warned not to swim in the sea.

Deal beach has been downgraded from ‘excellent’ to ‘sufficient’ - despite Southern Water spending millions on improving the area.

Now those living there are worried a do-not-swim warning could soon be introduced, something they say would put people off visiting.

It comes seven years after Southern Water announced Deal would enjoy a £3.9m investment as part of its ‘Magnificent Seven’ scheme.

Two other beaches in Kent - Leysdown and Minster Leas on Isle of Sheppey - were also included in the project, and are currently rated as ‘good’ and ‘excellent’.

But Deal's score has now fallen to ‘sufficient’ - meaning the water meets the minimum standard set by the Environment Agency (EA).

The government body says “faecal bacteria” was found in the sea during checks last year.

Now residents fear the quality could continue to drop as the town was previously rated as ‘excellent’ in 2019, before being downgraded to ‘good’ two years later.

Southern Water said in 2017 how it chose the beach around Deal Castle for its "groundbreaking" project following a "year-long investigation into the sources of pollution".

But residents say they can't understand where the money has been spent as beaches either side of Deal - St Margaret's Bay and Sandwich Bay - both currently enjoy better water quality levels.

St Margaret’s Bay, closer to Dover, has been rated as ‘excellent’, while Sandwich Bay is currently ‘good’.

Giulia Billi, who has lived in Deal for the past two years, regularly swims in the sea and wants to see a “plan of action” to fix the issue.

“I have a chronic health condition and I notice an improvement when I swim,” she said.

“My fear now is the water quality could continue to drop and we could have a situation where we end up with a do-not-swim warning.

“If we go to ‘poor’ it will affect the town greatly. A lot of tourists come here to use the beach and it will impact people like me who love to swim here.”

Residents’ fears have increased after seeing how St Mary’s Bay and Littlestone, on Romney Marsh, have been affected by a do-not-swim warning which is set to remain in place throughout the year.

The water on both beaches has been found to contain high levels of a bacterium that indicates the presence of human faeces.

For the past 18 months, people have been urged not to go into the sea at St Mary’s Bay, while the same advice was also issued in Littlestone in January after the water there was found to be polluted.

Business owners on Marsh said earlier this year how they have been thrown into “turmoil” by the warning - something Deal traders fear could now happen in their town.

Peter St. Ange, who has owned The Sea Cafe on Deal beach for the past 18 years with his wife Julie, believes tourists “will go elsewhere” if the situation does not improve.

The 61-year-old said: “I’m shocked to hear our levels have dropped so much. I think it's out of order.

“Water companies have been pumping into our seas for too long and now everyone is starting to see the effects.

“It would be an absolute disaster if we were to have a do not swim warning here. It would kill our coastal town.

“If you were to read that you can no longer swim in Deal, people would simply go somewhere else.”

Other residents are calling for further testing to be done by the authorities so people can decide when to swim in the sea.

Mayor of Deal, Cllr Oliver Richardson, has described the situation as an “ecological emergency” and has been “saddened” by the recent downgrade.

“We are aware of the works that have been carried out on our beaches and saddened to learn we have gone from ‘excellent’ to ‘sufficient’ water quality levels,” he said.

“Lots of people enjoy a swim in the sea and in Deal that happens all year round, it’s a part of who we are.

“Deal Town Council has declared an ecological emergency and this issue will be brought before our next environment committee.”

Another regular swimmer in the town, Jill Carter, has lived in Deal for 22 years and says swimming in the sea has huge mental health benefits.

“Generally in the summer, I go in the sea from June towards the end of October most days a week,” the 60-year-old added.

“In terms of mental health, swimming is amazing for me. From the minute I start in the summer I feel so much better.

“When I swim I will always go home and shower now. I wouldn't have always done this before. My son has been put off it entirely.

“We have a lot of housebuilding going on in Deal so all of the new sewage pipes in the town could be having an impact. I don't think the infrastructure in Deal is suitable for the massive expansion here.

“I would like to see more regular testing done by the authorities. This can allow people to make an informed decision on whether to go into the sea.”

Despite the concerns a do-not-swim warning could soon be in place, EA figures show how the levels of bacterium in Deal’s water are still significantly lower than in St Mary’s Bay and Littlestone.

In a statement, Southern Water said “no single cause” has been identified for the “disappointing decline” in Deal.

“Storm overflows are not prevalent along this stretch of coastline,” it said.

“We are continuing to work with all parties to examine the possible contribution of various factors, including road, industrial and agricultural run-off, wildlife, and other beach and water users – and we have carried out our own checks on local pipes and sites, and possible illegally connected private wastewater pipes.

“We are committed to playing our part to help restore Deal’s water quality as soon as possible.”

Asked by KentOnline where the £3.9m has been spent, the company said it “worked closely with Dover District Council (DDC)” on the project.

It said: “Our 2017 funding was used to target issues around bathing water quality across target areas, including Deal Castle beach.

“We built additional storage at two locations in our region, repaired sewers, found and fixed misconnections, refurbished pumping stations and worked closely with councils to manage litter and other sources of contamination.”

Bosses at the EA, the main body responsible for monitoring and regulating bathing water quality in the UK, believe the “wet summer” in 2023 could have played a part in reducing the quality of the water.

A spokesman said: “Suspected pollution can come from a variety of sources.

“Deal Castle was rated as sufficient in 2023 due to a particularly wet summer washing where pollutants, including faecal bacteria, will have been washed off farms and roads into the sea.

“Between May and September, the EA takes more than 7,000 water samples at 451 designated bathing waters across England.

“It would kill our coastal town…”

“The samples are tested in our labs and the results are uploaded onto the Swimfo website, to help the public make informed decisions about where to swim.

“On Swimfo, the public can also access pollution risk forecasts, updated daily to indicate any expected temporary reduction in water quality due to rain, wind, and high tides.

“Last year, 96% of bathing waters in England were rated sufficient, good or excellent, and 90% good or excellent.

“Anyone who suspects pollution in our seas and rivers can contact our 24-hour incident hotline: 0800 807060.”

Labour-led DDC said it is “disappointed” the water quality has dropped in Deal, and will “continue to liaise with Southern Water”.