A £1.9million lagoon on Southend seafront has been branded a “stinking pool of green slime” - but the council insists it is a “natural occurrence”.

Philip Miller, owner of Adventure Island, filmed the state of the Three Shells Beach Lagoon, posing it on X and calling it a "total disgrace".

He claimed the lagoon, which is next door to the theme park, is “full of rubbish, seaweed and stinks to high heaven”.

The artificial shallow pool was touted to become a major seafront attraction when it opened in 2016, bringing visitors to the town and boosting the economy.

Martin Terry, councillor for community safety, said the algae in the lagoon is a “natural occurrence”, but admitted it does “smell”.

In the video, Mr Miller said: “Here we are again. It’s just the beginning of the summer holidays and this is the state of the so-called lagoon. It’s full of rubbish, full of seaweed and it stinks to high heaven. There’s hardly a soul on it and this is what we have to put up with.

“It’s been going on for years and years. It’s a shame you can’t get the smell in the video. The rest of the seafront has got loads of people. It’s got to the stage where the man with deckchairs doesn’t even want to put deckchairs here. Thank you Southend Council.”

The £1.95m project, which was nearly three years in the making, was funded by the Coastal Communities Fund, Southend Council and the Stockvale group, which owns Adventure Island.

The water and the rocks regularly become covered in algae, causing concerns that children could slip on the rocks.

Southend Council has previously claimed the lagoon was largely self-cleaning because of the tides.

Mr Terry added: “The thing with algae is it is a natural occurrence and the lagoon does lie within the curtilage of the site of special scientific interest. I know the council is aware of it, but it’s not a matter of going down there and jet washing or removing the weed instantly.

“I imagine it’s not straightforward because it’s a natural bloom of weed. There will be some action taken, but I can’t be sure what that will be because it lies within the SSSI site. The whole of our foreshore is within that. We had some rocks in a swimming pool in Leigh and we were told we couldn’t clear them away because it was a natural habitat for crabs.”

Mr Terry added: “It does smell because I ride past there regularly on my bike, but it is a natural occurrence.”

Matt Dent, cabinet member for culture, tourism and business says: “The lagoon is part of the estuary and not a swimming pool, and as such is controlled in large by the estuary itself.

“We are aware of issues caused by this being part of the natural environment, such as seaweed becoming trapped in the rocks and decaying which can cause smells and the presence of microalgae.

“Whilst the tide washes and refreshes the lagoon naturally at high tide, over the years we have regularly drained the lagoon when tides are high to allow a complete refresh. At the start of July, officers also agreed a plan with Stockvale representatives to carry out a more intensified programme of draining and refilling to deal with the smell.

“This has involved draining it during the week and letting it refill for weekends and now the summer holidays. This has dealt with the smell and enabled us to clear the lagoon floor.

“We will be looking to drain the lagoon again after the summer season and repeat this process.

“We would also like to remind visitors that, like with all parts of the seafront, people need to be vigilant, supervise children, wear appropriate footwear and heed the warning signs present on the site which tell people not to climb the rocks.”