RESIDENTS on Portland were told to prepare for the worst last night as ferocious waves threatened to swamp the Chiswell community.

The sound of high-pitched flood warning sirens echoed around Victoria Square as authorities warned of the approaching sea soon after high tide around 10.30pm.

Coastguards described sea conditions as ‘horrendous’ with reports of towering 15ft waves. The sirens sound if the sea breaches Chesil Beach and there is ‘severe flooding with extreme risk to people and property.’ Amazingly, police had to apprehend a man who ran onto the beach at Chesil Cove, risking his life.

Residents still in their homes were told to move to upper floors and not to come down again until told it was safe to do so. Portland Beach Road was also closed as water came over and swamped the carriageway.

Islanders trapped in Weymouth were able to go to a rest centre set up at The Wey Valley School.

Plans were in place to evacuate emergency health cases from Portland by air using coastguard and police helicopters.

Chiswell had been swarming with council workers, police officers and Environment Agency staff during the evening as it was one of two areas issued with the a severe flood warning – the highest state of alert meaning there is a risk to life.

The other high risk area was Preston Beach Road in Weymouth which was closed all night as a precaution.

At Portland, authorities advised people to be prepared for flooding and to leave their homes if they wished, advising them to stay with relatives or friends on higher ground or making their way to a dedicated rest centre set up at Portland Heights Hotel. Most chose to stay at home and were given sandbags and information leaflets.

Residents Edwin and Janet Timbrell said they had turned off their electricity, gas and water and removed what they could out of the way of any potential flooding.

Mr Timbrell said: “I asked them how much time we would have after the siren sounded. They said it would only sound if the water was coming over so we acted accordingly.”

Neighbour Alistair Green said that the emergency services had done a ‘great job’.

Ken Tucker and Phillip Traves, both from Portland who had gone to look at the waves, said they were concerned for the residents threatened with flooding.

As high tide was striking, Portland Coastguard launched a search after an object believed to be a liferaft was spotted in the sea by a member of the public on shore. It was confirmed by the crew of the coastguard helicopter as an upturned liferaft but no-one was found in distress. Investigations are ongoing.

A spokesman for Portland Coastguard added last night: “Severe flood warnings are in place for Chiswell, Portland, and Preston Beach Road. The sea state is severe enough on Portland that the criteria has been met and warning sirens were sounded at 10.30pm. Residents have either evacuated or taken to upper floors facing away from the sea.

The Preston Beach Road is closed with waves overtopping. All services are working together to ensure safety of life and are monitoring the situation.”