ECONOMICALLY important beaches in some populated parts of Devon could be lost to the sea if flood defences are retained over the next 50 years, a report suggests.

Popular coastal resorts such as Teignmouth could lose their miles of golden sand because of tidal erosion if their "hard" sea defences are maintained, according to the Shoreline Management Plan (SMP) for Devon and Dorset.

The plan, being drawn up by local authorities and other public bodies, is looking at how the coastline of the English Channel coast is likely to change over the next 100 years.

In many areas, it warns that putting up sea barriers will just result in the sand washing away. It could be replaced, but this is seen as too expensive and environmentally damaging in the long term.

Councillor Mike Haines, chairman of the South Devon and Dorset Coastal Authorities Group, said: "While the long-term options for some areas may seem a little dramatic, it is important to understand they are only technical possibilities, not hard and fast plans.

"We know that the climate and tidal patterns can change fairly quickly, so over the next 50 years or so we will continue to monitor the coast and can expect to have many different proposals based on information available at the time."

The SMP advises on whether to hold the line of current defences, have a policy of no active involvement or engage in what is termed managed regression, where some land is surrendered to the sea to strengthen other areas.

It has drawn up a list of possible scenarios which can be used by politicians to determine where and to what extent schemes should be funded.

In the section referring to the area of South Devon from Holcombe to Hope's Nose, which includes Teignmouth, it says: "It is unlikely that defence of Teignmouth would cease. Though as a result, the beaches would disappear in the long term without intervention."

Further along the coast, in an area under the heading "Tor Bay", which stretches from Hope's Nose to Berry Head, it says that areas which have defences "would be maintained in the long term... (but) this would lead to loss of beaches as sea levels rise without intervention".

The beaches can be replaced indefinitely with imported sand, but Halcrow, which produced the report, has said that this has high cost problems, plus environmental impacts from wherever the material is extracted. But Teignmouth Mayor Fred Tooley argued that current methods should mean that replacing beach sand can continue in the long term as dredgers keeping the entrance to the harbour open take material washed from the beach back where it came from.

"Over the past 40 to 50 years, it has always depended on which way the wind is blowing to the amount of sand on the beach," he said. "Dredging is being done currently and it seems to be a success."

A similar picture was painted for some of the areas around Seaton in East Devon. But other areas of the coastline have had recommendations for their beach areas to be enlarged.

Under the plan, Exmouth would see an area called the Maer, currently separated from the beach by a sea wall and road, allowed to re-merge with the beach in future decades as the sea level rises, to ensure the beach remains.