The South West is facing a huge social and economic upheaval as the number of pensioners living in the region is predicted to explode by more than half-a-million in the next 20 years, the Western Morning News has found.

Drawn to a better quality of life, pockets of the Westcountry have long been popular with pensioners, a trend which now means around 9,000 people over the age of 50 are moving to the region each year – comfortably the biggest influx in England.

But with Government statisticians forecasting that the "oldest old", those aged 85 and over, will double by 2030 in the South West, analysts have raised serious concerns about the strain likely to be placed on housing, healthcare and benefits.

"Population ageing is an important issue facing planners and service providers at national, regional and local levels," said an Office for National Statistics (ONS) report, which singled out the South West as the prime location for the growing population of pensioners.

"Provision of health and social care, the raising of retirement ages and incentives for more people aged 50 to remain in employment are among the many issues facing the Government."

In its recent report, the South West Observatory think tank said that mature adults in the region are healthier than counterparts in other parts of England, a fact born out by the below average claimant rates of disability allowances.

But forecasts indicate a surge in the number of people suffering life-limiting illnesses, such as dementia, by 2030. It added that climate change was another factor policy makers needed to consider, with both increasing and decreasing temperatures causing fatalities.

ONS forecasts suggest that by 2030, more than 38 per cent of the population of West Somerset will be of retirement age or over — the biggest proportion in the UK and almost double the national average.

In 20 years time, Exeter and Plymouth will be the only local authorities in the Westcountry with a proportion of the population at state pension age that is below the UK average.

While ageing will be evident throughout the UK it will be more profound in the South West. According to the ONS, over a quarter of the region's population is expected to be aged 65 and over – above any other English region.

While the Government has made few explicit references to how it proposes to deal with an ageing population, an independent review of the state pension age was announced in the first Queen's Speech of the new Parliament, a move to halt pension costs spiralling.

Another problem noted by the ONS could be the population imbalance caused by falling birth rates after the mid-1960s. It says younger generations "contain fewer people than those aged around 40, and hence there are likely to be fewer people working to help support the retired population in future, unless steps are taken such as raising the retirement age".

The post-war "baby boom", allied to the improvements to healthcare that have brought down mortality rates, is the driving force behind the UK's ageing population.

The concentration of older people in the far South West can be explained by the attraction of the region's peaceful and healthy lifestyle, but also the exodus of young people looking for better paid work and higher education opportunities elsewhere.

In alliance with the local health trust, Cornwall Council has set up a panel of older people's "champions" from representative groups to help shape policy and services.

Armand Toms, cabinet member for adult care and support, said: "The future shows that there is a clear need for the NHS, primary care trust, the third sector and Cornwall Council to work together to meet the demands of the increase in the elder population in Cornwall.

"We know that there will be a 50 per cent increase in the numbers of elder people in the next 15 years and we recognise that we need to plan now to deliver services to match these increases."

Stuart Barker, cabinet member responsible for adult and community services of Devon County Council, which has helped fund an independent Senior Council, said the costs of caring for an older population were rising.

He said: "Councils have to be thinking outside the box, offering services that are more personal and that offer greater choice. Yes, it's thinking smarter but it's also about questioning why we are doing what we are doing."