The population of Dartford will increase by 13,500 by 2026, one of the biggest rises in England over the next decade.

In 2016 the population was 105,100. By 2026 the Office for National Statistics expects it to reach 118,600, a rise of 12.8%.

The average growth in the country is just 5.9%.

Every two years the ONS estimates how the population will change over the next 25 years.

In Dartford the percentage of the population made up by pensioners is to rise from 14.7% in 2016 to 15.6% 10 years later. And by 2036 the ONS thinks over 65s will make up 18.4% of the population.

While people are living longer due to improvements in healthcare and technology, the ageing population also puts greater pressure on the NHS and social care.

Caroline Abrahams, Age UK charity director, said: “The fact there are growing numbers of older people is a cause for real celebration, but these figures underline the need to ensure our care system is fit for the future.

“The government’s decision to produce a social care green paper was welcome but realistically it will be years before its proposals impact in local areas, so action is needed now to shore up what remains of our care system.”

Figures for Dartford also show the female population is expected to grow slightly faster than the male population.

The ONS estimates there will be an overall net increase of 7,300 migrants by 2026. The most significant increase was in migrants from other parts of England, with a net rise of 6,300 estimated.

Andrew Nash, from the ONS, commented: “While the overall populations of all regions in England are projected to increase over the next decade, reasons for these increases vary greatly depending on where you live.

“For instance, projected population change in London is mainly caused by natural change and not migration.

“This is because London’s net inflow of international migrants is offset by a similar number of people moving to other parts of the UK.

“That contrasts with the north east, where growth is mostly down to migration. What’s also clear is the population is ageing in all regions, with the number of people aged 65 and over growing rapidly.”

Tower Hamlets in London is projected to be the fastest growing local authority, with the population increasing by 17.8% by 2026. Only 15 local authorities have populations which are expected to fall. The City of London has the biggest drop of 12.5% followed by Barrow in Cumbria.

The ONS predicts by 2041 the population of Dartford will have grown to 133,900.