Britain's beaches were the best they've ever been thanks to last year's dry summer

Aberdeen Beach in Scotland is one of the country’s 734 beaches classed as having “excellent water quality” (Rex)

The number of bather-friendly beaches soared to record levels last summer as the driest weather for a decade sharply reduced the amount of rain washing pollution into the sea.

Nearly three quarters of the country’s 734 beaches were classed as having “excellent water quality” during last year’s bathing season, a third more than the previous summer, according to the latest figures from the Marine Conservation Society.

At the other end of the spectrum only 14 beaches failed to meet acceptable water pollution standards, or less than two per cent of the total – compared to 42 beaches the year before.

The jump in sea water standards continues a general trend towards cleaner water, as sewage companies improve their treatment and drainage methods and monitor their networks more effectively, for example to help locate and clear pipe blockages faster. The general public are also playing their part, with dog owners “cleaning up” after their pets more often, said Dr Laura Foster, the society’s Pollution Programme Manager.

But the biggest reason for the rapid improvement in water quality is the rain, which causes sewers to overflow and washes the waste into the sea, along with other sources of pollution, such as farmland chemicals, she said.

This means that, while the underlying trend is towards better sea water, pollution levels can still fluctuate considerably from one year to the next – and even from one day to the next, since they are largely dictated by the weather over the previous 24 to 48 hours, says Dr Foster.

“If it’s a wetter summer this year, it’s likely that we won’t have such good results,” said Dr Foster, adding that pollution levels would nonetheless be far lower than ten years ago under the same weather conditions.

The Marine Conservation Society measures pollution levels on Britain’s beaches on a regular basis throughout the bathing season. This runs from 15 May to 30 September in England and Wales and from 1 June to 15 September in Northern Ireland and Scotland.