Bathers warned not to swim at nine popular Dublin swimming spots due to heavy rainfall

Sarah Slater

Bathers are being warned not to swim as a precaution at nine popular swimming spots in Dublin due to heavy and persistent rainfall.

While the latest test results from June 15th for all of the bathing areas are excellent, forecast heavy and prolonged rainfall over Thursday and Friday means prior warning notices have been put in place at all bathing locations under the control of Dún Laoghaire-Rathdown County Council.

The council said that the situation will be monitored over the weekend with further testing scheduled for next Tuesday with results expected on Thursday, June 25th.

Earlier this month, all nine locations were affected by a no swimming advisory.

“A prior warning or an advisory not to swim is a precautionary notice. It means water quality may deteriorate due to factors such as heavy rainfall, so people are advised not to swim as a precaution,” the council said in a statement.

The affected swimming spots are Seapoint, Killiney, Whiterock, Forty Foot, Sandycove, Dún Laoghaire Baths, Corbawn Strand, Coliemore Harbour, and Blackrock Baths.

“The beaches and bathing areas in Dún Laoghaire-Rathdown are popular swimming spots all year round; hundreds of swimmers visit Seapoint, Sandycove, the Forty Foot, Hawk’s Cliff, and Killiney every day of the year,” the council added.

Under the Bathing Water Regulations, the council pointed out that they have “responsibilities in relation to the management of bathing areas” in the county.

This includes identifying bathing areas, establishing bathing water profiles and monitoring water quality at these locations, managing short-term pollution incidents and communicating health risks to swimmers.

Water is sampled and tested twice monthly outside of bathing season and once per week during the season. The bathing season runs from June 1st until September 15th annually.

“This is much more frequent than the minimum requirement of four tests per year,” the council noted.

A sample of at least 250ml is taken at each bathing area and all samples are brought to Dublin City Council’s central laboratory as soon as possible, usually on the same day.

Taking samples at all locations and delivering them to the laboratory takes three to five hours.

To properly test the water, the laboratory uses a technique which requires the growth of bacteria, because of this, it usually takes up to 48 hours to complete the tests and send the results back to the council.

The council pointed out that for this reason, “we prefer to test the water early in the week wherever possible to avoid delays over the weekend. On occasion we have to test on Thursdays or Fridays and in these cases the results may take four to five days to return.”

Last month the Environmental Protection Agency (EPA) classed the water quality at Dún Laoghaire Baths as "poor" due to isolated pollution incidents such as storm water overflows in 2025.

The agency said that a bathing restriction/advisory notice be issued.

However, the council questioned the EPA’s stance and noted that over a three-year-period up to 2026 the water met "good" standards and up until the current prohibition testing indicated it is excellent and safe for swimming.