Castlewellan Lake water deemed safe

Castlewellan Lake water deemed safe

27 August 2025

CASTLEWELLAN Lake is now safe for people to use.

The latest analysis of water samples has prompted Newry, Mourne and Down Council to declare the waterway can be used, but mystery still surrounds what contaminated the picturesque lake.

The lake is located at the town’s stunning forest park which attracts thousands of visitors annually and is maintained by the local authority

Popular with canoeists, paddle boarders, anglers and dog walkers, council officials have been sampling the water since May and several weeks ago advised the public not to enter the lake after samples had been analysed.

While the lake is not one of the district’s designated bathing waters — due to the high level of recreational use — water samples are tested by the council even though the local authority is not legally obliged to do so.

Council officials say the testing regime is in place to provide guidance on water quality at a waterway which it manages and is also hugely popular with local people and visitors alike.

Water testing is due to end next month when the bathing season officially ends, with council officials also flagging up water quality issues at Camlough Lake in South Armagh.

Members of the public had been advised to stay out of both lakes, but it’s understood the quality issue is not linked to blue algae.

The green light for people to return to Castlewellan Lake comes as the summer holidays draw to a close, with public warnings that people could become ill if they entered the lake now lifted. 

Signs erected on the banks of the waterway urging people to exercise caution have also been removed.

A local authority spokesman confirmed the water quality at Castlewellan Lake has improved, following recent retesting.

The local council explained that while the waterway is not designated as a bathing water, due to the high level of recreational use, the organisation has undertaken water quality testing from May and will continue to do so until September.

It said testing was undertaken to provide users with guidance regarding the quality of the water and that on two occasions this month analysed samples found the water to be below acceptable standards.

As a precaution, guidance was issued to recreational users and resampling was undertaken, with the all clear given last Wednesday.

The public had been advised that the lake’s poor water quality had the potential to cause minor health risks, particularly if water was swallowed, inhaled or came into contact with broken skin. 

The council said people who used the lake may have experienced mild stomach upsets, skin rashes or other minor illnesses. 

Last week, Slieve Croob councillor Alan Lewis said he was working with the council to ensure the lake did not pose a public health risk.

He said people were asked to adhere to signage which has been erected at the lake and to monitor social media updates from the council.

Confirmation of issues with the water quality at the picturesque lake comes as work on a £5.5m revitalisation programme continues across the sprawling forest park backed by the National Lottery Heritage Fund and local council.