Lake phenomenon sparks whirl of fear

White ‘scum’ likely caused by disturbed water, say NRW

- By ANDREW FORGRAVE Countryside and Tourism Editor

Awhirlpool periodically seen at one of Wales’ largest natural lakes has “terrified” those who have seen it.

Measuring roughly 30ft across, the phenomenon on Llyn Padarn has caused unease at a lake popular with swimmers and paddlers.

When it appeared again this week, accompanied by a drift of different-coloured water, the immediate fear in nearby Llanberis, Gwynedd, was a pollution incident. With events planned this weekend, word spread of the need for extra caution.

However, waste water discharges have been ruled out by Dwr Cymru Welsh Water, which said all its local storm overflows were “operating as designed”.

Natural Resources Wales, the environmental regulator, is monitoring the situation but it said there had not been any recent pollution reports.

One possibility is heavy rain at the start of the week - this may have pushed the extra volumes of water into Afon y Bala which feeds into Llyn Padarn nearby.

As well as creating a “whirlpool-like effect’, material dislodged from surrounding mountains may have stained inflowing water.

Dr Natasha Lucas, an oceanographer and climate scientist who works at Bangor University, captured photos of the disturbed water on Monday, September 1. She said the mechanics were simply explained.