"It started just after the two days of heavy rains last week," Matt Hendrie said of his property in Nentoura Road.

"I've got two dams about 10 metres long. One is around two metres deep and the other is four metres deep.

"I went out to see what if any damage had been done by the rains and saw the bubbles in the smaller dam.

"The bubbles have been going non-stop for 24 hours now."

Mr Hendrie said his concerns were further raised because he was aware his property was about 90 metres above old coal workings.

"We never had any problems until the mine, then owned by Powercoal but now owned by Centennial, started mining under the place in 1996," he said.

"We had ground movements serious enough to require a mine subsidence survey."

That survey resulted in the Mine Subsidence Board paying for remedial work to Mr Hendrie's home.

"I'm not saying the bubbles have anything to do with the coal workings, I just don't know what is causing them, but methane gas seems to be one possibility.

"I'd like to know whether this is normal or whether it portents something more sinister," Mr Hendrie said.

■ If anybody knows what might be causing the bubbles in Mr Hendrie's dams, or knows of similar circumstances, a letter to the Lakes Mail editor would be welcome.