There are concerns in east Galway after Mountbellew Lake was found to have dried up in recent days.
The lake and its hinterland was once part of the Bellew Estate and it's regarded as a significant amenity in the town.
It's understood a fault with a sluice gate caused the issue.
A number of agencies have bene alerted and are assessing the situation including Galway Council and Fisheries Ireland.
Local Councillor Michael Connolly says it's not known yet whether the incident has had an adverse impact on wildlife there.
He says the waterway drained very quickly and it's lucky that it didn't cause any flooding.
'I got a call yesterday morning from the lock keeper saying that the side of the sluice gate had been breached and that there was a problem.
I was in there in a matter of minutes , we contacted the council, the fisheries, and environmental people and everybody have been contacted.
The water was leaving the lake at a tremendous rate , there was simply no stopping it , and it was making its way down towards the bridge and on the river , and luckily there was no flooding or no flooding of any property.'