North Wales Police say they're evacuating the village of Pennal, near Machynlleth, in Powys, after a breach in the dam of a local reservoir, which has allowed a small amount of water to escape.
Residents are being taken to a nearby leisure centre.
The water is flowing over the top of the reservoir stone wall into a quarry below which has the Afon Pennal running through it.
A crack has been discovered in the wall, causing a small amount of water to escape.
Should be wall be completely breached, the contents of the reservoir will go into the river which flows through the village of Pennal, which is around half a mile from the reservoir.
Police officers are evacuating residents in the area and would ask visitors and locals to avoid the village at this current time.
The village has around 600 inhabitants.
For more details, read the full story on ITV Wales.
Parts of Britain are braced for more flooding as a "once-in-50-years storm" is set to hit the south-west and Wales.
The South East and mid Wales have been worst hit by the rain which has battered Britain. The rain is set to continue.
Flooding and heavy rain hit many areas across Britain today, with the Environment Agency issuing further flood warnings.