A Bronze Age Flood In The British Isles

There was a catastrophic weather even which hit Ireland and Wales during the period 2354 BC and 2345 BC. Among other things, this event permanently flooded a village and forest Cardigan Bay in Wales.

There is a Gaelic legend that explains it, which has very close parallels across Ireland and Wales in other locations as well.

The Laigin people from Ireland at one stage controlled Llyn peninsula. I wonder if this is how we find almost identical "let the tap running" explanation for the legend in both Ireland and Wales?

In "The Lleyn peninsula : It's history, literature & antiquities" we read that:

"...practically every lake in Wales has some story or other connected with it. The story about the lake Glasfryn is very interesting. The story says that in the olden times there was a well where the lake is now, and this well, kept by a maiden named "Grassi," was called "Grace's Well." Over the well was a door, presumablv a trapdoor, which Grassi used to open when people wanted water, and shut immediately afterwards. One day Grassi forgot to shut the door, and the water overflowed and formed a lake. For her carelessness Grassi was turned into a swan, and her ghost is still said to haunt Glasfryn House and Cal-Ladi. This little lake is now the home and breeding-place of countless swans..." . . .

[I]n "Historical and descriptive notices of the city of Cork and its vicinity" first published in 1839 by John Windele. On Pages 42-43 we can read this:

A short distance to the south west, from the City, is Lough na famog, (probably the Lough Ere of the Hajiology,) now called the Lough of Cork, a considerable sheet of water supplied by streams from the adjoining hills; the high road runs along its eastern shore, and the other sides are skirted by grounds, unhappily without tree or shrub, to add a feature of beauty or interest to the picture. It is the scene of one of CROKER'S charming Fairy Legends, detailing the bursting forth of the lake, through the negligence of the princess Fioruisge (Irish: Fior-uisge - spring water), daughter of King Corc. In taking water from the charmed fountain, she forgot to close the mouth of the well, and the court, the gardens, the King, and his people, were buried beneath the flowing waters.

The incident is common to almost every lake in Ireland.

Six centuries ago, Cambrensis had a similar legend concerning Lough Neagh, which Hollinshed has repeated in a less diffusive style. "There was," he says, "in old time, where the pool now standeth, vicious and beastlie inhabitants. At which time was there an old saw in everie man his mouth, that as soon as a well there springing, (which for the superstitious reverence they bare it, was continuallie covered and signed,) were left open and unsigned, so soone would so much water gush out of that well, as would forthwith overwhelme the whole territorie. It happened at length, that an old trot came thither to fetch water, and hearing her childe whine, she ran with might and maine to dandle her babe, forgetting the observance of the superstitious order tofore used: But as she was returning backe, to have covered the spring, the land was so farre overflown, as that it past hir helpe; and shortly after, she, hir suckling, and all those that were within the whole territorie, were drowned; and this seemeth to carie more likelihood with it, because the fishers in a cleare sunnie daie, see the steeples and other piles plainlie and distinctlie in the water."

The legend that there was an inundated settlement in Cardigan Bay was corroborated a few years ago when a winter storm cleared away sands in the bay that had concealed it. Tree rings dated the event and confirmed that it happened at the same time as parallel events in Ireland.

It isn't implausible, however, that the modern neglected well legends derive not from a direct memory of the actual event, but from a similar winter storm that revealed the inundated settlement and demanded an explanation, much like the one a few years ago that led to the modern archaeological discovery.

This also begs the question of whether there was a global sea level rise in the Atlantic Ocean at this time, perhaps due to some glacial dam finally breaking and flooding the ocean, that might have a connection to Plato's Atlantis myth, or even to the Biblical flood myth.