Last summer water levels were so low at both Vyrnwy and the Clwedog reservoirs that remains of the homes and bridges, deliberately flooded to proved water for England were exposed, drawing vistors from many miles to see the rarely seen remains.
And with seven weeks of hardly any rain at the start of the year there were fears that the UK could be facing even worse drought worries this year.
However March has brought torrential rain and heavy snow, and with them flood warnings for the River Severn.
With the forecast for sunshine and showers for the rest of March, there are bound to be more rainbows like the one that wowed the visitors to the lake on Saturday.
Both Severn Trent and Welsh Water say their reservoirs are full - 98 per cent full in north west Wales and 99 per cent full in north East Wales.
Severn Trent says its reservoirs were on average 92 per cent full on March 13.
Heavy showers hit the Welsh hills and Shropshire on Saturday including at Lake Vyrnwy were walkers, cyclists and paddlers on and around the reservoir all got a soaking.
The reservoir’s dam was a spectacular sight with the water overtopping the lake itself and cascading down into the River Vyrnwy below.
The Vyrnwy flows into the Severn at the confluence near Melverley.