Bala Lake is the largest natural body of water in Wales (or rather it was: its level is altered by the hand of man, raised by Thomas Telford to help support the flow of the Ellesmere Canal). The lake is four miles long by a mile wide, and it is subject to sudden and dangerous floods.
The waters of the lake are famously deep and clear. The River Dee enters the lake at its south-western end, runs through the lake and flows out of its north-eastern end near where the town of Bala sits at its northern end. According to legend, whilst the Dee itself flows through the lake, the waters never mix, though modern science does not support the fancy.
A narrow gauge railway, the Bala Lake Railway, runs for several miles along the lake's southern shore.
Origins of name
George Borrow wrote of the lake in Wild Wales in 1856, "The lake has certainly not its name, which signifies 'Lake of Beauty', for nothing". The Welsh name for the town of Bala is 'Y Bala', which sits at the eastern end of the lake. A 'bala' signifies either an 'outlet' or else perhaps 'an isthmus between two lakes or areas of wet ground'. The Welsh name includes the personal name 'Tegid'. An older now redundant English name for the lake is Pemble Mere or Pimble Mere - many variant spellings are recorded.
Bala Lake has abundant pike, perch, brown trout, roach, eels and gwyniad. It also contains the very rare mollusc Myxas glutinosa, the glutinous snail.
In the 1990s the lake suffered from blooms of blue-green algae which indicated a significant and worrying eutrophication of the lake. Investigation by the Environment Agency in partnership with the water industry, the farming community and others has put in place a plan for reducing pollution inputs to the lake. Detailed limnological work undertaken from the 1990s, as part of the work to understand and manage the occurrence of algal blooms, had many interesting results and which in passing dispassionately disproved the legend that the waters of the Dee flow unmixed through the lake.
The lake now forms part of the River Dee regulation system and the level at its outflow is automatically controlled. Depending on flow conditions and the level of water in Llyn Celyn, water can flow either into the lake or out from the lake at the normal outflow point.
Bala has two sailing clubs and a number of companies provide kayaks, yachts and various other types of boats for rent.