View from Bala
|Primary inflows||River Dee|
|Primary outflows||River Dee|
|Official name: Llyn Tegid|
|Designated:||7 November 1991|
|Max. length||5.95km (3.7mi)|
|Max. width||1km (0.6mi)|
|Surface area||4.84 km2 (1.87 sq mi)|
|Max. depth||42 m|
Bala Lake ([ˈbala]; Welsh: Llyn Tegid, [ˈɬɨ̞n ˈtɛɡɨd]) is a large lake in Gwynedd, Wales. It was the largest natural body of water in Wales prior to the level being raised by Thomas Telford to help support the flow of the Ellesmere Canal. It is 4 miles (6.4 km) long by 1 mile (1.6 km) wide, and is subject to sudden and dangerous floods. The River Dee runs through it and the waters of the lake are famously deep and clear. The town of Bala sits at its northern end and the narrow gauge Bala Lake Railway runs for several kilometres 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". In English the lake is named after the nearby town of Bala, whose name means "outlet of a lake" in Welsh. An older, now unused, 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, eel. It also contains the endemic gwyniad, now listed as critically endagered by the IUCN due to the introduction of the invasive and non native ruffe. It also contains the very rare mollusc Myxas glutinosa - the glutinous snail. According to legend, whilst the Dee itself flows through the lake, the waters never mix. However this was not confirmed by the detailed limnological work undertaken from the 1990s, as part of the work to understand and manage the occurrence of algal blooms on 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.
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.
Bala has two sailing clubs and a number of companies provide kayaks, yachts and various other types of boats for rent.