With a volume of water equivalent to 24,000 Olympic swimming pools Llyn Brenig has a surface area of 920 acres (that’s 613 football pitches). The lake was established in 1976, 3 years after construction of the dam wall was commenced. Maintained by Dwr Cymru (Welsh Water), the lake is maintained as a top up resource for the river Dee but it is unusual for it to be used for this. The lake has three “no go” areas, highlighted in yellow. The North end of the lake is a wildlife reserve; an osprey nest is marked with yellow buoys at the mouth of the West creek and the area adjacent to the dam and outlet is also off limits.
The water level is 1200 Ft above sea level with shallow sloping hills surrounding the water. This gives relatively steady winds with a stronger wind force compared with an equivalent position at sea level. The adiabatic lapse rate dictates that the temperature will be just over 3 degrees centigrade colder than at sea level, further increasing the energy of the wind. We don’t sail in December, January or February because of the water temperature.