| Llyn Brenig | |
|---|---|
 | |
  Llyn Brenig | |
| Location | Conwy & Denbighshire |
| Coordinates | 53°05′N 3°32′W / 53.083°N 3.533°W |
| Type | reservoir |
| Basin countries | United Kingdom |
| Max. length | 4km (2.5mi) |
| Max. width | 1.6km (1mi) |
| Surface area | 920 acres (3.7 km2) |
| Shore length1 | 9 mi (14 km) |
| 1 Shore length is not a well-defined measure. | |
Llyn Brenig is a reservoir located on Denbigh Moors in North Wales. The artificial lake, which was constructed between 1973 and 1976, was created by building an embankment dam across the Afon Brenig valley. It lies at 1,200 ft (370 m) above sea level on the border between the counties of Conwy and Denbighshire. It is used to manage the flow in the River Dee as part of the River Dee regulation system.
The reservoir's purpose is to protect the water supply for North West England and north-east Wales, particularly Liverpool and its surrounding area. Its surface area of 920 acres (3.7 km2) makes it the fourth largest lake in Wales, behind Bala Lake (Llyn Tegid), Llyn Trawsfynydd and Lake Vyrnwy.