Cerrigydrudion

Coordinates: 53°01′34″N 3°33′43″W / 53.026°N 3.562°W / 53.026; -3.562

Cerrigydrudion, sometimes spelt Cerrig-y-drudion, is a village and community in Conwy, Wales. Until 1974 it was part of the historic county Denbighshire, when it became part of the newly formed county of Clwyd. When the county of Clwyd was abolished in 1996, the village was transferred to the new Conwy County Borough. The village formerly lay on the A5, but a short by-pass now takes the road along the south-western edge of the village. Prior to the by-pass being built, Cerrigydrudion was the highest village on the A5 between London and Holyhead.

Geography and history

Geographically the area is classed as moorland and less favourable grassland. It is on the outskirts of Mynydd Hiraethog. The oldest feature of the village is the parish church dedicated to Saint Mary Magdalene. It is believed to have existed in 440 AD. It is also mentioned in the 'Norwich Taxation' of 1254. The village is the largest in the area known as Uwchaled which also includes Llangwm, Pentrefoelas, Pentre-llyn-cymer, Dinmael, Glasfryn, Cefn Brith, Llanfihangel Glyn Myfyr and Cwm Penanner. Llangwm and Pentrefoelas are stand-alone parishes whilst the remainder fall within the parish of Cerrigydrudion. However, there are multiple Nonconformist chapels throughout the area of Uwchaled, located in many of the minor villages and hamlets.

Llyn Brenig

Llyn Brenig is a reservoir located in Wales, in the heart of the Denbigh Moors, at a height of 1200 feet, 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 which is designed to protect the water supply for North West England and north-east Wales, particularly Liverpool and its surrounding area.

Construction and operation

Construction began in 1973 and was completed in 1976. It has a capacity of 60 million m³ and was first filled in 1979. With a surface area of around 920 acres (3.7 km²), it is the fourth largest lake in Wales, behind Llyn Tegid (Bala Lake), Llyn Trawsfynydd and Lake Vyrnwy. The lake has a perimeter of some 9 miles (14 km).

The catchment of the reservoir is very significantly over-reservoired. This means that the reservoir cannot fill from its own catchment within one annual hydrological cycle. When the reservoir level is drawn down, it can take several years for it to completely re-fill again. Llyn Brenig is therefore only used during drought conditions when the capacity of Llyn Celyn and Llyn Tegid are no longer predicted to be capable of maintaining the flow in the River Dee.