Llyn Brenig is a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

located on Denbigh Moors in

North Wales North Wales ( ) is a Regions of Wales, region of Wales, encompassing its northernmost areas. It borders mid Wales to the south, England to the east, and the Irish Sea to the north and west. The area is highly mountainous and rural, with Snowdon ...

. The artificial lake, which was constructed between 1973 and 1976, was created by building an

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface ...

across the ''Afon Brenig'' valley. It lies at above sea level on the border between the counties of

Conwy Conwy (, ), previously known in English as Conway, is a walled market town, community and the administrative centre of Conwy County Borough in North Wales. The walled town and castle stand on the west bank of the River Conwy, facing Deganwy ...

and

Denbighshire Denbighshire ( ; ) is a county in the north-east of Wales. It borders the Irish Sea to the north, Flintshire to the east, Wrexham to the southeast, Powys to the south, and Gwynedd and Conwy to the west. Rhyl is the largest town, and Ruthi ...

. 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 North West England is one of nine official regions of England and consists of the ceremonial counties of England, ceremonial counties of Cheshire, Cumbria, Greater Manchester, Lancashire and Merseyside. The North West had a population of 7,4 ...

and north-east

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

, particularly

Liverpool Liverpool is a port City status in the United Kingdom, city and metropolitan borough in Merseyside, England. It is situated on the eastern side of the River Mersey, Mersey Estuary, near the Irish Sea, north-west of London. With a population ...

and its surrounding area. Its surface area of makes it the fourth largest lake in Wales, behind Bala Lake (Llyn Tegid),

Llyn Trawsfynydd Llyn Trawsfynydd is a large artificial reservoir situated near the village of Trawsfynydd in Gwynedd, North Wales. With a total surface area of the reservoir is slightly more extensive than Wales's largest natural lake, Bala Lake at . History ...

and

Lake Vyrnwy Lake Vyrnwy (, or ') is a reservoir in Powys, Wales, built in the 1880s for Liverpool Corporation Waterworks to supply Liverpool with fresh water. It flooded the head of the River Vyrnwy, Vyrnwy () valley and submerged the village of Llanwddyn ...

History

Construction began in 1973 and was completed in 1976. An earthen bank with stone, which is up to at its highest point, dammed the ''Afon Brenig'' near the village of ''Pentre-Llyn-Cymmer'', Cerrigydrudion. The northern half of the reservoir is in

community A community is a social unit (a group of people) with a shared socially-significant characteristic, such as place, set of norms, culture, religion, values, customs, or identity. Communities may share a sense of place situated in a given g ...

of Nantglyn. Its perimeter is about . Brenig, which has a capacity of 60 million m³, was first filled in 1979. Water supply of the catchment into the lake is significantly "over-reservoired", this means the catchment area of Llyn Brenig does not have capacity to refill the reservoir within one annual hydrological cycle. It can take several years for the reservoir to refill again after its water level have been drawn down. Water is only drawn from Llyn Brenig during drought conditions when

Llyn Celyn Llyn Celyn () is a reservoir constructed between 1960 and 1965 including the highly controversial Tryweryn flooding in the valley of the River Afon Tryweryn, Tryweryn in Gwynedd, Wales. This included the forcible removal of the Capel Celyn vil ...

and Bala Lake are no longer predicted to be capable of maintaining the flow in the River Dee. The lake holds a commercial trout farm and commercial logging is conducted around parts of the lake.

Leisure

Llyn Brenig is a popular destination for outward bound activities such as

hiking A hike is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer time. "Hi ...

and

mountain biking Mountain biking (MTB) is a sport of riding bicycles off-road, often over rough terrain, usually using specially designed mountain bikes. Mountain bikes share similarities with other bikes but incorporate features designed to enhance durability ...

, fishing and watersports. It has a visitor centre and cafe.

Watersport activities

Fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...

canoeing Canoeing is an activity which involves paddling a canoe with a single-bladed paddle. In some parts of Europe, canoeing refers to both canoeing and kayaking, with a canoe being called an 'open canoe' or Canadian. A few of the recreational ...

, paddle boarding and

open water swimming Open water swimming is a swimming discipline which takes place in outdoor bodies of water such as open oceans, lakes, and rivers. Competitive open water swimming is governed by the International Swimming Federation, World Aquatics (formerly kno ...

are all permitted on the lake. Power craft for angling and recreation are available for hire, while Llyn Brenig has its own sailing club. In 1990 Llyn Brenig was the only Welsh reservoir used for the World Fly Fishing Championships.

Archeology

During construction of the Llyn Brenig, archeologist found that the Afon Brenig valley had been used for thousand of years by upland communities crossing the Denbigh Moors. Finds included a camp used by

Mesolithic The Mesolithic (Ancient Greek language, Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic i ...

people ( radiocarbon analysis of the

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

from their fires to around 5700 BC),

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

artifacts, a ring cairn (a Bronze Age

burial mound Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objec ...

), and several barrows. There are a number of

archaeological Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...

trails around Llyn Brenig.

Ospreys

A pair of

osprey The osprey (; ''Pandion haliaetus''), historically known as sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor, reaching more than in length and a wingspan of . It ...

s began breeding at the lake in 2018, becoming the fifth site in Wales. In 2020 filming of ''The Bridge'', a

Channel 4 Channel 4 is a British free-to-air public broadcast television channel owned and operated by Channel Four Television Corporation. It is state-owned enterprise, publicly owned but, unlike the BBC, it receives no public funding and is funded en ...

reality television Reality television is a genre of television programming that documents purportedly unscripted real-life situations, often starring ordinary people rather than professional actors. Reality television emerged as a distinct genre in the early 1990s ...

programme, may have disturbed the ospreys during the breeding season. In April 2021, vandals cut down the osprey nest platform with a chainsaw. The same pair of ospreys returned to Llyn Brenig in 2022 and hatched chicks at a replacement nest in the same location. The Brenig Osprey Project, partnership between North Wales Wildlife Trust and Dŵr Cymru Welsh Water, provides a manned viewpoint, a hide, and online video streaming of the nest during the nesting season.

References

External links

Clwyd-Powys Archaeological TrustLlyn Brenig Sailing ClubWelsh Water WebsiteNorth Wales Wildlife Trust Ospreys at Llyn Brenig
{{authority control Brenig Brenig River regulation in Conwy County Borough River regulation in Denbighshire RBrenig