Chew Valley Lake () is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contr ...

Chew Stoke Chew Stoke is a small village and civil parish in the affluent Chew Valley, in Somerset, England, about south of Bristol and 10 miles north of Wells. It is at the northern edge of the Mendip Hills, a region designated by the United Kingdom as ...

, Chew Valley,

Somerset ( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of Somerset , lor ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

. It is the fifth-largest artificial lake in the United Kingdom, with an area of . The lake, created in the early 1950s, was opened by

Queen Elizabeth II Elizabeth II (Elizabeth Alexandra Mary; 21 April 1926 – 8 September 2022) was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until her death in 2022. She was queen regnant of 32 sovereign states during ...

in 1956. It provides much of the

drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, ...

for the city of

Bristol Bristol () is a City status in the United Kingdom, city, Ceremonial counties of England, ceremonial county and unitary authority in England. Situated on the River Avon, Bristol, River Avon, it is bordered by the ceremonial counties of Glouces ...

and surrounding area, taking its supply from the

Mendip Hills The Mendip Hills (commonly called the Mendips) is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running from Weston-super-Mare and the Bristol Channel in the west to the Frome valley in the east, the hills ...

. Some of the lake water is used to maintain the flow in the

River Chew The River Chew is a small river in England that flows for some through the North Somerset countryside to form the Chew Valley before merging with the River Avon. The spring from which the Chew rises is just upstream from Chewton Mendip. Th ...

. Before the lake was created, archaeological investigations were carried out that showed evidence of occupation since

Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several pa ...

times and included

Roman Roman or Romans most often refers to: * Rome, the capital city of Italy * Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a lett ...

artefacts. The lake is an important site for wildlife and has been designated a

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle ...

(SSSI) and a

Special Protection Area A Special Protection Area (SPA) is a designation under the European Union Directive on the Conservation of Wild Birds. Under the Directive, Member States of the European Union (EU) have a duty to safeguard the habitats of migratory birds and certa ...

(SPA). It is a national centre for

birdwatching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, by ...

, with over 260 species recorded. The lake has indigenous and migrant water birds throughout the year, and two nature trails have been created. The

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring ( indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. ...

and

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is '' flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. ...

provide

habitats In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for some less common plants and insects. Some restricted use for recreational activities is permitted by the owner,

Bristol Water Bristol Water is a British water company which supplies 266 million litres of drinking water daily to over 1.2 million customers in a area centred on Bristol, England. It is regulated under the Water Industry Act 1991. Sewerage services in ...

, including

dinghy sailing Dinghy sailing is the activity of sailing small boats by using five essential controls: * the sails * the foils (i.e. the daggerboard or centreboard and rudder and sometimes lifting foils as found on the Moth) * the trim (forward/rear angle o ...

and fishing, primarily for

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...

Location

Chew Valley Lake is in the Chew Valley at the northern edge of the

, surrounded by meadows and woods and close to the villages of

Chew Magna Chew Magna is a village and civil parish within the Chew Valley in the unitary authority of Bath and North East Somerset, in the ceremonial county of Somerset, England. The parish has a population of 1,149. To the south of the village is Ch ...

and

Bishop Sutton Bishop Sutton () is a village on the northern slopes of the Mendip Hills, within the affluent Chew Valley in Somerset. It lies east of Chew Valley Lake and north east of the Mendip Hills, approximately ten miles south of Bristol on the A368, We ...

. When it was built in the 1950s, its 1,200 acres (4.9 km²) were flooded with 4,500 million imperial gallons (20,000,000 m³) of water from the Mendip hills, with a catchment area of 14,000 acres (57 km²). It is shallow, with an average depth of 14 ft (4 m) at top level and a maximum depth of just 37 ft (11 m). It is fed by small rivers, and it flows into the

for 17 miles (27 km) before it joins the Avon to head out to sea. The deepest part is near the dam and the outlet tower, where the steeply sloping shores of Walley Bank and the north shore result in depths of up to 20 ft (6 m). "Denny Island", above the surface throughout the year, is wooded and provides a habitat for wildlife. The lake is owned and operated by Bristol Water, which created it in 1956 when the demand became too large for nearby

Blagdon Lake Blagdon Lake lies in a valley at the northern edge of the Mendip Hills, close to the village of Blagdon and approximately south of Bristol, England. The lake was created by Bristol Water (Bristol Waterworks Company as it was known then), whe ...

. Working with the

Avon Wildlife Trust The Avon Wildlife Trust aims to protect and promote wildlife in the area of the former county of Avon — now Bath and North East Somerset, Bristol, North Somerset and South Gloucestershire, in England. It has its headquarters in Bristol and r ...

, Somerset Wildlife Trust and other environmental groups, Bristol Water has encouraged various species of birds and plants, and created a venue for visitors. It has two landscaped picnic areas. Facilities include a

tea shop A teahouse (mainly Asia) or tearoom (also tea room) is an establishment which primarily serves tea and other light refreshments. A tea room may be a room set aside in a hotel especially for serving afternoon tea, or may be an establishment whic ...

, with indoor and outdoor seating areas with a view of the lake, and information centre. There are a souvenir shop and small art gallery and two nature trails. The Grebe Trail is a hard-surfaced, all-weather path suitable for pedestrians, pushchairs and wheelchairs and covers a circuit 0.75 miles (1.2 km) long, starting and finishing at the wooded picnic area. The Bittern Trail is reached from the Grebe Trail by the footbridge over Hollow Brook. The grassy path is often waterlogged in winter, but there is a boardwalk over a short section. The trail runs along the east shore, visits an open bird hide and returns to the footbridge, making a 1-mile (1.5-kilometre) circuit. Bristol Water imposes conditions on visitors, particularly related to the areas where dogs are allowed.

Access and transportation

Access to the waterside is restricted in places to reduce the disruption to wildlife. Paths around the lake are generally flat and, where paths are surfaced, wheelchair access is possible. Visitors are officially invited to use public transport, but overwhelmingly arrive by private car, encouraged by the provision of parking spaces. The "Chew Valley Explorer" bus route 672/674 provides access. In 2002 a 1.9-mile (3-kilometre) safe cycle route, the Chew Lake West Green Route, was opened along the B3114 on the western part of the lake. It forms part of the

Padstow Padstow (; kw, Lannwedhenek) is a town, civil parish and fishing port on the north coast of Cornwall, England. The town is situated on the west bank of the River Camel estuary approximately northwest of Wadebridge, northwest of Bodmin and ...

West Country Way,

National Cycle Network The National Cycle Network (NCN) is the national cycling route network of the United Kingdom, which was established to encourage cycling and walking throughout Britain, as well as for the purposes of bicycle touring. It was created by the cha ...

Route 3. It has all-weather surfacing, providing a smooth off-road facility for ramblers, mobility-challenged visitors and cyclists of all abilities. It was funded by

Bath and North East Somerset Bath and North East Somerset (B&NES) is a unitary authority district in England. Bath and North East Somerset Council was created on 1 April 1996 following the abolition of the county of Avon. It is part of the ceremonial county of Somerset. ...

Council with the support of

Sustrans Sustrans is a United Kingdom-based walking, wheeling and cycling charity, and the custodian of the National Cycle Network. Its flagship project is the National Cycle Network, which has created of signed cycle routes throughout the United K ...

and the Chew Valley Recreational Trail Association. Minor roads around the lake are also frequently used by cyclists.

Bristol Airport Bristol Airport , at Lulsgate Bottom, on the northern slopes of the Mendip Hills, in North Somerset, is the commercial airport serving the city of Bristol, England, and the surrounding area. It is southwest of Bristol city centre. Built on ...

is approximately 10 miles (15 km) away. The nearest major road is the A368, which runs along the southern edge of the lake and provides access from

Bath Bath may refer to: * Bathing, immersion in a fluid ** Bathtub, a large open container for water, in which a person may wash their body ** Public bathing, a public place where people bathe * Thermae, ancient Roman public bathing facilities Pl ...

and

Weston super Mare Weston-super-Mare, also known simply as Weston, is a seaside town in North Somerset, England. It lies by the Bristol Channel south-west of Bristol between Worlebury Hill and Bleadon Hill. It includes the suburbs of Mead Vale, Milton, Oldmix ...

. The A37 and A38 are slightly further away, providing access from

. The lake is also easily accessible from the

M5 motorway The M5 is a motorway in England linking the Midlands with the South West England, South West. It runs from junction 8 of the M6 motorway, M6 at West Bromwich near Birmingham to Exeter in Devon. Heading south-west, the M5 runs east of West Brom ...

at junctions 18 and 22, with visitors instructed to follow signs to Bristol Airport. Car parking is available at the visitor centre and Woodford Lodge, for which a charge is made, and a small amount of parking is available at points around the lake; some of these are restricted to those with fishing permits.

History

The area the lake covers was once rich farmland. Farms and houses had to be removed before the land was flooded, and old roads, hedgerows and tree stumps can reappear when dry summers cause the level of the lake to drop. Prior to the flooding of the

archaeological Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscap ...

excavations In archaeology, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is the area being studied. These locations range from one to several areas at a time during a project and can be condu ...

were carried out by

Philip Rahtz Philip Arthur Rahtz (11 March 1921 – 2 June 2011) was a British archaeologist. Rahtz was born in Bristol. After leaving Bristol Grammar School, he became an accountant before serving with the Royal Air Force during the Second World War. D ...

and

Ernest Greenfield Ernest Greenfield was a British archaeologist. He served with the Royal Air Force during the Second World War. During war service he became friends with Philip Rahtz who persuaded Greenfield to take up professional archaeology. His excavations i ...

employed by the Ministry of Works, from 1953 to 1955. The excavations found evidence of people belonging to the consecutive periods known as

Upper Palaeolithic The Upper Paleolithic (or Upper Palaeolithic) is the third and last subdivision of the Paleolithic or Old Stone Age. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories coin ...

Mesolithic The Mesolithic ( 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 is often used synonymo ...

and

(Old, Middle and New

Stone Age The Stone Age was a broad prehistoric period during which stone was widely used to make tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years, and ended between 4,000 BC and 2,000 BC, with ...

Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...

and

Iron Age The Iron Age is the final epoch of the three-age division of the prehistory and protohistory of humanity. It was preceded by the Stone Age ( Paleolithic, Mesolithic, Neolithic) and the Bronze Age ( Chalcolithic). The concept has been mostly ...

, including implements such as stone knives,

flint Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start ...

blades and the head of a mace, along with buildings and graves. The artefacts from this period are held at

Bristol City Museum and Art Gallery Bristol Museum & Art Gallery is a large museum and art gallery in Bristol, England. The museum is situated in Clifton, about from the city centre. As part of Bristol Culture it is run by the Bristol City Council with no entrance fee. It holds ...

. Further evidence of Neolithic and Bronze Age occupation is provided by the archaeological survey of the

Area of Outstanding Natural Beauty. Excavations have also uncovered Roman remains, indicating agricultural and industrial activity from the second half of the first century to third century AD. The finds included a

villa A villa is a type of house that was originally an ancient Roman upper class country house. Since its origins in the Roman villa, the idea and function of a villa have evolved considerably. After the fall of the Roman Republic, villas became ...

at Chew Park where wooden writing tablets (the first in the UK) with ink writing were found. The tablets were sent to the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

, but other Roman material is on display at the Bristol City Museum and Art Gallery with the lake's other historical artefacts. Further excavations around the village of Moreton, which has now been totally submerged, found evidence of a thriving community in

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

times and possibly the remains of the

Nunnery A convent is a community of monks, nuns, religious brothers or, sisters or priests. Alternatively, ''convent'' means the building used by the community. The word is particularly used in the Catholic Church, Lutheran churches, and the Anglican ...

of Santa Cruz. During the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

farming was the most important activity in the area covered by the lake, supported by four

flour mill A gristmill (also: grist mill, corn mill, flour mill, feed mill or feedmill) grinds cereal grain into flour and middlings. The term can refer to either the grinding mechanism or the building that holds it. Grist is grain that has been separated ...

s powered by the River Chew. Stratford Mill was demolished and re-erected in the grounds of

Blaise Castle Blaise Castle is a folly built in 1766 near Henbury in Bristol, England. The castle sits within the Blaise Castle Estate, which also includes Blaise Castle House, a Grade II* listed 18th-century mansion house. The folly castle is also Grade I ...

Museum, in north-west Bristol. The largest settlement was Moreton, which is listed in the

Domesday Book Domesday Book () – the Middle English spelling of "Doomsday Book" – is a manuscript record of the "Great Survey" of much of England and parts of Wales completed in 1086 by order of King William I, known as William the Conqueror. The manusc ...

of 1086, and survived until the flooding of the lake, when the remains of the Moreton Cross were moved to

Parish Church. There is evidence of

lime kilns A lime kiln is a kiln used for the calcination of limestone ( calcium carbonate) to produce the form of lime called quicklime (calcium oxide). The chemical equation for this reaction is : CaCO3 + heat → CaO + CO2 This reaction can take ...

, which were used in the production of mortar for the construction of local churches. Farming, both arable and

dairy A dairy is a business enterprise established for the harvesting or processing (or both) of animal milk – mostly from cows or buffaloes, but also from goats, sheep, horses, or camels – for human consumption. A dairy is typically located on ...

, continued until the flooding of the lake, with most households also keeping pigs. There were

orchard An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit- or nut-producing trees which are generally grown for commercial production. Orchards are also sometimes a feature of ...

s for fruit production, including apples, pears and

plum A plum is a fruit of some species in ''Prunus'' subg. ''Prunus'.'' Dried plums are called prunes. History Plums may have been one of the first fruits domesticated by humans. Three of the most abundantly cultivated species are not found ...

s. Moreton was also the site of a

gunpowder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). T ...

mill in the 18th century.

Reservoir

Plans for the building of the reservoir were under discussion before the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

, and an

Act of Parliament Acts of Parliament, sometimes referred to as primary legislation, are texts of law passed by the legislative body of a jurisdiction (often a parliament or council). In most countries with a parliamentary system of government, acts of parliame ...

submitted by the Bristol Waterworks Company was passed in 1939. Following this, farms were bought by the company and farmed by the previous owners as tenancies. Farms and buildings still remaining in private hands were acquired by

compulsory purchase Compulsion may refer to: * Compulsive behavior, a psychological condition in which a person does a behavior compulsively, having an overwhelming feeling that they must do so. * Obsessive–compulsive disorder, a mental disorder characterized by ...

. The sanction for construction was given in 1949 and the contract awarded to A.E. Farr, who employed 300 people on the site. The main dam was stabilised by injecting concrete into the cracks in the

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of be ...

. The core of the dam was made of puddled

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay pa ...

mixed with

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...

. This was the first time the gain in strength brought about by the use of sand drains had been quantified. The lake was inaugurated by

, accompanied by

Prince Philip Prince Philip, Duke of Edinburgh (born Prince Philip of Greece and Denmark, later Philip Mountbatten; 10 June 1921 – 9 April 2021) was the husband of Queen Elizabeth II. As such, he served as the consort of the British monarch from E ...

, with the unveiling of a commemorative stone and plaque, which can be seen from the dam, on 17 April 1956, although it was not full until 25 February 1958. Flowers were presented to the Queen at the opening of Chew Valley Lake by Judith Blair Brown, daughter of Kennedy Brown, who worked at Bristol Water Works at the time of construction of the lake. During the storm of 10 July 1968, the lake gained an extra 471 million imperial gallons (2,140,000 m³) and rose 19 inches (480 mm) in under 12 hours. At one point worried Bristol police issued a warning that the dam might not hold, prompting localised evacuation of populated valley areas downstream including

Pensford Pensford is the largest village in the civil parish of Publow in Somerset, England. It lies in the Chew Valley, approximately south of Bristol, west of Bath and north of Wells. It is on the A37 road from Bristol to Shepton Mallet. Pensfor ...

and

Keynsham Keynsham ( ) is a town and civil parish located between Bristol and Bath in Somerset, England. It has a population of 16,000. It was listed in the Domesday Book as ''Cainesham'' (as it is pronounced), which is believed to mean the home of ...

Ecology

The lake is designated a

(SSSI) and a

(SPA) (Site Code: UK9010041) largely because of the diversity of species and habitats. Providing further protection, much of the area around the lake also falls within the

Area of Outstanding Natural Beauty An Area of Outstanding Natural Beauty (AONB; , AHNE) is an area of countryside in England, Wales, and Northern Ireland, that has been designated for conservation due to its significant landscape value. Areas are designated in recognition of ...

(AONB). The lake appears to have a higher sedimentation rate than would be expected in other similar reservoirs, being in the region of 100–150 t.km⁻².yr⁻¹.

Geology

The main geological outcrops around the lake are

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.' ...

, largely consisting of red

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

resulting in the underlying characteristic of the gently rolling valley landscape. Bands of

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

from the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

period contribute to the undulating character of the area. There are also more recent

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. ...

deposits beside the course of the River Chew.

Birds

Over 270 species of birds have been recorded at Chew, an internationally important site for wintering and migrating wildfowl. From late July to February, up to 4,000

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

s (Anatidae) of twelve different species may be present, including internationally important numbers of

northern shoveler The northern shoveler (; ''Spatula clypeata''), known simply in Britain as the shoveler, is a common and widespread duck. It breeds in northern areas of Europe and across the Palearctic and across most of North America, wintering in southern ...

(''Anas clypeata'') and

gadwall The gadwall (''Mareca strepera'') is a common and widespread dabbling duck in the family Anatidae. Taxonomy The gadwall was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae''. DNA studies have shown that ...

(''Anas strepera''). Up to 600

great crested grebe The great crested grebe (''Podiceps cristatus'') is a member of the grebe family of water birds noted for its elaborate mating display. Taxonomy The great crested grebe was formally described by the Swedish naturalist Carl Linnaeus in 1758 in t ...

s (''Podiceps cristatus'') gather to moult on the lake in autumn. Data on bird species and their numbers on the lake, dating back to the first "

ringing Ringing may mean: Vibrations * Ringing (signal), unwanted oscillation of a signal, leading to ringing artifacts * Vibration of a harmonic oscillator ** Bell ringing * Ringing (telephony), the sound of a telephone bell * Ringing (medicine), a ring ...

" in 1964, is available from the Chew Valley Ringing Station. Numerous other birds can be seen, especially during the spring and autumn

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

Sand martin The sand martin (''Riparia riparia''), also known as the bank swallow (in the Americas), collared sand martin, or common sand martin, is a migratory passerine bird in the swallow family. It has a wide range in summer, embracing practically the ...

s (''Riparia riparia'') arrive early and can usually be seen hawking over the water for insects in the second or third week of March. Flocks of tits (Paridae), swallows (Hirundinidae) and terns (Sternidae) can regularly be seen. Waders, such as lapwings (''Vanellus vanellus''),

dunlin The dunlin (''Calidris alpina'') is a small wader, formerly sometimes separated with the other "stints" in the genus ''Erolia''. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from ''dun'', "dull brow ...

(''Calidris alpina'') and

common snipe The common snipe (''Gallinago gallinago'') is a small, stocky wader native to the Old World. The breeding habitats are marshes, bogs, tundra and wet meadows throughout the Palearctic. In the north, the distribution limit extends from Iceland ov ...

(''Gallinago gallinago''), are attracted to the muddy shores if the water level drops in autumn. By midwinter up to 55,000

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

s, mostly

black-headed gull The black-headed gull (''Chroicocephalus ridibundus'') is a small gull that breeds in much of the Palearctic including Europe and also in coastal eastern Canada. Most of the population is migratory and winters further south, but some birds ...

(''Chroicocephalus ridibundus'') and

common gull The common gull or sea mew (''Larus canus'') is a medium-sized gull that breeds in the Palearctic, northern Europe. The closely related short-billed gull is sometimes included in this species, which may be known collectively as "mew gull". Ma ...

(''Larus canus''), may be roosting. Good numbers of reed warblers (''Acrocephalus scirpaceus'') and

sedge warbler The sedge warbler (''Acrocephalus schoenobaenus'') is an Old World warbler in the genus '' Acrocephalus''. It is a medium-sized warbler with a brown, streaked back and wings and a distinct pale supercilium. Sedge warblers are migratory, crossing ...

s (''A. schoenobaenus'') nest in the fringing reeds, along with

grebes Grebes () are aquatic diving birds in the order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Some flightless species exist as well, most notably i ...

(Podicipedidae) and Eurasian coots (''Fulica atra''). Much of the management work carried out in the nature reserve is aimed at encouraging ducks to breed, and small numbers of tufted duck (''Aythya fuligula''),

common pochard The common pochard (; ''Aythya ferina'') is a medium-sized diving duck. The scientific name is derived from Greek '' aithuia'', an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin ''ferina'', "wild game", ...

(''Aythya ferina''),

common shelduck The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic, mainly breeding in temperate and wintering in subtropical regions; in ...

(''Tadorna tadorna'') and

raise broods most years. Recent breeding successes also include

water rail The water rail (''Rallus aquaticus'') is a bird of the Rallidae, rail family which breeds in well-vegetated wetlands across Europe, Asia and North Africa. Northern and eastern populations are bird migration, migratory, but this species is a perma ...

(''Rallus aquaticus'') and

Cetti's warbler Cetti's warbler (''Cettia cetti'') is a small, brown bush-warbler which breeds in southern and central Europe, northwest Africa and the east Palearctic as far as Afghanistan and northwest Pakistan. The sexes are alike. The bird is named after ...

(''Cettia cetti''). A wetland reserve has been created at Heron's Green Pool on the opposite side of the causeway to the lake. A shallow pool fringed with Cyperaceae, sedges (Cyperaceae), Juncaceae, rushes (Juncaceae) and Calamagrostis, reedgrasses (''Calamagrostis'') and surrounded by lightly grazed, rough grassland may also prove attractive to snipe and lapwings.

Fish

In late summer large shoals of common roach, roach (''Rutilus rutilus'') and perch (''Perca fluviatilis'') fry congregate around the margins and weed beds, which are predated by the brown trout (Salmo trutta fario, ''Salmo trutta'' morpha ''fario'') and rainbow trout (''Oncorhynchus mykiss''). Chew Valley also holds a large population of northern pike, pike (''Esox lucius''), and fishing for these is permitted at certain times of the year.

Insects

Chironomidae, Aquatic midges (Chironomidae) provide the highest proportion of the fly life of the lake. The

(Salmonidae) will feed at the surface on these and Corixidae, water boatmen (Corixidae), and below the surface on the caddisfly (Trichoptera) larvae and pupae; they will also take the adult caddisflies when they emerge. Other aquatic fauna including ''daphnia'' and snails are also found in the lake. Large populations of dragonflies, including migrant hawker (''Aeshna mixta'') and significant numbers of ruddy darter (''Sympetrum sanguineum''), occur at the lake. Eleven species of wainscot moth make their home in the reed beds, including the nationally local brown-veined wainscot (''Archanara dissoluta''), twin-spotted wainscot (''Archanara geminipuncta'') and silky wainscot (''Chilodes maritimus'').

Vegetation

The lake is surrounded with fringing reedbeds, carr (fen), carr woodland and grassland, which are managed by

. The water conditions are eutrophic with run off from local fields and streams. Open-water plant communities are rather sparse, largely comprising Potamogeton, fennel pondweed (''Potamogeton pectinatus''), Potamogeton, lesser pondweed (''Potamogeton pusillus''), Groenlandia, opposite-leaved pondweed (''Groenlandia densa'') and Ranunculus, water-crowfoot (''Ranunculus spp.''). On neutral soils around the reservoir, pepper-saxifrage (''Silaum silaus''), saxifrage, burnet-saxifrage (''Pimpinella saxifraga'') and scabious, devil's-bit scabious (''Succisa pratensis'') occur, and on calcareous soils fairy flax (''Linum catharticum''), Cirsium, dwarf thistle (''Cirsium acaule'') and salad burnet (''Sanguisorba minor'' subspecies ''minor'') are found. The small and medium-sized fields around the lake are generally bounded by hedges and occasionally by tree belts and woodland, some of which date back to the most evident period of enclosure of earlier open fields which took place in the late medieval period. Mature oak (''Quercus'') and ash tree, ash (''Fraxinus excelsior'') trees are characteristic of the area with occasional groups of Scots pine (''Pinus sylvestris'') and chestnuts (''Castanea sativa''). Many elm (''Ulmus'') trees have been lost in this area, and dead/dying elms are also evident in the surrounding landscape. Four areas of woodland containing 157 trees has been planted by The Life for a Life Charity around the lake on the Restaurant side, for the cremated remains of loved ones to be placed beneath them. These forests contain Scots pine (''Pinus sylvestris''), English oak (''Quercus robur''), rowan (''Sorbus aucuparia'') and the silver birch (''Betula pendula'').

Leisure use

The lake is used for a wide variety of leisure pursuits.

Birdwatching

During 2005–2006 Bristol Water started restoring two artificial islands. These are intended to provide safe nesting and roosting sites for a range of wildfowl. Permits to enter the reservoir enclosure and to use the access roads, paths and bird hides are available (for a fee) only to members of ornithological and naturalist societies recognised by Bristol Water. They can be obtained from Woodford Lodge and include conditions of use imposed by the owners.

Sailing

Chew Valley Lake Sailing Club has a sailing area, approximately 1.9 miles (3 km) long, for

. The lake is divided into two areas: a restricted summer area which is available during the fishing season (mid-March to mid-October), and the full area which can be used throughout the winter and on Sunday afternoons. The sailing area is marked out by lines of small white buoys. Racing marks are red buoys with flags, although large inflatable marks are used of open events. The club can cater for fleets of over one hundred boats and it hosts large national events. Normal club racing has fleet starts for the following dinghy classes: Flying Fifteen (keelboat), Laser (dinghy), Solo (dinghy) and Topper (dinghy) as well as a handicap fleet run under the Portsmouth yardstick scheme. Five slipways enable easy launching. Off the water, the clubhouse facilities include large changing rooms, hot showers, hot food at the weekends, a bar and terrace overlooking the lake. The club caters for disabled people with facilities on both floors and a lift. Royal Yachting Association sailing courses are held at the club for members including race training, youth training, powerboat training, race officer training as well as more informal training run within each fleet.

Fishing

Bristol water control fishing in the lake requiring permits and restricting the areas which can be used. Motor boats can also be booked for fishing.

References

Bibliography

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External links

BBC: pictures and video of Chew Valley LakeBristol Water's Information on Chew Valley LakeCVL birding – News on the latest bird sightings at Chew Valley Lake, with maps and photographsRiver Chew websiteChew Valley Lake Sailing Club
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