The Dee Estuary ( cy, Aber Dyfrdwy) is a large

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

by means of which the River Dee flows into

Liverpool Bay Liverpool Bay is a bay of the Irish Sea between northeast Wales, Cheshire, Lancashire and Merseyside to the east of the Irish Sea. The bay is a classic example of a region of freshwater influence. Liverpool Bay has historically suffered from red ...

. The estuary starts near Shotton after a five-mile (8 km) 'canalised' section and the river soon swells to be several miles wide forming the boundary between the

Wirral Peninsula Wirral (; ), known locally as The Wirral, is a peninsula in North West England. The roughly rectangular peninsula is about long and wide and is bounded by the River Dee to the west (forming the boundary with Wales), the River Mersey to t ...

in north-west England and

Flintshire , settlement_type = County , image_skyline = , image_alt = , image_caption = , image_flag = , image_shield = Arms of Flint ...

in north-east

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

. The Dee Estuary's largest towns along it include Hollywell,

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 fir ...

Connah's Quay Connah's Quay ( cy, Cei Connah), known locally as "The Quay" and formerly known as Wepre, is a town and community in Flintshire, lying within the Deeside conurbation along the River Dee, near the border with England. It is the largest town in F ...

, Shotton, Queensferry,

Saltney Ferry Saltney Ferry (Mold Junction) railway station was located on the western edge of the village of Saltney, Flintshire (now effectively a suburb of Chester). History Opened 1 June 1891 by the London and North Western Railway, it was served by wha ...

Chester Chester is a cathedral city and the county town of Cheshire, England. It is located on the River Dee, close to the English–Welsh border. With a population of 79,645 in 2011,"2011 Census results: People and Population Profile: Chester Loca ...

(City),

Heswall Heswall is a town on the Wirral, Merseyside, England. At the 2001 Census, the population was 16,012, including the nearby villages of Barnston and Gayton. Before local government reorganisation on 1 April 1974 it was part of the administr ...

West Kirby West Kirby is a resort town on the north-west corner of the Wirral Peninsula in Merseyside, England, at the mouth of the River Dee, Wales, River Dee. Within the boundaries of the Historic counties of England, historic county of Cheshire, to th ...

and

Neston Neston is a town and civil parish on the Wirral Peninsula, in Cheshire, England. It is part of the unitary authority of Cheshire West and Chester. The village of Parkgate is located to the north west and the villages of Little Neston and Ness ...

as well as other villages and towns alongside it. The A548 also passes along the estuary in Wales and parts of

Cheshire West and Chester Cheshire West and Chester is a Unitary authorities of England, unitary authority with Borough status in the United Kingdom, borough status in the ceremonial county of Cheshire, England. It was established on 1 April 2009 as part of the 2009 str ...

and

Merseyside Merseyside ( ) is a metropolitan county, metropolitan and ceremonial counties of England, ceremonial county in North West England, with a population of List of ceremonial counties of England, 1.38 million. It encompasses both banks of the Merse ...

in England. The

North Wales Coast Line The North Wales Coast Line ( cy, Llinell Arfordir Gogledd Cymru), also known as the North Wales Main Line ( cy, Prif Linell Gogledd Cymru or cy, label=none, Prif Linell y Gogledd), is a major railway line in the north of Wales and Cheshire, ...

follows the course of the Dee Estuary between

Prestatyn Prestatyn is a seaside town and community in Denbighshire, Wales. Historically a part of Flintshire, it is located on the Irish Sea coast, to the east of Rhyl. Prestatyn has a population of 19,085, History Prehistory There is evidence that the ...

and Chester.

Geology

The estuary is unusual in that comparatively little water occupies so large a basin. One theory is that larger rivers such as the

Severn , name_etymology = , image = SevernFromCastleCB.JPG , image_size = 288 , image_caption = The river seen from Shrewsbury Castle , map = RiverSevernMap.jpg , map_size = 288 , map_c ...

and/or

Mersey The River Mersey () is in North West England. Its name derives from Old English and means "boundary river", possibly referring to its having been a border between the ancient kingdoms of Mercia and Northumbria. For centuries it has formed part ...

once flowed into the Dee. The current view is that the estuary owes its origin to the passage of

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

ice southeastwards from the

Irish Sea The Irish Sea or , gv, Y Keayn Yernagh, sco, Erse Sie, gd, Muir Èireann , Ulster-Scots: ''Airish Sea'', cy, Môr Iwerddon . is an extensive body of water that separates the islands of Ireland and Great Britain. It is linked to the Ce ...

during successive

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

s, eroding a broad and shallow

iceway ::''This page is about the geomorphological feature. For other uses of the term see Nordic skating or Csilla ( Star Wars planet).'' An iceway is a linear channel eroded through bedrock by the passage of glacial ice. The term was coined by geogra ...

through the relatively soft

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 period ...

sandstones 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 silicates) b ...

and

Coal Measures In lithostratigraphy, the coal measures are the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coal ...

mudstones 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.'' ...

underlying the area. The inner parts of this channel were filled by glacially derived sands and gravels long ago, and infilling by mud and silt has continued since. It is also thought that prior to the

s, the estuary received larger river flows as the upper Severn flowed into the Dee near

Chirk Chirk ( cy, Y Waun) is a town and community in Wrexham County Borough, Wales, south of Wrexham, between it and Oswestry. At the 2011 census, it had a population of 4,468. Historically in the traditional county of Denbighshire, and later Clwy ...

. For a period, the Mersey may also have flowed into the Dee by means of a channel which it cut through the base of the Wirral Peninsula.Proudman Oceanographic Laboratory – Dee Estuary

Conservation

The estuary is a major wildlife area and one of the most important estuaries in Britain, amongst the most important in Europe for its populations of waders and wildfowl. The

Environment Agency The Environment Agency (EA) is a non-departmental public body, established in 1996 and sponsored by the United Kingdom government's Department for Environment, Food and Rural Affairs, with responsibilities relating to the protection and enha ...

is the Conservation Authority, and the estuary is protected or listed under several schemes: *

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 of ...

(SSSI) *

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 cert ...

(SPA) * Sensitive Marine Area (SMA) *

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectively ...

site *

Ramsar site A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention,8 ha (O) *** Permanent 8 ha (P) *** Seasonal Intermittent < 8 ha(Ts) **

RSPB The Royal Society for the Protection of Birds (RSPB) is a Charitable_organization#United_Kingdom, charitable organisation registered in Charity Commission for England and Wales, England and Wales and in Office of the Scottish Charity Regulator, ...

's Dee Estuary Nature Reserve.

Fishery

The estuary supports some important natural fisheries, including

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

and

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-salmoni ...

on their way to and from the freshwater river, as well as sea-fisheries and shell-fisheries, especially cockles.

Trade and industry

From earliest times, the Dee estuary was a major trading and military route, to and from

. From about the 14th century, Chester provided facilities for trade with Ireland, Spain, and Germany, and seagoing vessels would "lay to" in the Dee awaiting favourable winds and tides. As the Dee started to silt up, harbouring facilities developed on the Wirral bank at

Shotwick Shotwick is a small village and former civil parish, now in the parish of Puddington, on the southern end of the Wirral Peninsula in the unitary authority of Cheshire West and Chester and the ceremonial county of Cheshire, England. The village ...

, Burton,

, Parkgate, Dawpool, and "Hoyle Lake" or

Hoylake Hoylake is a coast, seaside town in the Metropolitan Borough of Wirral, Merseyside, England. It is at the north west of the Wirral Peninsula, near West Kirby and where the River Dee, Wales, River Dee meets the Irish Sea. Historic counties of En ...

.Stephen J. Roberts, ''A History of Wirral'', 2002, The excavation of the New Cut in 1737, to improve access to Chester, diverted the river's course to the Welsh side of the estuary, but failed to stem the silting up of the river, and Chester's trading function declined as that of

Liverpool Liverpool is a city and metropolitan borough in Merseyside, England. With a population of in 2019, it is the 10th largest English district by population and its metropolitan area is the fifth largest in the United Kingdom, with a popul ...

on the

River Mersey The River Mersey () is in North West England. Its name derives from Old English and means "boundary river", possibly referring to its having been a border between the ancient kingdoms of Mercia and Northumbria. For centuries it has formed part ...

grew. However, Chester was still a major port of passenger embarkation for Ireland until the early 19th century. The Dee Estuary was industrialised from quite early on in the

Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...

, and some industry remains today. Notable among these are Shotton Steel, formerly owned by

John Summers & Sons John Summers & Sons Ltd was a major United Kingdom iron and steel producer, latterly based on the Dee Estuary at Shotton, Flintshire. The company was absorbed into British Steel Corporation in 1967; British Steel became Corus in 1999 and this c ...

, and now owned by

Tata Steel Tata Steel Limited is an Indian multinational steel-making company, based in Jamshedpur, Jharkhand and headquartered in Mumbai, Maharashtra. It is a part of the Tata Group. Formerly known as Tata Iron and Steel Company Limited (TISCO), Tata ...

; the gas-fired

power station A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid. Many p ...

; three separate

paper mill A paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags, and other ingredients. Prior to the invention and adoption of the Fourdrinier machine and other types of paper machine that use an endless belt, ...

s; a chemical manufacturing plant; and numerous smaller manufacturing industries. The estuary also receives the treated sewage effluent from Queensferry works and from Chester

sewage treatment Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...

works. At the mouth of the estuary is the

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

sweetening plant at

Point of Ayr :''There are two other similarly named points in the British Isles: Point of Ayre, Isle of Man and Point of Ayre, Orkney, Scotland.'' Point of Ayr ( cy, Y Parlwr Du) is the northernmost point of mainland Wales. It is situated immediately to ...

on the site of the former

colliery Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from ...

. There are also commercial docks at

Mostyn Mostyn is a village and community in Flintshire, Wales, and electoral ward lying on the estuary of the River Dee, located near the town of Holywell. It has a privately owned port that has in the past had a colliery and ironworks and was invol ...

although their use is limited by the tide. Signs of past industry are visible along the whole length of the estuary especially on the

Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peop ...

side. Large stretches of what now appear as flood embankments are long abandoned industrial waste heaps, some still containing highly reactive and caustic materials, including large heaps of Galligu, a by-product of the

LeBlanc process The Leblanc process (pronounced leh-blaank) was an early industrial process for making ''soda ash'' (sodium carbonate) used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from ...

used at the

James Muspratt James Muspratt (12 August 1793 – 4 May 1886) was a British chemical manufacturer who was the first to make alkali by the Leblanc process on a large scale in the United Kingdom. Early life James Muspratt was born in Dublin of English parent ...

alkali works at

. The Dee estuary also supported industries concerned with the synthesis of

PCB PCB may refer to: Science and technology * Polychlorinated biphenyl, an organic chlorine compound, now recognized as an environmental toxin and classified as a persistent organic pollutant * Printed circuit board, a board used in electronics * ...

s and some pharmaceuticals and was also home to several industrial waste oil-reclamation industries. As a consequence of its industrial heritage, there are extensive areas of contaminated ground along the shores of the estuary. The estuary also plays a part in the most modern of industries as it provides the first stage of transport of

Airbus A380 The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was annou ...

wings on their way to

Toulouse Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Par ...

via barge to Mostyn docks.

References

External links

Metropolitan Borough of Wirral: Dee Estuary SSSIDee Estuary bird lifeJoint Nature Conservation Committee (JNCC)RSPB Dee Estuary websiteThe Dee Estuary Website
{{authority control Metropolitan Borough of Wirral Rivers of Cheshire Sites of Special Scientific Interest in Cheshire Coast of Flintshire Bodies of water of Flintshire Sites of Special Scientific Interest in Clwyd Sites of Special Scientific Interest in Flintshire Estuaries of England Estuaries of Wales Ramsar sites in England Ramsar sites in Wales Special Protection Areas in Wales England–Wales border River Dee, Wales