Dee Estuary
Encyclopedia
The Dee Estuary is a large estuary
by means of which the River Dee
flows into Liverpool Bay
. The estuary starts near Shotton
after a five miles (8 km) 'canalised' section and the river soon swells to be several miles wide forming the boundary between the Wirral Peninsula
in north-west England
and Flintshire
in north-east Wales
.
and/or Mersey
once flowed into the Dee. The current view is that the estuary owes its origin to the passage of glacial ice southeastwards from the Irish Sea
during successive ice age
s, eroding a broad and shallow iceway
through the relatively soft Triassic
sandstones and Coal Measures
mudstones which underlie 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 ice age
s, the estuary received larger river flows as the upper Severn flowed into the Dee near Chirk
. 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.
is the Conservation Authority and it is protected or listed under several schemes:
Large parts of the area are within the RSPB's Dee Estuary Nature Reserve RSPB Dee Estuary Nature Reserve Website
The estuary supports some important natural fisheries, including Salmon
and Trout on their way to and from the freshwater river, as well as sea-fisheries and shell-fisheries, especially Cockle
s.
. 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
, Burton, Neston, Parkgate
, Dawpool
, and "Hoyle Lake" or Hoylake
. 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
on the River Mersey
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 the industrial revolution
and some industry remains today. Notable amongst these are the gas fired power station
at Connah's Quay
, three separate paper mill
s and 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
works. At the mouth of the estuary is the natural gas
sweetening plant at Point of Ayr
on the site of the former colliery. There are also commercial docks at Mostyn
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
side. Large stretches of what now appear as flood embankments are long abandoned industrial waste heaps, some still containing highly reactive and caustic materials.
The Dee estuary also supported industries concerned with the synthesis of PCB
s and some pharmeceuticals 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
wings on their way to Toulouse
via barge to Mostyn docks.
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
by means of which the River Dee
River Dee, Wales
The River Dee is a long river in the United Kingdom. It travels through Wales and England and also forms part of the border between the two countries....
flows into Liverpool Bay
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...
. The estuary starts near Shotton
Shotton, Flintshire
Shotton is a town in Flintshire, north Wales, lying on the River Dee. The name derives from the Old Norse words sjò and tùn . It is continuous with the towns of Connah's Quay and Queensferry in what is called Deeside...
after a five miles (8 km) 'canalised' section and the river soon swells to be several miles wide forming the boundary between the Wirral Peninsula
Wirral Peninsula
Wirral or the Wirral is a peninsula in North West England. It is bounded by three bodies of water: to the west by the River Dee, forming a boundary with Wales, to the east by the River Mersey and to the north by the Irish Sea. Both terms "Wirral" and "the Wirral" are used locally , although the...
in north-west England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and Flintshire
Flintshire
Flintshire is a county in north-east Wales. It borders Denbighshire, Wrexham and the English county of Cheshire. It is named after the historic county of Flintshire, which had notably different borders...
in north-east Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
.
Geology
The estuary is unusual in that comparatively little water occupies so large a basin. One theory is that larger rivers such as the SevernRiver Severn
The River Severn is the longest river in Great Britain, at about , but the second longest on the British Isles, behind the River Shannon. It rises at an altitude of on Plynlimon, Ceredigion near Llanidloes, Powys, in the Cambrian Mountains of mid Wales...
and/or Mersey
River Mersey
The River Mersey is a river in North West England. It is around long, stretching from Stockport, Greater Manchester, and ending at Liverpool Bay, Merseyside. For centuries, it formed part of the ancient county divide between Lancashire and Cheshire....
once flowed into the Dee. The current view is that the estuary owes its origin to the passage of glacial ice southeastwards from the Irish Sea
Irish Sea
The Irish Sea separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel. Anglesey is the largest island within the Irish Sea, followed by the Isle of Man...
during successive ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s, eroding a broad and shallow iceway
Iceway
An iceway is a linear channel eroded through bedrock by the passage of glacial ice. The term was coined by geographer Ronald Kay Gresswell in a paper in 1964 in relation to the origins of the Dee and Mersey estuaries on the boundary of northwest England and northeast Wales...
through the relatively soft Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
sandstones and Coal Measures
Coal Measures
The Coal Measures is a lithostratigraphical term for the coal-bearing part of the Upper Carboniferous System. It represents the remains of fluvio-deltaic sediment, and consists mainly of clastic rocks interstratified with the beds of coal...
mudstones which underlie 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 ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s, the estuary received larger river flows as the upper Severn flowed into the Dee near Chirk
Chirk
Chirk is a small town and local government community, the lowest tier of local government, part of Wrexham County Borough in Wales. It has a population of over 4,000....
. 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.
Conservation
The estuary is a major wildlife area and is one of the most important estuaries in Britain and amongst the most important in Europe for its populations of waders and wildfowl. The Environment AgencyEnvironment Agency
The Environment Agency is a British non-departmental public body of the Department for Environment, Food and Rural Affairs and an Assembly Government Sponsored Body of the Welsh Assembly Government that serves England and Wales.-Purpose:...
is the Conservation Authority and it is protected or listed under several schemes:
- Site of Special Scientific InterestSite of Special Scientific InterestA Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...
(SSSI) - Special Protection AreaSpecial Protection AreaA Special Protection Area or SPA is a designation under the European Union Directive on the Conservation of Wild Birds.Under the Directive, Member States of the European Union have a duty to safeguard the habitats of migratory birds and certain particularly threatened birds.Together with Special...
(SPA) - Sensitive Marine Area (SMA)
- Natura 2000Natura 2000Natura 2000 is an ecological network of protected areas in the territory of the European Union.-Origins:In May 1992, the governments of the European Communities adopted legislation designed to protect the most seriously threatened habitats and species across Europe. This legislation is called the...
site - Ramsar siteRamsar ConventionThe Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
Large parts of the area are within the RSPB's Dee Estuary Nature Reserve RSPB Dee Estuary Nature Reserve Website
Fishery
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
and Trout on their way to and from the freshwater river, as well as sea-fisheries and shell-fisheries, especially Cockle
Cockle (bivalve)
Cockle is the common name for a group of small, edible, saltwater clams, marine bivalve molluscs in the family Cardiidae.Various species of cockles live in sandy sheltered beaches throughout the world....
s.
Trade and Industry
From earliest times, the Dee estuary was a major trading and military route, to and from ChesterChester
Chester is a city in Cheshire, England. Lying on the River Dee, close to the border with Wales, it is home to 77,040 inhabitants, and is the largest and most populous settlement of the wider unitary authority area of Cheshire West and Chester, which had a population of 328,100 according to the...
. 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
Wirral Peninsula
Wirral or the Wirral is a peninsula in North West England. It is bounded by three bodies of water: to the west by the River Dee, forming a boundary with Wales, to the east by the River Mersey and to the north by the Irish Sea. Both terms "Wirral" and "the Wirral" are used locally , although the...
bank at Shotwick
Shotwick
Shotwick is a village and civil parish on the Wirral Peninsula in the unitary authority of Cheshire West and Chester and the ceremonial county of Cheshire, England...
, Burton, Neston, Parkgate
Parkgate, Cheshire
Parkgate is a village on the Wirral Peninsula, in the part that lies in the unitary authority of Cheshire West and Chester and the ceremonial county of Cheshire, in the North West of England...
, Dawpool
Thurstaston
Thurstaston is a village on the Wirral Peninsula, England. It is part of the West Kirby & Thurstaston Ward of the Metropolitan Borough of Wirral...
, and "Hoyle Lake" or Hoylake
Hoylake
Hoylake is a seaside town within the Metropolitan Borough of Wirral, on Merseyside, England. It is located at the north western corner of the Wirral Peninsula, near to the town of West Kirby and where the River Dee estuary meets the Irish Sea...
. 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
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
on the River Mersey
River Mersey
The River Mersey is a river in North West England. It is around long, stretching from Stockport, Greater Manchester, and ending at Liverpool Bay, Merseyside. For centuries, it formed part of the ancient county divide between Lancashire and Cheshire....
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 the industrial revolution
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...
and some industry remains today. Notable amongst these are the gas fired power station
Power station
A power station is an industrial facility for the generation of electric energy....
at Connah's Quay
Connah's Quay
Connah's Quay is the largest town in Flintshire, North Wales, lying on the River Dee, near the border with England. It can be accessed by road from the A550, by rail from the nearby Shotton station and also lies on the National Cycle Network Route 5. It is situated near the region's industrial...
, three separate paper mill
Paper mill
A paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags and other ingredients using a Fourdrinier machine or other type of paper machine.- History :...
s and a chemical manufacturing plant, and numerous smaller manufacturing industries. The estuary also receives the treated sewage effluent from Queensferry
Queensferry, Flintshire
Queensferry is a town in Flintshire, North Wales, lying on the River Dee near the border with England.Queensferry lies along the B5441 and B5129 roads, and is bypassed by the A494 dual carriageway. It is contiguous with Deeside...
works and from Chester sewage treatment
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...
works. At the mouth of the estuary is the natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
sweetening plant at Point of Ayr
Point of Ayr
Point of Ayr is the northernmost point of mainland Wales. It is situated immediately to the north of Talacre in Flintshire, at the mouth of the Dee estuary. It is to the southwest of the Liverpool Bay area of the Irish Sea...
on the site of the former colliery. There are also commercial docks at Mostyn
Mostyn
Mostyn is a small village in Flintshire, North Wales, lying on the estuary of the River Dee, and located near the town of Holywell.Mostyn once served as a port from which ferries used to sail to Dublin on the Liverpool-Dublin route...
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
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
side. Large stretches of what now appear as flood embankments are long abandoned industrial waste heaps, some still containing highly reactive and caustic materials.
The Dee estuary also supported industries concerned with the synthesis of PCB
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
s and some pharmeceuticals 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
Airbus A380
The Airbus A380 is a double-deck, wide-body, four-engine jet airliner manufactured by the European corporation Airbus, a subsidiary of EADS. It is the largest passenger airliner in the world. Due to its size, many airports had to modify and improve facilities to accommodate it...
wings on their way to Toulouse
Toulouse
Toulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
via barge to Mostyn docks.