Irwell Valley
Encyclopedia
The Irwell Valley extends from the Forest of Rossendale
in North West England
, through to the cities of Salford
and Manchester
. The River Irwell
runs through the valley, along with the River Croal
.
Shallow seas covered most of south-east Lancashire
in the Upper Carboniferous period when deposits of mud and sand were laid down. These later became beds of shale
s and sandstone
s alternating with layers of gritstone
. There are also beds of New Red Sandstone
and Manchester Marl
s. The glaciers of the Pleistocene
epoch further shaped the landscape and then retreated, leaving behind deposits of sand, pebbles and boulder clay
that formed the fluvioglacial ridges
of the Irwell Valley. Ashclough, a 5.8 hectare (14.3 acre) site which comprises the steep banks of the river between Prestolee and Little Lever, has been designated a Site of Special Scientific Interest (SSSI) because of its geological interest, primarily because it is the best site in the area displaying Ashcough Marine Band
and its associated strata. Ashclough is a site of national importance for interpreting the coal measure paleogeography of Great Britain.
During the Industrial Revolution
factories, mills and terraced hovels grew up along the river banks and the region became filled with cotton mills, coal mines, print works, bleach works, dye works, chemical works, paper works, in fact almost every kind of industry. Wet Earth Colliery
was located in the valley at Clifton
, along with a number of bleach and dye works including Lever Bank Bleach Works
. A number of canals were built to transport goods through the valley, the largest of which is the Manchester Ship Canal
. Although many of the smaller canals were abandoned with the coming of the railways, isolated sections of the Manchester Bolton & Bury Canal still remain, and there are plans to restore it for leisure purposes.
The waste from the industries along the Irwell polluted the river so heavily that by the 1850 it was virtually devoid of wildlife. However, since the late 19th century many attempts have made to improve the quality of the water. In 1891 the Mersey and Irwell Joint Committee was formed. This body ordered local authorities to provide sewage treatment
facilities and industrial concerns were told to use the best practical means of preventing pollution. In 1939 this body was superseded by the Lancashire Rivers Board, but wartime conditions brought about further deterioration of the river. In 1951 the Rivers (Prevention of Pollution) Act was passed and this board disappeared to be replaced by the Mersey River Board, which was replaced in turn by the Mersey and Weaver River Authority in 1965. In 1974 all the river authorities were merged into the Regional Water Authorities. Since then there has been a gradual improvement in water quality, and today wildlife is returning to the Irwell.
- a process once used in the manufacture of washing soda for textile bleaching - was dumped on at least two sites. One site at Nob End
, to the south of Bolton
, is now a SSI Site. Another such site is at Lower Hinds in Bury
. The waste on both sites has, over the years, weathered-down to calcium carbonate
which has provided an ideal environment for a number of calcareous plants, unique in what is predominately an area of acidic soil. These plants, along with non-indigenous
garden escapees such as Giant Hogweed
and Himalayan Balsam
, have added much variety to the flora of the valley.
The M60
passes through the valley and the bridge at junction 16 in at Clifton
is used as a summer roost for over 100 Daubenton's bat
s.
is one of the largest public art initiatives and the longest sculpture trail in the UK. The trail consists of a scenically varied, 30 miles (48.3 km) walking route based on the well-established Irwell Valley Trail stretching from Salford Quays
to the moors above Bacup
. Since 1987 over 30 pieces of public art have been commissioned from regional, national and international artists.
Rossendale
Rossendale is a local government district with borough status. It is made up of a number of small former mill towns in Lancashire, England centered around the valley of the River Irwell in the industrial North West...
in North West England
North West England
North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East...
, through to the cities of Salford
City of Salford
The City of Salford is a city and metropolitan borough of Greater Manchester, England. It is named after its largest settlement, Salford, but covers a far larger area which includes the towns of Eccles, Swinton-Pendlebury, Walkden and Irlam which apart from Irlam each have a population of over...
and Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
. The River Irwell
River Irwell
The River Irwell is a long river which flows through the Irwell Valley in the counties of Lancashire and Greater Manchester in North West England. The river's source is at Irwell Springs on Deerplay Moor, approximately north of Bacup, in the parish of Cliviger, Lancashire...
runs through the valley, along with the River Croal
River Croal
The River Croal is a river located in Greater Manchester, England. It is a tributary of the River Irwell.Rising at the confluence of Middle Brook and Deane Church Brook, it flows eastwards through Bolton, collecting Gilnow Brook and the larger River Tonge at Darcy Lever...
.
Geology
Lancashire
Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston...
in the Upper Carboniferous period when deposits of mud and sand were laid down. These later became beds of shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
s and sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
s alternating with layers of gritstone
Gritstone
Gritstone or Grit is a hard, coarse-grained, siliceous sandstone. This term is especially applied to such sandstones that are quarried for building material. British gritstone was used for millstones to mill flour, to grind wood into pulp for paper and for grindstones to sharpen blades. "Grit" is...
. There are also beds of New Red Sandstone
New Red Sandstone
The New Red Sandstone is a chiefly British geological term for the beds of red sandstone and associated rocks laid down throughout the Permian to the beginning of the Triassic that underlie the Jurassic Lias; the term distinguishes it from the Old Red Sandstone which is largely Devonian in...
and Manchester Marl
Marl
Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...
s. The glaciers of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
epoch further shaped the landscape and then retreated, leaving behind deposits of sand, pebbles and boulder clay
Boulder clay
Boulder clay, in geology, is a deposit of clay, often full of boulders, which is formed in and beneath glaciers and ice-sheets wherever they are found, but is in a special sense the typical deposit of the Glacial Period in northern Europe and North America...
that formed the fluvioglacial ridges
Fluvioglacial landform
Fluvioglacial landforms are landforms molded by glacial meltwater. This discharge of glacial streams, both over the surface and beneath the ice sheet , is higher in the warmer summer months. As subglacial water often flows under pressure, it has a high velocity and is very turbulent...
of the Irwell Valley. Ashclough, a 5.8 hectare (14.3 acre) site which comprises the steep banks of the river between Prestolee and Little Lever, has been designated a Site of Special Scientific Interest (SSSI) because of its geological interest, primarily because it is the best site in the area displaying Ashcough Marine Band
Marine band (geology)
Marine band is a geological term for a bed of rock, commonly black or dark grey shale, containing an abundance of fossils of marine organisms. These strata represent episodes of flooding by seawater and are important in enabling the comparison or correlation of rock sequences in different localities....
and its associated strata. Ashclough is a site of national importance for interpreting the coal measure paleogeography of Great Britain.
Industrial history
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...
factories, mills and terraced hovels grew up along the river banks and the region became filled with cotton mills, coal mines, print works, bleach works, dye works, chemical works, paper works, in fact almost every kind of industry. Wet Earth Colliery
Wet Earth Colliery
The Wet Earth Colliery has a unique place in British coal mining history, apart from being one of the earliest pits in the country; it is the place where the engineer James Brindley made water run uphill...
was located in the valley at Clifton
Clifton, Greater Manchester
Clifton is a small town within the metropolitan borough of the City of Salford, in Greater Manchester, England. It lies in the Irwell Valley in the northern part of the City of Salford....
, along with a number of bleach and dye works including Lever Bank Bleach Works
Lever Bank Bleach Works
Lever Bank Bleach Works was a Bleach Works at Ladyshore, near Little Lever, Bolton. The works was owned by Thomas Ridgway & Sons. Former British Prime Minister Tony Blair would appear to be a direct descendent of this family.-Location:...
. A number of canals were built to transport goods through the valley, the largest of which is the Manchester Ship Canal
Manchester Ship Canal
The Manchester Ship Canal is a river navigation 36 miles long in the North West of England. Starting at the Mersey Estuary near Liverpool, it generally follows the original routes of the rivers Mersey and Irwell through the historic counties of Cheshire and Lancashire. Several sets of locks lift...
. Although many of the smaller canals were abandoned with the coming of the railways, isolated sections of the Manchester Bolton & Bury Canal still remain, and there are plans to restore it for leisure purposes.
The waste from the industries along the Irwell polluted the river so heavily that by the 1850 it was virtually devoid of wildlife. However, since the late 19th century many attempts have made to improve the quality of the water. In 1891 the Mersey and Irwell Joint Committee was formed. This body ordered local authorities to provide 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...
facilities and industrial concerns were told to use the best practical means of preventing pollution. In 1939 this body was superseded by the Lancashire Rivers Board, but wartime conditions brought about further deterioration of the river. In 1951 the Rivers (Prevention of Pollution) Act was passed and this board disappeared to be replaced by the Mersey River Board, which was replaced in turn by the Mersey and Weaver River Authority in 1965. In 1974 all the river authorities were merged into the Regional Water Authorities. Since then there has been a gradual improvement in water quality, and today wildlife is returning to the Irwell.
Local wildlife
Some industrial waste products, such as spoil from mining, or alkaloids from other industrial processes were disposed of locally. One caustic alkali, known as Leblanc process wasteLeblanc process
The Leblanc process was the industrial process for the production of soda ash used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: Production of sodium sulfate from sodium chloride, followed by reaction of the sodium sulfate with coal and calcium...
- a process once used in the manufacture of washing soda for textile bleaching - was dumped on at least two sites. One site at Nob End
Nob End
Nob End is the site of a former waste tip, and now a Site of Special Scientific Interest near Kearsley, Bolton, England.Standing at the confluence of the River Irwell and River Croal it was used around 1850-70 as a tip for alkaline waste from the production of sodium carbonate by the Leblanc...
, to the south of Bolton
Bolton
Bolton is a town in Greater Manchester, in the North West of England. Close to the West Pennine Moors, it is north west of the city of Manchester. Bolton is surrounded by several smaller towns and villages which together form the Metropolitan Borough of Bolton, of which Bolton is the...
, is now a SSI Site. Another such site is at Lower Hinds in Bury
Bury
Bury is a town in Greater Manchester, England. It lies on the River Irwell, east of Bolton, west-southwest of Rochdale, and north-northwest of the city of Manchester...
. The waste on both sites has, over the years, weathered-down to calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
which has provided an ideal environment for a number of calcareous plants, unique in what is predominately an area of acidic soil. These plants, along with non-indigenous
Indigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...
garden escapees such as Giant Hogweed
Giant Hogweed
Heracleum mantegazzianum, commonly known as giant hogweed, cartwheel-flower, wild parsnip, wild rhubarb, giant cow parsnip, or giant cow parsley, is a plant in the family Apiaceae. It typically grows to heights of , sometimes reaching...
and Himalayan Balsam
Himalayan Balsam
Impatiens glandulifera is a large annual plant native to the Himalayas. Via human introduction it is now extant across much of the Northern Hemisphere.-Etymology:...
, have added much variety to the flora of the valley.
The M60
M60 motorway
The M60 motorway, or Manchester Orbital, is an orbital motorway circling Greater Manchester, a metropolitan county in North West England. It passes through all Greater Manchester's metropolitan boroughs except for Wigan and Bolton...
passes through the valley and the bridge at junction 16 in at Clifton
Clifton, Greater Manchester
Clifton is a small town within the metropolitan borough of the City of Salford, in Greater Manchester, England. It lies in the Irwell Valley in the northern part of the City of Salford....
is used as a summer roost for over 100 Daubenton's bat
Daubenton's bat
Daubenton's Bat, Myotis daubentonii, is a Eurasian bat with quite short ears. It ranges from Britain to Japan and is considered to be increasing its numbers in many areas.The name commemorates the French naturalist Louis-Jean-Marie Daubenton....
s.
Irwell Sculpture Trail
The Irwell Sculpture TrailIrwell Sculpture Trail
The Irwell Sculpture Trail is the largest public art scheme in England, commissioning regional, national and international artists. The Trail includes 28 art pieces and follows a well established footpath stretching from Salford Quays through Bury into Rossendale and up to the Pennines above...
is one of the largest public art initiatives and the longest sculpture trail in the UK. The trail consists of a scenically varied, 30 miles (48.3 km) walking route based on the well-established Irwell Valley Trail stretching from Salford Quays
Salford Quays
Salford Quays is an area of Salford in Greater Manchester, England, near the end of the Manchester Ship Canal. Previously the site of Manchester Docks, it became one of the first and largest urban regeneration projects in the United Kingdom following the closure of the dockyards in...
to the moors above Bacup
Bacup
Bacup is a town within the Rossendale borough of Lancashire, England. It is located amongst the South Pennines, along Lancashire's eastern boundary with West Yorkshire. The town sits within a rural setting in the Forest of Rossendale, amongst the steep-sided upper-Irwell Valley, through which the...
. Since 1987 over 30 pieces of public art have been commissioned from regional, national and international artists.