River Poulter
Encyclopedia
The River Poulter is a tributary river of the River Idle
in Nottinghamshire
, England
, which rises near Scarcliffe in Derbyshire. It has supplied power for a number of mills along its route, most of which are now gone, although the mill ponds remain, and Cuckney mill building is still used as a primary school. The river has been dammed in order to create several lakes for the Dukeries estates of Welbeck Abbey
and Clumber House now the National Trust
property of Clumber Park
. The ornamental Gouldsmeadow Lake, Shrubbery Lake and Great Lake on the Welbeck estate are supplied by a tributary of the Poulter, while Carburton Forge Dam and Carburton Dam were built to power a forge and a mill. Clumber Lake, consisting of an upper and lower lake, which is spanned by a Grade II listed ornamental bridge, is part of the Clumber estate, and has suffered from subsidence.
After the parklands, the river flows eastwards past the village of Elkesley
, to join the River Idle just outside the village and close to the A1 road. The water quality of the river is good, with most indexes showing that the river is not far from being unpolluted. This enables it to support populations of fish, while the lakes provide significant habitat for large numbers of birds.
in Derbyshire
, close to the 520 feet (158.5 m) contour, and skirts around the southern edge of the village, before flowing in a north-easterly direction towards Nether Langwith. At the western edge of Langwith, it passes under the abandoned track of the railway which served Langwith Colliery, and then skirts around a modern fish farm. Owl Sick, a stream which rises at Owl Spring in Scarcliffe Park joins it near the village, and is itself joined by a stream which rises near Whaley Hall Farm, and flows in a south-easterly direction through Whaley and the Poulter Country Park. The Country Park was once the location of the waste tips from Langwith Colliery, which closed in 1978. By 1987, most of the site had been cleared, although one of the shafts was retained, as water continued to be pumped from the pit into the river, in order to keep the neighbouring Creswell mine drained. The waste tips were then landscaped in 1988 to form the country park.
The combined streams flow into the millpond which supplied Scarcliffe Mill, one of four mills known to have existed along this stretch. Records from Newstead Priory indicate that there was a mill here in 1432, and it was marked on maps of the late 19th century. By 1938 the last mill was no longer in use, and the building was demolished in the 1960s. The mill pond has become silted as a result of the poor condition of the dam and sluice, but could form a central part of a conservation area based on Apsley Grange, a large building on the opposite side of the road. Below the mill site, a small brick building once held pumps which were used to regulate the levels in the river, and to pump water to Langwith Colliery. Next, the river passes through one arch of an impressive two-arched viaduct which was built in the 1870s by the Midland Railway
. Although passenger traffic ceased in 1964, as part of the Beeching cuts
, the line remained open for goods trains, and became part of the Robin Hood Line
from Worksop
to Nottingham
in 1998. The other arch of the viaduct crosses the Whaley Thorns
road, under which the river flows immediately afterwards.
Passing through Langwith, the river splits into two channels, which pass either side of some houses and join up again at a green open space, at a location where a stone sign indicates that this was the site of a sheep dip in 1896. The next of a series of lakes, called "The Lake", and covering an area of 5.4 acres (2.2 ha), lies just to the east of Nether Langwith, beyond which the flow is augmented by the treated output from Langwith Sewage Treatment Works.
Langwith Mill House follows, marking the location of a cotton mill built in 1786. The building had four storeys and was one of the largest of its type in the region. Cotton milling stopped in 1848, and the mill found a new use as a corn mill from 1886. The building still stands, but is in a poor state of repair, and is on the Buildings at Risk Register. The mill house is a Grade II Listed building, and housed a restaurant for a time, but is now empty. Soon the river splits, the northern channel dropping down, while the southern artificial channel maintains its level as it supplied the first of two mills at Cuckney. There have been mills here for several centuries, for a cotton mill was destroyed by fire in 1792. A lake called Cuckney Dam, covering 8.2 acres (3.3 ha), provided the water to power its replacement, which ceased operation on 12 July 1844. After the machinery had been removed, the Duke of Portland turned the building into a National School. The mill building remains in use as part of Cuckney Primary School, and the weir and sluices have been retained. The drop in level of some 13 feet (4 m) between the mill pond and the river beyond has enabled the school to harness the river to generate electricity. The 7 kW crossflow turbine which generates a significant proportion of the energy used by the school, was funded by a grant from Powergen's Green Plan fund and a Clear Skies grant.
Flowing around the northern edge of Cuckney, the river reaches the second corn mill which was situated to the east of the village. The mill building has been demolished, but again the sluices and weir are still visible.
. The resident engineer for the project was Bland William Croker, who had assisted Clark with the construction of the Szechenyi suspension bridge in Budapest
. The western channel of the Poulter flows through a culvert into the Great Lake, while the lower eastern channel flows through a culvert into Carburton Forge Dam.
Beyond the lake, a weir with a track over it drops the level to Carburton Forge Dam, built to provide power for a forge. 10 acres (4 ha) of land were leased to John Wheeler of Worcester in 1695 by the Duke, on which he was empowered to build the forge, a dam pool and floodgates. Deeds held by the Nottinghamshire Archive Service record an agreement between Wheeler and the Duke to pay compensation annually as a result of the stream supplying the forge flooding the Duke's land. The forge flourished until the 1770s, with a writer called Pococke describing how "the pigs [of iron] were brought from Derbyshire to be melted into bars for use" in 1751. The fifth Duke later removed all traces of the forge. Beyond Carburton Forge Dam, another weir drops the level again to Carburton Dam. A "water corn mill, walke mill or fulling mill" is known to have been here in 1678, as it is mentioned in a lease agreement. The five Welbeck lakes cover a total area of 151 acres (61.1 ha). Again there are two channels below the lake, the main southern channel being at a lower level than the northern one. Both cross under the B6034 Worksop
to Ollerton
road, and leave the Welbeck estate.
Improvements to the lake were carried out in 1786 under the direction of Mr Marson, who was the estate manager. The 4th Duke of Newcastle built a cascade just below the bridge in 1823, and a new one in 1835, when the work was completed by Mr Grey. The Duke described the construction as "ingenious and well managed." There were problems in 1842, when the culvert feeding water from the lake to an engine which supplied water to the house was found to be clogged with fine tree roots. In the spring of 1845, 1846 and 1847, the Duke drained the lake in order to make it wider and to improve the banks, which he felt looked "neither natural nor handsome" in places.
Below the ornamental bridge, a weir drops the level of the lake by around 3.3 feet (1 m). In Victorian times, the park had two independent water supply systems, one supplying the house and its associated buildings, with the other supplying the farm and the village of Hodsock. Around 500 people lived on the estate at the time. The house supply came from an Artesian well, and was pumped to an underground reservoir, which held 60000 gallons (272.8 m³) of water, from where it travelled 0.5 mile (0.80467 km) by gravity. The difference in levels of the two parts of the lake was sufficient to power a Gilbert Gilkes and Gordon turbine, which drove the pump. The two systems became one in 1931, when a new treble ram vertical pump was installed, which was driven by the existing turbine. Pumping is now normally done by electric pumps, but the original machinery is still in place, and was for a number of years used to supply the park with water if there was a power cut.
More recently, the lake which covers some 79 acres (32 ha) has been affected by subsidence caused by coal mining below it, and UK Coal funded remedial work in the 1980s and in 2004. The lowering of the water level during this work revealed the charred remains of the Lincoln, a one-third scale naval frigate which the Duke bought in 1871, and which was destroyed by fire in the 1940s. The river leaves the lake by a weir and cascade near Hardwick village, beyond which there is a ford, and another weir a little further beyond that drops the level again, before the river passes under West Bridge on the A614 Worksop to Ollerton road. Most of the rest of the route is through woodland, in the middle of which a ford crosses the river near Crookford farm. Finally, the river is crossed by the B6387 Ollerton to Gamston road, and the A1 road near Gamston Airport, before joining the River Idle just downstream of the point where the River Maun
and River Meden
meet, and the Idle begins.
. Magnesian limestone is so named because if contains quantities of the mineral Dolomite
, which is rich in Magnesium
. Where this rock reaches the surface, springs often occur, and the Poulter starts at such a spring. Further to the east, the Magnesian Limestone is covered by another layer of porous rock called the Triassic
Sherwood Sandstone
aquifer, which is the major geological component of the area. Continuing eastwards, both are then covered by a layer of Mercia mudstone
. The groundwater levels in these aquifers affect whether they supply water to the river system, or take water from it, and levels are lower than they have historically been, as a result of the extraction of groundwater, particularly for public water supply, and by fracturing of the aquifers as a result of subsidence caused by deep coal mining.
Above Cuckney, where the Environment Agency have a gauging station which records flows in the river, the catchment for the River Poulter covers some 12 square miles (31.1 km²), which has an average annual rainfall of 24 inches (609.6 mm) (based on figures from 1961 to 1990). About a third of this finds its way into the river. Water quality is good. The Environment Agency use a six stage rating scale, from 'A' to 'F', called the General Quality Assessment, to classify rivers. 'A' on the GQA is the best quality of water, while 'F' is the poorest. Factors which affect the quality are levels of ammonia, levels of dissolved oxygen and the Biochemical oxygen demand
(BOD), which measures the amount of dissolved oxygen needed by organisms to break down organic matter in the water. These factors are generally worse when the water is discharged from sewage treatment processes, and tend to be worse in summer, when such discharges make up a greater proportion of the total flow in the river. The upper Poulter, above Welbeck Lake, is rated at 'B' on the GQA scale, despite the fact that the flows are augmented by the outflow from Langwith Sewage Treatment Works, which contributes around 1.2 Ml/d (megalitres per day) and by water from Langwith fish farm, which can be up to 0.9 Ml/d, but which is seasonal in nature.
The quality of the water remains good through the length of the river. Figures for the final section before it joins the River Idle show that the levels of ammonia and dissolved oxygen are those which would be expected in a natural ecosystem. Between 1991 and 2006, the BOD has been reduced by more than 50 percent, but there is still room for improvement. Levels of phosphates and nitrates, which are affected by agricultural activity, are quite high, but some improvements have occurred. Water quality is also measured by two biological indexes. These are NTAXA, which relates to the total number of invertebrate species found in samples of the water, and ASPT, (the Average Score Per Taxon), calculated from the numbers of specific invertebrates which are graded according to their sensitivity to organic pollution. The assessment for the years 2004 to 2006 rated the final section as grade A (very good) on the first index, and grade B (good) on the second. This indicates that the water is not far short from unpolluted.
. The size of the lakes results in the water moving much more slowly, and they support populations of cyprinids, pike
and eel
s, which thrive in water which is relatively static. The lower reaches of the river are used for spawning by fish which inhabit the River Idle.
The lakes provide habitat for large numbers of birds. Clumber lake is fringed by alder
, sallow
and ash trees, with some sedge
marsh. It was one of the first sites in the country used by gadwall
for breeding, and also has a population of goosander
in the winter. Hobbys
frequent the reed bed below Clumber Dam in August and September, where they hunt swallows and martins
. The upper lake is fringed by oak, yew, beech and scots pine trees, and provides habitat for willow tits
and woodpecker
s, with blackcap
s visiting in the summer. Mandarin duck
s also visit occasionally.
River Idle
The River Idle is a river in Nottinghamshire, England. Its source is the confluence of the River Maun and River Meden, near Markham Moor. From there, it flows north through Retford and Bawtry before entering the River Trent at Stockwith near Misterton...
in Nottinghamshire
Nottinghamshire
Nottinghamshire is a county in the East Midlands of England, bordering South Yorkshire to the north-west, Lincolnshire to the east, Leicestershire to the south, and Derbyshire to the 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...
, which rises near Scarcliffe in Derbyshire. It has supplied power for a number of mills along its route, most of which are now gone, although the mill ponds remain, and Cuckney mill building is still used as a primary school. The river has been dammed in order to create several lakes for the Dukeries estates of Welbeck Abbey
Welbeck Abbey
Welbeck Abbey near Clumber Park in North Nottinghamshire was the principal abbey of the Premonstratensian order in England and later the principal residence of the Dukes of Portland.-Monastic period:...
and Clumber House now the National Trust
National Trust for Places of Historic Interest or Natural Beauty
The National Trust for Places of Historic Interest or Natural Beauty, usually known as the National Trust, is a conservation organisation in England, Wales and Northern Ireland...
property of Clumber Park
Clumber Park
Clumber Park is a country park in the Dukeries near Worksop in Nottinghamshire, England. It was the seat of the Pelham-Clintons, Dukes of Newcastle.It is owned by the National Trust and open to the public.-History:...
. The ornamental Gouldsmeadow Lake, Shrubbery Lake and Great Lake on the Welbeck estate are supplied by a tributary of the Poulter, while Carburton Forge Dam and Carburton Dam were built to power a forge and a mill. Clumber Lake, consisting of an upper and lower lake, which is spanned by a Grade II listed ornamental bridge, is part of the Clumber estate, and has suffered from subsidence.
After the parklands, the river flows eastwards past the village of Elkesley
Elkesley
Elkesley is a village in Nottinghamshire, England. According to the 2001 census it had a population of 805. It is located 6 miles south of Retford.The parish church of St Giles was built c. 1300 in Decorated style, and was partially reconstructed in 1845...
, to join the River Idle just outside the village and close to the A1 road. The water quality of the river is good, with most indexes showing that the river is not far from being unpolluted. This enables it to support populations of fish, while the lakes provide significant habitat for large numbers of birds.
Course
The river Poulter rises at a spring to the south west of ScarcliffeScarcliffe
Scarcliffe is a small village and civil parish in the Bolsover district of Derbyshire, England. It is sometimes called Scarcliffe with Palterton...
in Derbyshire
Derbyshire
Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...
, close to the 520 feet (158.5 m) contour, and skirts around the southern edge of the village, before flowing in a north-easterly direction towards Nether Langwith. At the western edge of Langwith, it passes under the abandoned track of the railway which served Langwith Colliery, and then skirts around a modern fish farm. Owl Sick, a stream which rises at Owl Spring in Scarcliffe Park joins it near the village, and is itself joined by a stream which rises near Whaley Hall Farm, and flows in a south-easterly direction through Whaley and the Poulter Country Park. The Country Park was once the location of the waste tips from Langwith Colliery, which closed in 1978. By 1987, most of the site had been cleared, although one of the shafts was retained, as water continued to be pumped from the pit into the river, in order to keep the neighbouring Creswell mine drained. The waste tips were then landscaped in 1988 to form the country park.
The combined streams flow into the millpond which supplied Scarcliffe Mill, one of four mills known to have existed along this stretch. Records from Newstead Priory indicate that there was a mill here in 1432, and it was marked on maps of the late 19th century. By 1938 the last mill was no longer in use, and the building was demolished in the 1960s. The mill pond has become silted as a result of the poor condition of the dam and sluice, but could form a central part of a conservation area based on Apsley Grange, a large building on the opposite side of the road. Below the mill site, a small brick building once held pumps which were used to regulate the levels in the river, and to pump water to Langwith Colliery. Next, the river passes through one arch of an impressive two-arched viaduct which was built in the 1870s by the Midland Railway
Midland Railway
The Midland Railway was a railway company in the United Kingdom from 1844 to 1922, when it became part of the London, Midland and Scottish Railway....
. Although passenger traffic ceased in 1964, as part of the Beeching cuts
Beeching Axe
The Beeching Axe or the Beeching Cuts are informal names for the British Government's attempt in the 1960s to reduce the cost of running British Railways, the nationalised railway system in the United Kingdom. The name is that of the main author of The Reshaping of British Railways, Dr Richard...
, the line remained open for goods trains, and became part of the Robin Hood Line
Robin Hood Line
The Robin Hood Line is a railway line running from Nottingham to Worksop, Nottinghamshire. The stations between Shirebrook and Whitwell are in Derbyshire.The towns and villages served by the route are listed below:*Nottingham*Bulwell*Hucknall...
from Worksop
Worksop
Worksop is the largest town in the Bassetlaw district of Nottinghamshire, England on the River Ryton at the northern edge of Sherwood Forest. It is about east-south-east of the City of Sheffield and its population is estimated to be 39,800...
to Nottingham
Nottingham
Nottingham is a city and unitary authority in the East Midlands of England. It is located in the ceremonial county of Nottinghamshire and represents one of eight members of the English Core Cities Group...
in 1998. The other arch of the viaduct crosses the Whaley Thorns
Whaley Thorns
Whaley Thorns is a former colliery village in Bolsover , Derbyshire, close to the Nottinghamshire border. Whaley Thorns lies just north of Nether Langwith and Langwith, 1.5 miles south-east of Creswell, and west of Cuckney....
road, under which the river flows immediately afterwards.
Passing through Langwith, the river splits into two channels, which pass either side of some houses and join up again at a green open space, at a location where a stone sign indicates that this was the site of a sheep dip in 1896. The next of a series of lakes, called "The Lake", and covering an area of 5.4 acres (2.2 ha), lies just to the east of Nether Langwith, beyond which the flow is augmented by the treated output from Langwith Sewage Treatment Works.
Langwith Mill House follows, marking the location of a cotton mill built in 1786. The building had four storeys and was one of the largest of its type in the region. Cotton milling stopped in 1848, and the mill found a new use as a corn mill from 1886. The building still stands, but is in a poor state of repair, and is on the Buildings at Risk Register. The mill house is a Grade II Listed building, and housed a restaurant for a time, but is now empty. Soon the river splits, the northern channel dropping down, while the southern artificial channel maintains its level as it supplied the first of two mills at Cuckney. There have been mills here for several centuries, for a cotton mill was destroyed by fire in 1792. A lake called Cuckney Dam, covering 8.2 acres (3.3 ha), provided the water to power its replacement, which ceased operation on 12 July 1844. After the machinery had been removed, the Duke of Portland turned the building into a National School. The mill building remains in use as part of Cuckney Primary School, and the weir and sluices have been retained. The drop in level of some 13 feet (4 m) between the mill pond and the river beyond has enabled the school to harness the river to generate electricity. The 7 kW crossflow turbine which generates a significant proportion of the energy used by the school, was funded by a grant from Powergen's Green Plan fund and a Clear Skies grant.
Flowing around the northern edge of Cuckney, the river reaches the second corn mill which was situated to the east of the village. The mill building has been demolished, but again the sluices and weir are still visible.
Welbeck Lakes
Beyond the mill site, there are two channels, the western one at the level of the mill pond, and the eastern one at a lower level. Both channels head towards the first of the ornamental lakes which are supplied by the river. At this point, the river has dropped some 360 feet (109.7 m) from its source. Welbeck Great Lake is part of the Welbeck estate, which was owned by the Dukes of Portland, and is now owned by the Bentinck family. The Millwood Brook flows into Gouldsmeadow Lake and through Shrubbery Lake, before joining the Great Lake. In the 1760s, the Duke employed the architect and civil engineer Robert Mylne to construct a three arched bridge, which had to be both functional and beautiful. Mylne experienced problems with the piers moving, which resulted in the central 90 feet (27.4 m) arch collapsing in February 1768, after which Mylne was sacked. In the 1840s, the Fifth Duke, who went on to build an underground ballroom and tunnels on the estate, employed the engineer William Tierney Clark to construct a suspension bridgeSuspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...
. The resident engineer for the project was Bland William Croker, who had assisted Clark with the construction of the Szechenyi suspension bridge in Budapest
Budapest
Budapest is the capital of Hungary. As the largest city of Hungary, it is the country's principal political, cultural, commercial, industrial, and transportation centre. In 2011, Budapest had 1,733,685 inhabitants, down from its 1989 peak of 2,113,645 due to suburbanization. The Budapest Commuter...
. The western channel of the Poulter flows through a culvert into the Great Lake, while the lower eastern channel flows through a culvert into Carburton Forge Dam.
Beyond the lake, a weir with a track over it drops the level to Carburton Forge Dam, built to provide power for a forge. 10 acres (4 ha) of land were leased to John Wheeler of Worcester in 1695 by the Duke, on which he was empowered to build the forge, a dam pool and floodgates. Deeds held by the Nottinghamshire Archive Service record an agreement between Wheeler and the Duke to pay compensation annually as a result of the stream supplying the forge flooding the Duke's land. The forge flourished until the 1770s, with a writer called Pococke describing how "the pigs [of iron] were brought from Derbyshire to be melted into bars for use" in 1751. The fifth Duke later removed all traces of the forge. Beyond Carburton Forge Dam, another weir drops the level again to Carburton Dam. A "water corn mill, walke mill or fulling mill" is known to have been here in 1678, as it is mentioned in a lease agreement. The five Welbeck lakes cover a total area of 151 acres (61.1 ha). Again there are two channels below the lake, the main southern channel being at a lower level than the northern one. Both cross under the B6034 Worksop
Worksop
Worksop is the largest town in the Bassetlaw district of Nottinghamshire, England on the River Ryton at the northern edge of Sherwood Forest. It is about east-south-east of the City of Sheffield and its population is estimated to be 39,800...
to Ollerton
Ollerton
Ollerton is a town in Nottinghamshire, England, on the edge of Sherwood Forest in the area known as the Dukeries. It forms part of the civil parish of Ollerton and Boughton....
road, and leave the Welbeck estate.
Clumber Lake
Both then pass under the road which serves the tiny hamlet of Carburton, with the upper channel, which is called Flood Dyke, ending in a field. From here there is a sluice and the water flows through a culvert into an open section where there is another sluice, and a second culvert to rejoin the lower channel. The upper sluice is marked "sluices" on the 1898 map, and also fed a large fish pond to the east of the channel. The fish pond was disused by 1919, when it was marked as swampy ground. The lower channel flows past a building marked "Wheel House (pumping station)" in 1898. It then continues under Carburton bridge to supply Clumber Lake, which was part of the Clumber estate of the Dukes of Newcastle, but has been owned by the National Trust since 1945. The Clumber estate was described in the 18th century as "A black heath full of rabbits, having a narrow river running through it, with a small boggy close or two." This changed in 1772, when the Second Duke of Newcastle started construction of Clumber Lake, to complement his new house. A dam was built at the bottom end of the estate, the river bed was excavated to create a wide expanse of water, and an ornamental bridge was erected at the western end. The project took 15 years to complete, and cost £6,612. The bridge, which consists of three unequal arches with balustrading along the top, was designed by Stephen Wright, and is some 230 feet (70.1 m) long. It is a Grade II* listed structure.Improvements to the lake were carried out in 1786 under the direction of Mr Marson, who was the estate manager. The 4th Duke of Newcastle built a cascade just below the bridge in 1823, and a new one in 1835, when the work was completed by Mr Grey. The Duke described the construction as "ingenious and well managed." There were problems in 1842, when the culvert feeding water from the lake to an engine which supplied water to the house was found to be clogged with fine tree roots. In the spring of 1845, 1846 and 1847, the Duke drained the lake in order to make it wider and to improve the banks, which he felt looked "neither natural nor handsome" in places.
Below the ornamental bridge, a weir drops the level of the lake by around 3.3 feet (1 m). In Victorian times, the park had two independent water supply systems, one supplying the house and its associated buildings, with the other supplying the farm and the village of Hodsock. Around 500 people lived on the estate at the time. The house supply came from an Artesian well, and was pumped to an underground reservoir, which held 60000 gallons (272.8 m³) of water, from where it travelled 0.5 mile (0.80467 km) by gravity. The difference in levels of the two parts of the lake was sufficient to power a Gilbert Gilkes and Gordon turbine, which drove the pump. The two systems became one in 1931, when a new treble ram vertical pump was installed, which was driven by the existing turbine. Pumping is now normally done by electric pumps, but the original machinery is still in place, and was for a number of years used to supply the park with water if there was a power cut.
More recently, the lake which covers some 79 acres (32 ha) has been affected by subsidence caused by coal mining below it, and UK Coal funded remedial work in the 1980s and in 2004. The lowering of the water level during this work revealed the charred remains of the Lincoln, a one-third scale naval frigate which the Duke bought in 1871, and which was destroyed by fire in the 1940s. The river leaves the lake by a weir and cascade near Hardwick village, beyond which there is a ford, and another weir a little further beyond that drops the level again, before the river passes under West Bridge on the A614 Worksop to Ollerton road. Most of the rest of the route is through woodland, in the middle of which a ford crosses the river near Crookford farm. Finally, the river is crossed by the B6387 Ollerton to Gamston road, and the A1 road near Gamston Airport, before joining the River Idle just downstream of the point where the River Maun
River Maun
The River Maun is a river in Nottinghamshire, England. Its source lies in Kirkby-in-Ashfield, and from there it flows north east through Mansfield , Edwinstowe and Ollerton, these being the heart of the Sherwood Forest area...
and River Meden
River Meden
The River Meden is a river in Nottinghamshire, England. Its source lies just north of Huthwaite, near the Derbyshire border, and from there it flows north east through Pleasley and Warsop before merging temporarily with the River Maun near Bothamsall...
meet, and the Idle begins.
Hydrology
The source of the river Poulter is in a region where the underlying geology is an extensive water-bearing porous rock structure called the Magnesian Limestone aquiferAquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
. Magnesian limestone is so named because if contains quantities of the mineral Dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
, which is rich in Magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
. Where this rock reaches the surface, springs often occur, and the Poulter starts at such a spring. Further to the east, the Magnesian Limestone is covered by another layer of porous rock called the 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...
Sherwood 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,...
aquifer, which is the major geological component of the area. Continuing eastwards, both are then covered by a layer of Mercia mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
. The groundwater levels in these aquifers affect whether they supply water to the river system, or take water from it, and levels are lower than they have historically been, as a result of the extraction of groundwater, particularly for public water supply, and by fracturing of the aquifers as a result of subsidence caused by deep coal mining.
Above Cuckney, where the Environment Agency have a gauging station which records flows in the river, the catchment for the River Poulter covers some 12 square miles (31.1 km²), which has an average annual rainfall of 24 inches (609.6 mm) (based on figures from 1961 to 1990). About a third of this finds its way into the river. Water quality is good. The Environment Agency use a six stage rating scale, from 'A' to 'F', called the General Quality Assessment, to classify rivers. 'A' on the GQA is the best quality of water, while 'F' is the poorest. Factors which affect the quality are levels of ammonia, levels of dissolved oxygen and the Biochemical oxygen demand
Biochemical oxygen demand
Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for...
(BOD), which measures the amount of dissolved oxygen needed by organisms to break down organic matter in the water. These factors are generally worse when the water is discharged from sewage treatment processes, and tend to be worse in summer, when such discharges make up a greater proportion of the total flow in the river. The upper Poulter, above Welbeck Lake, is rated at 'B' on the GQA scale, despite the fact that the flows are augmented by the outflow from Langwith Sewage Treatment Works, which contributes around 1.2 Ml/d (megalitres per day) and by water from Langwith fish farm, which can be up to 0.9 Ml/d, but which is seasonal in nature.
The quality of the water remains good through the length of the river. Figures for the final section before it joins the River Idle show that the levels of ammonia and dissolved oxygen are those which would be expected in a natural ecosystem. Between 1991 and 2006, the BOD has been reduced by more than 50 percent, but there is still room for improvement. Levels of phosphates and nitrates, which are affected by agricultural activity, are quite high, but some improvements have occurred. Water quality is also measured by two biological indexes. These are NTAXA, which relates to the total number of invertebrate species found in samples of the water, and ASPT, (the Average Score Per Taxon), calculated from the numbers of specific invertebrates which are graded according to their sensitivity to organic pollution. The assessment for the years 2004 to 2006 rated the final section as grade A (very good) on the first index, and grade B (good) on the second. This indicates that the water is not far short from unpolluted.
Flora and Fauna
The upper reaches of the river are diverse, both in terms of their physical nature and their ecological importance. They include an area of wet woodland, which provides a rich habitat for many species. The quality of the water in the river is sufficient to support various fish species. The river above Welbeck Lake provides habitat for a significant population of wild brown troutBrown trout
The brown trout and the sea trout are fish of the same species....
. The size of the lakes results in the water moving much more slowly, and they support populations of cyprinids, pike
Esox
Esox is a genus of freshwater fish, the only living genus in the family Esocidae — the esocids which were endemic to North America, Europe and Eurasia during the Paleogene through present.The type species is E. lucius, the northern pike...
and eel
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
s, which thrive in water which is relatively static. The lower reaches of the river are used for spawning by fish which inhabit the River Idle.
The lakes provide habitat for large numbers of birds. Clumber lake is fringed by alder
Alder
Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...
, sallow
Willow
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
and ash trees, with some sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
marsh. It was one of the first sites in the country used by gadwall
Gadwall
The Gadwall is a common and widespread duck of the family Anatidae.- Description :The Gadwall is 46–56 cm long with a 78–90 cm wingspan. The male is slightly larger than the female, weighing on average 990 g against her 850 g...
for breeding, and also has a population of goosander
Common Merganser
The Common Merganser or Goosander Mergus merganser is a large duck, of rivers and lakes of forested areas of Europe, northern and central Asia, and North America. It eats fish and nests in holes in trees...
in the winter. Hobbys
Hobby (bird)
A hobby is a fairly small, very swift falcon with long, narrow wings. There are four birds called hobby, and some others which, although termed falcon, are very similar. All specialise in being superb aerialists...
frequent the reed bed below Clumber Dam in August and September, where they hunt swallows and martins
Swallow
The swallows and martins are a group of passerine birds in the family Hirundinidae which are characterised by their adaptation to aerial feeding...
. The upper lake is fringed by oak, yew, beech and scots pine trees, and provides habitat for willow tits
Willow Tit
The Willow Tit is a passerine bird in the tit family Paridae. It is a widespread and common resident breeder throughout temperate and subarctic Europe and northern Asia. It is more of a conifer specialist than the closely related Marsh Tit, which explains it breeding much further north...
and woodpecker
Woodpecker
Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....
s, with blackcap
Blackcap
The Blackcap is a common and widespread sylviid warbler which breeds throughout temperate Europe, western Asia and northwestern Africa, and winters from northwestern Europe south to tropical Africa...
s visiting in the summer. Mandarin duck
Mandarin Duck
The Mandarin Duck , or just Mandarin, is a medium-sized perching duck, closely related to the North American Wood Duck. It is 41–49 cm long with a 65–75 cm wingspan.-Description:...
s also visit occasionally.