River Misbourne
Encyclopedia
The River Misbourne rises in a field on the outskirts of Great Missenden
, Buckinghamshire
, and flows down the Misbourne valley to join the River Colne
just north of where the latter is crossed by the A40
Western Avenue.
It passes through Little Missenden
, Old Amersham
, Chalfont St Giles
and Chalfont St Peter
, and under the Chiltern railway line
and the M25
on its way down the valley. It has for some years suffered from reduced or no flow because of abstraction for supply from the aquifer
s feeding it. The low flow caused its course to be neglected or partially obstructed, so when the water companies undertook remedial measures which restored the flow there were episodes of flooding in Chalfont St Peter and Chalfont St Giles village centres. Later work has restored the integrity of the course, and no floods have occurred since then.
The river is a 'perch' stream, flowing over a bed of impermeable material on top of a porous substrate. This state is only quasi-stable, since in periods of low rainfall the water table drops below the level of the impermeable layer. If ground works are then carried out which damage this layer, the river can sink into the porous substrate and disappear.
The upper part of the river was dry for over 3 years starting in November 2003 but re-appeared in February 2007 following several months of above-average rainfall which raised the water table.
Great Missenden
Great Missenden is a large village in the Misbourne Valley in the Chiltern Hills in Buckinghamshire, England, situated between the towns of Amersham and Wendover. It closely adjoins the villages of Little Missenden and Prestwood. The narrow High Street is bypassed by the main A413 London to...
, Buckinghamshire
Buckinghamshire
Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....
, and flows down the Misbourne valley to join the River Colne
River Colne, Hertfordshire
The Colne is a river in England which is a tributary of the River Thames. It flows mainly through Hertfordshire and forms the boundary between the South Bucks district of Buckinghamshire and the London Borough of Hillingdon...
just north of where the latter is crossed by the A40
A40 road
The A40 is a major trunk road connecting London to Fishguard, Wales and officially called The London to Fishguard Trunk Road in all legal documents and Acts...
Western Avenue.
It passes through Little Missenden
Little Missenden
Little Missenden is a village in Buckinghamshire, England. It is in the Chiltern Hills, about three miles south east of Great Missenden, three miles west of Amersham.The toponym "Missenden" is derived from the Old English for "valley where marsh plants grow"...
, Old Amersham
Amersham
Amersham is a market town and civil parish within Chiltern district in Buckinghamshire, England, 27 miles north west of London, in the Chiltern Hills. It is part of the London commuter belt....
, Chalfont St Giles
Chalfont St Giles
Chalfont St Giles is a village and civil parish within Chiltern district in south east Buckinghamshire, England, on the edge of the Chilterns, 25 miles from London, and near Seer Green, Jordans, Chalfont St Peter, Little Chalfont and Amersham....
and Chalfont St Peter
Chalfont St Peter
Chalfont St Peter is a village and civil parish in Chiltern district in south-east Buckinghamshire, England. It is in a group of villages called The Chalfonts which also includes Chalfont St Giles and Little Chalfont. The villages lie between High Wycombe and Rickmansworth. Chalfont St Peter is...
, and under the Chiltern railway line
Chiltern Main Line
The Chiltern Main Line is an inter-urban, regional and commuter railway, part of the British railway system. It links London and Birmingham on a 112-mile route via the towns of High Wycombe, Banbury, and Leamington Spa...
and the M25
M25 motorway
The M25 motorway, or London Orbital, is a orbital motorway that almost encircles Greater London, England, in the United Kingdom. The motorway was first mooted early in the 20th century. A few sections, based on the now abandoned London Ringways plan, were constructed in the early 1970s and it ...
on its way down the valley. It has for some years suffered from reduced or no flow because of abstraction for supply from the aquifer
Aquifer
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...
s feeding it. The low flow caused its course to be neglected or partially obstructed, so when the water companies undertook remedial measures which restored the flow there were episodes of flooding in Chalfont St Peter and Chalfont St Giles village centres. Later work has restored the integrity of the course, and no floods have occurred since then.
The river is a 'perch' stream, flowing over a bed of impermeable material on top of a porous substrate. This state is only quasi-stable, since in periods of low rainfall the water table drops below the level of the impermeable layer. If ground works are then carried out which damage this layer, the river can sink into the porous substrate and disappear.
The upper part of the river was dry for over 3 years starting in November 2003 but re-appeared in February 2007 following several months of above-average rainfall which raised the water table.