Lead Agencies: Public Sector Environment
Agency
Voluntary Sector RSPB
Rivers and streams are exceptionally varied and
dynamic habitats forming invaluable wildlife habitat. Interactions between
topography, geology and rainfall influence their biological and physical
diversity.
Rivers and streams in Northamptonshire vary
from the fast flowing streams rising in the southern and western uplands of the
county, to the wide, slow-moving lowland River Nene.
These watercourses form, either in their own
right or in association with other habitats, a vital nature conservation and
wildlife resource for the county.
Habitats included in this plan:
Rivers
Streams
Associated Plans:
Open Standing
Water
2.1 Definitions
Of the major rivers that flow through
Northamptonshire, the Tove, Great Ouse, Avon and Nene have their sources in the
southern and western upland areas of the county. Whilst the Great Ouse and Tove
flow east into Bedfordshire and the Avon flows west into Warwickshire, the Nene
flows from its source near Daventry in the south west, to Wansford in the north
east, before crossing the county boundary into Peterborough. The River Welland
forms part of Northamptonshire’s northern boundary.
Northamptonshire’s southern and western uplands
constitute the north-eastern extent of the Cotswold limestone range. The many
small tributaries of the upper Nene are mostly spring fed, flowing through a
mixed arable and pastoral landscape. The streams are mostly small, winding,
narrow channels with bed substrates ranging from solid limestone to gravels and
muddy silts.
Tributaries drain into the Nene along its
entire length through Northamptonshire, the major tributaries being the
Brampton Nene, River Ise, Harper’s Brook and Willow Brook. These streams and small rivers vary
considerably in size, volume and water quality. Some drain agricultural land
whilst others have almost entirely urban catchments. Similarly there is
variation in the riparian habitat associated with each of these watercourses;
some are highly engineered drainage channels, whilst others are open and
exposed in the agricultural landscape, denuded of bank-side trees and shrubs.
Some lengths of stream remain secluded and
relatively untouched, allowing trees, shrubs and thick vegetation cover to
develop, providing corridors along which flora and fauna can move and disperse,
as well as supporting a diverse invertebrate fauna.
This section
of the River Ise is the best example of a lowland river on clay in the county
and has a variety of semi-natural features now uncommon in areas of intensive
agriculture.
From around Northampton the River Nene develops
into a typical lowland river, being wide and slow moving. Between Northampton and Thrapston the river
remains in close association with the gravel workings, both current and
disused. From Thrapston downstream to Wansford the river retains its lowland
character remaining in association with flood meadows, wet grazing pasture and
some arable fields.
The water level between Northampton and the
Dog-in- a Doublet Sluice, Cambridgeshire, is maintained artificially to enable
navigation, flowing through a landscape which is broad and open. Some stretches
are bordered by woodland, such as downstream of Oundle, and along many
stretches mature willow pollards line the riverbank.
Most of the rivers and streams in
Northamptonshire have been engineered or managed to some extent and this is
particularly true of stretches of watercourses running through or downstream of
urban areas.
The River Nene is eutrophic; receiving treated
sewage effluent discharges from the Whilton, Billing, Broadholme and Corby
sewage treatment works. Agricultural run-off also contributes to the levels of
nitrates and phosphates in the river. This nutrient rich water supports high
plant productivity, especially along the fringes. Routine weed cutting is
undertaken along the length of the river for flood defence purposes and, along
the section between Northampton and Wansford, to ensure the river remains
navigable.
Water is abstracted from the Nene at Duston and
Wansford for drinking and at various locations for crop irrigation.
2.2 National Status
Rivers and streams are of immense wildlife
value. This value is derived from the morphology, shape, size, gradient and
base rock material of the channel. These characteristics help to support a wide
diversity of flora and fauna, many of which are only associated with running
water and some which are unique to specific river types.
Rivers and streams are, in essence, wildlife
arteries in the landscape, providing continuous corridors along which species
of flora and fauna can migrate. In some areas, such as urban and intensively
farmed landscapes, watercourses may provide the only opportunity for species to
move from one area to another.
2.3
Local Status
The Environment Agency is responsible for the
management of 542km of the River Nene and its tributaries in Northamptonshire. Virtually
all the streams and rivers in the county have been managed to some extent to
aid drainage of farmland, reduce the frequency of flooding and to maintain
navigation.
Despite this, there remain many stretches of
quiet and secluded watercourse throughout the county. 92 County Wildlife Sites
have been designated for riparian sites and several SSSIs that include
stretches of rivers and riverside habitats have been notified in
Northamptonshire.
3
CHARACTERISTIC SPECIES
3.1 National Priority
Species
Otter (Lutra lutra), Water vole (Arvicola terrestris), White-clawed crayfish (Austropotamobius
pallipes) and Compressed river mussel (Pseudanodonta complanata).
3.2 Local Priority Species
Black poplar (Populus nigra betulifolia),
Beautiful demoiselle (Calopteryx virgo), Lister’s river snail (Viviparus
contectus) and White-legged
damselfly (Platycnemis pennipes)
See Appendix 1 Rivers and
Wetlands Priority Species for full lists
·
Eutrophication is a major threat to the water
quality and conservation status of watercourses in Northamptonshire. Elevated
phosphate concentrations in particular, caused primarily by treated sewage
effluent discharges can, under suitable conditions, stimulate excessive growth
of algae and duckweed. In combination with low river flows and prolonged warm
summers, there is the possibility that algal blooms could occur in some of the
major watercourses in the county. Not only can these blooms be directly toxic,
but once developed they increase turbidity and reduce light penetration into
the water, adversely affecting the entire ecosystem. It is not uncommon for
algal blooms to strip dissolved oxygen from the water leading to major fish
kills.
·
Elevated nitrate and phosphate levels can also
promote excessive growth of fringe vegetation, leading to an increased need for
maintenance works, which have the potential to further damage the river channel
and its associated flora.
·
Other pollutants also affect water quality
throughout the county. The long-term impact of persistent pesticides, heavy
metals and oestrogenic substances present in historic and, to a lesser extent,
in current discharges are not fully understood. They may have acute or chronic
toxic effects or cause abnormalities such as sterility in certain species.
Accidental or
deliberate pollution incidents periodically occur, with varying consequences
depending upon the material discharged and the time of year.
·
Abstraction for public water supply and
irrigation continues to adversely affect flows in the county’s major rivers.
Low flows exacerbate the problems of eutrophication, as outlined above.
·
Land drainage and management, particularly in
the upper reaches of streams and rivers, has led to the interception of springs
and the drainage of wet flushes and mires, reducing the flow of groundwater
into rivers and streams. Drainage has also provided the opportunity to extend
arable cultivation to the edge of riverbanks, with the loss of the buffering
effect of headlands and margins. This has resulted in the loss of marginal,
bank-side and instream habitat; increased siltation of gravel beds that are
rich in invertebrates and used as spawning grounds by fish; increased seepage
of herbicides and pesticides into the watercourse and a continued demand for
regular maintenance works.
·
Alien and invasive species remain a threat if
not managed appropriately. Species such as Himalayan balsam and Japanese
knotweed are highly invasive, able to spread and colonise new areas quickly,
choking and crowding out native vegetation.
·
Navigational and flood defence structures and
impoundments such as water mills, on-line lakes, weirs and locks can prevent fish
migration.
·
Fishing and fish farming can be a source of
conflict with nature conservation interests. This may result from the
establishment of fish farms and the associated changes in flow patterns in the
adjacent watercourses or the generation of sediment and polluting loads.
Escapes of non-native crayfish and fish into watercourses have the potential to
cause considerable damage to populations of native species. There is also the
potential for direct conflicts between anglers and species such as Cormorant,
Heron, Otter or Pike, and for disturbance of rivers and their banks during the
bird breeding season.
·
Climate change may affect the status of the
county’s rivers and streams in the long term, though the probable local affects
are still poorly understood.
·
The Environment Agency currently protects and
maintains water resources and quality through statutory licensing.
·
Much of the engineering work undertaken on the
county’s watercourses occurred prior to 1991 (when the Water Act provided new
powers and duties to protect the water environment) and was not always carried
out sympathetically in environmental terms.
Whilst improvement
targets are largely aimed towards long-term water quality objectives, some
river restoration has taken place and all engineering works are now screened
for potential environmental impacts.
·
The Environment Agency has undertaken a range
of habitat enhancement initiatives on the Nene, Welland and a number of their
tributaries. This work has included bank reprofiling, pool and riffle
reinstatements, creation of fish refuges and washlands, meander reinstatements
and tree planting schemes.
·
The Environment Agency holds data from River
Corridor and Habitat surveys, fishery and invertebrate survey data, water
quality and abstraction data and some species survey data for otters, water
voles, waders, native crayfish and rare aquatic plants. This data predominantly
relate to stretches termed as “Main River” which are those lengths maintained
by the Environment Agency for flood defence. Regular flow monitoring is also
undertaken by the Agency.
·
Anglian Water Services Ltd. (AWS) holds
abstraction data for its reservoirs. English Nature holds data relating to
riverine SSSIs and Northamptonshire Wildlife Trust holds historical data, site
records and maintains a biological record database.
6. RIVERS AND STREAMS OBJECTIVES AND ACTIONS
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|
OBJECTIVE
|
ACTION |
LEAD AGENCY |
PARTNERS |
TARGETS |
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6.1 |
Policy and Legislation |
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Objective One: Encourage sympathetic management of all
watercourses for wildlife |
Monitor and enforce appropriate water quality
standards. Produce strategies to reduce the impact of abstraction (Catchment
Abstraction Management Strategies – “CAMS”) and discharges (under the EU
Water Framework Directive) |
Environment Agency |
Anglian Water, Farming and Wildlife Advisory
Group |
First stage of CAMS completed by 2006. All surface and ground waters to have “good”
ecological quality by 2016. |
|
|
Objective Two: Ensure that BAP species and their habitats
are given an appropriate level of protection in local plans |
Include habitat and species protection
policies in local plans and/or supplementary guidance |
Local Authorities |
Wildlife Trust, Environment Agency, English
Nature |
By 2003 |
|
6.2 |
Site Safeguard and Management |
|
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Objective Three: Establish best practice for riparian
management with landowners and managers |
Promote good practice e.g. establishment of buffer
strips along riverbanks, through agri-environment schemes and the provision
of advice |
Department for Environment, Food and Rural
Affairs |
Farming and Wildlife Advisory Group,
Environment Agency |
20% of main rivers buffered by 2006 |
|
|
Objective Four: Encourage a catchment wide approach to
identifying sites suitable for conservation initiatives and for the targeting
of improved management regimes |
Design and implement habitat improvement
programmes on the most suitable stretches of river. Develop whole river
restoration schemes |
Environment Agency |
Department for Environment, Food and Rural
Affairs, Farming and Wildlife Advisory Group , English Nature , Local
Authorities, Landowners |
5 habitat improvement plans implemented by
2006 |
|
|
Objective Five: Stop and reduce the spread of alien weed
species on river and stream banks |
Develop and implement a collaborative
strategy to identify affected areas, and to eradicate the problem species
where feasible |
Environment Agency |
BAP Partners |
Strategy developed by 2002. |
|
6.3 |
Research and Monitoring |
|
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Objective Six: Establish comprehensive baseline data sets
from which current riverine ecological quality can be determined. Develop
monitoring programmes to determine changes in habitat quality and species
distributions |
Collate and interpret current available data
on the county’s rivers. Identify gaps in existing knowledge and implement surveys
as appropriate. Use this baseline to initiate regular monitoring of riverine
ecology |
Environment Agency |
Wildlife Trust, English Nature |
Monitoring programme already established.
Monitoring programmes under the Water Framework Directive to commence in 2007 |
|
6.4 |
Advisory
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Objective Seven: Influence riparian management plans, policies
and decisions to protect and enhance watercourses |
Use and apply survey and monitoring data to ensure
appropriate management strategies are adopted |
Environment Agency |
BAP Partners |
Advisory Strategy in place by 2002 |
|
|
Objective Eight:
Encourage better practical management skills
for both maintenance crews and staff involved in decision-making processes
(e.g. planners; development control and decision support staff) |
Establish training courses to enable workers
to gain new, or refresh existing skills and knowledge |
Environment Agency |
Wildlife Trust, Farming and Wildlife Advisory
Group Local Authorities |
Training programmes established by 2003 |
|
6.5 |
Communication and Publicity |
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Objective Nine: Ensure opportunities are taken to raise
awareness of the importance of rivers and streams for nature conservation,
amenity and aesthetic value |
Produce and promote information on the
county’s rivers to encourage conservation and sensitive river management.
Provide representatives and interpretation at local shows and events. Provide
on-site interpretation |
Wildlife Trust |
Environment Agency, RSPB, English Nature,
Anglian Water, Local Authorities |
Collaborative plan in place by 2003 |
|
|
Objective Ten: Publicise the progress made in delivering
this Action Plan in a BAP Annual Report |
|
|
BAP Partners |
Annual |