summary

 
©Crown Copyright. All rights reserved. Hertfordshire County Council, LA 076678, 2001

LOCATION

The valley of the river Stort between its confluence with the Lea at Rye Meads and the southern edge of Bishop's Stortford.

 
©Crown Copyright. All rights reserved. Hertfordshire County Council, LA 076678, 2001

LANDSCAPE CHARACTER

An enclosed landscape, focused on the Stort Navigation with its locks and the more natural original river with its side loops. The landform is dominant, although the watercourses within it are relatively insignificant visually. The valley is predominantly rural with significant localised urban impact, varying with the degree to which industry is water related.

KEY CHARACTERISTICS

• river valley
• generally rural in character
• generally enclosed, lacking panoramic views, therefore focused on river
• variation in urban impact, dependent on whether industry is water-related or not

DISTINCTIVE FEATURES

• narrowboats on river
• relic water-related industrial, versus 20th-century non-related industry - graffiti etc
• tranquil watercourse, willow-fringed with locks

Farm track near Thorley church (M. Pole)

assessment

PHYSICAL INFLUENCES

Geology and soils. The flat valley bottom consists of stoneless mainly calcareous clayey soils over river alluvium (Thames series), with better drained loamy or clayey soils over chalky till on the lower slopes (Melford series).

Topography. Flat with gentle side slopes.

Degree of slope. The river has a fall of 1 in 750 between Bishop's Stortford and Rye Meads; the side slopes are between 1 in 100 and 1 in 500.

Altitude range. 32m to 55m along the river; 35m to 60m on the edge of the floodplain.

Hydrology. The river valley contains the original river Stort, the channelled Stort Navigation and tributaries such as Canons Brook. Parts of the original river channel are retained as 'side loops', as at Pishiobury. These support diverse ecological communities and are very rich in fish habitat.

Land cover and land use. This area is open farmland with wetlands and open water. The floodplain contains a mix of pasture and wetland vegetation, with some arable and the Navigation is a significant recreational amenity. The A414, set just above the floodplain on the northern slope, marks a break between this predominantly wetland vegetation and the arable slopes above. There has been significant mineral extraction within the river valley between Redericks and Hollingson Meads.

Vegetation and wildlife. This natural floodplain of extensive riverside grasslands and wetlands is a major ecological and landscape resource. Wetland species dominate, mainly willow and alder, the latter an uncommon species elsewhere in Hertfordshire. The river's flora includes rarities such as shining pondweed, arrowhead, yellow waterlilies and red and flat-stalked pondweeds. It supports large numbers of invertebrates, birds and mammals, including water vole, although the canalised main river is now severely degraded. It can be divided into three ecological sub-areas.

• The upper Stort contains high quality alluvial floodplain grasslands and calcareous fen communities, together with some alder/ash/willow woodland. The SSSIs at Sawbridgeworth Marsh and Thorley Flood Pound are very important for tall wash grassland, marsh, reedbed and permanent grassland, which provides habitat for snipe, water rail, wildfowl and ground-nesting birds.
• The section of river between Sawbridgeworth and Pye Corner is rather degraded by mineral extraction but still contains some old alluvial pasture, as at Hollingson Mead. The post-extraction gravel pits are developing local value for wildlife.
• The most important floodplain grasslands in Hertfordshire occur in the lower Stort at Hunsdon (SSSI) and Parndon Meads. Hunsdon Mead is managed on the ancient Lammas system of haymaking followed by winter grazing and supports an interesting and now uncommon flora, including green-winged orchid.

HISTORICAL AND CULTURAL INFLUENCES

The historic landscape pattern of this area is generally less disturbed than many others and has largely retained its natural landform and, in part, land use. Traditionally it was grazing marsh for the historic parkland estates on the south-facing slopes to the north. The Stort at this point was probably an important boundary in pre-history. Within and adjacent to the towns the river is heavily influenced by water-related industrial use, dating mainly from the 19th and 20th centuries.

Field pattern. The field pattern in this area is discontinuous and variable, relating to the traditional unenclosed pattern of grazing meadows but interrupted by mineral extraction.

Transport pattern. This is a busy area, with a dual carriageway (A414) on the northern edge of the lower reaches of the floodplain, a railway snaking to either side of it and the B181, A1184, B1004, A414 and other minor lanes crossing it.

Settlements and built form. Sawbridgeworth has an Edwardian character near the river, with 19th-century water-related industrial buildings, some now converted but retaining their scale. The maltings on both sides of the railway and along the Stort are the most extensive remaining range of pre-20th century maltings buildings in Hertfordshire. The southern edge of Bishop's Stortford, by contrast, has a 20th-century urban industrial character, with graffiti, industrial buildings and blank walls backing on to the Navigation. The estates associated with the middle reaches of the river are screened by vegetation (Wallbury) or topography (Hyde Hall) and lie outside the floodplain. (See also Area 81 for the parklands traditionally associated with the river, set on the northern slopes above the floodplain.)

Other built features: Locks - consistent black/white timber; bridges of 19th or 20th-century brick; lock houses; narrowboats.

OTHER SOURCES OF AREA-SPECIFIC INFORMATION

Biodiversity Action Plan for Hertfordshire, p.55.

English Nature Natural Area Profile; East Anglian Plain.

English Nature: SSSI notifications

evaluation

VISUAL AND SENSORY PERCEPTION

Views of the area from outside are concealed by intervening vegetation and buildings, not landform, while views within the area are limited by vegetation. The scale of landscape elements is small and there is a significant sense of enclosure. This is a coherent but discordant area, with noise from railway, road traffic and planes. Although it lies outside the urban envelope it is heavily influenced visually by it.

Rarity and distinctiveness. Some of the habitats within the SSSIs are now rare within the county or nationally. This is one of the more intact river valleys in the county.

VISUAL IMPACT

The impact of built development is high but localised in this area, with the urban/transport corridor and a telemast.

ACCESSIBILITY

Frequency/density of footpaths and towpaths - widespread in river valley, absent elsewhere.

Noted recreational land uses: walking, boating, fishing.

Frequency/density of waymarked routes - widespread.

Condition: fair; medium width; surface: gravelled but muddy.

Harcamlow Way along towpath and redundant railway

COMMUNITY VIEWS

This area is highly valued in its entirety for its distinctive and accessible landscape spanning the county boundary and with added value to out-of-county visitors (A).

LANDSCAPE RELATED DESIGNATIONS

SSSIs at Hunsdon Mead, Sawbridgeworth Marsh and Thorley Flood Pound, all for hay meadows and/or species-rich grassland.

Landscape Development Area.

The Stort Valley is recognised as a High Biodiversity Area (HBA) for its grasslands and wetlands.

 

CONDITION
Land cover change:	widespread
Age structure of tree cover:	mixed
Extent of semi-natural habitat survival:	widespread
Management of semi-natural habitat:	not obvious
Survival of cultural pattern:	declining
Impact of built development:	low
Impact of land-use change:	high
ROBUSTNESS
Impact of landform:	apparent
Impact of land cover:	prominent
Impact of historic pattern:	interrupted
Visibility from outside:	concealed
Sense of enclosure:	partial
Visual unity:	coherent
Distinctiveness/rarity:	rare

guidelines

STRATEGY AND GUIDELINES FOR MANAGING CHANGE: IMPROVE AND CONSERVE

• resist any development within or adjacent to the floodplain which could damage the ecological interest of the river
• encourage landowners to create buffer strips along the watercourse, to prevent ploughing right up to it and increase its ecological diversity and value as an ecological corridor
• encourage landowners to avoid the use of pesticides, herbicides and fertilizer near the river channel, in order to reduce loss of ecological diversity or eutrophication of the water
• encourage good practice in water and vegetation management, especially in the SSSIs
• encourage research into or consultation on grazing or vegetation management systems that do not conflict with flood defence requirements
• encourage the conservation and enhancement of riverside and other wetland habitats and the connection of wetlands along the river valley
• support the establishment of agri-environmental schemes within ESAs and CHAs (Countryside Heritage areas)
• ensure that mineral restoration proposals are adhered to and that they are designed to maximise nature conservation potential by contributing to the BAP objective of creating a 'necklace' of wetland habitats along the river valley
• resist any further proposals for mineral extraction in this area which might affect the local water table or permanently damage the local landscape character or high ecological value

Stort Valley lock at Twyfordbury (P. Shears)