summary

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

LOCATION

Valley of the river Rib from its confluence with the Lea at Bengeo northwards to Wadesmill and Thundridge.

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

LANDSCAPE CHARACTER

Flat valley bottom with extensive wetland vegetation. Extensive mineral extraction on both valley slopes.

KEY CHARACTERISTICS

river valley with significant wetland vegetation , within which the river is an insignificant feature

pastoral

influenced by extensive mineral workings on valley slopes

Thundridge and Wadesmill settlements face each other at a major bridging point

DISTINCTIVE FEATURES

• willow and alder on valley floor

Lower Rib valley north of Bengeo (HCC Landscape Unit)

assessment

PHYSICAL INFLUENCES

Geology and soils. Stoneless clayey soils, in places calcareous, over river alluvium.

Topography. Flat valley floor.

Degree of slope. There is a drop of 5m between Wadesmill/Thundridge and Bengeo, giving a fall of 1 in 1100, which is very slight.

Altitude range. 40 to 45m.

Hydrology. The Rib is a small river which suffered from low flow during 1995-98. It exhibits strong human influence in its lower reaches, where numerous closely spaced weirs impound and interrupt its flow. This has a detrimental ecological impact but reduces the need for fish rescues in drought periods.

Land cover and land use. Much of the river valley floor is in intensive agricultural production, usually arable, although there is a little pasture, mainly at the southern end around Bengeo. There are also areas of wetland vegetation, particularly adjacent to former or existing mineral workings on the slopes above, and a large fishing lake south of Westmill Farm.

Vegetation and wildlife. Willow and alder. There are few hedges within the floodplain, reflecting its former use as grazing pasture. Most of the river valley grasslands have been ploughed up or improved. The river itself has some remnant alder stands of some ecological value, but it is badly degraded in places.

HISTORICAL AND CULTURAL INFLUENCES

Historically this area would have been grazing marsh, but this has largely been superseded by arable cultivation and wetland vegetation, which merges with the plantations screening the mineral extraction sites on the lower valley slopes.

Field pattern. Regular to geometric medium scale on the west bank; lacking elsewhere.

Transport pattern. There are no roads within the river valley, save for the A602 and the A10(T) crossings at Wadesmill/Thundridge. The B158 runs well above the floodplain on the western slopes.

Settlements and built form. There are no settlements within the river valley except the lower part of Wadesmill on the north bank.

evaluation

VISUAL AND SENSORY PERCEPTION

At the southern end the river appears hemmed in by urban development and estate woodland. The landscape has a medium-scale generally organic appearance, the small river meandering across the floodplain with water meadows and wetland vegetation to either side. It is tranquil except at the crossing points and the extreme southern end.

Rarity and distinctiveness. This area demonstrates the impact of human intervention on natural resources.

VISUAL IMPACT

The main impact on this area is the extensive range of mineral workings, both active and restored, on the lower valley slopes, especially on the eastern bank. The golf course attached to Hanbury Park is a poor example of restoration; south of Westmill Farm a large man-made lake is used for fishing.

ACCESSIBILITY

There is one very short stretch of public footpath at the extreme southern end of this area - none elsewhere.

COMMUNITY VIEWS

This area is regarded as of some value for its distinctiveness, perhaps more so the stretch between Tonwell and Wadesmill (D).

 

CONDITION
Land cover change:	widespread
Age structure of tree cover:	mixed
Extent of semi-natural habitat survival:	fragmented
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:	prominent
Impact of land cover:	prominent
Impact of historic pattern:	relic
Visibility from outside:	concealed
Sense of enclosure:	contained
Visual unity:	incoherent
Distinctiveness/rarity:	unusual

guidelines

STRATEGY AND GUIDELINES FOR MANAGING CHANGE: IMPROVE AND CONSERVE

• protect remaining river valley habitats of nature conservation interest by establishing buffer zones against herbicide, pesticide and fertilizer run-off and maintain them as wildlife refuges. Where possible, link them in to habitats within the wider landscape via woodlands and hedges
• do not create new hedges within the river valley. Replacement hedges should only be established along historic field boundaries
• promote de-intensification of agricultural practices within the river valley
• encourage a reversion from arable to pasture and mixed farming, ensuring that grasslands are managed to maximise their nature conservation potential
• resist the targeting of redundant or derelict pasture for development
• resist development that could lower the water table within the river valley and affect wetland habitats
• all golf courses should respect local landform and use only locally indigenous trees and shrubs, unless they are reflecting historic parkland influence
• promote the re-introduction of permanent pasture and flooding regimes as normal agricultural practices, to increase landscape and habitat diversity
• encourage the establishment of wetland species along watercourses, such as black poplar and willow
• encourage an extension of the local footpath network along the river valley, with small, low-key car parks at access points

Active quarry on slopes of river valley north of Bengeo (P. Shears)