National Character Area 111

Northern Thames Basin - Analysis: Landscape Attributes & Opportunities

Analysis supporting Statements of Environmental Opportunity

The following analysis section focuses on the landscape attributes and opportunities for this NCA.

Further analysis on ecosytem services for this NCA is contained in the Analysis: Ecosytem Services section.

Landscape attributes

A diverse mixture of large urban areas, smaller urban settlements, as well as remote villages and hamlets surrounded by agricultural lands, grasslands/heathlands and woodlands.

  • The CPRE Intrusion Map (2007) found the area to be 32 per cent urban, 55 per cent disturbed and only 13 per cent classified as undisturbed due to the network of towns, roads and other infrastructure that criss-cross this area.
  • Since the 1960s the area of disturbance and urbanisation has expanded out from London, Colchester and other towns to encase most of the Hertfordshire area and South Essexand has extended to most of the Essex heathlands and wooded hills and ridges.
  • Remoteness is still achievable in parks, woods and fields throughout the area. A recent addition to this is the development and management of the community woodlands, Watling and Thames Chase.
  • Levels of tranquillity are still high in the more rural areas of the Northern Thames Basin.

Underlying Chalk aquifer. London Clay gives rise to heavy acidic soils often prone to flooding in winter and cracking in summer. The river valleys are fringed by well-drained fertile brown soils, produced from alluvial deposits which in Essex creates a more open ‘heathy’ landscape.

  • The chalk layer that underlies the London Clay in the west of the NCA is a main source of recharge for the principal aquifer supplying London.
  • London Clay has traditionally been used as pastoral lands due to its poor quality soil but with developments in farming such as use of fertilisers and improved ploughing methods and a drive for self-sufficiency after the Second World War caused this area to develop into arable farming in the 1950s.
  • Almost 60 per cent of agricultural land is Grades 1 to 3 with the majority of the grade 1 and 2 land in the ‘heathy’ areas of Essex.
  • From 2000 to 2009, the dominant agricultural land use was cereal production (43 per cent) and grass and uncropped land (29 per cent) as fits in with the soil types in this area. The areas of cereal grown decreased by 6 per cent and grass and uncropped land decreased by 7 per cent. These have probably been replaced by oilseed, stock feed and other arable crops as these increased during the same period.

A varied pattern of woodlands across the area including considerable ancient semi-natural woodland.

  • Woodlands help to maintain the distinction between urban and rural areas by filtering views and helping to visually contain the extent of individual settlements.
  • Many areas of larger woodland offer key recreational resources.
  • Overall woodland covers 6 per cent of the area (15,488ha.) which understates the influence of woodland within this NCA and its very high recreational value. Reflecting this, the NCA includes the areas of two Community Forests – Watling Chase (Hertfordshire) and Thames Chase (east of Ilford and Romford and south of Brentwood) which now form part of the Green Grid of the Thames Gateway.
  • The pattern of woodlands is varied across the area. The eastern part in Hertfordshire is heavily wooded both on the plateauxand in the river valleys including the Broxbourne Wood complexas are the Bagshot hills and ridges of Essex.
  • Other areas within the London Clay lowlands and Essexheathlands are more open in character although woodland is found in areas of now derelict plotlands, in the remnant shelterbelts around Colchester, on the well- wooded hills around Laindon, Hockley and Rayleigh and in the river valleys of the Essexheathlands.
  • Nearly half of the remaining woodlands are ancient semi-natural (2.4 per cent of the area) and a further 0.7 per cent is made up of planted ancient woodland sites (PAWS) including past lime woods within Hertfordshire. The ancient semi-natural woodland is a distinctive feature of much of the area, dominated by hornbeam coppice with oak standards, as in the Broxbourne woods complexof Hertfordshire. These ancient woodlands are of high nature conservation value and include the Epping Forest SPA (1,700 ha) and the Wormley-Hoddesdon Park Woods (336 ha). Priority habitats include 2,500 ha of wet woodland and 1,900 ha of lowland mixed broadleaf woodland.
  • Woodlands in the area include Epping Forest and Wormley-Hoddesdon Park Wood both of which are Special Areas of Conservation (SAC) and also Broxbourne Wood which is a National Nature Reserve (NNR).
  • They are a haven for wildlife in a heavily urban and agricultural environment, allowing a more diverse species population to continue in this area, for example the BAP priority species, the dormouse, has good populations in the woodlands of the south Essexarea and along the Essexhills and ridges.

Significant areas of remnant wood pasture and pollarded veteran trees, including Hainault Forest, Thorndon Country Park, Wormley and Hoddesdon Great Park, and Epping Forest, comprising a distinctive ecological habitat and recreational resource.

  • Wood pasture was once a dominant feature of this NCA providing the interlinking fabric between the wooded and open commons and areas of ancient woodland in the Essexwooded hills and ridges and the Essex heathlands. It was a characteristic of the Royal Hunting forests of the area as still preserved within Epping and Hainault forests within the Essexwooded hills and ridges. This is a particularly important habitat and landscape asset having suffered a dramatic reduction in area over the last century as sites have been lost to development, agricultural intensification and recreational development – especially as golf courses.
  • The ancient pollards provide local oases of species richness for lichens. This is especially where old forest species have survived in undisturbed pockets of woodland (with the surrounding woodland buffering the ancient pollards from the damaging effects of air pollution) and where old exposed trees are set in undrained, unploughed valley parkland. Management by pollarding over the centuries has produced boles of increasing age and decay, which provide the habitats vital to deadwood feeding invertebrates as well as bats.

Field patterns are very varied across the basin reflecting historical patterns.

  • Informal patterns of enclosure from the 18th century or earlier reflect the medieval colonisation of the heaths and woodlands and are common in the Hertfordshire plateauxand river valleys and Essexwooded hills.
  • Within the London Clay lowlands regular Roman planned enclosures are a subtle but important feature to the east of the area. In the Essexheathlands 18th and 19th century enclosures of heathlands and commons followed by extensive 20th century field enlargement is dominant.
  • These features represent the long history of human settlement in the area and it gives an historical character to the area that can be promoted and maintained in future developments.
  • In many areas a scattered appearance of settlements creates open views of the landscape and gives a sense of place.
  • The tradition of enclosures gave rise to the use of hedgerows as boundaries. Although many are now gone due to the change in recent years to larger field farming they can still create important habitats for many species and connect fragmented habitats to provide connectivity throughout the landscape.

A series of river valleys draining south to the Thames and east to the North Sea/Thames Estuary, including the Ver, Colne and Lea in Hertfordshire, and the Roding, Wid and Chelmer, Roach, Crouch and Blackwater in Essex.

  • River valleys are a prominent and distinctive feature; cutting into the clay lowlands they often intimate pastoral character contrasting with the more open arable land surrounding.
  • Many contain remnant flood plain wetlands and new wetlands created both through gravel extraction as in the Lea Valley and through the construction of reservoirs.
  • Much reduced in extent, the NCA still includes some 5,100 ha of wet woodland, 2,500 ha of coastal and flood plain grazing marsh and 300 ha of fen. SPAs associated with wetlands include Abberton Reservoir, the gravel pits and reservoirs of the Lea Valley, and parts of the estuaries of the Crouch and Roach, Blackwater and Essex Colne.
  • Many river systems have been adapted to cope with urban development affecting their ecological status so future work through the Water Framework Directive will have the challenge of improving these sections of river.
  • Recent work to improve the chemical and biological status of the rivers has resulted in their improvement and work is continuing to maintain and improve their status further.
  • This area includes 4 Ramsar sites which provide habitats for over wintering birds as well as various important plant and invertebrate species. Some of the species found in these sites are internationally important and British Red Data Book species.

A rich heritage of geological, archaeological and historical evidence chronicling past landscape and climate change, human settlement and activities within this landscape since the prehistoric period, that have all helped to shape the landscape of today.

  • Characteristics of the landscape today links to historical settlement patterns such as the scattered arrangement of villages and hamlets surrounded by dispersed farming settlements.
  • After the Anglian glaciations the area – particularly the Thames and its tributaries – was occupied at times by early humans, with flint artefacts found at many sites throughout the London Basin.
  • Field boundaries are dominated by informal enclosure patterns of the 18th century surrounded by thorn hedgerows which have become patchy over time due to enlargement of the fields after the Second World War and lack of management.
  • Interspersed throughout the landscape is evidence of Roman occupation including the origins of towns such as Colchester (the largest Roman city in Britain), St. Albans and Welwyn and roads such as the A12 as well as the East Coast mainline railway.
  • During the 16th, 17th and 18th centuries the growth of London’s importance had an influence which resulted in
    the development of market towns and also rural estates and country houses created by London merchants. This particularly impacted on the Hertfordshire area.

A mixture of priority habitats, the most abundant being woodlands (wet and lowland mixed deciduous), and coastal and flood plain grazing marshes.

  • Wet woodlands are the largest priority habitat found in this area with the majority present in south Essexand Hertfordshire. A large area of this woodland type is found in the Waltham Abbey/Loughton area of Essex.
  • The lowland deciduous woodlands are the second largest habitat and are found most abundantly in the Essex heathland area and in Hertfordshire.
  • Coastal and flood plain grazing marshes are the most abundant habitat after woodlands and they are found evenly distributed over the whole area except for London.
  • Habitats found within the London area are small patches of reed beds, lowland meadows and fens. On the very edge of this area are also wet woods and lowland heaths.
  • As the greatest amounts of habitats are made up of those reliant on water, how water is used and preserved in this area could have a huge impact.
  • These habitats are now rare as a consequence of agricultural land drainage, gravel extraction and landfill and
    river valleys providing the routes of transport infrastructure and power lines (much evident in the Lea Valley).

A significant complex of designed parklands, especially in Hertfordshire, with their mature parkland trees.

  • Within Hertfordshire, the 16th, 17th and 18th centuries saw the growth of rural estates and country houses for London merchants. The landscape parklands surrounding these houses are a particular feature of the area, such as the grounds of Brockett Hall near Welwyn and Hatfield House. These extend the character and habitat of remnant wood pasture.

A number of distinctive landscapes captured in the arts through the centuries.

  • Landscape settings for the arts include Epping Forest and Dedham Vale (on the Stour in the very north-east of this NCA), the setting for Constable’s painting the Hay Wain.
  • The Hertfordshire countryside was also the setting to E. M. Forster’s book, Howards End.
    Important Tertiary and Quaternary deposits, the latter demonstrating the close inter-relationship between geological history and human development.

  • Exposures of Tertiary sedimentary deposits reveal fossil remains at a number of SSSI within the NCA. The fluvial Quaternary sediments deposited by the Thames river system before the Anglian glaciation occur predominantly along the northern edge of the London Basin, while sediments deposited after the Anglian glaciation are found along the flood plains of the current rivers, including the Thames and Lea.
  • The youngest sediments are sands and gravels deposited by the Thames in its current location since the last ice age. These deposits also preserve a record of past landscapes and climates.
  • Archaeological artefacts found in these Quaternary deposits assist in deciphering our human history with evidence of some of the earliest human occupation.

Providing comparatively undeveloped countryside on the very edge of London, accentuated by its well-wooded and prominent hills and ridges, particularly on the Hertfordshire plateaux and the Essex wooded hills.

  • The comparatively undeveloped nature of the countryside is felt by residents to be one of the over-riding characteristics of this disparate landscape.
  • It is both a product of the Metropolitan Green Belt that has restricted the coalescence of settlements over much of the NCA and the medieval origins of parts of the landscape that, in the main, has created a relatively enclosed and intimate ‘bosky’ landscape with development off the higher plateaux. This characteristic tends to contain the visual influence of development in parts (but not all) of the NCA.The NCA provides easily accessible countryside both to the large and growing population of the NCA and that of north London, serving a population in excess of 4 million.

An area of mixed farming, with arable land predominating on the Hertfordshire plateaux, parts of the London Clay lowlands and the Essex heathlands, and grassland often characteristic of the river valleys, while orchards and horticulture are found on the lighter sandy soils of past

  • Differences in agriculture reflect the underlying soils with arable, up until the post Second World War years, associated with the lighter soils of the Hertfordshire plateauxand the Essexheathlands. With agricultural improvements and under-drainage, arable production has spread into the London Clay lowlands and some river valleys, although since 2000 there has been a slight increase in the areas under grassland and a slight fall in the areas under arable and horticulture.
  • Orchards and horticulture are found on the lighter sandy soils of past heathland north of Colchester in the Essex
    heathlands and in parts of the Essexwooded hills and ridges.

A varied field pattern reflecting historical evolution with hedgerows and hedgerow trees once a common feature contributing considerably to the enclosed and wooded character of the Hertfordshire plateaux and river valleys and the Essex wooded hills and ridges, while some strong hedgerow patterns remain in the London Clay lowlands and the Essex heathlands.

  • Roman grid field divisions are still evident on the Dengie Peninsula while medieval and later informal enclosures are characteristic of the Hertfordshire plateauxand river valleys and parts of the Essexwooded hills and ridges, and river valleys elsewhere.
  • Parliamentary enclosures are more characteristic of the Essexheathlands and London Clay lowlands.
  • Across much of the area hedgerows were characteristically thick with a large population of hedgerow elms that have been lost in the last 40 years to Dutch elm disease, significantly opening up the landscape.

Landscape opportunities

  • Safeguard existing green infrastructure and enhance and create new green infrastructure including: open spaces (parks, woodlands, informal open spaces, nature reserves, lakes, accessible countryside, the natural elements of historic sites, built conservation areas and civic spaces); linkages (river corridors and canals, pathways, cycle routes and greenways); networks of ‘urban green’ (the collective resource of private gardens, allotments, pocket parks, street trees, verges and green roofs).
  • Plan for significant new green infrastructure provision in association with areas of new urban development to expand and link the existing ecological networks. Manage future developments so that green infrastructure incorporates accessible greenspace, sustainable urban drainage systems and new habitats, forming corridors linking urban areas with more open areas of countryside.
  • Plan to restore, manage and expand habitats on former industrial sites to provide opportunities to enhance biodiversity and the landscape, while ensuring that the legacy of the industrial heritage remains legible within the landscape. These developing habitats form an important component of the landscape character and are of wildlife and recreational value.
  • Increase tree cover and street trees and conserve the ‘Manchester poplar’ to improve the urban environment, moderate the climate in urban areas, and enhance the urban and historic landscape.
  • Manage, expand and connect pockets of habitats in urban areas, conserving their wildlife and historical interest as well as providing opportunities for people to learn about and enjoy the natural environment and enabling communities to volunteer to monitor and manage its future.
  • Plan to link and connect potentially fragmented habitats into a more cohesive network and enable movement of species.
  • Retain and manage open countryside and semi-natural habitats, for example, in the river valleys.
  • Conserve and enhance networks of rivers and canals for wildlife, to enhance local landscapes and to provide multiple benefits such as walking or cycling routes, and other multi-user access provision.
  • Safeguard wetlands and create new wetland habitats.
  • Manage existing woodlands and plan to extend woodland planting in appropriate locations, particularly in urban and former industrial areas and where opportunities exist to expand or link existing woodland areas. Ensure that new woodlands are located to enhance the local landscape character in terms of typical scale, type and location, avoiding impacting on other sites of biodiversity value or features of historic or geological interest. Provide access and recreational opportunities where appropriate.
  • Restore and manage field boundaries in the remaining agricultural areas. Bring hedgerows into improved management to restore historic field patterns, provide habitats and corridors for wildlife and enhance local landscapes.
  • Protect and enhance the remaining pockets of farmland, including permanent grassland, and support farming to develop ecological networks and enhance the character of the landscape.
  • Manage the existing access network of public rights of way, cycle routes and towpaths, and plan new links, particularly within urban areas and to the wider countryside.
  • Ensure that people have access to greenspace and to green routes, close to where they live and work.