National Character Area 129

Thames Basin Heaths - Key Facts & Data

Landscape and nature conservation designations section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

North Wessex Downs Area of Outstanding Natural Beauty (AONB) designation applies to 20,604 ha or 17 per cent of the total NCA area (Natural England, 2011).

Designated nature conservation sites

The NCA includes the following statutory nature conservation designations (Natural England, Special Protection Areas; Special Area of Conservation; Ramsars; National Nature Reserves; Sites of Special Scientific Interest and Local Nature Reserves, 2021):

Please note: (i) Designated areas may overlap (ii) all figures are cut to Mean High Water Line, designations that span coastal/marine areas below this line will not be included.

Condition of designated sites
All designated sites within England are covered by Sites of Scientific Interest (SSSI) units. The condition to these SSSI units within the NCA are as follows (Natural England, Sites of Special Scientific Interest Units, 2021; 2023):



Landscape and nature conservation designations map for NCA129

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Landform, geology and soils section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Elevation

Elevation ranges from 8m above sea level to 296m with a mean of 76 m. Low elevations are found in the east where the land slopes down into the London Basin towards the sea and also along the major river valleys (Natural England, 2010).

Landform and process

Landform is dominated by flat or gently sloping plateaux with numerous watercourses incising broad or sometimes steep-sided river valleys. At the eastern end around Woking the land falls into the depressed area of the London Basin. Other low lying areas are flood plains of the River Kennet and lower reaches of the Loddon and Blackwater. The River Kennet has a wide flood plain with a lowland river and vale character. The Hampshire Downs chalk scarp lies at the western edge, associated with springline watercourses. Waterbodies resulting from sand and gravel extraction are strung along the River Blackwater and also River Kennet west of Newbury (London Basin Natural Area profile, Thames Basin Heaths Countryside Character Area description).

Bedrock geology

In the west, Chalk emerges from beneath younger bedrock and rises up into the neighbouring NCAs as outcrops of the Chilterns, Berkshire Downs and Hampshire Downs. Chalk is unique, being deposited under specific conditions in tropical seas during the Cretaceous period.

During periods of submersion and uplift, sands and mudstones were laid down over the Chalk and contain fossils reflecting shallow marine, freshwater and terrestrial situations. Reading Beds were deposited first by ancient river systems, followed by London Clay which Now formed under shallow semi-tropical seas and is exposed in the Kennet Valley. Succeeding Bagshot, Barton and Bracklesham Beds were laid down on a large coastal plain. These beds create the height of the plateaux, with the youngest bedrock being restricted to the east and concentrated around Chobham. Tertiary earth movements which created the fold of the London Basin are also illustrated in the exposures at Duncroft Farm Pit south of Newbury (London Basin Natural Area profile, Thames Basin Heaths Countryside Character Area description).

Superficial deposits

Quaternary sands and gravels were deposited across the area by braided river systems flowing from ice sheets in the north. Deposits cap the plateaux, with the oldest (pre-dating the Anglian) in the west, and have been shaped into terraces by watercourses down-cutting valleys into the plateaux, for example Kennet, Blackwater and Wey. Alluvial deposits are also found following watercourses (London Basin Natural Area profile, Thames Basin Heaths Countryside Character Area description).

Designated geological sites

The NCA includes the following geological sites (Natural England, Geological and Mixed Sites of Special Scientific Interest, 2021):

wdt_ID NCA_ID NAME NCAAreaHa Interest type Area (ha) 2021 Percent of NCA (2021) Count
2361NORTH NORTHUMBERLAND COASTAL PLAIN37,669.6Geological6.80.01
2371NORTH NORTHUMBERLAND COASTAL PLAIN37,669.6Mixed1,029.52.75
2382NORTHUMBERLAND SANDSTONE HILLS72,694.6Geological45.40.14
2393CHEVIOT FRINGE51,591.3Geological17.10.02
2404CHEVIOTS36,487.9Geological165.00.52
2414CHEVIOTS36,487.9Mixed3,488.99.61
2425BORDER MOORS AND FORESTS127,155.9Geological85.70.18
2435BORDER MOORS AND FORESTS127,155.9Mixed35.80.01
2446SOLWAY BASIN98,350.4Geological7.20.02
2456SOLWAY BASIN98,350.4Mixed5,569.25.74

Soils and Agriculture Classification

Soils are largely nutrient-poor acidic soils with a mainly light or slowly permeable character favouring forestry and pasture over arable. Arable crops indicate localised areas of more fertile loamy soils (London Basin Natural Area profile, Thames Basin Heaths Countryside Character Area description).

The main grades of agricultural land in the NCA are broken down as follows (as a proportion of total land area) (Natural England, Provisional Agricultural Land Classification, 2019):


Landform, geology and soils map for NCA129

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Key waterbodies and catchments section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Major rivers/canals

The following major rivers/canals (by length) have been identified in this NCA (Natural England, data informing the 2014 National Character Area Profiles, 2010):

wdt_ID REF_CODE NAME_1 Name Length (km) SumOfShape_Length
11NORTH NORTHUMBERLAND COASTAL PLAINRiver Aln7.67,587.2
21NORTH NORTHUMBERLAND COASTAL PLAINRiver Coquet5.55,516.0
31NORTH NORTHUMBERLAND COASTAL PLAINWhiteadder Water2.92,904.9
410NORTH PENNINESBlack Burn11.911,853.4
510NORTH PENNINESCroglin Water10.010,042.3
610NORTH PENNINESCrowdundle Beck4.34,337.4
710NORTH PENNINESDevil's Water20.520,464.6
810NORTH PENNINESHarwood Beck9.79,740.2
910NORTH PENNINESRiver Allen4.94,889.0
1010NORTH PENNINESRiver Derwent15.315,268.4

Please note: other significant rivers (by volume) may also occur. Tidal stretches of rivers are not included, which may include some major rivers.

All watercourses feed the River Thames via the Kennet, Loddon, Wey or Mole. Main rivers flow on London Clay except the Pang and the reach of the Kennet upstream of Newbury which flow over chalk.

Numerous minor watercourses drain off the plateaux in small gullies to enter river valleys below including the Kennet, Hart and Blackwater.

The Basingstoke Canal links Basingstoke to the River Thames via the Wey Navigation. The Kennet and Avon Canal links the Thames at Newbury to the Avon at Bath and Now constructed alongside the River Kennet in this area.

Several waterbodies arising from mineral extraction are strung along the Blackwater and Kennet valleys.

Water quality

Nitrate Vulnerable Zones (NVZs) are areas designated as being at risk from agricultural nitrate pollution. These can impact surface water (waterbodies and waterways located above ground) and groundwater (water bodies and waterways located below ground).

Waterbodies such as lakes can also be designated as “eutrophic waters” if the enrichment of the waterbody by nitrate pollution causes accelerated growth of algae, impacting the quality of the water and the balance of organisms within it.

The following NVZs are located within the NCA (Environment Agency, Nitrate Vulnerable Zones Designations, 2021):

Water framework directive

River basin management plans cover river basin districts and describe the challenges that threaten the water environment and how these challenges can be managed and funded. The plans include the classification of water quality of surface waters and ground waters.



Click on the Water Framework Directive layers on the below map to view the corresponding river names.

Key waterbodies and catchments map for NCA129

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Trees and woodlands section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Total woodland cover

Ancient woodland is any area that has been wooded continuously since at least 1600 AD. National Forest Inventory (NFI) woodland includes all forests and woodlands (0.5 hectares and over). The total woodland cover within the NCA is as follows (Forestry Commission, National Forest Inventory, 2020; 2023; Natural England, Ancient Woodland, 2021; 2024; this does not consider Natural England’s ‘Ancient Woodland – Revised (England) – Completed Counties’ data as this is being updated in tranches and no full dataset is yet available):

Distribution and size of woodland and trees in the landscape

Woodland is a major element of landscape character, covering more than a quarter of the area as a result of the dominant acid, sandy soils making woodland a more favoured land-use choice over agriculture. Very extensive woodland cover is found in the east, with a concentration of large, predominantly conifer plantation areas between Bracknell and Aldershot. In the extensively settled east, suburban housing, roads and golf courses are surrounded by woodland. In the west, a smaller but still significant plantation area is found around Mortimer. Here the dominant distribution pattern is an irregular patchwork of small woodlands. Woodland is associated with all the Ministry of Defence landholdings. Ancient woodland sites are limited in the east because much of the woodland is plantation or secondary woodland on commons or former heathlands. In the west, there are many ancient sites with the larger examples being near Hermitage and Pamber Heath (both replanted). Beyond the woodlands, trees are common in hedgerows and in limited areas of wood pasture and parkland. Forestry plantations are mainly coniferous, usually Scots pine and some Christmas trees. Bracken is common, with heather in open areas. Secondary and semi-natural woodland is mainly oak with birch and, in the east, rhododendron is frequent. The few valley bottom and plateaux gulley woodlands in the west are dominated by alder (London Basin Natural Area profile, Thames Basin Heaths Countryside Character Area description).

Woodland types

A statistical breakdown of the area and type of woodland found across the NCA is detailed below (Forestry Commission, National Forest Inventory, 2020; 2023):

Area and proportion of ancient woodland and planted ancient woodland sites (PAWS) within the NCA (Natural England, Ancient Woodland, 2021; 2024):


Trees and woodlands map for NCA129

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Boundary features and patterns

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Boundary features

Boundaries are minimal where woodlands and heathlands dominate on the plateaux. Unenclosed landscape is unusual in south-east England. Hedgerows dominate and, near the Hampshire Downs in the west, also hedgebanks. Drainage dykes and other channels are found in the Kennet Valley. Post-and-rail fencing is common in horse-grazed fields. Hedgerows typically consist of oak, holly, ash or hazel. Bracken and gorse are present in some boundaries. Hedgerow trees are common (Thames Basin Heaths Countryside Character Area description; Countryside Quality Counts, 2003).

Field patterns

Field pattern away from large urban centres is ancient with small, irregular fields and small farms. Some may originate from the original woodland clearance or ‘assarting’. Medium-sized fields with slightly curving boundaries are associated with arable crops. Enclosure of common land by phased encroachment is sometimes evident.

Regular small- to medium-sized fields are associated with straight roads and areas of recent development. Small fields, often used as paddocks, are associated with urban fringes.

Heathland areas brought into cultivation, often by large estates in the 19th century, have regular fields bounded by hawthorn hedgerows (Thames Basin Heaths Countryside Character Area description; Countryside Quality Counts, 2003).

Agriculture section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

The following tables provide the most recently available statistics from Defra on agriculture within the NCA.

Farm type

The following farm types are located within this NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Farm size

The following table outlines the sizes of farms within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Farm ownership

The following table outlines the ownership of farms within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Land use

The following table outlines the types of agricultural land use within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Livestock numbers

The following livestock are farmed within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Farm labour

The following table outlines the types of farm labour within the NCA (Defra, Structure of the agricultural industry in England and the UK at June, 2025):

Please note: (i) Some of the Census data are estimated by Defra so may not present a precise assessment of agriculture within this area (ii) Data refers to commercial holdings only (iii) Data includes land outside of the NCA where it belongs to holdings whose centre point is recorded as being within the NCA.



Note that the below map only shows agri-environment scheme coverage, and not other schemes.

Agriculture map for NCA129

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Key habitats and species section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Habitat distribution/coverage

Recognised semi-natural habitat covers more than 11 per cent of the NCA (excluding watercourses) and is associated as much with the most densely developed areas in the east as it is with the less developed areas.

The largest areas of semi-natural habitat are all found in the east, dominated by woodland and heathland, with additional diversity provided in parklands and by small areas of grassland, fen and watercourses. There is a wide range of habitats and enhanced species richness due to the contrast between the dry habitats on the plateaux and the wet habitats on the flood plains, combined with varied geology. For example, the Basingstoke Canal and River Kennet flow over chalk and clay, while meadows on calcareous alluvial deposits support calcicole (lime- loving) species as well as the more typical plants.

Acid soils on the plateaux can support heathland and acid grassland. Heathland is predominantly in the east, with the largest tracts near Farnborough and Camberley, associated with Ministry of Defence land holdings. Smaller areas are fragmented amongst plantations and dense development including Chobham Common which is bisected by the M3. In the west, Greenham Common heathland area is by far the largest at only 27 ha. Common land across the NCA often supports small heathland areas. Dry heath, humid and wet heath are all found, often with areas of encroaching scrub or woodland, valley mires, ponds and acid grassland. Heather, gorses and grasses characterise dry heaths whilst wet heath includes cross-leaved heath, willows, mosses and purple moor grass, and humid heath includes cross- leaved heath and heath rush. Acid grassland is less species rich than neutral grassland but supports species of restricted distributions.

Woodland covers more than a quarter of the NCA but only 13 per cent exists as ancient woodland and another 6 per cent is ancient re-planted woodland. In the east, the predominance of conifer plantation on non-ancient sites means that there is limited woodland nature conservation interest. Woodland on former heathland areas and common land is often set in a mosaic with fragments of open heathland and grassland. Ancient woodlands in the Pang Valley are recognised for their nature conservation value. Wet woodlands associated with minor streams flowing down gullies off the plateaux and in the Kennet Valley support rare plants. (See Section 4 also.)

Besides wet woodland, other wetland interest is present and has a particular focus in the west around the River Kennet catchment. The Kennet Valley supports reedbeds, meadows, water-filled gravel pits with bird interest and stretches of chalk river. Base-rich fens occur at the interface of the London Basin and the Hampshire Downs and Chilterns. Basingstoke Canal, together with associated ‘flashes’ and heathland, are also nationally important.

Parkland is scattered across the NCA and may support a mosaic of habitats. Highclere Park contains fen, wet woodland, wet and dry grassland and veteran trees hosting diverse lichen, mosses and invertebrates.

The eastern area is of international importance for its bird populations. Heathland supports important numbers of breeding nightjar, woodlark and Dartford warbler. Other species include merlin, hen harrier, short-eared owl and hobby. On the eastern boundary there are a complex of internationally important feeding and roosting sites for wintering wildfowl including gadwall and shoveler around Egham (Highclere Park SSSI citation; London Basin Natural Area profile).

Key Habitats

The NCA contains the following areas of key main habitats, as mapped by the national Priority Habitat Inventory (Natural England, Priority Habitats Inventory, 2021; 2024; Natural England, Wood Pasture and Parkland, 2020). Note: lakes and ponds were not included in 2021 data:






Key habitats and species map for NCA129

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Settlement and development patterns section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Settlement patterns

On the edge of Greater London and including part of the M25, the eastern third is densely developed with large towns and numerous smaller settlements connected by numerous A roads and the M3. Some areas such as Ascot have low density housing permitting extensive gardens and golf courses including Wentworth. Development has been intensive and rapid in the last 50 years.

In the west, hamlets and farmsteads are scattered, but relatively densely, across the countryside with medieval market towns including Newbury, Odiham, Kingsclere and Reading. This settlement pattern is associated with small woodlands and wood pasture and Now established when farmers employed a wood-pasture economy similar to that of the New Forest where they supplemented farming with coppicing or brick making. Villages are commonly linear but locally there is a clear nucleus, typically with a village green. Towns such as Newbury and Thatcham and also villages such as Burghfield have seen recent development.

Riding schools and stud farms are a feature on urban fringes.

Areas of historically open, poor agricultural land have influenced settlement patterns. Common-edge settlement patterns are found scattered. In the east, development has replaced large areas of former heathland. Military bases and large parks or estates, such as Stratfield Saye, Dogmersfield and The Vyne, developed where extensive open land Now available.

Barracks, army housing, camps and exercise grounds are dominant around the military bases of Aldershot and Farnborough. In the west, Aldermaston and now-abandoned Greenham Common airbase are features
(Countryside Character Area description; Countryside Quality Counts, 2003).

Main settlements

The Thames Basin Heaths NCA contains the following large settlements: Ascot, Camberley, Farnborough, Woking, Newbury, Odiham, Kingsclere and Reading. These are linked by major transport routes (M3, M4, M25 and A34). The total estimated population for this NCA (derived from ONS 2001 census data) is: 768,821 (Thames Basin Heaths Countryside Character Area description; Countryside Quality Counts, 2003, Natural England, 2012).

Local vernacular and building materials

Brick replaced timber-framed buildings as the dominant tradition in the 16th century. Farm buildings have historically been roofed with straw thatch, tile and slate (Thames Basin Heaths Countryside Character Area description; Countryside Quality Counts, 2003).

Settlement and development patterns map for NCA129

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Key historic sites and features section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Origin of historic features

This is an important occupation area since the Mesolithic linked to exploitation of the rivers and since the 18th century, the proximity to London. Features include henges, long and round barrows, Roman settlements, sunken lanes, traces of ancient field systems and lynchets, flood meadows, waterside mills, heathlands and remnants of the early medieval hunting forests of Eversley and Bracknell.

The important remains of Silchester, the Roman civitas capital, lie north of Basingstoke.

Park estates and modest country houses were established from the 18th century to allow enjoyment of the rural scene within easy distance of London. Large parklands include Stratfield Saye, Dogmersfield and The Vyne.

Historical small farm size often meant that there Now little capital to replace buildings so medieval and 16th/17th century farm buildings and moated farmsteads often survive.

Common-edge settlements typically developed from the 16th century to 19th centuries through the encroachment onto the common by squatters. Few early buildings survive although there is often a once-isolated medieval farmstead (Thames Basin Heaths Draft Historic Profile, Thames Basin Heaths Countryside Character Area description).

Designated historic assets

The NCA includes the following designated historic assets (Historic England, National Heritage List for England, 2021; 2024):

Listed buildings

The NCA includes the following listed buildings (Historic England, National Heritage List for England, 2021; 2024):

Heritage at Risk Register

The NCA includes the following designated historic assets listed within the Heritage at Risk Register (Historic England, Heritage at Risk Register, 2021; 2023):



Key historic sites and features map for NCA129

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Recreation and access section contains a map

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated. The maps contain live frequently updated datasets.

Public access

The following areas of public access for recreation are located within this NCA (Natural England, 2021; National Trust, 2021):


Please note: Public access areas may overlap.

The following linear routes or public access for recreation are located within this NCA (Natural England, 2021; Sustrans; 2021):

Recreation and access map for NCA129

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Experiential qualities

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Tranquillity

Based on the CPRE map of tranquillity (2006) the Thames Basin Heaths become progressively more tranquil to the west; poor tranquillity scores are found in the east.

A breakdown of tranquillity values for this NCA are detailed in the table below (CPRE, Tranquillity Map, 2006):

Dark skies

Light pollution is a generic term referring to artificial light that shines where it is neither wanted nor needed, and can impact on people’s experience of the countryside within the NCAs. CPRE host an interactive map, depicting the light pollution and dark skies within the NCA.

Intrusion

The 2007 Intrusion Map (CPRE) shows the extent to which rural landscapes are ‘intruded on’ from urban development, noise (primarily traffic noise), and other sources of visual and auditory intrusion. This shows that the only areas of undisturbed land now lie to the very west of the area.

A breakdown of intrusion values for this NCA is detailed in the table below (CPRE, Intrusion Map, 2007):

Notable trends from the 1960s to 2007 are that in 1960 the western half of the area Now largely free from intrusion which Now no longer the case by 2007.