National Character Area 115

Thames Valley - 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.

The Thames Valley, covering parts of Berkshire, Buckinghamshire, Surrey and Hertfordshire as well as part of Greater London, includes part of the North Wessex Downs and the Chilterns Areas of Outstanding Natural Beauty (AONBs) – covering 158 ha and 114 ha respectively (Natural England, 2011).

Relationship with the coast

The adjacent coastline includes the following Marine Plan – Marine Character Areas (MCAs):

  • Thames and Medway Estuaries

 

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 NCA115

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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

There is a difference of 125m between the lowest point of 1m and the maximum height of 126m (London Basin Natural Area Profile, Thames Valley Countryside Character Area description).

Landform and process

In its northern parts, the landform reflects the rolling hills characteristic of the nearby Chilterns. Here, the Chalk is overlain by clay and gravel, giving rise to a plateau and a series of knolls. The central part of the Thames Valley is dominated by the Thames flood plain, giving way to clay vales further south. There are lakes in the east resulting from mineral workings (London Basin Natural Area Profile, Thames Valley Countryside Character Area description).

Bedrock geology

The Thames Valley is geologically part of the London basin which is a syncline – a concave fold with the oldest sediments at its periphery – formed 20 to 40 Ma as a result of the Alpine Orogeny (mountain-building). The region became dry land during this time. The oldest rock here is the chalk, which Now laid down in warm shallow seas during the Cretaceous period. It is overlain by Palaeogene and Neogene sands and mudstones. Following a marine transgression some 55 Ma, the London Clay Now laid down. Overlying this are the Bagshot, Barton and Bracklesham Beds. These sands and clays were deposited on a large coastal plain. There are very small areas of sediments of other formations (London Basin Natural Area Profile, Thames Valley Countryside Character Area description).

Superficial deposits

Important Quaternary sediments are present, recording the changing temperatures during this period and the presence and absences of ice sheets. The Anglian ice sheet advanced as far south as the northern rim of the London Basin and forced the young River Thames to change its course to its current one. Fluvial sediments deposited by the Thames river system before the Anglian Ice Age, occur predominantly along the northern edge of the London Basin, parallel with the axis of the syncline. Sediments deposited after the Anglian Ice Age are found along the flood plains of the current rivers. The youngest sediments are sands and gravels deposited by the Thames in its” current location since the last ice age (London Basin Natural Area Profile, Thames Valley 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

Heavy clayey soils resulting from the underlying geology (London Basin Natural Area Profile, Thames Valley 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 NCA115

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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.

The Thames Valley is drained by the River Thames and its many tributaries.

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 NCA115

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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 within the Thames Valley is generally confined to a matrix of small farm woods. However, the north-western edge is characteristically wooded, extending up to the southern edge of the Chiltern Hills (London Basin Natural Area Profile, Thames Valley 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 NCA115

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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

The estimated total length of resource is 3,614 km. In 2011 165 km of boundary features were under Environmental Stewardship agreements including ditches (9km), hedgerows (124km) and woodland (31km). Mature oaks are a characteristic feature of hedgerows in the NCA (Countryside Quality Counts Draft Historic Profile, Countryside Character Area).

Field patterns

Regular field patterns on the flood plain suggest late enclosure, while smaller field patterns on the higher ground suggests earlier enclosure of drier land (Countryside Quality Counts Draft Historic Profile, Countryside Character Area).

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 NCA115

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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

A range of BAP habitats exists at several discrete locations, for example Burnham Beeches. There are areas of wet woodland throughout the NCA, and an expanse of mixed deciduous lowland woodland at Windsor Forest (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 NCA115

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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

About 45 per cent of land is within greenbelt. The area has a high rate of change to urban with expansion of urban into peri-urban evident at Slough, Rickmansworth, Bracknell, Reading and Wokingham. In the more rural parts there is also evidence of continued development on previously undeveloped land (Office for National Statistics census data 2001).

Main settlements

Main settlements include Slough, Rickmansworth, Bracknell, Reading and Wokingham. The total estimated population for this NCA (derived from ONS 2001 census data) is: 1,420,439 (Office for National Statistics census data 2001).

Local vernacular and building materials

Large houses set within 18th or early 19th century ornamental parkland, concentrated to the north of Bracknell, provide a stark contrast with sporadic modern development. There are very few villages remaining of traditional
character (Country Quality Counts Draft Historic Profile Thames Valley Countryside Character Area description).

Settlement and development patterns map for NCA115

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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

Royal estates and palaces include Hampton Court; large houses set within 18th or early 19th century ornamental parkland, concentrated to the north of Bracknell; and Eton College (Countryside Quality Counts Draft Historic Profile, Thames Valley 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 NCA115

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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 NCA115

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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) none of this NCA can be officially considered as tranquil. The lowest scores for tranquillity are around the urban areas and Heathrow Airport. Expanses of parkland such as Windsor Great Park score medium tranquillity.

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 almost the entire NCA is disturbed by visual and auditory intrusion.

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 a steady growth in urban areas.