National Character Area 108

Upper Thames Clay Vales - Summary and Headline Statements of Environmental Opportunity


The Upper Thames Clay Vales National Character Area (NCA) is a broad belt of open, gently undulating lowland farmland on predominantly Jurassic and Cretaceous clays. Blenheim Palace World Heritage Site falls within the NCA, along with around 5,000 ha of the North Wessex Downs Area of Outstanding Natural Beauty (AONB) and smaller areas of the Chilterns AONB and the Cotswolds AONB. Two of its Special Areas of Conservation (SAC) are designated for their lowland meadow vegetation communities, while Little Wittenham SAC has one of the most studied great crested newt populations in the UK. There are contrasting landscapes, including enclosed pastures of the claylands with wet valleys, mixed farming, hedges, hedge trees and field trees and more settled, open, arable lands. Mature field oaks give a parkland feel in many places.

The area encircles the Midvale Ridge NCA and covers an extensive area of low-lying land extending from Wiltshire and Gloucestershire to the west of Swindon through to Aylesbury in Buckinghamshire in the east. It comprises two separate sub-character areas: the Wiltshire, Oxfordshire and Buckinghamshire Vales to the north; and the Vales of White Horse and Aylesbury to the south. The area is dominated by watercourses, including the Thames and its tributaries, and there are also lakes associated with mineral extraction areas, such as the Cotswold Water Park. Watercourses and lakes provide important areas for wildlife and recreation. There are a number of major transport routes and patches of intensive industrial influence, including Didcot Power Station. There is little woodland cover (around 3 per cent) but hedgerows and mature field and hedgerow trees are a feature, and many watercourses are fringed with willow or poplar.

The area’s internationally important lowland meadows require enhanced management alongside improved care of adjacent land, and its wetland habitats require appropriate hydrological regimes to be secured and an ecological network that is resilient to climate change. Wet grassland and wetland habitats also offer opportunities to manage floodwaters and improve water quality.

Potential growth of urban areas, particularly around Oxford and Swindon, may provide opportunities for creation of significant areas of accessible natural greenspace as part of comprehensive green infrastructure planning.

Headline Statements of Environmental Opportunity (SEO)

See the Statements of Environmental Opportunity section for more details on the headlines listed below.


Along the Thames and its tributaries, promote sustainable farming and best practice mineral working in order to conserve and restore seminatural habitats, historic features, geodiversity, soil quality and soil carbon stores and also to regulate water flow in this area and downstream. Ensure conservation of Oxford Meadows Special Area of Conservation and North Meadow and Clattinger Farm Special Area of Conservation. Engage the public in river heritage and maintain traditional land management practices where appropriate.


Manage farmland across the Upper Thames Clay Vales to produce food sustainably and to maintain sense of place. Taking a catchment approach, improve filtration of pollutants and regulation of water flow by realising a farmland habitat mosaic that incorporates strategic areas of wet grassland, reedbed, wet woodland and ponds as well as ditches and hedgerows.


Ensure that heritage assets, especially characteristic features such as ridge and furrow, abandoned medieval villages, Roman roads, canals and historic parkland, including Blenheim Palace World Heritage Site, are maintained in good condition. Integrate conservation of these features with sustainable food production and provide public access to key examples. Seek opportunities to restore the wider historic setting of a feature, particularly in relation to the historic Royal Hunting Forests of Bernwood, Braydon and Wychwood.


Realise sustainable development that contributes positively to sense of place and built heritage. Ensure adequate greenspace in association with all development and most importantly in growing settlements such as Aylesbury and Swindon. Create and manage greenspace to provide benefits for biodiversity, floodwater management, filtration of pollutants, tranquillity and recreation, and secure strategic access routes between town and country.