thumb|Cotswold Lakes from the air
thumb|A lake at the Cotswold Lakes
thumb|Lakeside holiday accommodation
thumb|Bulrushes and coots on one of the lakes
The Cotswold Lakes (formerly known as Cotswold Water Park) is the United Kingdom's largest marl lake system, straddling the Wiltshire–Gloucestershire border, north-west of Cricklade and south of Cirencester. There are 180 lakes, spread over .
The park is a mix of nature conservation activities, including nature reserves; recreation, including sailing, fishing, a country park and beach with water sports and play areas; rural villages; and holiday accommodation. It is a significant area for wildlife and particularly for wintering and breeding birds. The local wildlife trusts (Gloucestershire and Wiltshire) are involved in partnership with the Cotswold Lakes Trust charity in working with local communities and organisations in the area.
History
The lakes were created in the second half of the 20th century by extraction of glacial Jurassic limestone gravel, which had eroded from the Cotswold Hills, and these filled naturally from rivers and streams after workings began to be exhausted in the early 1970s.
Prior to the establishment of the Cotswold Water Park Trust, certain elements of, or activities within the area were overseen by the Cotswold Water Park Society Limited. The Society's chief executive of the time, Dennis Grant, was imprisoned in 2011 for defrauding the organisation of more than £650,000, and the trust was subsequently relaunched as a registered charity working for the benefit of people and wildlife in the area.
In 2021, the name of the charity changed from Cotswold Water Park Trust to Cotswold Lakes Trust. In 2024, a steering group of local business owners, in collaboration with the Cotswold Lakes Trust, proposed the renaming of the region from Cotswold Water Park to Cotswold Lakes. This idea quickly gained traction, receiving backing from various operators and parish councils. On 31 July 2024, Cotswold District Councillors passed a motion to support the name change.
Location
Information may be found in detailed maps of locations and facilities, and other publications produced by the Cotswold Lakes Trust.
It is that part of the Upper Thames catchment in North Wiltshire and south Gloucestershire which has been subjected to over 50 years of sand and gravel extraction. For ease of orientation, the Cotswold Lakes is split into three areas.
- The western section encompasses the villages of South Cerney, Cerney Wick, Ashton Keynes, Somerford Keynes, Poole Keynes, Siddington, Oaksey, Minety and Leigh; and includes the uppermost reaches of the River Thames, as well as its tributaries including the River Churn, Swill Brook and Cerney Wick Brook.
- The central section encompasses Driffield, Ampney St Peter, Poulton, Down Ampney, Meysey Hampton, Cricklade, Latton and Marston Meysey; and features further Thames tributaries such as the Ampney Brook. Gravel extraction in the Latton area in the 1990s created additional lakes.
- The eastern section includes Fairford, Kempsford, Lechlade, Buscot, Inglesham and Castle Eaton; and features additional Thames tributaries including the River Coln and River Leach. Lechlade in the eastern section marks the start of the navigable River Thames.
The Cotswold Lakes area sits low in an historic river valley and as such is exposed to fluctuations in ground water levels. Much of the farmland in this area is made up of flood meadows which take up water from the River Thames. Many of the lakes are connected by underground culverts, allowing transfer of water between them. There is also transfer of water through ground water feeds and via a myriad of ditches and streams. Restoration schemes for many of the active mineral workings are taking into account the vital function of these flood water storage areas, as well as creating an important habitat for a number of Local and UK Biodiversity Action Plan species (LBAP and UKBAP).
Cotswold Lakes Trust nature reserves
The Cotswold Lakes Trust (formerly the Cotswold Water Park Trust) is a registered charity. It owns, leases or manages a number of sites within the area, and all are managed for a combination of conservation, public access, education and amenity. All these sites are important refuges and breeding grounds for several species of bats, dragonflies, damselflies, birds, mammals, fish, butterflies and other invertebrates. The Cotswold Lakes has its own Local Biodiversity Action Plan (LBAP) It includes 2.5 km (1.6 miles) of permissive footpath and cycleway as well as three bird viewing hides, and is an important site for breeding and wintering birds such as Eurasian coot, great crested grebe, gadwall, tufted duck, little egret and grey heron. It is about half a mile (0.8 km) east of Somerford Keynes. The reserve was one of the oldest gravel workings in the upper Thames Valley. The extraction of the First Terrace Pleistocene gravels left behind an unusually deep lake, which is sealed by beds of Kellaway clay.
Waterhay Reedbeds
A silt lagoon was formed by the mineral workings that created the Cleveland Lakes. This is now colonised and provides a suitable habitat for wintering and breeding birds and a refuge for reptiles and mammals.
Only a few of the lakes are accessible for public use. It is a site of Site of Special Scientific Interest notified in 1994.
- Natural England information on the citation
- Natural England information on the Cotswold Lakes Site
In January 2021, further areas were given SSSI status and a consultation begun on further extending the area covered.
Gloucestershire Wildlife Trust reserves
The Gloucestershire Wildlife Trust activities are based in the eastern section of the Cotswold Lakes. There are four nature reserves called Whelford Pools, Edward Richardson & Phyllis Amey, Roundhouse Lake and Bryworth Lane.
175px|thumb|Example: emperor dragonfly ([[Anax imperator)]]
175px|thumb|Example: [[great crested grebe]]
175px|thumb|Example: [[Melanargia galathea|marbled white on knapweed]]
175px|thumb|Example: [[amphibious bistort]]
175px|thumb|Example: bee orchid ([[Ophrys apifera)]]
175px|thumb|Example: snakeshead fritillary ([[Fritillaria meleagris)]]
175px|thumb|Example: male and female [[mallard]]
Whelford Pools reserve (SSSI)
- Natural England Unit 8 of the Cotswold Lakes, the Whelford Pool (most northerly)
- Natural England Unit 9 of the Cotswold Lakes, the Whelford Pool
The Pools () and () are in the eastern section of the park, between Fairford and Lechlade. The site was purchased by the Gloucestershire Wildlife Trust in 1979 with grant aid from the Worldwide Fund for Nature (WWF). The pools are separated by a narrow bund, and drain south towards the River Coln and the River Thames. The Court Brook is the northern boundary. Mallard Lake (Lower Moor Farm) and Upper Waterhay.
Clattinger Farm reserve (SSSI)
- Natural England citation and map information for Clattinger Farm
- Natural England unit details for Clattinger Farm
Clattinger Farm () is a site near Malmesbury. It is not within the Cotswold Water Park SSSI definitions, but a separate SSSI adjacent to the park. It is a prime example of enclosed lowland grassland and is a hay meadow of international importance. This land has been farmed traditionally without artificial fertilisers. and Sandpool Farm.
Upper Waterhay Meadow reserve (SSSI)
- Natural England citation and map for Upper Waterhay
- Natural England unit detail for Upper Waterhay Meadow
Upper Waterhay Meadow () is a site near Cricklade. It is outside the Cotswold Water Park SSSI but is a separately assessed SSSI within the Cotswold Water Park. It provides protection and support for the snake's head fritillary. Example clusters include the more unusual creamy white than the dark purple (see citation reference which includes photograph of cream coloured flowerhead).