|Basin countries||United Kingdom|
|Max. length||1,200 yd (1,097.3 m)|
|Surface area||65 acres (26 ha)|
|Max. depth||48 ft (14.6 m)|
|Water volume||1,200 million L (260 million imp gal; 970 acre⋅ft)|
|Surface elevation||275 feet (83.8 metres)|
Drift Reservoir is a reservoir in Cornwall, England, UK, just north of the village of Drift and west of Penzance. The reservoir is 1,200 yards (1,100 m) long and covers 65 acres (26 ha). The dam is at the southern end of the reservoir, and the northern end, splits into north-western and north-eastern shallow arms. It is currently managed, jointly by the South West Lakes Trust and South West Water. There is public access to the dam and parking area only.
The reservoir was first given statutory approval in 1938 (Under the Penzance Corporation Act 1938) but construction was deferred until after World War II and finally completed by the West Cornwall Water Board in 1961. It is the principal source of water for the Penwith area.
The valley of Trewidden Vean, now known as the Lost Valley, was evacuated starting in 1938, with the last family leaving in 1961; it was then flooded and became the Drift Reservoir. The water level in the reservoir sometimes drops low enough to reveal the remains of houses and roads; this happened in the 1970s, the 1990s, and in the summer of 2018.
Natural history and ecology
Drift reservoir, due to its geographical location close to the sea, plus good areas of shallow water and exposed mud is an important landfall for migrating waders. The north-west arm of the reservoir is managed by the Cornwall Birdwatching and Preservation Society (CBWPS) and the bird hide, due to insurance considerations, is open to members of that organisation only. A successful bird reserve needs an area that is free of continuous disturbance and in 2001 a no fishing area was established in the north-west arm, along with a reed bed of Phragmites australis. A year later it was reported that the no fishing area had helped breeding birds which included common coot (Fulica atra), mallard (Anas platyrhynchos) and mute swan (Cygnus olor).
Although generally hosting only small numbers of birds (244 species recorded), the reservoir has attracted a considerable number of North American vagrant shorebirds and wildfowl, including a number of lesser scaup (Aythya affinis). In May 2016 a Dalmatian pelican (Pelecanus crispus) was seen in western Cornwall and was frequently seen on the reservoir. There are 5,000 year old fossil remains of this species from Somerset and this bird could be the first recorded in Britain since then. At the same time as the Dalmatian pelican, a cackling goose, (Branta hutchinsii), which is a scarce but regular North American vagrant was at the reservoir.
Rainbow trout (Oncorhynchus mykiss) and blue trout are released in the reservoir for trout fishing along with the native brown trout (Salmo trutta). The Cornish open float tube competition is held annually in May.
- Penhallurick, Roger (1978). The Birds of Cornwall and the Isles of Scilly. Penzance: Headlands Publications. pp. 42–55. ISBN 0 905920 02 3.
- "150 years of dams". South West Water. Retrieved 27 May 2016.
- Land's End. Explorer Map 102 (B2 ed.). Southampton: Ordnance Survey. 2010. ISBN 978 0 319 24116 5.
- "Drift Reservoir". Cornwall Birdwatching & Preservation Society. Retrieved 27 May 2016.
- Pool, Peter A S (1974). The History of the Town and Borough of Penzance. Penzance: The Corporation of Penzance.
- Greg Martin (28 July 2018). "Driest summer on record reveals the lost village beneath Cornish reservoir". Cornwall Live. Retrieved 12 September 2018.
- Greg Martin (9 September 2018). "More Lost Valley revealed as water levels drop at Drift reservoir". Cornwall Live. Retrieved 12 September 2018.
- Craven, Brian (2002). Birds in Cornwall (Ydhyn yn Kernow) 2001 (71 ed.). Cornwall Bird-Watching and Preservation Society. pp. 172–4.
- Craven, Brian (2003). Birds in Cornwall (Ydhyn yn Kernow) 2002 (72 ed.). Cornwall Bird-Watching and Preservation Society. pp. 169–71.
- "Dalmatian pelican seen 'for first time' in UK at Land's End". BBC News. 10 May 2016. Retrieved 27 May 2016.
- "Trout Fishing at Drift Reservoir". SW Lakes. Retrieved 27 May 2016.