If you walk along along the road from Nancherrow Bridge to Tregeseal you'll see, on your right, a small “well” behind a metal fence. This is the shote and the fence carries a notice to the effect that this shote was the sole source of water for the people of Nancherrow until 1963.
It's not so obvious now but back in 1963 there was still a foundry and gas works about 50 yards upstream of the shote and a bit further back in time the upper valley was home to numerous batteries of tin stamps and most of the water now in the river would have been in the leats and launders directing water to the stamps and drop hammers.. It was an intensely industrialised place all the way up to the tin streaming at Hailglower and the river was not an ideal place to be getting your water.
In the late 1950s things began to change. Between 1958 and 1960 the river valley between Skimmel Bridge and Lower Drift was deforested to prepare for the construction of the dam at Drift. The dam was completed and flooding commenced on 14 January 1961. By 3 February 1961 the reservoir was full and water had started coming over the spill weir. A lot of early mining history was destroyed but clean piped water could now be delivered to the people of Nancherrow and many other settlements in West Penwith.
Plans for the reservoir had originally been approved in 1938 but World War 2 led to postponement of the badly needed amenity. Besides providing fresh water to the people of West Penwith, Drift has also become a significant bird watching location with numerous rare sighting on its list.
The reservoir is about 1200 yards long and covers 65 acres with a maximum depth of 48 feet and a holding capacity of 1200 million litres. It supplies water to most of West Penwith, with the exception of St Ives, via pumps and auxiliary reservoirs at:
Chywoone (Mousehole, Newlyn and Penzance),
Cryor (St Just and the north coast round to Zennor),
Leha (Land's End, St Buryan and Lamorna)
Tin and the Newlyn River, Gerald Williams, Journal of the Trevithick Society no 42 2015
For a video of work on the dam see: