aerial photograph of Scammonden Reservoir West Yorkshire. The 16 sq mile reservoir holds 7800 million litres of water and is unusual in that the M62 Motorway is built on top of Scammonden Dam making it the Uk's only motorway built on a dam. Drinking water from Scammonden Water supplies Huddersfield through an underground pipe. Construction of the reservoir involved submerging Deanhead village although the village church remains just above the water level on the right of the image. The Reservoir was completed in 1969 with the motorway opening in 1970.