Rutland Water is Anglian Water's drinking water reservoir in the county of Rutland, England, to the east of the county town, Oakham. It was known as Empingham Reservoir during its construction and until its official opening in 1976. The centre of its dam is at British national grid reference . It provides a reserve supply of water in the driest and most densely populated quarter of the United Kingdom and is one of the largest artificial lakes in Europe. By surface area it is the largest reservoir in England, but by capacity it is exceeded by Kielder Water.