Rutland Water is Anglian Water's drinking water reservoir in the county of Rutland, England, just 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 SK942078.
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.
Set in 3,100 acres (12.5 km2) of the countryside, it has a 25-mile (40 km) circular track for walking and visitors may hire a bicycle.
Since the water is drawn upon when needed, the relative areas of land and water vary a little but the flatter parts of the lake margin are enclosed by banks so that the wetland nature reserve is maintained (grid reference SK886073