Only accessible from the north east and south east sides, as it is in wild and unspoilt countryside. Prior to becoming a reservoir, it was a natural lake measuring two and a half miles long, approximately three eighths of a mile wide and the depth was around ninety six feet lower than it is now. Parliament passed a bill in 1929 authorising the Manchester Water Corporation the use of Haweswater as a reservoir for Manchester.
The construction of this dam, at the time, was considered to be cutting edge technology, as forty four separate buttressed units, joined by flexible joints, were used to construct this hollow buttressed dam. The reservoir is now four miles long, about a third of a mile wide and one hundred and ninety eight feet deep. When this reservoir is full it holds approximately eighty four billion litres of water. Haweswater reservoir is now owned and maintained by United Utilities.
However, prior to this valley being flooded in 1935 the villages of Mardale Green and Measand had to be demolished. The stone from the village church was used in constructing the dam. However, all the bodies from the churchyard had to be exhumed – these were all then reburied at Shap. In extremely dry weather, the sunken village of Mardale can be seen as stone walls and the village bridge is visible.
Haweswater reservoir is nestled in the mountains between Grasmere and Keswick, the reservoir is approximatley 245 meters above sea level when full, it has 1 island and is primarily fed by Mardale and Riggindale Becks