The reservoir's sole purpose is to provide drinking water, and as such, it supplies Angus, Dundee, and parts of Perth and Kinross.

Backwater, together with the smaller Lintrathen Reservoir 4 kilometres (2.5 mi) to the south, is capable of supplying some 300,000 people with drinking water.

[1] The project was initiated by the Dundee Corporation Waterworks in 1964 and absorbed into the newly created East of Scotland Water Board in 1968, before final completion and the official opening by Queen Elizabeth II on 9 October 1969.

The reservoir extends for 3 kilometres behind the dam and has a peak capacity of 24.55 million cubic metres (867×10^6 cu ft).

The reservoir can be reached by taking the B951 turn-off from the A93 (around 5 miles south of Spittal of Glenshee) to the north-west, or from the A926 at Kirriemuir to the south-east.