The reservoir collects water from the Tweedsmuir Hills, which is then conveyed 28 miles (45 km) via underground pipelines and tunnels to Edinburgh.

Design was carried out by chartered civil engineers Robert H Cuthbertson & Partners on behalf of the water authority, and construction started in 1976.

In 1983, Lothian Regional Council commissioned a short film - "A Different Valley" - on the construction of the dam and associated works.

[7] A later 16th-century chronicle by Robert Lindsay of Pitscottie describes James V hunting at Meggetland in June 1528 (but really July 1530) with 12,000 courtiers and followers.

[9] Mary, Queen of Scots and Lord Darnley stayed for few days in August 1566 while hunting in Meggetland.

[12] They found little sport, and Mary issued a proclamation that no one should shoot deer with handguns or bows.