In size it is 3.4 km2, more than three times the size of the second biggest lake Fjallavatn, which also lies on the island of Vágar.Among the locals, there is a debate regarding the name of the lake. The inhabitants of Sørvágur take pride in the fact that the lake is named after their village. On the other hand, the inhabitants of Miðvágur want to name the lake "Leitisvatn", since, on their side of the lake, the land alongside the body of water is called Leiti.
Though the village of Miðvágur is situated closer to the lake than Sørvágur, the lake is named for the latter because the faroese Landnám Sørvágur was settled before Miðvágur. Sørvágur—alongside Bøur and Sandavágur—is considered to be one of the three original Landnámsbygdum (original settlements) on Vágar. The three Landnámsbygdir divided the land on the island among them into three equal sizes of 60 marks. A division of the island into three equal portion will bring Sørvágsvatn firmly inside the boundaries of Sørvágur and therefore the lake has been named after this village.
The locals mostly refer to Sørvágsvatn/Leitisvatn simply by calling it 'Vatnið' (the Lake). Among the inhabitants on the island everyone knows what "the Lake" is, and it is mostly when people from other parts of the Faroes refer to the lake—either by calling it Sørvágsvatn or Leitisvatn—that the debate will occur.
During World War II the British army built an airfield by the lake. They also built a station to support seaplanes. The first aircraft to land on the lake was a Catalina from the British Navy, which landed on in 1941.