Lake Hvannabrekkuvatn is estimated to be 0.65 km² in area and is 30 m above sea level. From the lake flows a stream that joins another stream which flows from Lake Selvatn and together they form river Hraunhafnará. River Skálavatnsá flows into the lake. Hvannabrekkuvatn is shallow with the average depth of the lake not more than 1.5 m. It contains both Arctic char and brown trout – decent fish. The lake is in the land of Skinnalón.