Lake Selvatn is 0.38 km²in area, has been measured at a depth of about 40m and lies at 131m above sea level. The estuary is called Gudduós , where a small creek flows from the lake. This creek joins the Hólmsá river which flows into Elliðavatn. There is some fishing in Selvatn and the fish there are said to be big, Arctic char up to 4 pounds and brown trout that can reach 8 pounds.