River Lambá has its source in Grunnuvötn at Arnarvatnsheiði and flows a short distance north of Hólmavatn. It merges Skammá, which runs from Hólmavatni, before it falls into river Kjarrá. Fish can’t migrate from Kjarrá into Lambá because of the high waterfall just above the junction. Lambá is a fun brown trout river, and the fish are usually rather big, up to 6 lbs. There are also Arctic char, and it is not uncommon to catch fish that are 2-3 pounds. Those who buy a license in Lambá do not have access to Lake Hólmavatn.