Drammenselva in the context of "Skien watershed"

The Skien watershed is the third largest watershed of Norway after those of the Glomma and the Drammen rivers. The catchment area is 10,780 square kilometres (4,160 mi), and the maximum length is 252 kilometres (157 mi).

The Skien watershed includes rivers which feed Lake Norsjø above Skien;

Drammensfjord (English: Drammen Fjord) is a fjord in along the border of Akershus and Buskerud counties in Norway that connects to Ytre Oslofjord on the west side. It stretches about 30 kilometres (19 mi) to the north and northeast. The Drammenselva river discharges into the head of the fjord. The fjord shares its name with the city of Drammen, which is located at the head of the fjord. Drammen Municipality is located on its west and north sides. The land on the east side of the fjord is called Hurumhalvøya or the Hurum peninsula and this is located in Asker Municipality. The peninsula lies between the Drammensfjord and the Oslofjord.

The fjord narrows to a strait at Svelvik on the west side and Verket in Asker on the east side. The strait is crossed by an automobile ferry. This narrowing, some 200 metres (660 ft) broad and 10 metres (33 ft) deep, combined with the large freshwater inflow from the river Drammenselva (one of Norway's largest rivers) and from the river Lierelva, results in the water north of the strait being brackish. On the surface the water is fairly fresh, resulting in bathing areas that are free of jellyfish, while deeper the water has a higher salt concentration, with saltwater fish such as cod, pollock, flounder, and mackerel.