Nidelva (Aust-Agder)

Nidelva in Blakstad

The Nidelva is a river in southern Norway. It gets its name at the confluence of Nisserelva and Fyreselv and forms the main flow of Arendalsvassdrag that s discharges at a catchment area of 4015 km ² water masses of 110 m³ / the year. From the mouth at Arendal in Aust- Agder, where the river flows into three arms into the Skagerrak, to the most distant origins of its source rivers, the water has a length of 210 km.

The entire river system is one of 15 hydroelectric power plants to the most regulated waters in Norway. The highest measured outflow was at the power plant Rygene about 1200 m³ / s with a flood in October 1987. However, is found in Reiersøl ( municipality Froland ) a stone on which much higher water levels from 1860, are engraved in 1892 and 1916.

In the last 22 kilometers of river Nidelva leads the salmon. Since there is no self-reproducing salmon in the river, liming, cultivation and fish ladders are planned.

Nidelva in Reiersøl

The river squeezes a few kilometers upstream of the mouth by a narrow place