About Porttipahta Dam

Porttipahta is the second-largest artificial reservoir in Finland, built between 1967 and 1970 on a tributary of the Kemijoki in Finnish Lapland. The 35-metre-high earth-fill dam impounds approximately 1,350 million cubic metres of water across an area of around 214 square kilometres. Like its sister reservoir Lokka, Porttipahta was created by flooding a large area of Sámi traditional territory, displacing families and submerging reindeer pastures. Together, Lokka and Porttipahta form the core of the Kemijoki hydropower system, the most powerful river system in Finland, providing a significant share of Finnish domestic electricity generation. The reservoir sits at an elevation of around 244 metres above sea level and is seasonally ice-covered for much of the year. Porttipahta is valued for fishing, particularly brown trout and grayling that thrive in the cold, nutrient-poor Arctic waters. The surrounding landscape of fell birch forests and open fells is characteristic of the northern boreal and sub-Arctic zones.