To the east, the land rises towards the forested slopes of the Kaimai and Mamaku Ranges. The upper reaches of the Waikato River are used for hydroelectricity, helped by several large artificial lakes in the region's south-east. The lowest and earliest-created such lake is Lake Karapiro, now developed as a world-class rowing centre, where the world championships were held in 2010. The river flows out of the country's largest lake, Lake Taupo, which is served by several important fishing rivers such as the Tongariro, on the Central Plateau, draining the eastern side of Mount Ruapehu and its neighbours.