The Manapouri Power Station is a hydroelectric power station and the largest hydroelectric power plant in New Zealand. It is located on New Zealand's South Island on the western branch of the Lake Manapouri in Fiordland National Park. The majority of the electrical energy produced (about 610 MW) 160 kilometers southeast consumed for aluminum production near Bluff. According to the original plans from the 60's for the use of the lake for the hydropower raising the water level by 30 meters envisaged; In addition, the Lake Manapouri and a little further north to Lake Te Anau should be combined into a large lake. Massive protests of the New Zealand population against the planned destruction of the environment prevented these plans. Today's power plant was in 1963 largely built underground. Because flow problems in the tunnel to Doubtful Sound, the power plant was in 1972 only produce an output of 585 MW instead of the planned 700 MW after its entry into service. Only a second tunnel (Second Manapouri Tailrace Tunnel), which was completed in 2002, increased the capacity to 850 MW. The second tunnel was built by FDI joint venture consisting of the construction companies Fletcher, New Zealand, Dillingham, USA and Ilbau, Austria. The client was the local power plant operators Meridian Energy.