In 1960 Comalco Industries Pty. Ltd. was granted the rights to develop the water power of Lakes Manapouri and Te Anau, but in February 1963 a new arrangement was agreed upon and the Government announced that the State would proceed with the development at an early date. It was established that Manapouri would be an economic source of power for the national network. In replacement of its rights to harness the water power, Comalco was given certain options on power so that an aluminium industry could be developed in Southland earlier than otherwise would have been possible. Stage I development of 400,000 kW from four machines involving an underground power station at Manapouri and a 6¼-mile tunnel to Doubtful Sound, with first power scheduled to be available in 1968, is now under construction. Stage II development would raise the installed capacity to 700,000 kW.