Benmore Dam is the largest dam within the Waitaki power scheme, located in the Canterbury Region of New Zealand's South Island. There are eight other power stations in the Waitaki Power Scheme.The dam is the largest earth-filled water-retaining structure in New Zealand. Its core is low permeability clay material, supported by two massive shoulders of river gravel. Lake Benmore has a volume of 12.5 million cubic metres, about 1.5 times as much water as Wellington Harbour.