A Brief History
Long before the Clutha Mata-Au had a name, before the Moa-hunters, and before the gold-rush, a mighty earthquake ripped through the Cromwell and Kawarau Gorges, providing new outfalls for Lakes Wanaka and Wakatipu. The Upper Clutha Mata-Au and the Kawarau Rivers were born, and the confluence of these powerful rivers cut the famous 'Cromwell Junction.'
Maori explorers, Ngai Tahu and Kai Tahu ki Otago, followed the Mata-Au inland, through a wild and untouched land, hundreds of years before Abel Tasman sighted New Zealand. Their seasonal explorations yielded prized argillite stone, fibres from flax, from the fronds of the cabbage tree and from the leaves of the Celmisia mountain daisy. They also came for foods such as Moa, eel, duck and pigeon. In time, they established campsites and seasonal inland settlements.
Nathaniel Chalmers, a young twenty-three old in search of good sheep country, was the first European to ascend the river in 1853. He was guided by two old Maoris, Chief Reko and Kaikoura, paying them in advance with a three-legged iron pot. The old Maoris were veterans of the river route, such that when Nathaniel Chalmers fell ill, they simply constructed a mokihi, or koradi (flax flower-stalk) raft, and guided him down the river, fearlessly running major rapids in the Cromwell and Roxburgh Gorges.
Perched above 'the meeting of the waters' grew the 1860's gold-rush town of Cromwell, overlooking the spectacular Cromwell Gap Rapid. When the gold workings declined, farming and fruit-growing became the town's mainstay. Little changed until the 1980's, when the then National government's 'Think Big' agenda brought massive upheaval as plans for New Zealand's largest concrete gravity dam moved ahead, despite widespread protest.
The exploitation of the Clutha for maximum power at any cost, was driven by departmental and political ambitions that would prove too insidious to be checked, even by the courts. The inexorable weight of the NZED (New Zealand Electricity Department) and the MOW (Ministry of Works), coupled with a secret deal made by naive government ministers providing COMALCO (Rio Tinto) with cheap electricity, set the agenda and fuelled the official lust for power.
Threatened landowners went to the High Court, winning their case against the Government. But the democratic provisions of the New Zealand legal system were over-ruled by the Government, lead by Prime Minister Robert Muldoon, and the dam went ahead, in what can only be described as one of the most shameful chapters in the history of New Zealand.
During construction of the dam, the bed-rock was found to be microfractured because of a major earthquake faultline. Vast amounts of slurry concrete were pumped into the rock to stop water leaks. Subsequent landslide stabilization problems halted the project while experts debated safety issues. Eventually, the Government decided to proceed, and 18kms of drainage tunnels, with 24-hour pumping and monitoring stations, were embedded in the 'slide zones' of the gorge. A massive cost blow-out brought the total cost to nearly $2 billion, amidst continuing controversy over the dam's safety, viability and necessity.
In 1992, the rushing waters of the Cromwell Gorge were silenced as the reservoir behind the Clyde Dam began rising. Filled in three stages between 1992-93, the reservoir gradually flooded the spectacular Cromwell Gorge, the historic heart of Cromwell, many orchards and homes, the settlement of Lowburn and the surrounding fertile farmland - a total of 2300 hectares of the best orchard and farmland in Central Otago.
The lifespan of the dam is estimated to be 80 years, but opponents doubt that it will survive that long, given the ongoing instability of the Cromwell Gorge, the risks posed by earthquakes and landslides, and the speed of reservoir sedimentation.
