SAVING MANAPŌURI THE CAMPAIGN THAT CHANGED A NATION

Three guys on a road trip park up and wander down to the edge of Lake Manapōuri. They roll up their trousers and test the water with bare feet. They take photos, then head back to the car.

A passerby remarks that it’s not a bad spot. “There’s nobody here,” one of the guys replies with wonderment. “It’s the perfect place.”

He’s lying. Fifty metres along the beach, there are two other people, having a late breakfast at a picnic table. They finish up, and return to their van and the rest of their holiday.

Then there’s nobody left. Just an empty beach and a still lake stretching towards islands and outcrops, and the irregular ridgeline of the surrounding mountains. Somewhere distant there’s the rumble of a boat chugging across the lake. Sparrows descend on the picnic table, searching for crumbs. A pair of paradise ducks swoops overhead. It is the perfect place.

But 50 years ago, the powers that be were prepared to sacrifice all this. In the name of progress and industrialisation, the government wanted to artificially raise the level of Lake Manapōuri, which lies within Fiordland National Park, to generate more electricity. They’d already built a power station at the lake’s western end – water dropping 178m from the lake to underground power turbines, then discharged down a 10km tunnel drilled through the mountains to Doubtful Sound and the Tasman Sea. The electricity this created was all destined for a single aluminium smelter at Tiwai Pt near Bluff, 160km away.

But by damming the Waiau River that flows from Lake Manapōuri, engineers argued they could raise the lake’s height by up to 30m, increasing the amount of water it held and thereby improving the power station’s operation, and generating power nearly 100% of the time, even in dry periods. Doing so, however, would mean drowning many of the lake’s 33 islands, and flooding surrounding native forest for kilometres inland. The electricity department, the Ministry of Works, successive governments, and the giant multinational company behind the scheme – Comalco – argued the effects on the lake would actually be beneficial; at worst, negligible.

Ideas of harnessing Lake Manapōuri reached back to 1904, when a Public Works Department engineer, Peter Hay, presciently noted its suitability for generating electricity and smelting aluminium. But even in those unregulated days, Hay foresaw difficulties with the plan, given