where everything is music.: water power

There used to be a boardwalk. Now it is closed off, rotting, ridden with holes and plastered in slippery leaves. It has been raining for three days now, really raining, the kind of rain that can only occur in a place that receives upwards of seven meters of rain a year. Three days ago the sky opened up and water began pouring out of it in the way it might during a tropical afternoon storm or a monsoon – a kind of rain that comes quickly and leaves a short while later. But this rain doesn't leave. It continues unabated for days.

On Monday, having played board games, baked, done yoga, ate and watched moves for far too long, we gear up. Everyone digs out the most protective, waterproof combination they can find. I wear my dry suit, neoprene booties, neoprene gloves, a neoprene balaclava and my diving mask. Then we pile into the back of the van and drive to Bowen Falls.

At 160 meters tall, Lady Bowen Falls is three times higher than Niagra Falls. It's fed by a glacier, but the sheer mountains surrounding it lack soil and thus do not absorb rainwater, so when it rains hard like this, Bowen floods quickly. The mountains funnel rainwater into an ever-swelling river that churns through an alpine valley, then shoots like a firecracker into the sky before dropping over a ledge the height of a 50-story building.

Bowen Falls is not only a magnificent example of hydrology, it also supplies the community of Milford Sound with drinking water and electricity. About 150 people live in Milford Sound, and every time one of us flushes a toilet, drinks a glass of water or takes a shower, we are using pure, untreated glacier melt-off that has been locked up in ice for 30,000 years. Humans arrived in New Zealand 800 years ago, so the water coming off Bowen Falls has never before touched another human being. This astounds me. In London, they say, the water coming from the tap has already been cycled through eight people.

We're lucky here. Not only because we can turn on the tap and drink glacier water (as well as brew beer from it), but because when it rains hard and there is no work and the one road into this place is closed off due to rock slides, we venture into the most raw, wild display of nature I have ever imagined. We can go under Bowen Falls while it is flooding.

I've known this for weeks. I think I'm ready. I've been warned to cover every possible piece of skin. I'm expecting it to be intense.

But nothing can prepare me for the reality of it. We pile out of the van – seven of us, five kayak guides and two friends – and walk along a narrow, crumbling piece of asphalt, the start of the old trail. On one side is the loamy, pulsing ocean; on the other, a cliff dripping with ferns, sphagnum moss and rivulets of water. We reach a solid metal gate and climb over it, like teenagers sneaking onto the football field at night. The boardwalk on the other side curves against the ocean for a while, then disappears into the forest. As we follow it deeper toward the falls, water becomes the only sound. Rain pelts the leaves and splatters into a forest that has become swampland practically overnight.

The wind picks up as we approach. Bowen Falls creates its own winds, gusting over 100 kilometers per hour at its base. Trees become gnarled bonsais, their branches and trunks swept away from the falls and frozen in fantastic shapes as if reaching their arms toward the sea in a plea for help, a desperate attempt to get away from this reckless display of power.

Then there is nothing. Even with a diving mask, I cannot see anything but driving water against a backdrop of gray. I can hardly breathe; I must constantly spit out mouthfuls of water. There is no sound but the roar of the falls. I concentrate only on putting one foot in front of the other, battling against the force of the wind, leaning into it with all my weight, trying not to lose sight of Ricki's orange jacket somewhere ahead. At some point, the boardwalk ends, and we struggle on. Often the wind knocks us over and we sit, clutching tussocks of grass, helping each other crawl forward. We cannot talk or see each other's faces, aware only of the vague blurs of color and groping hands that we know belong to fellow human beings.

The force of the wind and water is overwhelming, breathtaking, astonishingly powerful. It is like intense heat or cold: impossible to describe until you've felt it for yourself. I feel like there should be a TV camera on me, like I am a foolish meteorologist risking life and limb to deliver a report from the middle of a hurricane. But there are no cameras. There isn't even the sensation of wetness anymore. Everything else drops away until there is only the rush of adrenaline coursing through our veins and the understanding that for all our bravo, mother nature is able to knock us and anything we build swiftly and surely on its ass.