Excerpted with permission, Meltdown in Tibet: China’s Reckless Destruction of Ecosystems from the Highlands of Tibet to the Deltas of Asia, by Michael Buckley. Available from Palgrave Macmillan Trade. Copyright © 2014. (Scientific American is part of Macmillan Publishers.)

AUGUST 2005: My introduction to the tremendous power of the rivers of Tibet comes via a rafting ride on the Drigung River, a few hours’ drive from Lhasa. This is a baptism fueled by pure adrenaline, a baptism that raises lots of questions—and gets me going on research.

Feeling rather ridiculous—decked out in a flashy wetsuit, rubber booties, lifejacket, and helmet—I waddle over to the big blue raft. All the gear is in the interests of warmth and waterproofing—and safety. Georgia gives us a briefing on what to do if ejected from the craft (don’t try and tie a res­ cue rope around your neck). Georgia, from Australia, is conducting safety rescue courses for the Tibetan rafting trainees. She’s our safety kayaker on this day trip, scouting rapids ahead and trolling for anybody that happens to be floating past.

Instructions over, we turn to face the river itself, which is swollen by monsoon rains—definitely moody—frothy and foaming in parts. No room for error here. From this point, rapids are class III and IV—and our lives are in the hands of Captain Ram. Ram is a bearded   young Nepalese with long hair tied back in a ponytail, and a warped sense of humor. Happily, Ram has ten years of white-water rafting and kayaking experience on rivers in Nepal. He gives us a briefing on when to paddle forward, backward, stop, jump to the left side of the boat, jump to the right.

There are not many rivers in the world where you can raft above 13,000 feet. In Tibet, most terrain starts at this elevation, and it’s all uphill from there. I check my watch: the altitude at the put-in point is 13,400 feet.

We push off into the swirling Drigung Chu, nerves on edge. The majestic landscape flashes by in a blur—not much time to take it in when your energy is concentrated on remaining glued to the raft. But you feel the raw power of the river as no onlooker can. And you begin to realize that rivers are not all that simple—a point emphasized by the menacing waves crashing around your head. Rafters have more specific lingo for them: standing waves, pillow waves, eddies, seams, and drops—and deadly “holes.”

On the river today are two matching inflatable blue rafts, both with a Nepalese Captain Ram at the helm. They provide a sort of stereo rafting effect for those with altitude-induced illusions. Injected into this is a dose of high spirits created by competitiveness among rafters—broad­ siding boats, and drenching occupants by batting paddles on the surface. In the rafts: a couple from Germany, two Swiss guys, a brother and sister from the United States, a Dutchman, a Tibetan woman. I have missed most names, but remember the nationalities. Apart from high water, there’s a lot of adrenaline floating around. The symphony of first-time rafters: high-pitched yelps, yahooing, and the occasional scream as waves crash over the bows, drenching all in frigid water. A good deal of the vocalizing emanates from Lodol, the young Tibetan woman on board next to me. She’s on the lam: everybody at work has been told she’s taken a day off to deal with family problems—and lord knows what she has told her family, as they would surely fear for her safety.

I’m trying to figure out if Captain Ram is bent on deliberately steering us into troubled waters at times to increase the excitement. In any case, he’s a wizard at reading the river—looking for the best line through the rapids, steering clear of submerged rocks—and avoiding “holes” (like the spin- cycle of a washing machine, only much magnified) that can flip a small craft. Forward! Forward! yells Ram,  urgently  at one point. That translates as Fast forward! I think. There’s no special command for Jump out of your skin!—which could easily be applied when we reach a spot with barely enough space for the raft to squeeze through. It’s a kind of gate formed by rocks, so our raft has to be very precise. But we pull it off. Everybody good?  inquires Ram. He calls for a group high-five with upright paddles.

Woman overboard! We have lost the college student from Virginia, along with the Dutchman—both swept out of the raft by a freak wave. But they are soon back with us, all in one piece though somewhat shaken. To the rescue is Phuntsok, the Tibetan trainee rafter aboard. In a few more sea­ sons, he should be able to take over the helm from experienced rafters like Ram. Tibetan trainees have to overcome cultural taboos about fast-flowing rivers—normally places to stay well away from because they are associated with drowning. There is no tradition of pleasure boating in Tibet. Tibetans don’t spend any time on rivers, they don’t fish, and they look down on the boatmen who ply traditional yak-skin coracles at river crossings.

In calmer waters, we finally relax on the paddle and take in the scenery. And wave at Tibetans lining the banks. Some wave back, others just stare, open-mouthed. Foreigners are alien enough, but ones dressed in colored wetsuits and helmets must surely appear quite bizarre. When we stop for lunch at the river’s edge, curious Tibetans edge closer—not so shy.

On the Drigung, you get to experience just how powerful Tibet’s rivers are. The rafting gives you a huge adrenalin hit. I’m on a euphoric high that stays with me for the rest of the day. But lunchtime conversation takes a surprising turn. The rafting guides are not talking about first descents, they’re talking about last descents. The Drigung River is the site of the first commercial rafting trip in Tibet, only started a few years back. But the run may soon be inaccessible; dam building could block the river, according to one guide.

After lunch, we resume the rafting descent: more bouts of being heaved around and showered in freezing water. This alternates with more tranquil stretches where I even relax enough to indulge in bird spotting: I sight a hoopoe, an exotic-looking bird with a spiky orange crest and black-and­ white wings.
All too soon, the wild ride comes to an end. The gear is stowed away. The rafts are deflated, rolled up, and packed onto a minibus. We help our­ selves to mugs of hot tea, which is good because my fingers are numb from the icy Drigung waters. And yet while most of me feels numb, my brain is exceedingly clear and calm. I have survived the ride.

But something leaves a bad taste. At the tail end of the rafting run, we passed a small dam under construction. The guides mentioned there’s a much bigger one downstream on the Drigung. Hydro megaprojects are popping up all over, one guide said, to supply the Chinese industrial ventures with power. Chinese engineers want to bore tunnels to divert rivers from Tibet to the north and east, to supply water-starved Chinese cities. That sticks in my head. The water diversion, the dams, the huge tunnels. What on earth are China’s engineers getting up to?

This new information surprises me. As a guidebook writer I have traveled to the Tibetan world numerous times, and have read everything I could lay my hands on. But this is the first time I have heard of dam building in Tibet. And yet it makes sense: Tibet has very powerful rivers, with the potential to generate huge amounts of hydropower. The more I dwell on this, the more I am convinced I should get cracking and research it—and relay this news to others.