Call this a gentle disagreement. :-)
The lesson of massive engineering projects from the past - dams are a perfect example - is that unintended consequences are left for others to amend. Rivers exist in a state of dynamic equilibrium with their watersheds. We force a river to a single course and a single level and we end up with a New Orleans catastrophe-in-waiting. Meanwhile, depleted of the Mississippi's renewing muds, the delta lands and bayous south of New Orleans are receding rapidly and will soon be washed into the Gulf of Mexico.
The Everglades water containment schemes of the last century are now being reversed to try to restore some of the previous natural flow-through, at a cost of many billions. The Glades have suffered permanent damage in the meantime, and are a shadow of their former reach and condition.
Flood control is good, right? The Aswan Dam in Egypt has stopped the refertilization of the Nile watercourse by silt-laden flood waters. It's a nightmare for agriculture in a region that has precarious agriculture to start with. Lake Havasu in our own West is now a third filled with silt. There isn't a large dam you can name that doesn't have this problem.
Rivers move their courses, they swell and ebb, they change the land over which they wander, and the land and the river develop a dependence on each other. We interrupt that at great peril. Dams promote more and more people living on flood plains. A recipe for disaster, and a guarantee that in the future those who live next to rivers will consider it their "right" and the government's sober responsibility to make sure they are never discomfitted because of their shortsightedness.
The environmental impacts extend beyond the physical and geological. Sensitive species of animals (river dolphins, for one) are being hit hard by this dam. Migrating fish will no longer migrate. Water temperatures and pH will be different, pressuring native populations. Water speed through the river will be greatly reduced. Do you know that upstream of the dam, major cities dump as much as half of their sewage untreated into the river? At minimum, this unflushed biomass burden will suck the stilled river free of oxygen. There are, of course, worse effects from the flow of untreated sewage into a now-slow river.
You object to calling the flooding of traditional village lands, the water burial of historical and archaelogical sites, and the drowning of natural river valleys and habitats anything but the euphemism "relocation." If the "relocated" people's homes and villages are now under water, then how did they not lose them? I'm glad they got new ones, but if you read in other sources, you'll find that this was a nightmare for those affected.
There are benefits to the Three Gorges dam. I like that the power it produces means less coal burned in plants that would otherwise have to be built, for one. I'm not driven by ideology here, and don't condemn all natural engineering projects out of hand. But after several years of reading arguments both pro and con, I've decided that the evidence shows the problems the dam creates do not justify the benefits.
Dam-building has usually proceeded in the context of fictitious "public goods" asserted by businessmen (in capitalist countries) and politicians (in socialist countries), but the real goods are those realized by those in power, and not those who must live with the consequences. I see no departure from pattern here.
You might look up Hech Hechy Valley or Glen Canyon sometime for a diversion. Here's a good place to start:
The Place No One Knew: Glen Canyon on the Colorado
http://www.amazon.com/gp/product/0879059710/sr=8-1/qid=1148397629/ref=pd_bbs_1/102-4247228-4282534?%5Fencoding=UTF8This is my opinion, nothing more, nothing less, nothing personal.
Peace.