But this is just the beginning of the upheaval that the Three Gorges Dam will wreak upon the river and the livelihoods of those it has supported for thousands of years. Whether for better or worse, there is no disputing the gargantuan scale of the project. So too will untold quantities of potentially priceless historical relics dating back to the Stone and Bronze ages. Above all, an estimated 1.2 million people will have to leave their homes in the biggest ever dam-forced human migration in history. As China gears up for the crucial and sensitive task of moving them, the questions that have dogged the dam's builders from the outset are intensifying.
China says it is.
Officials acknowledge there are problems, but say they will be outweighed by the benefits. They include curbing flooding in the lower reaches of the river, which bursts its banks with fatal regularity every year. The dam will provide the equivalent of 10 nuclear power station's worth of electricity, which China badly needs, without adding to the problem of greenhouse gases. The dam's critics, most of them from the West, say the dam's ability to control floods may be limited, because the river's lower reaches are fed by three other tributaries that also contribute to flooding. A string of smaller dams would have had the same effect on floods and produced as much electricity, without as many environmental side effects, according to Probe International, a Canadian group that has campaigned against the dam.