The former premier of China and current chairman of the National People’s Congress is also worried about the two-month interruption to Yangtze River traffic when the diversion channel is dammed late next year, Sanxia gongcheng bao (Three Gorges Project Daily) reported.

During an inspection trip last month to the dam site near Yichang, Hubei province, Mr. Li said the Three Gorges project will not only control floods, generate electricity and improve navigation, but also contribute to the success of the south-north water transfer scheme in which water from the Yangtze River is to be moved to parched north China.

Mr. Li listed the three main goals of the Three Gorges dam project’s second phase, to be completed in 2003. The reservoir is to be filled to the 135-metre level, with everyone living below that level to be resettled before then; the first group of turbines is to start generating electricity; and the permanent ship lock is to begin operating.

He said the quality of the dam project as a whole is sound, thanks to the introduction of market principles, and good management and supervisory systems, but that project quality will only really be tested after the reservoir is filled.

And although great progress has been made to date in building the dam, he expressed deep concern about the project’s 26 turbines, which will be the world’s largest. Citing “many unknown factors,” he said uncertainty surrounds the manufacture and installation of the 700 MW turbines. (GE Canada’s hydro division, GE Hydro, is building three of the units at its plant in Lachine, Que.)

The Itaipu dam on the Parana River between Brazil and Paraguay – currently the world’s biggest dam – has 18 turbines. Most of the engineers and technicians who worked on Itaipu, which was completed in 1982, have now retired, Mr. Li said, apparently regretting the loss of their expertise.

Mr. Li said lessons must be learned from a serious technical accident that occurred during installation of the turbines at the Gezhouba dam, located about 40 km downstream of the Three Gorges site and completed in 1988. He gave no further details about the accident.

He asked builders of the Three Gorges dam to be aware that installing the turbines and the electricity-transmission equipment will require advanced technology, a great deal of care, and a high degree of technical and psychological preparation.

Another major challenge will be the damming of the diversion channel, which Mr. Li said is likely to be tougher and more complex than the November 1997 operation to block the river’s main channel. Of particular concern is the fact that navigation on the Yangtze will have to be interrupted for 67 days, he said.

During this time, all boat passengers will have to disembark and freight will have to be transported overland to the other side of the dam. This will present many difficulties and require complicated co-ordination among local governments, shipping companies and dam authorities, Mr. Li said. Moreover, companies that sustain economic losses as a result of the interruption to navigation will have to be compensated, he said.