THREE GORGES DAM SITE, Hubei Province -- The major structure of the gigantic Three Gorges Dam on the Yangtze River, China's longest, was completed Saturday. The project, often compared to the Great Wall in its scale, absorbed and benefited from a great amount of opinions from opponents, which enabled its schemes to improve continuously.

"Naysayers contributed significantly to the Three Gorges Project, "said Pan Jiazheng, head of the experts panel for the project and academician of the Chinese Academy of Sciences and the Chinese Academy of Engineering.

Pan, together with another 50 or so members from the panel, witnessed the completion of concrete placement for the Three Gorges Dam's main wall Saturday.

"As for a project, it is not necessarily favorable if there is no opposing opinions. The more naysayers, the more thorough and detailed related researches and proofs may go," said Pan during an interview with Xinhua.

Now in his 80s, Pan himself had been an opponent to the Three Gorges project before he became a chief tech advisor for the feasibility study on the project.

According to Pan, in the 1950s, debates centered on China's financial and technological capabilities for the project. However, such concerns have webbed gradually since the late 1980s, along with China's endeavors to grow powerful economically and technologically.

In 1986, the Ministry of Water Resources invited 412 experts to start the feasibility study for the Three Gorges project, and Pan was appointed the head of the group.

The Three Gorges project was approved by the National People's Congress, China's top legislature, in April 1992, 38 years after related researches and proof officially began in 1954.

Pan said, "Generations of scientists, both at home and from abroad, participated in the planning, designing and consulting of the project."

"Opinions and proposals from those scientists, including naysayers, were solicited. Views from opponents helped improve the democratic and scientific decision for the project," Pan stressed.

He said in the process of proof, some experts and scholars made researches on budgetary estimates for the project, future silting in the project's reservoir, possibility for geographic disasters, including earthquakes, the project may induce, cost of residents relocation and any effect the project may have on ecosystem and environment. They also studied engineering problems and technical means, advancing various proposals and opinions.

Some used to worry that the project would become a siphon of funds. Actually, it has saved 20 billion yuan (2.5 billion U.S. dollars) and managed to limit the total cost at approximately 180 billion yuan (22.5 billion U.S. dollars).

"Not all of its generators have begun operation, but the project has achieved an annual balance between expense and revenue," Pan said.

He said from 2006, annual income by the 14 operational sets of generators of the project will cover the funds allocated the Central Government for the project in each of the coming years.

"Nothing on earth embraces advantages only. It is imperative for us to maximize the advantages while minimize the disadvantages," Pan said.