The staccato of simple paper firecrackers marked the completion of the 607-foot-high, 1.4-mile-long Three Gorges dam.
Formidable tasks remain before the hugely controversial project is completed, including the construction of power-generating facilities and a ship lift, said Pu Haqing, deputy director of the State Council Three Gorges Project Construction Committee, the official Xinhua News Agency reported.
The final 12 of the dam's 26 generators are to be installed over the next two years, finishing the project in 2008, a year ahead of schedule, according to Xinhua.
Begun in 1993, the project has steamed ahead with the backing of the Communist leadership despite objections to its $22 billion cost and environmental and social impact.
More than 1.3 million people have been relocated to make way for the dam and its reservoir.
Environmentalists and engineers have warned that the reservoir risks becoming polluted with waste from cities and towns upriver, many of which lack adequate sewage treatment plants.
The China Yangtze River Three Gorges Project Development Corp. has spent $2.5 million on a vessel to collect as much as 7 million cubic feet of garbage that accumulates at the dam each year, according to Xinhua.
The government maintains that when it is fully operational, the dam will alleviate flooding on the Yangtze and produce electricity for an economy whose rapid growth has created energy shortages in recent years.
Saturday's simple celebration was not attended by senior Chinese leaders.
Plans for a more elaborate celebration were canceled, Xinhua reported, without giving a reason. Elaborate state celebrations have been rolled back amid a growing disparity between the urban rich and rural poor.