A general view shows the Three Georges Dam in this photo taken on July 8, 2007. [newsphoto]

The Yangtze River, flowing more than 3,900 miles from the mountains of Tibet through fertile plains here in Hubei province and on to the East China Sea, was playing its traditional life-giving role Thursday, feeding the Chinese economy as it has for centuries.

As barges laden with goods churned upstream and irrigation canals branched out like capillaries, the river's even flow seemed in many ways remarkable. Other rivers in China have swollen out of their banks, with floods killing about 700 people and causing an estimated $7 billion in damage to buildings and farmland over the past two weeks.

The Yangtze's flow across the Hubei flatlands marks the latest chapter in China's millenary struggle to control its waters. Since before written history began, the river has alternated between giving life to China's farmers through irrigation and killing them through seasonal flooding.

The cycle always seemed beyond man's control. But this year, for the first time, the mammoth Three Gorges Dam, 220 miles upstream from here, was used to regulate the river, releasing limited amounts of water and trapping the excess of summer rains in a huge reservoir.

The engineers who have run the dam since it was finished a year ago said the 606-foot-high structure, the world's largest flood-control and hydroelectric barrier, passed its first real test as the waters peaked Tuesday. Boat traffic was halted as engineers let up to 48,000 cubic meters per second rush through 18 giant sluices. But the rest of the backed-up water stayed on the other side of the 7,575-foot-wide concrete barrier, in a pool stretching back more than 100 miles between steep gorges.

Hubei provincial officials predicted the riverbed could handle the limited flow as it headed downstream to the Yangtze's mouth just north of Shanghai. The water level at Shashi, about 50 miles upstream from here, peaked at the 43-meter danger level, they reported; by Wednesday, it had started to decline.

"The biggest flood crest on the Yangtze River this year has passed through the Three Gorges Dam, and the middle and lower reaches of the Yangtze were protected," Yuan Jie, the engineer in charge of water flow, told the official New China News Agency on Wednesday. "The crest was tamed in the reservoir."

Zhuan Xingjia, a laborer with a conical straw hat and sun-bronzed skin who works on a dredging barge docked at Jianli, hailed the news and took comfort in the calm waters around him, but he cautioned that the Yangtze has not always been so subdued.

"The dam has done us some good; this year is nothing like '98," he said. "You should have seen it then," he added, gesturing at the dike that protects low-lying Jianli suburbs. "It was up to there."

That was one of at least four large-scale floods -- in 1931, 1935, 1954 and 1998 -- that have devastated riverside towns and farms since complete meteorological records have been kept. But in addition to the record-setting outpourings, thousands of lesser floods have taken their annual toll for centuries, making the battle to control the Yangtze an important part of Chinese culture and history from its earliest days.

In Wuhan, the provincial capital 130 miles northeast of here, a bronze statue and a commemorative stele have been erected to honor Yu the Great, a legendary emperor who won his subjects' hearts 4,000 years ago by digging canals to divert seasonal floods away from the city. More recently, Mao Zedong pledged famously that under communism the Chinese would be able to bend nature to their will -- and he, too, got a memorial beside the Yangtze.

China's modern governments, including the current one headed by President Hu Jintao, have been stacked with engineers eager to make Mao's words come true. Li Peng, who got his start supervising municipal waterworks, put the Three Gorges project into motion when he was premier in the late 1980s. President Jiang Zemin, who had studied engineering in the Soviet Union, turned the first earth in 1993. Hu, a hydraulic engineer who personally followed the progress of construction, was in charge when the dam was completed last year.

The project has been heavily criticized since construction began 14 years ago. More than a million people were displaced to make way for the reservoir, often with little regard for their desires, and corruption undermined government pledges to pay them compensation for the land. Conservationists asserted that the huge backup of water would affect the climate and become a cesspool for Chongqing, a huge city 250 miles upstream. Some critics voiced worry that, because of flaws, the concrete construction could give way under pressure, sending a wall of water coursing toward downstream communities.

In its first flood-prevention operation, however, the dam drew only praise from those living downstream. "The dam has done us a lot of good," said Wu Jinghua, who was lunching with his wife, niece and nephew at a Jianli amusement park 500 yards from the riverbank. "We haven't felt a thing from the flooding so far."

Most of the flooding this year affected people living along the Huai River, north of here in Anhui and Jiangsu provinces, and along the Jialing River, a tributary of the Yangtze in Sichuan province to the west. Jialing River communities in mountainous areas around Chongqing were particularly hard-hit, prompting President Hu to visit and promise government help in rebuilding.

Shaanxi, to the northwest, also suffered from heavy rains last week that killed 16 people and left 14 more missing, according to the Civil Affairs Ministry. More than 8,000 houses collapsed from mudslides, leaving 35,000 people homeless, the ministry said, and roads and electronic communications were cut.

Hubei province was hit as well, however, along smaller streams as they flowed toward the Yangtze. The tributaries were swollen by what the provincial Civil Affairs Bureau described as the heaviest rains in a half-dozen years. Eighty people have been killed so far this summer and 28 were reported missing, the bureau said.

Overall, according to an estimate by the Xinhua News Agency, the flooding affected nearly 120 million people -- almost 10 percent of the population -- despite the apparent taming of the Yangtze.

(Our Special Courtesy to the Washington Post)