The Xiaolangdi Water-Control Project was officially hailed a success yesterday after eight years as a pilot operation. The project is the most difficult ever built on the world's muddiest natural waterway, the Yellow River.

Tourists visit the Xiaolangdi reservoir April 7, 2009. [Xinhua]

The project, which would have to deal with heavy floods and high sedimentation for years, was ready for a safe run, a panel of experts and officials said. The check was co-sponsored by the National Development and Reform Commission and the Ministry of Water Resources.

The project was completed in 2001 at a cost of 35.2 billion yuan (US$5.1 billion), with over US$1.1 billion loaned by the World Bank. Around 9.18 billion yuan went into rehabilitating the 200,000 displaced residents in 221 villages of Henan and Shanxi provinces. They were compensated as scheduled, Liu Yunjie, an official in charge of the settlement program, said.

The investment was used well and passed by the State audit, the officials concluded. After a day of spot inspection, about 40 km north of Luoyang, Henan province, the experts conceded that the project was of excellent quality. However, they urged the management to keep an eye on a few key technical problems discovered before.

For example, a crack atop the surface of the 160-m-high dam found two years ago needed repair for the dam to be able to hold floodwater at its maximum capacity.

However, expert Wang Hong said: "The crack caused by unhomogeneous deformation would not affect the safe operation of the dam" as it has experienced dramatic fluctuation of crests over the past years during flushing out of silt build-up on the riverbed. Heavy sedimentation downstream was successfully cleared eight times. It is believed silting could be prevented in the next 20 years.

The project also helped fight droughts downstream by supplying water to neighboring areas. It also supplied hydropower to the power crisis-hit Henan province, officials said.