The Chinese government launched an unprecedented "underwater palace" project Thursday in a bid to protect Baiheliang, the world's oldest water survey device which will be submerged once the Three Gorges reservoir is filled.

Shan Jixiang, director of the State Bureau of Cultural Relics, said that Baiheliang, an 1.6 km-long massive reef important for observing water level changes, will be covered by an elliptical transparent shield so visitors in the future can still see it.

The massive project, which will cost 140 million yuan (US$16.9 million), is expected to be completed in 2005.

Shan said the project well reflects that the Chinese government takes much responsibility for protecting cultural relics and China always holds a careful attitude toward respecting history as well as responsibility for both ancestors and offspring when conducting the Three Gorges Project.

Located at the upper reaches of the Yangtze River, Baiheliang only emerges from the water during dry seasons. Therefore, it was a very important marker for ancestors to observe the changes of the water level and according to it, they could predict if they could have a good harvest.

On the massive reef, there are more than 20 vivid fishery sculptures, serving as the water level markers.

Meanwhile, about 30,000 characters of Chinese poems are also left on the stone, which were carved by Chinese poets of different dynasties.

The stone inscriptions on Baiheliang recorded about 1,200 consecutive years of the river's water levels during the dry seasons as well as its low water periods.

However, similar water survey devices at other rivers of the world only included the local water level information of less than 100 years. In comparison, the stone inscriptions on Baiheliang are much more affluent than those discovered at the Nile River.

Therefore, Baiheliang has gained fame as "a miracle in world water survey history." Engineers also consulted the water level information on Baiheliang when designing the world's largest water engineering project, the Three Gorges Project.

The massive Three Gorges Project, whose reservoir will begin to store water this June, will inundate numerous cultural relic sites.

To ensure those precious cultural relics receive the best protection, the Chinese government has mobilized two thirds of the country's archaeological institutions to meet at the Three Gorges reservoir area and excavate cultural relics.

Since 1994, China's cultural relics protection departments have started to research how to protect Baiheliang. Experts once raised several solutions, such as building an underwater museum, or reproducing it and laying it on the bank but submerging the original one.

Finally, the solution issued by Prof. Ge Xiurun, academician of the Chinese Academy of Engineering, was accepted.

He suggested the covering of the Baiheliang reef by a water pressure-free container with an arch shape. Fresh water will be instilled in the container, making its inside and outside water pressure balanced.

Two underwater channels will be built from the riverbanks, so visitors can see the stone inscriptions on Baiheliang by walking through the underwater channel.

Experts have made simulation tests via computer to ensure the water pressure-free container is not damaged by silting and water flow.

(Xinhua News Agency February 14, 2003)