A Chinese water resources official on Sunday called on people to improve the awareness of water saving and protection in a bid to curb pollution of rivers from spreading and worsening.

Li Xiaoqiang, chief of publicity section with the Yellow River Conservancy Committee, made the remark over the phone while commenting on the fact that pollution had spread to one third of the Yellow River system.

In this picture published on August 26, 2008 a paper mill in Yongle Town of north China's Shanxi Province discharges waste water to the Yellow River. Crops along the river are severely damaged. [Photo: People's Daily]

With a mainstream of 5,464 km, the Yellow River, billed as the "mother river" of China, originates from Qinghai province, flows eastward through Sichuan and Gansu provinces, Ningxia Hui and Inner Mongolia autonomous regions, and Shaanxi, Shanxi and Henan provinces before emptying into the Bohai Sea from Shandong Province in east China. It has 35 main tributaries.

The Yellow River Conservancy Committee said in a bulletin released last Thursday that it monitored the mainstream of the Yellow River and its tributaries last year, with the combined length totaling 13,492.7 km, and found 4,557.6 km, or 33.8 percent of the waterways monitored, to have polluted water classified as type-five negative.

The Yellow River Conservancy Committee is an organization affiliated to the Ministry of Water Resources and has its headquarters in Zhengzhou, capital of central China's Henan Province. It is assigned with the mission to overseeing the welfare of the Yellow River system.

Only 2,174 km of the waterways, or 16.1 percent of the river sections monitored, were said to have water quality classified as types one and two, both standards suitable for drinking.

The bulletin also showed that the river system had an increase of 18.9 percent in rainfall last year in comparison with that of 2006, but received more pollution too: waste and sewage water discharged into the river system totaled 4.29 billion tonnes last year.

Industrial sector was blamed as the No.1 polluter, followed by living sewage contributed by urbanites living along the river system and the service trade.

In 2006, the organization monitored 12,510.8 km of the Yellow River system, of which, 31.1 percent were found to have type-five negative water. And 4.26 billion tonnes of waste and sewage water was discharged in the Yellow River system in that same year.

The Yellow River and its legions of tributaries flow through arid north China, making the river system hard to clean on its own, said Li.

The State Council, China's Cabinet, launched a nationwide campaign among industrial enterprises to save energy and reduce the discharge of pollutants enormously in the second half of last year.

"It is a good thing though it takes arduous efforts too," said Li. "I wish a harmony could be achieved between development, utilization, and protection of the river someday."