The farmer in Chongxing Town, northwestern China's Ningxia Hui Autonomous Region, used to plant rice on his third of a hectare farm, but switched to maize last year as it requires less water. His income dropped by US$250.

"I don't know what I will plant in the future if the river has less and less water," he sighed.

Between 2001 and 2005, the average runoff of the Yellow River was about 25 percent below normal. Some parts of the river were dry for nine consecutive years beginning in 1990.

The Yellow River plays a vital role in China as it provides water for 12 percent of China's 1.3 billion people.

China has taken measures to protect water sources and control the total volume used by cities along the Yellow River, which prevented the river from drying up over the last six years.

The average runoff in the Yellow River in the past four year is 42.8 billion cubic meters, down 26 percent from normal levels.

"Water levels in the Yellow River are low because the demand for water is too high," said Li Guoying, head of Yellow River Conservancy Committee.

Experts predict that by 2010 the river will be down by 10 billion cubic meters of water.

China has a per capita water resources of 2,200 cubic meters, only 31 percent of the world's average. Currently, about 400 out of China's 660 cities lack water and 136 have reported severe water shortages.

Water shortages have been made worse by pollution. Both the Yangtze River and the Yellow River, the two longest rivers in China, have sounded alarms.

Only two out of 11 lakes along the Yangtze River reported fine water quality during spot tests in 2003. Meanwhile, statistics showed 70 percent of cities along the Yellow River did not have standard water supply.

Despite the shortages wasteful water practices are still often seen. Every year 27 billion cubic meters of water was taken from Yellow River but it is not efficiently used by farmers or cities.

A noted water resources expert in China, Zhang Guangdou, wrote recently that even after the gigantic South-to-North Water Diversion Project, the Yellow River will still lack water due to agriculture and industrial development.

The key to ensuring the water supply is to use water economically and according to supply, Zhang said.

"We will take measures to ensure that water consumption levels out in the year 2030," said Vice Minister of Water Resources Hu Siyi at a conference to mark World Water Day 2006 on Wednesday.

In order to save water, 17 provinces have begun to introduce quotas on water use in the past five years, while more than 10 provinces the price of tap water has continued to increase.

The Yellow River starts in Qinghai Province in the northwest and flows through Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi and Henan, before passing through Shandong and emptying into the Bohai Sea.