The South-North Water Diversion Project is expected to begin supplying water to Beijing by the end of this week, but rumors are doing the rounds that the capital may have to wait longer for water from South China because the central route canal has frozen.

In a widely circulated blog posting, an "observer" claims to have noticed the "slow flow" in the central route canal, saying this could prevent water from reaching the capital in winter. The "observer" also says silting could damage the canal.

The blogger's claims are absurd, to say the least. The blog posting says the central canal will transfer water at the rate of 22.4 cubic meters per second, or one-tenth of the designed capacity, because a China Central Television news video shows a Rubber Duck moving 10 centimeters per second in its water.

People with even the basic knowledge of physics know that the velocity of a floating object is not equal to that of water, because the former meets resistance from the latter from below and air from above. Besides, the water velocity varies with depth - a river that is calm might have fierce currents flowing below the surface. A rough calculation shows a speed of 10 cm per second means 8 kilometers in 24 hours. If the canal water indeed travels at such a slow pace, as the blog posting claims, the water should not have crossed South China even today.

The fact, however, is, water in the canal reached Zhengzhou, Henan province, in Central China earlier this month, three days after the project's central route was opened and flowed into Hebei province in North China a few days ago. Does the blogger know these facts?

The South-North Water Diversion Project's ultimate aim is to transfer 44.8 billion cubic meters of freshwater northwards from the Yangtze River every year. The eastern route canal will transfer water through Jiangsu, Zhejiang, Hebei and Shandong provinces, the central route to Beijing and Tianjin, and the western route to Shanxi, Shaanxi, Gansu and Qinghai provinces and the Inner Mongolia and Ningxia Hui autonomous regions.