Morakot has also brought torrential rains to east China's Zhejiang province, causing massive river flooding and landslides.
The Ministry of Civil affairs says eight people have been killed by Typhoon Morakot in the mainland, and three are missing. It says Morakot has caused some 10 billion yuan in direct economic losses.
The Tiaoxi River is one of the four rivers running through Hangzhou, the capital of Zhejiang province.
Its water level was driven up high by days of heavy rainfall. Early Tuesday, the water level exceeded the warning level by nearly one meter.
More than ten thousand people living along the river were in danger.