Authorities have evacuated nearly 60,000 people from their homes in Guangdong, as days of heavy rain caused massive flooding in China's most populous province.
Eleven people have gone missing, while no casualties have been reported so far.
Footage on state media and online show large swathes of land inundated by the floods and rescuers ferrying people on lifeboats in waist-deep water.
Several major rivers have burst their banks, and authorities are closely monitoring "dangerously high" water levels.
They had warned that the level of a river in northern Guangdong could hit a "once in 100 years" peak on Monday morning, though this had yet to materialise by noon.
Much of Guangdong is part of the low-lying Pearl River delta, which is prone to floods due to the rise in sea levels and storm surges.
The delta is a major manufacturing base in China and one of the country’s most densely-populated regions, with Guangdong alone home to around 127 million people.
Provincial capital Guangzhou as well as smaller cities Shaoguan and Heyuan were among the worst hit.
Across the province about 1.16 million households lost power over the weekend, but 80% had their electricity restored by Sunday night.
Flights have been cancelled and delayed at Baiyun International Airport in Guangzhou due to continuous rain, while schools have been ordered shut in at least three cities.
Dozens of homes across the province have either collapsed or have been severely damaged, with authorities estimating a direct economic loss of nearly 140.6m yuan ($19.8m).
Videos shared online show fast-moving torrents collapsing walls and bridges.
A Weibo user said her family scrambled to move furniture from the first storey of their house to upstairs. "The heavy rains have flooded half of the first storey of our home," the user wrote on Sunday night. "I wonder if the second storey would also be flooded overnight. I feel helpless."
“It rained like a waterfall for one and a half hours on the highway when I was driving home last night,” said another user on Weibo. “I couldn’t see the road at all.”
China's meteorological authorities have warned that heavy rains will continue in Guangdong and coastal areas of neighbouring Fujian until at least Tuesday.
"Moderate to heavy" rain is expected in other parts of the country, including Beijing, Tianjin and Heibei.
Last July, China's capital Beijing and surrounding provinces such as Hebei were inundated with heavy rain and flooding after a series of typhoons from the Pacific Ocean made landfall in the country.
That week, Beijing experienced the most rainfall in 140 years.
