Video from state television showed rescuers in lifejackets rowing rafts through deep floodwater to help the elderly or infirm evacuate.
Others were seen swimming through the murky water with life rings under their arms,pushing inflatable pools containing belongings or even young children.
Authorities have brought in huge pumps to clear water from subways and shopping malls,with clothing and other items left floating in the muddy water.
Business owners were seen trying to clear debris and thick mud smothering their premises.

Residents in Congjiang attempt to clear up and rescue their belongings (Picture: STR/AFP via Getty Images)
The Guangxi township of Meilin is one of the worst hit areas. Floodwaters reached more than 13ft (4metres) above safe levels at their peak.
Experts have warned rural areas will face ‘significant challenges’ due to limited infrastructure and resources to manage or prevent flood damage.
And the clean-up effort will likely be hindered as a tropical depression made landfall earlier on Thursday,only a couple of weeks after Typhoon Wutip killed at least five people.
Chinese meteorologists said the current system isn’t expected to strengthen into another typhoon,but it could still bring disruptive rain across densely populated areas.
It comes as the Chinese National Meteorological Center issued heat alerts in northern parts of the country earlier this week,with temperatures reaching highs of 38°C in Beijing.
Travellers with flights to Catania, Sicily, have been urged to check the status of their journey.
Abigail Lainton was travelling with her siblings on a tourist vessel from the Saona Island in the Dominican Republic when it suddenly blew up in the water.
More than 800 people are still missing.
The temperature was 48°C at the time.