The torrential rains from early Sunday to Tuesday morning drenched the city in east China's Jiangsu Province, with the average precipitation exceeding 400 millimeters within 24 hours.
By Tuesday, the water plant has not fully resumed water supply because it is still inundated in water one meter deep.
Another water plant nearby has started to supply water to the affected residents.
The pumping stations in the city are working around the clock to remove the water that has inundated the main streets.
Local authorities have taken class-2 flood control measures and opened all coastal drainage gates to direct flood water into the sea.