Vehicles slowly make their way through flood water in Shanghai. [Photo/Sina Weibo]

"Come to Shanghai and I can take you for a trip on water. Remember to bring a boat!"

"I have to sail across the sea to go to school."

"Are there any apps for me to rent a raft?"

Pictures of flooded Shanghai went viral on China's biggest micro-blogging platform Sina Weibo, with many making fun of a bad traffic and criticizing the backward drainage system of one of the most prosperous cities in China.

The standard for most districts is to handle rain falling at 36 millimeters per hour but the storm this time is far worse and many places are flooded, affecting residents' daily lives, according to the Shanghai Drainage Administration.

Drainage system coverage in areas near the Outer Ring Road remains low and cannot combat extreme weather.

After the downpour, the administration used 51 specialized teams and 21 operational pumps to compliment the drainage system. Relative departments initiated emergency measures.

Shanghai issued an alert on Wednesday morning warning of potential geological disasters as the storm was forecast to continue causing problems.

As of 11 am, districts such as Hongkou and Putuo had received rainfall of more than 240 millimeters, according to the administration.

Numerous flights were cancelled and some schools' classes suspended.