Soon after property is handed over to the buyer, JMB is borned afterwards.
And developers hold no responsibility in this kind of stuff, although JMB also consist of developer as one of the committee member.
Developers only liable for the property quality and warranty issue.

What make u think that basement car park will not flood. Won't you remember the flood happened in Dataran Merdeka.all the cars in the basement soaked in the water. That's why the SMART TUNNEL being built after that incident. Water is flowing into the basement and trap in the basement, no way out as river level is higher than basement level or you can say basement is lower than river level.what do u think? I think the only way is to have a pump. A pump is enough or not, let the engineer count on the the amount of water flowing in.