Something is not working

I was not working, took a little break and just came back. Heard that there was a heavy downpour this morning, and a pleasant surprise, no flooding. Is the system working or the amount of rainfall fell short of the 100mm in less than 3 hours? It seems that we have had two of such 100mm rain within 2 hours and flooding occurred. I still remember someone saying that the Marina Barrage is not only a reservoir but a flood control system and that there would be no more floods. It is a very expensive piece of equipment and it better works. And I think it is supposed to work in auto mode, or is it? Maybe the parameters were wrongly set and thus it did not trigger to release water from the Marina Bay Reservoir fast enough, or enough in volume to avoid the flood. or maybe there have reset it right now and this morning's rain would be easily taken care of by the system. Or maybe we have an expensive piece of equipment but failed by the minor blockages of culverts and drains here and there. Let's hope that another 100mm rainfall within a few hours will not do the same damage again. I was shocked by the picture of Bishan Park.