The torrential rain and subsequent flooding that has so far claimed at least 20 lives and forced an estimated 340,000 people from their homes in Jakarta this week is as much a manmade disaster as one pouring from the heavens. Every year during the October to February rainy season, Jakarta is at risk of flooding. The last time it was this bad, in 2002, government pledged to do something. Now the water is back. An estimated 80 percent of North Jakarta remained under garbage-filled water Monday afternoon as boats ferried emergency supplies to stricken areas and forecasters predicted weeks of rain still to come. More than 50,000 people have sought emergency medical aid from disease borne by the filthy waters and the capital is paralyzed.