1) Jakarta is vulnerable to sinking because it lies on a low flat basin at the mouth of the Ciliwung River on the Jakarta Bay. Its factors are the tons of flooding and that 40% of the city lies below sea level and is sinking by as much as six inches, annually.
2) A flood that happened caught governments attention. The existing seawall was breached. Their plan was to strengthen the existing wall to Jakarta.
3) Some of the hurdles they face are whether or not the government can afford this cost. They will need lots of things like pipes and such that can be very pricey. The author is impressed because he didn't think the government was actually going to pitch in an help.