dismayed by images on television of darkened, waterlogged buildings in Lower Manhattan, and wondered how the area would have fared if it “had a Dutch approach to the problem.” American society, he said, “is more dependent on self-protection and taking care of your own household,” attitudes that make it difficult to mobilize public attention and money to prevent disasters ahead of time.

While his country has invested heavily in flood control, Mr. Kuijken, the delta commissioner, says this does not mean idly throwing around money but instead involves a careful cost-benefit calculation.