Read the passage. A city flood map relied on water levels from one river gauge. Residents on low side streets insisted that their blocks flooded during moderate storms, even when the gauge stayed below flood stage. Engineers added street-level sensors and found that leaves blocking storm drains could flood those streets without the river overflowing. A student makes this generalization: Broad measurements can miss local conditions that determine how people actually experience a problem. Which detail most precisely supports the generalization without going beyond the passage?