Flooding occurs whenever water accumulates faster than the ground can absorb it or rivers (and other drainage routes) can carry it away. Rain intensity, duration and topography, as well as soil condition and ground cover, all contribute to varying degrees of flooding.
One of the more frightening things about flooding is that it is one of the most common of all natural disasters and can occur nearly anywhere, at any time.
The impacts of flooding also increase as population and urban development grows.
Pooling of water poses a significant risk, not as much from swift moving water, but more from one's inability to judge water depth. Water only inches deep can be next to water that is several feet deep.