ARROYO FLOOD
An arroyo is a river, which is normally dry. When there are storms approaching these areas, Fast-moving River will normally form along the gully and cause damages.
This is the most common type of flooding. When the actual amount of river flow is larger than the amount that the channel can hold, river will overflow its banks and flood the areas alongside the river. And this may cause by reasons like snowmelt or heavy spring rain.
In most of the urban area, roads are usually paved. With heavy rain, the large amount of rainwater cannot be absorbed into the ground and leads to urban floods.