Snowpack is the source of much of the streamflow in the West. Floods in Arizona result from various conditions including heavy summer thunderstorms, strong winter low pressure systems and remnants of tropical storms. A number of flood fatalities have occurred during recent months, increasing concern about flooding. Six Mexican immigrants drowned in a sewer drain beneath the streets of Douglas, and flood waters swept 11 hikers to their deaths in a canyon near Page. Because of these events, many people are acutely aware of the hazards of flooding.
People feel forewarned and fear the worst.
Some view this year's event as similar to those that occurred in the more distant past, such as in 1972 and before. This time span also was a period of rapid growth for Arizona.