It takes like two inches of rain in AZ to wipe phoenix off the map cause problems. It takes almost a foot before anyone bats an eyelash here (unless you're in a valley).
Earlier this year (I made a thread on it), it was raining all day while I was at school. When I was coming home on the bus, a lot of the roads were washed out with steady flowing creeks where they used to be, but the bus kept going. We then made it to Calvey Creek (creek that runs by my house) to find that it literally turned into Calvey Lake. Fences were wrapped around trees and horses were running loose in the dry part of the street. The road to get home became the bottom of the lake so I had to be returned to school and wait for a parent to get me. I think about eight inches of rain fell in about four hours.
