It is common in Cochise County for portions of washes to be dry for long periods and to have no distinct banks. These same "dry" washes can carry significant flows at high velocities. Visible signs of a watercourse on property could be a vegetation line near the watercourse when a defined flow path is not visible.
Watercourse means any lake, river, creek, stream, wash, arroyo, improved or unimproved channel, or other body of water through which waters flow at least periodically where the peak flow is fifty cubic feet per second (50 cfs) or greater during the base flood discharge.
Additionally, some properties are subject to complete flooding, or sheet flow, which may have been determined to constitute a Floodplain, although there is no designated or visible signs of a watercourse.
The Federal Emergency Management Agency (FEMA) has done studies to determine the areas of potential flooding problems. They are the final authority on where the Floodplain boundaries are.