"Preparedness" is conducted before a disaster occurs in order to build emergency management capacity. It has three elements: the development of emergency operation plans; practice at putting the plans into effect (exercises); and public education. Preparedness planning seeks to anticipate problems and project possible solutions to minimize disaster damage.
"Response" activities provide emergency assistance to save lives, preserve property and protect the environment. Rescuing overturned boaters or people stranded in trees from raging floodwaters is a response function. A goal of all emergency responders is to reduce the probability of additional injuries or damage, and to start the recovery process as soon as possible.
"Recovery" is the process of returning systems to normal levels, such as replacing a bridge that was washed away by flooding, or restoring a water system that was inundated by floodwaters. Some activities can be accomplished in the short term, such as adding gravel to washed out roads; while other activities take years, such as replacing bridges over major rivers.
"Mitigation" activities normally occur before an emergency or disaster, or directly on the heels of a disaster. Such activities include building dikes, adopting flood plain and/or zoning regulations, and creating building codes that include plans for storm shelters. The primary purpose for mitigation is to eliminate or reduce the probability of a disaster, such as a flood. It will include action to postpone, dissipate or lessen the effects of the disaster.