Mitigation includes activities that eliminate or reduce the chance of occurrence or the effects of a disaster. Federal Emergency Management Agency (FEMA) pre-disaster mitigation programs have shown that communities can do a lot to prevent major emergencies or disasters from affecting them negatively.
If communities cannot prevent disasters, they can at least reduce the damaging impact. For example, requiring roof reinforcements will reduce damage from hurricane winds. Preventing new construction in floodplains or placing structures on columns in them can reduce the chance of flooded homes.