Changes to the plan may be necessary, based on after-action review, and it may need other modifications from time to time, as new information becomes available, new infrastructure becomes a part of the community, new hazards are identified, mitigation efforts are completed, and lessons are learned. Therefore, it is important to establish procedures for maintaining the plan.

The public works agency should review and update the plan whenever changes occur to any of the following:

• Resource inventory
• Infrastructure inventory
• Administrative practices
• Available technology
• Risk and vulnerability assessments

The emergency plan should be reviewed once per year at a minimum.