Ranking Hazards
- Thomas Breckel
- Jul 15
- 3 min read
Blog Title: How to Rank Hazards for Your Emergency Plan (And Why It Matters)
Emergencies can happen anywhere, at any time. Whether you're planning for your home, a school, or a business, one of the most important steps is figuring out which emergencies you're most at risk for. That way, you can prepare wisely and not waste time or money.
This blog will walk you through how to rank hazards step by step. You'll learn a simple formula and how to use it. We’ll also give you examples to help you understand the process.
Why Should I Rank Hazards?
Not all emergencies are equal. Some are very rare but very dangerous (like earthquakes). Others are common but not too severe (like short power outages). Ranking hazards helps you:
Focus on the biggest threats first.
Use your time and money more wisely.
Write a better Emergency Operations Plan (EOP) or Hazard Identification and Risk Assessment (HIRA).
You can’t prepare for everything—but you can prepare for what’s most likely to hit you hardest. Hazard ranking turns guesswork into smart planning.
The Simple Formula for Hazard Severity
We use this equation:
SEVERITY = (Impact Score – Mitigation Score)
This means: First, we add up the scores for how bad the hazard is.
Then we subtract points if you already have ways to reduce the risk.
Let’s look at each category below. Each one is rated from 1 (low) to 4 (high).
Step-by-Step: How to Score a Hazard
1. Probability (How likely is it?)
1 = Unlikely (less than 1% chance per year)
2 = Possible (1–10%)
3 = Likely (10–100%)
4 = Highly Likely (happens every year)
2. Warning Time (How much notice will you have?)
1 = Days
2 = Hours
3 = Minutes
4 = No warning at all
3. Property Impact (How bad is the damage?)
1 = Affected (minor or no damage)
2 = Minor (repairable, still usable)
3 = Major (hard to use, big repairs)
4 = Destroyed (total loss)
4. Spatial Extent (How big is the affected area?)
1 = Less than 1% of your area
2 = 1–10%
3 = 10–50%
4 = More than 50%
5. Population Impact (What happens to people?)
1 = Minor (a few injuries or disruptions)
2 = Limited (some injuries, closures)
3 = Critical (many injuries or shutdowns)
4 = Catastrophic (many deaths, long-term disruptions)
6. Economic Impact (How does it hurt money and jobs?)
1 = Minor (no big effects)
2 = Limited (small losses)
3 = Critical (big job/income losses)
4 = Catastrophic (long shutdowns, major losses)
7. Mitigation Efforts (What do you have in place?)
1 = Not Needed
2 = Adequate (you’re prepared)
3 = Some (need more)
4 = Very Limited or None (no prep at all)
Step-by-Step Example #1: Tornado (for a rural home in Ohio)
Step-by-Step Example #2: Utility Failure (for an office in town)
Ready to Try It Yourself?
Use the list below. Score each hazard for your home or organization using the categories above:
Cyber Attack
Dam/Levee Failure
Drought
Earthquake
Extreme Temperatures
Flood
Hazardous Materials Incident
Infectious Diseases
Invasive Species
Landslide, Erosion, and Subsidence
Man-Made/Terrorism
Tornado
Utility Failure
Wind/Severe Storm
Winter Storm
Wildfire
Once you’re done, rank them by severity score. Focus your plans and resources on the top-scoring hazards.
Tips for Success
Review your rankings once a year.
Update if something changes (like new construction, or buying a generator).
Talk to neighbors or coworkers about their top hazards.
Final Thoughts
You don’t need to prepare for everything. But you do need to prepare for the right things. Hazard ranking helps you stay safe, smart, and ready.
Take the first step: Pick three hazards from the list today and score them with your family or team.
It could make all the difference when disaster strikes.
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