Local Mitigation Planning Policy Guide Side-by-Side Comparison
Learn more at fema.gov June 2022 6
2011 Local Mitigation Plan Review Guide 2022 Local Mitigation Planning Policy Guide (changes
in yellow)
such as tornados, the plan may state that the entire
planning area is equally at risk to that hazard.
Extent
means the strength or magnitude of the
hazard. For example, extent could be described in
terms of the specific measurement of an
occurrence on a scientific scale (for example,
Enhanced Fujita Scale, Saffir‐Simpson Hurricane
Scale, Richter Scale, flood depth grids) and/or other
hazard factors, such as duration and speed of
onset. Extent is not the same as impacts, which are
described in sub‐element B3.
For participating jurisdictions in a multi‐
jurisdictional plan, the plan must describe any
hazards that are unique and/or varied from those
affecting the overall planning area.
B2.
The plan must include the history of previous
hazard events for each of the identified hazards.
The plan must include the probability of future
events for each identified hazard.
Probability
means the likelihood of the hazard
occurring and may be defined in terms of general
descriptors (for example, unlikely, likely, highly
likely), historical frequencies, statistical
probabilities (for example: 1% chance of
occurrence in any given year), and/or hazard
probability maps. If general descriptors are used,
then they must be defined in the plan. For example,
“highly likely” could be defined as equals near
100% chance of occurrence next year or happens
every year.
Plan updates must include hazard events that
have occurred since the last plan was developed.
B1-c. The plan must provide the extent of the hazards
that can affect the planning area. When describing
extent using charts or scales (e.g., Saffir-Simpson scale
for hurricane wind speed; Enhanced Fujita scale for
tornado), the plan must document how the scale
applies to each jurisdiction.
Extent is defined as the range of anticipated intensities
of the identified hazards. The information must relate
to each of the plan participants or the planning area,
depending on the hazard. Extent is most commonly
expressed using various scientific scales.
B1-d. The plan must include information on previous
hazard events for each hazard that affects the planning
area. At a minimum, this includes any state and federal
major disaster declarations for the planning area since
the last update.
Previous occurrences can be included in a variety of
ways, but should include an emphasis on significant
events, as determined by the community. If no events
have occurred for a hazard, this must be stated.
B1-e. The plan must include the probability of future
events for the identified hazards that can affect the
planning area. Probability may be met in a variety of
ways; however, general descriptors must be
quantitatively defined.
Probability must include the effects of future
conditions, including climate change (e.g., long-term
weather patterns, average temperature and sea levels),
on the type, location and range of anticipated
intensities of identified hazards.
Probability of future hazard events means the
likelihood of the hazard occurring or reoccurring. It may
be defined in historical frequencies, statistical
probabilities, hazard probability maps and/or general
descriptors (e.g., unlikely, likely, highly likely). If general
descriptors are used, they must be quantified or
defined in the plan. For example, “highly likely” could
be defined as “100% chance of occurrence next year”
or “one event every year.”
B1-f. For multi-jurisdictional plans, when hazard risks
differ across the planning area and between
participating jurisdictions, the plan must specify the
unique and varied risk information for each applicable
jurisdiction and their assets outside the planning area.