Master Plan
Nashua Fire Rescue, NH
The Nashua Hazard Mitigation Action Plan includes a very thorough community risk assessment. The
following section summarizes the process that led to the development of the plan as well as the resulting
Hazard Assessments, Goals, and Objectives. ESCI will then correlate the Hazard Mitigation Plan with the
Historical Service Demand and Performance of the City of Nashua.
Hazard and Risk Identification Process
The hazards in the Hazard Mitigation Plan Update 2019 align with the hazard names identified in the State
of New Hampshire Multi-Hazard Mitigation Plan Update 2018. Two hazards identified in the State plan that
do not impact Nashua are Avalanche and Coastal Flooding.
Avalanche
Coastal
Flooding
Inland
Flooding
Figure 35. Natural Hazards in Jurisdiction
Hazard Type Hazard Location Hazard Extent impact
This hazard does not occur in Nashua
This hazard does not occur in Nashua
All special flood hazard areas; areas
have been identified that experience
localized flooding on a regular basis.
Slopes along Merrimack & Nashua
Rivers prone to erosion.
Roadways with the potential to flood
include:
FEE Turnpike: Southbound at crossing
of Spit Brook Rd
Circumferential Hwy: Within Floodway
Daniel Webster Hwy: In 1% and .2%
Floodplain at Royal Crest Dr
Canal St: From Merrimack River to
Salvail Ct
Bridge St: Within Area With Reduced
Risk Due to Levee
E Dunstable Rd: Proximity to
Floodway and .2% Floodplain but no
flooding
Main Dunstable Rd: Within .2%
Floodplain from Valhalla Dr to Memory
Ave;
Proximity to .2% Floodplain for much
of its run
Spit Brook Rd: Within 1% Floodplain at
intersection with FEE Turnpike
W Hollis St: Within Floodway at
Nashua River crossing
E Hollis St: Within Area With Reduced
Risk Due to Levee from Denton Street
to Crown Street/Merrimack River
Concord St: Within Floodway/1%
Floodplain at crossing of Pennichuck
Brook and change into DW Highway
Broad St: Within .2% Floodplain at
Canter Ct and Broadcrest Ln, proximity
to .2% Floodplain at Spar Ave
Main St: Within Floodway at Nashua
River crossing
ESC) Emergency Services
Consulting International
This hazard does not occur in Nashua
This hazard does not occur in Nashua
FEMA flood probability elevation:
1%
0.2%
In the 1960s, the United States
government decided to use the 1%
annual exceedance probability (AEP)
flood as the basis for the National Flood
Insurance Program. The 1% AEP flood
was thought to be a fair balance
between protecting the public and
overly stringent regulations. Because
the 1% AEP flood has a1in 100 chance
of being equaled or exceeded in any 1
year, and it has an average recurrence
interval of 100 years, it often is referred
to as the “100-year flood.”
More recently, people talk about larger
floods, such as the "5o0o0-year flood," as
tolerance for risk is reduced and
increased protection from flooding is
desired. The "soo-year flood"
corresponds to an AEP of 0.2%, which
means a flood of that size or greater has
a 0.2% chance (or 1 in 500 chance) of
occurring in a given year.
This hazard does not occur in Nashua
This hazard does not occur in Nashua
Water damage to structures and their
contents.
Damage or loss of infrastructure,
including roads, bridges, railroads,
power and phone lines, City
communications, City radio system,
power generation facility, domestic
water, and wastewater treatment
plant.
Environmental hazards resulting from
damage.
Isolation of neighborhoods resulting
from flooding.
Sewer backups.
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