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APPENDICES 2017 City of Alabaster Floodplain Management Plan
C-3
App. C – Risk Assessment Data
1.0 Summary of Vulnerability and Impacts 2.0 HAZUS-MH: Flood Global Risk Report
1.0 Summary of Vulnerability and Impacts
Tables C-2 and C-3 summarize the City of Alabaster’s vulnerability to flooding
and other natural hazards, according to the methodology developed by the Shelby
County Hazard Mitigation Committee. These tables are an abridged version, based
upon the comparable Tables 6.6 and 6.7 found in chapter 6 of the 2016 Shelby County
Multi-Hazard, Multi-Jurisdictional Mitigation Plan prepared under the Committee’s
direction. Tables C-2 and C-3 include a summary of all hazards identified in Chapter 4
Risk Assessment in Section 4.2 of this Alabaster plan, except for dam and levee failures,
which were not addressed in the County plan.
To summarize and quantify the impacts and risks associated with the various
hazards, the Shelby County Hazard Mitigation Committee designed its own rating
methodology. Their methodology relies on the Committee’s qualitative assessment of
historical and anecdotal data, community input, and historic and projected hazard
events. This assessment is based upon the hazard ratings assigned by the Shelby
County’s Hazard Mitigation Committee described in Table C-1 below.
Table C-1 Hazards Rating Table
Category 0 1 2 3 4 5
Fatalities and Injuries
0 Fatalities
or Injuries
< 3 Fatalities
or Injuries
4 to 14
Fatalities or
Injuries
15 to 49
Fatalities or
Injuries
50 to 99
Fatalities or
Injuries
>100
Fatalities or
Injuries
Economic Loss
No Loss Less than
$500K cost From $500K
to $2.9Mil cost
From $3Mil
to $7.9Mil
cost
From $8Mil to
$19.9Mil cost
More than
$20Mil cost
Area Impacted
Local No
Evacuation Local minimal
evacuation
Local some
evacuation
1 mile some
evacuation
1 mile high
evacuation
>3 mile and
evacuation
Probability of Occurrence
Once Every
100+ Years Once every 36
to 99 years
Once every 10
to 35 years
Once every 4
to 9 years
Once every 1
to 3 years
More than
once a year
Repetitive Loss
< 3 3 to 10 11 to 24 25 to 49 50 to 99 > 100
Source: 2016 Shelby County Multi-Hazard, Multi-Jurisdictional Mitigation Plan
The Shelby County Hazard Mitigation Committee developed the historic and
future hazard profile vulnerability assessment summary tables (Tables C-2 and C-3)
using the above Hazards Rating Table (Table C-1) by assigning a value (1 through 5) for
each category. In addition, fatalities and injuries were assigned a weighting factor of 3,
APPENDICES 2017 City of Alabaster Floodplain Management Plan
C-4
and economic loss was assigned a weighting factor of 2. Table C-2 “Summary of
Historic Hazards and Community Impacts” below provides an assessment of the present
risk due to hazard events. A brief summary of future impacts of hazard events can be
found in Table C-3 “Summary of Future Hazards and Community Impacts.” Each of
tables prioritizes the overall risk and threat of the 13 hazards, according to their
vulnerability scores.
Table C-2. Summary of Historic Hazards and Community Impacts
Hazard
Hazard Status Hazard Profile Vulnerability
Index
Risk/Threat
Fata
lity
an
d In
jury
Eco
no
mic
Lo
ss
Exte
nt
of
Imp
act
Pro
bab
ilit
y o
f
Occu
rren
ce
Rep
eti
tive L
oss
Vu
lnera
bilit
y S
co
re
Pri
ori
ty
High Wind High/High 15 10 2 5 5 37 1
Urban Fires Moderate/Moderate 12 10 1 5 3 31 2
Flooding Moderate/High 6 8 2 4 3 23 3
Wildfires Moderate/Moderate 0 8 2 5 5 20 4
Extreme Temperature Moderate/Minimal 6 8 0 3 2 13 5
Hail Moderate/Minimal 6 4 0 5 1 16 7
Ice/Snow Storm Moderate/Moderate 6 4 1 4 1 16 6
Lightning Moderate/Low 6 2 0 3 2 13 8
Drought Moderate/Slight 0 4 0 3 2 9 9
Land Subsidence Moderate/Minimal 0 2 0 4 1 5 10
Landslides/Mudslides Low/Minimal 0 0 0 3 0 3 11
Earthquake Low/Moderate 0 0 0 1 0 1 12
Tsunami Low/Low 0 0 0 0 0 0 13
Source: 2016 Shelby County Multi-Hazard, Multi-Jurisdictional Mitigation Plan
Note: Dam and levee failures were not considered in the 2016 Shelby County Multi-Hazard, Multi-Jurisdictional Mitigation
Plan vulnerability assessment.
APPENDICES 2017 City of Alabaster Floodplain Management Plan
C-5
Table C-3. Summary of Future Hazards and Community Impacts
Hazard
Hazard Status Hazard Profile Vulnerability
Index
Risk/Threat
Fata
lity
an
d In
jury
Eco
no
mic
Lo
ss
Exte
nt
of
Imp
act
Pro
bab
ilit
y o
f
Occu
rren
ce
Rep
eti
tive L
oss
Vu
lnera
bilit
y S
co
re
Pri
ori
ty
High Wind High/High 15 10 2 5 5 37 1
Flooding High/High 9 8 3 4 5 29 2
Urban Fires - 9 8 2 5 4 28 3
Earthquake High/Moderate 9 10 5 1 0 25 4
Wildfires - 6 6 3 5 4 24 5
Ice/Snow Storm Low/Moderate 6 4 1 4 2 17 6
Lightning - 6 4 0 3 2 15 7
Extreme Temperature High/Moderate 6 2 1 3 2 14 8
Hail Moderate/Moderate 3 4 0 5 1 13 9
Drought Low/Low 0 4 0 3 3 10 10
Land Subsidence Low/ Moderate 0 2 1 4 1 8 11
Landslides/Mudslides Low/ Moderate 0 2 1 3 1 7 12
Tsunami - 0 0 0 0 0 0 13
Source: 2016 Shelby County Multi-Hazard, Multi-Jurisdictional Mitigation Plan
Note: Dam and levee failures were not considered in the 2016 Shelby County Multi-Hazard, Multi-Jurisdictional Mitigation
Plan vulnerability assessment.
APPENDICES 2017 City of Alabaster Floodplain Management Plan
C-6
2.0 HAZUS-MH: Flood Global Risk Report
FEMA’s HAZUS-MH risk assessment software was used to estimate losses due
to flooding for the City of Alabaster study area. The results of the modeled flood
scenario are included in the following Flood Global Risk Report generated from HAZUS-
MH, which have been integrated into this plan in Chapter 4. Risk Assessment.
Hazus-MH: Flood Global Risk Report
Region Name:
Flood Scenario:
Print Date: Friday, September 29, 2017
AlabasterFlood
scenario3
Disclaimer:This version of Hazus utilizes 2010 Census Data.
Totals only reflect data for those census tracts/blocks included in the user's study region.
The estimates of social and economic impacts contained in this report were produced using Hazus loss estimation methodology software
which is based on current scientific and engineering knowledge. There are uncertainties inherent in any loss estimation technique.
Therefore, there may be significant differences between the modeled results contained in this report and the actual social and economic
losses following a specific Flood. These results can be improved by using enhanced inventory data and flood hazard information.
Table of Contents
Section Page #
General Description of the Region
Building Inventory
4
3
General Building Stock
Essential Facility Inventory
Flood Scenario Parameters
5
Building Damage
7General Building Stock
Essential Facilities Damage
Induced Flood Damage
9
Debris Generation
Social Impact
Shelter Requirements
Economic Loss
10
Building-Related Losses
Appendix A: County Listing for the Region
Appendix B: Regional Population and Building Value Data
15
16
6
10
12
Page 2 of 16Flood Global Risk Report
General Description of the Region
Hazus is a regional multi-hazard loss estimation model that was developed by the Federal Emergency
Management Agency (FEMA) and the National Institute of Building Sciences (NIBS). The primary purpose of
Hazus is to provide a methodology and software application to develop multi -hazard losses at a regional
scale. These loss estimates would be used primarily by local, state and regional officials to plan and
stimulate efforts to reduce risks from multi-hazards and to prepare for emergency response and recovery.
The flood loss estimates provided in this report were based on a region that included 1 county(ies) from the
following state(s):
Alabama-
Note:
Appendix A contains a complete listing of the counties contained in the region .
The geographical size of the region is 43 square miles and contains 853 census blocks. The region contains
over 14 thousand households and has a total population of 39,975 people (2010 Census Bureau data). The
distribution of population by State and County for the study region is provided in Appendix B .
There are an estimated 15,585 buildings in the region with a total building replacement value (excluding contents)
of 4,489 million dollars (2010 dollars). Approximately 93.85% of the buildings (and 85.60% of the building value)
are associated with residential housing.
Page 3 of 16Flood Global Risk Report
General Building Stock
Hazus estimates that there are 15,585 buildings in the region which have an aggregate total replacement value
of 4,489 million (2014 dollars). Table 1 and Table 2 present the relative distribution of the value with respect to
the general occupancies by Study Region and Scenario respectively. Appendix B provides a general
distribution of the building value by State and County.
Building Inventory
Occupancy Exposure ($1000) Percent of Total
Table 1
Building Exposure by Occupancy Type for the Study Region
3,842,433Residential 85.6%
Commercial 431,912 9.6%
Industrial 126,507 2.8%
Agricultural 8,839 0.2%
Religion 46,499 1.0%
Government 4,109 0.1%
Education 28,673 0.6%
Total 4,488,972 100.0%
Residential $3,842,433Commercial $431,912Industiral $126,507Agricultural $8,839Religion $46,499Government $4,109Education $28,673
Total: $4,488,972
Building Exposure by Occupancy Type for the Study Region($1000's)
Page 4 of 16Flood Global Risk Report
Occupancy Exposure ($1000) Percent of Total
Table 2
Building Exposure by Occupancy Type for the Scenario
906,656Residential 75.9%
Commercial 222,142 18.6%
Industrial 37,892 3.2%
Agricultural 4,211 0.4%
Religion 13,146 1.1%
Government 3,381 0.3%
Education 7,279 0.6%
Total 1,194,707 100.0%
Residential $906,656Commercial $222,142Industrial $37,892Agricultural $4,211Religion $13,146Government $3,381Education $7,279
Total: $1,194,707
Building Exposure by Occupancy Type for the Scenario ($1000's)
Essential Facility Inventory
For essential facilities, there are 1 hospitals in the region with a total bed capacity of 228 beds.
There are 7 schools, 1 fire station, 1 police station and no emergency operation centers.
Page 5 of 16Flood Global Risk Report
Flood Scenario Parameters
Hazus used the following set of information to define the flood parameters for the flood loss estimate provided
in this report.
Scenario Name:
Return Period Analyzed:
Analysis Options Analyzed:
scenario3
Study Region Name: AlabasterFlood
100
No What-Ifs
Study Region Overview Map
Illustrating scenario flood extent, as well as exposed essential facilities and total exposure
Page 6 of 16Flood Global Risk Report
Building Damage
General Building Stock Damage
Hazus estimates that about 318 buildings will be at least moderately damaged. This is over 62% of the total
number of buildings in the scenario. There are an estimated 4 buildings that will be completely destroyed. The
definition of the ‘damage states’ is provided in Volume 1: Chapter 5 of the Hazus Flood Technical Manual.
Table 3 below summarizes the expected damage by general occupancy for the buildings in the region. Table 4
summarizes the expected damage by general building type.
Total Economic Loss (1 dot = $300K) Overview Map
Page 7 of 16Flood Global Risk Report
Table 3: Expected Building Damage by Occupancy
1-10 41-5031-4021-3011-20
Occupancy (%)Count Count (%) Count (%) Count (%) Count (%)
Substantially
Count (%)
Agriculture 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Commercial 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Education 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Government 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Industrial 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Religion 0 0 0 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00
Residential 134 167 74 57 16 4 29.65 36.95 16.37 12.61 3.54 0.88
Total 134 167 74 57 16 4
Damage Level 1-10 134Damage Level 11-20 167Damage Level 21-30 74Damage Level 31-40 57Damage Level 41-50 16Substantially 4
Total: 452
Counts By Damage Level
Page 8 of 16Flood Global Risk Report
Table 4: Expected Building Damage by Building Type
Building
Type
1-10 41-5031-4021-3011-20
(%)Count Count (%) Count (%) Count (%) Count (%)
Substantially
Count (%)
Concrete 0 0 0 0 0 0 0 0 0 0 0 0
ManufHousing 0 0 1 0 0 3 0 0 25 0 0 75
Masonry 3 4 0 0 0 0 43 57 0 0 0 0
Steel 0 0 0 0 0 0 0 0 0 0 0 0
Wood 132 163 73 57 16 1 30 37 17 13 4 0
Page 9 of 16Flood Global Risk Report
Before the flood analyzed in this scenario, the region had 228 hospital beds available for use. On the day of the
scenario flood event, the model estimates that 228 hospital beds are available in the region.
Essential Facility Damage
Table 5: Expected Damage to Essential Facilities
Classification Loss of Use
# Facilities
At Least
SubstantialAt Least
ModerateTotal
1Fire Stations 0 0 0
1Hospitals 0 0 0
1Police Stations 0 0 0
7Schools 2 0 2
If this report displays all zeros or is blank, two possibilities can explain this.
(1) None of your facilities were flooded. This can be checked by mapping the inventory data on the depth grid.
(2) The analysis was not run. This can be tested by checking the run box on the Analysis Menu and seeing if a message box
asks you to replace the existing results.
Page 10 of 16Flood Global Risk Report
Induced Flood Damage
Debris Generation
Hazus estimates the amount of debris that will be generated by the flood. The model breaks debris into
three general categories: 1) Finishes (dry wall, insulation, etc.), 2) Structural (wood, brick, etc.) and 3)
Foundations (concrete slab, concrete block, rebar, etc.). This distinction is made because of the different
types of material handling equipment required to handle the debris.
Analysis has not been performed for this Scenario.
Page 11 of 16Flood Global Risk Report
Social Impact
Shelter Requirements
Hazus estimates the number of households that are expected to be displaced from their homes due to
the flood and the associated potential evacuation. Hazus also estimates those displaced people that will
require accommodations in temporary public shelters. The model estimates 831 households will be
displaced due to the flood. Displacement includes households evacuated from within or very near to the
inundated area. Of these, 2,184 people (out of a total population of 39,975) will seek temporary shelter in
public shelters.
0 400 800 1200 1600 2000 2400
2,184
831
Persons Seeking ShelterDisplaced Households
Displaced Households/Persons Seeking Short Term Public Shelter
Page 12 of 16Flood Global Risk Report
Economic Loss
The total economic loss estimated for the flood is 98.83 million dollars, which represents 8.27 % of the total
replacement value of the scenario buildings.
Building-Related Losses
The building losses are broken into two categories: direct building losses and business interruption losses. The
direct building losses are the estimated costs to repair or replace the damage caused to the building and its
contents. The business interruption losses are the losses associated with inability to operate a business
because of the damage sustained during the flood. Business interruption losses also include the temporary
living expenses for those people displaced from their homes because of the flood.
47.46 47.46 47.46 47.46
The total building-related losses were 98.16 million dollars. 1% of the estimated losses were related to the
business interruption of the region. The residential occupancies made up 48.02% of the total loss. Table 6 below
provides a summary of the losses associated with the building damage.
Page 13 of 16Flood Global Risk Report
Table 6: Building-Related Economic Loss Estimates
(Millions of dollars)
Total OthersIndustrialCommercialResidentialAreaCategory
Building Loss
Building 29.95 8.42 3.39 0.84 42.60
Content 17.40 23.34 7.85 5.26 53.84
Inventory 0.00 0.52 1.18 0.02 1.72
Subtotal 47.35 32.28 12.42 6.12 98.16
Business Interruption
Income 0.00 0.17 0.00 0.02 0.19
Relocation 0.09 0.03 0.00 0.01 0.13
Rental Income 0.02 0.02 0.00 0.00 0.04
Wage 0.00 0.15 0.00 0.16 0.31
Subtotal 0.11 0.37 0.00 0.19 0.67
ALL Total 47.46 32.65 12.42 6.31 98.83
Residential $47Commercial $33Industrial $12Other $6
Total: $99
Losses by Occupancy Types ($M)
Page 14 of 16Flood Global Risk Report
Appendix B: Regional Population and Building Value Data
ResidentialPopulation
Building Value (thousands of dollars)
Non-Residential Total
Alabama
3,842,433Shelby 39,975 646,539 4,488,972
Total 39,975 3,842,433 646,539 4,488,972
Total Study Region 39,975 3,842,433 646,539 4,488,972
Page 16 of 16Flood Global Risk Report