Unit 3
FEMA Flood Module
Unit 3. Flood BCA Module
3-1
Unit 3 Objectives

Define a flood event and the different
types of flood zones and flood
mitigation projects

Describe the National Flood Insurance
Program (NFIP) tenets

Identify the sources of documentation
necessary to complete a successful
Benefit-Cost Analysis (BCA)

Review the Flood portion of the BCA
module

Identify available resources in the
BCA Tool
Unit 3. Flood BCA Module
3-2
Flood Module Overview
Flood Damages
Flood depths = flood elevations minus FFE
Flood depths = flood elevations minus FFE
Flood Elevations
(10-, 50-, 100-, 500- years)
First Floor Elevation (FFE)
Unit 3. Flood BCA Module
3-3
Flood Statistics
 Floods are the most common, most predictable, and most
costly of all natural disasters in the United States
 90 percent of all presidential disaster declarations involve
flooding
 Congress established the NFIP in 1968 to regulate affordable
flood insurance for communities in flood-prone areas
 Through NFIP, FEMA has identified and mapped out more
than 21,000 communities
Unit 3. Flood BCA Module
3-4
-4
Obtaining Riverine Data
Unit 3. Flood BCA Module
3-5
Flood Terminology Review Activity
Match the terms and
their definitions.
When you think that
you have the correct
answers, let the
instructor know.
Unit 3. Flood BCA Module
3-6
-6
BCA Information Provided by a
FIRM
 A FIRM provides important BCA data inputs:
 If the property is in the Special Flood Hazard Area (SFHA)
 Flood zone
 Base Flood Elevation (BFE) for the property
 Community number, map panel and effective date
Unit 3. Flood BCA Module
3-7
How to Read a Flood Insurance
Rate Map (FIRM)
Unit 3. Flood BCA Module
3-8
How to Read a FIRM
 The FEMA FIRM Tutorial is a step-by-step process that you may
follow to obtain hazard-specific information on a FIRM. The tutorial
educates users on the use and application of FEMA FIRMs.
 The full tutorial can be found at
http://www.fema.gov/media/fhm/firm/ot_firm.htm
 This tutorial will help the user:
 Find the correct FIRM panel
 Find the general location of a property
 Find the specific location of a property
 Identify the flood insurance risk zone designation
Unit 3. Flood BCA Module
3-9
How to Read a FIRM (continued)
Step 1: Find the
Correct Panel
Use the index to find
the FIRM panel you
need. This sample
index is composed of
four panels (0001,
0002, 0003, and 0004).
Determine the general
area of your property
and locate it on the
index. Check the title
boxes on the panels to
find the panel you need
– panel 0004 in this
example.
Unit 3. Flood BCA Module
3-10
How to Read a FIRM (continued)
Step 2: Find the General
Location
After obtaining panel
0004, find the general
location by referring to
features such as major
roads or city limits.
Unit 3. Flood BCA Module
3-11
How to Read a FIRM (continued)
Step 3: Find the Specific
Location of the Property
To find the specific location
and dimensions of the
property refer to:
 A plat map,
 A tax assessor’s map, or
 The property description
on the deed.
Then convert the known
property dimensions to inches
using the flood map scale and
measurements on the flood
map panel.
Unit 3. Flood BCA Module
3-12
How to Read a FIRM (continued)
Step 4: Identify the Flood
Insurance Risk Zone of the
Property
As shown on the map on the
right, the property you are
considering buying is partially
within the dark-tinted SFHA.
Identify the flood insurance risk
zone designation for the
property by finding the labeled
zone.
The SFHA near the property is
labeled Zone AE.
Unit 3. Flood BCA Module
3-13
Obtaining Data from a
Flood Insurance Study (FIS)
Unit 3. Flood BCA Module
3-14
BCA Information Provided by a
Flood Insurance Study
 A FIS provides important BCA data inputs:
 Flood elevation data from flood profiles
 Streambed elevation
 Flood discharges
Unit 3. Flood BCA Module
3-15
Obtaining Riverine Data
 This section outlines a step-by-step process to obtain hazard-specific
information from a FIRM and a FIS that are needed to complete a
comprehensive BCA
 The full FEMA tutorial can be found at
http://www.fema.gov/media/fhm/fis/ot_fis.htm
 This tutorial will help the user:
 Locate and effectively use a FIS flood profile
 Understand and identify flood frequencies
 Determine the BFE and Streambed Elevation of a riverine property
 Locate flood discharge data
Unit 3. Flood BCA Module
3-16
Flood Profiles
A flood profile is a graph of the flood elevations along the centerline of a
stream. Flood profiles show the predicted water surface elevation for the
100-year-flood event (1-percent-annual chance), and often show the flood
elevation profiles for the 10-, 50- and 500-year (equal to the 10-, 2-, and 0.2percent annual chance, respectively) flood events.
Other information shown on the flood profiles include:
 Location of flood map cross sections (a letter within a hexagon)
 Location of streets crossing streams
 Streambed elevation
Flood profiles should be used to determine the precise BFE for an area in
the floodplain, rather than the FIRM, where the BFEs are rounded to the
nearest whole foot. Precise streambed elevations can be derived using this
same method.
Unit 3. Flood BCA Module
3-17
Obtaining Riverine Base Flood
Elevations (BFE)
Step 1: Locate the property ( ) on the Flood Insurance Rate Map and
identify the flooding source
Unit 3. Flood BCA Module
3-18
Obtaining Riverine BFEs (continued)
Step 2: Locate the boundary of the property. Locate a physical feature
near the site that appears on the flood profile, such as a road or an
intersection.
Unit 3. Flood BCA Module
3-19
Obtaining Riverine BFEs (continued)
Step 3: Using the map scale, measure the distance along the stream
centerline on the FIRM from the reference location to the project site.
Note that this distance is greater than the straight-line distance from
the reference location to the project site.
Unit 3. Flood BCA Module
3-20
Obtaining Riverine BFEs (continued)
Step 4: Measure the distance from the reference location (e.g., road or
intersection) to the site on the profile.
Unit 3. Flood BCA Module
3-21
Obtaining Riverine BFEs (continued)
Step 5: Draw a vertical line to find where the site intersects the flood
profiles.
Unit 3. Flood BCA Module
3-22
Obtaining Riverine BFEs (continued)
Step 6: Draw a straight line to the edge of the graph to determine the
elevations for each of the 10-, 50-, 100-, and 500-year flood profiles
at the project site.
Unit 3. Flood BCA Module
3-23
Obtaining Streambed Elevation
The streambed, or the bottom of a stream below the water source,
provides a baseline for riverine measurement.
The Streambed Elevation is easily located on the flood profile by the
symbol indicated below and can be determined using the same
method as you would the BFE.
Unit 3. Flood BCA Module
3-24
Obtaining Flood Discharge Data
The Summary of Discharges Table lists the peak water discharges for
various flood frequencies at locations within the study area.
For example, using the summary of discharges table below, the 100-year
flood discharge for Cobb Brook at the confluence with the Rocky River is
1,080 cubic feet per second (cfs). This means that during the peak of the
100-year flood, 1,080 cubic feet of water will pass this point each second.
Unit 3. Flood BCA Module
3-25
Peak Discharges for a Site
To determine the peak discharges for a specific site:

Locate the flooding source identified for the project site on the
Summary of Discharges table (within the community’s FIS).

Identify the closest physical location to the project site that is listed
for the flooding source.

Enter the peak discharges for the closest location to the site for the
10-, 50-, 100-, and 500-year floods into the BCA Tool.
Unit 3. Flood BCA Module
3-26
Obtaining Coastal Data
Unit 3. Flood BCA Module
3-27
Coastal Stillwater Elevation

Most coastal floods are caused by coastal storms, usually hurricanes and
northeasters. Such storms bring air pressure changes and strong winds
that pile water up against the shore in what is called a storm surge.

Based on data from past storms, computer models simulate coastal storms
to determine the Stillwater Elevation -- the elevation of coastal floods
without waves.

Stillwater Elevations are found in the Summary of Stillwater Elevations
table in a FIS, typically in Section 3.
Unit 3. Flood BCA Module
3-28
Transects
As with riverine studies, a hydraulic analysis determines where moving water
goes. The coastal flood engineering survey uses techniques similar to those
used in a riverine study, but it uses transects instead of cross sections.
Unit 3. Flood BCA Module
3-29
Wave Runup

In addition to storm surge, wave action is an important aspect of
coastal storms. Wind-driven waves produce water velocities and
impacts that may cause significant structural damage.

When waves hit the shore, water moves with such force that it
keeps traveling inland, called wave runup.

The official BFE of coastal areas is the Stillwater Elevation plus
wave runup, or the wave crest elevation, whichever is greater. The
resulting BFE can be many feet higher than the Stillwater Elevation.
Unit 3. Flood BCA Module
3-30
Coastal Obstructions
Obstructions such as dunes or buildings break waves, dissipating the wave
energy so that wave height and BFEs are reduced as you go inland.
Unit 3. Flood BCA Module
3-31
Coastal High Hazard Area
Coastal High Hazard
Areas are the most
hazardous part of the
coastal floodplain due
to their exposure to
wave effects. These
areas are designated
as V Zones where the
"V" stands for "velocity
wave action," and
includes an increased
degree of risk. Coastal
flood areas not within
the coastal high hazard
area are mapped as A
Zones.
Unit 3. Flood BCA Module
3-32
Obtaining Coastal Data
Step 1: Locate the property and read the flood zone and BFE on a
FIRM. The BFE is listed in parentheses below the zone label. Unlike
Riverine properties, the BFE cannot be found in an FIS Flood Profile.
Property Location
Unit 3. Flood BCA Module
3-33
Obtaining Coastal Data
Step 2: Locate the property on the Transect Location Map in the FIS.
A description of the start of the transects can be found on the
Transect Location Map.
Property Location
Unit 3. Flood BCA Module
3-34
Obtaining Coastal Data
Step 3: Find the 100-year Stillwater Elevations at the start of the two
transects nearest the property in the Transect Data Table in the FIS.
Unit 3. Flood BCA Module
3-35
Obtaining Coastal Data
Step 4: Interpolate between the two 100-year Stillwater Elevations at
the transects to estimate the 100-year Stillwater Elevation at the
property.
 Transect 1 100-year Stillwater Elevation = 10.0 feet NGVD
 Transect 2 100-year Stillwater Elevation = 10.0 feet NGVD
 The property is halfway between Transect 1 and 2, so it would be
equal to the midpoint between these two transects, which is 10 ft.
NGVD.
 Stillwater Elevation = 10 feet NGVD
Unit 3. Flood BCA Module
3-36
Flood BCA Data Inputs and
Documentation
Unit 3. Flood BCA Module
3-37
Data Documentation Template
 Reminder: the Flood Data Documentation Template gives you
potential data sources and can be used as a data checklist
Unit 3. Flood BCA Module
3-38
Flood BCA Tool File Path
Depth Damage
Functions
Structure Information
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-39
Flood BCA Documentation:
General Guidance
Data used in place of
FEMA standards or
default values MUST
be documented
Documentation should include
justification for the use of data in
place of FEMA values.
 Hydrologic and hydraulic analyses
 Building Replacement and Contents Values
 Elevation Certificate(s)
All data must be obtained
from a credible source
 Federal, State, county, regional, and local
government agencies
 Qualified professionals such as licensed
architects, engineers, and surveyors
Unit 3. Flood BCA Module
3-40
Flood BCA Tool File Path
Mitigation Project Type
Unit 3. Flood BCA Module
3-41
Mitigation Project Types
Acquisition
 The purchase and demolition
of a building. Future damage
is eliminated because the
project site is deed-restricted
as open space.
Elevation
 The raising of a building on
an extended foundation or fill
to place the lowest floor at or
above the designated flood
elevation.
Unit 3. Flood BCA Module
3-42
Mitigation Project Types
Dry Flood Proofing/Flood Barrier
 Mitigation measures added or
incorporated into an asset to
prevent flood damage by
making the exterior walls
impermeable to floodwater.
Drainage Improvement
 An activity within or adjacent to
a flood source intended to
improve the flow capacity,
drainage, erosion and
sedimentation control, or
stability.
Unit 3. Flood BCA Module
3-43
Flood BCA Tool File Path
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-44
Flood BCA Documentation:
Mitigation Project Cost
 Mitigation Project Cost
 Unit II: Estimating Costs and Benefits
 Pre-construction, Construction, Ancillary, and Annual
Maintenance Costs
 Sources:
 Local historical cost data
 Current contractor bids
 Cost estimating software
Unit 3. Flood BCA Module
3-45
Flood BCA Tool File Path
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-46
Flood BCA Documentation:
Hazard-Specific Data
 FIS and/or Hydrology and Hydraulics (H&H) Study
 Riverine: Flood Profile, Streambed Elevation, Discharges
 Coastal: Stillwater Elevation (SWEL), BFE or 100-year
elevation including wave action
 FIRM
 Panel Number, Effective Date, Community ID Number
Unit 3. Flood BCA Module
3-47
Flood BCA Tool File Path
Structure Information
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-48
Flood BCA Documentation:
Structure Information
Elevation
Certificate
Unit 3. Flood BCA Module
3-49
Flood BCA Documentation:
Structure Information
SECTION B: FLOOD INSURANCE RATE MAP (FIRM) INFORMATION
 B1: NFIP Community Name &
Community Number
 B6: FIRM Index Date
 B2: County Name
 B7: Firm Panel Effective
Date/Revised Date
 B3: State
 B8: Flood Zone(s)
 B4: Map/Panel Number
 B9: BFE(s) (Zone AO, use
base flood depth)
 B5: Suffix
Unit 3. Flood BCA Module
3-50
Flood BCA Documentation:
Structure Information
SECTION C: BUILDING ELEVATION INFORMATION (SURVEY REQUIRED)
a) Top of bottom floor (including basement, crawlspace, or enclosure floor
b) Top of the next higher floor
c) Bottom of the lowest horizontal structural member (V Zones only)
Unit 3. Flood BCA Module
3-51
Other Sources of Structure
Elevation Data
 Professional Surveyor
 Estimated elevation from a known
elevation of neighboring structure
 Estimated elevation from highresolution topographic data (i.e.,
LiDAR)
Unit 3. Flood BCA Module
3-52
Flood BCA Documentation:
Structure Type and FFE
 First Floor Elevation (FFE)
Finished Walkout Basement
Finished Basement
Unfinished Basement
Unit 3. Flood BCA Module
3-53
Flood BCA Documentation:
Structure Information
Size of Building
 Measured in square feet
 Sources
Building Replacement Value
 Cost per square foot to build a comparable
structure
 Sources
Unit 3. Flood BCA Module
3-54
Flood BCA Documentation:
Residential Structure
 Foundation/Building Type, Number of Stories
What are some acceptable forms of documentation?
Where can you obtain them?
Unit 3. Flood BCA Module
3-55
Flood BCA Documentation:
Non-residential Structure
 Primary Use of Building / Number of Stories
 Sources: owner, local building inspector, local tax assessor’s office,
or title documents on letterhead from a credible source
 Service Types by Facility (Value of Public Service)/Annual Budget
 Service Name Examples: government, library, education, hospital,
emergency medical service (EMS), safe room, fire, police, or
Emergency Operations Center
 Sources: agency providing service or published annual report
Unit 3. Flood BCA Module
3-56
Flood BCA Tool File Path
Depth Damage
Functions
Structure Information
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-57
Flood BCA Documentation:
Depth Damage Functions
 Depth Damage Functions
 Choose from three options
 Default
 Library
 Custom
 If FEMA Standard Value is
not used, sources include:
historical loss records and
engineering judgments
Depth Damage
Functions
Structure Information
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-58
Flood BCA Documentation:
Depth Damage Functions
Adjusted Library
Depth Damage
Function for
Finished
Basements
Unit 3. Flood BCA Module
3-59
Flood BCA Tool File Path
Other
Avoided
Damages
Depth Damage
Functions
Structure Information
Hazard-Specific Data
Mitigation Project Cost
Mitigation Project Type
Unit 3. Flood BCA Module
3-60
Flood BCA Documentation:
Other Avoided Damages
 BCA Tool automatically estimates avoided losses/damages:
 Building and Contents Damages
 Displacement Costs
 Other Avoided Damages Table allows user-entered benefit
categories that may include:
 Debris removal
 Emergency Management Costs
 Disruption of Life
Unit 3. Flood BCA Module
3-61
Flood BCA Documentation:
Contents Value
FEMA Standard Value: Contents
 Residential and Default DDF (USACE) table:
100 percent of Building Replacement Value
(BRV)
 All Others: 50 percent of BRV
If default is not used, sources include:
 Insurance records
 Appraisals
 Receipts
 Estimates based on current market prices for
similar contents
Unit 3. Flood BCA Module
3-62
Flood BCA Documentation:
Displacement/Loss of Rent
Displacement/Loss of Rent
 Monthly costs – Rent, furniture rental, utilities
 one-time costs - moving and utility hook-up fees
 FEMA Standard Values
 $1.44 square foot per month for residential
 Loss of Rent for rental properties only and do not include onetime costs
Unit 3. Flood BCA Module
3-63
Flood BCA Documentation:
Documentation Exercise
What documentation is necessary
for the following benefits (damages
or losses avoided)?
 Displacement Costs
 Loss of Rent
 Contents Value
Unit 3. Flood BCA Module
3-64
BCA Tool Case Study
Flood
Case
Study 1
Unit 3. Flood BCA Module
3-65
Overview of Flood BCA Tool
 Add a new
structure
 Select the
State and
county from
the dropdown
Unit 3. Flood BCA Module
3-66
Overview of Flood BCA Tool
 Add a new
project
 Organization
is
subapplicant
 POC is the
person who
can answer
questions
about the
project
Unit 3. Flood BCA Module
3-67
Overview of Flood BCA Tool
 Associate the
structure with
the project.
Unit 3. Flood BCA Module
3-68
Overview of Flood BCA Tool
 Select Flood
to begin the
mitigation
project
analysis
Unit 3. Flood BCA Module
3-69
Overview of Flood BCA Tool
 Select
Mitigation
Project Type:
 Acquisition
 Elevation
 Dry Flood
Proofing/
Flood Barrier
 Drainage
Improvement
 Other
Unit 3. Flood BCA Module
3-70
Overview of Flood BCA Tool
 Tool asks a series
of questions to
ensure the user
has the
appropriate
documentation to
conduct a full
flood analysis
 If documentation
is deficient, Tool
will redirect user
to the DamageFrequency
Assessment
module
Unit 3. Flood BCA Module
3-71
Overview of Flood BCA Tool
 Source of Flood
Data?
 FIS
 H&H Study
 Both
 Project in a SFHA?
 Located on
FIRM
 Source of Flooding?
 Riverine
 Coastal
Unit 3. Flood BCA Module
3-72
Overview of Flood BCA Tool
 Enter the
project useful
life
 Select Yes to
detailed SOW
 Enter project
Mitigation
Project Cost
 Enter Annual
Project
Maintenance
Costs
Unit 3. Flood BCA Module
3-73
Overview of Flood BCA Tool
 Input
information
about flood
data source
using:
 FIS
 H&H Study
 FIRM
 Dynamic Help
will guide users
to location of
data
Unit 3. Flood BCA Module
3-74
Overview of Flood BCA Tool
 Riverine Data:
 FFE and
Diagram
Description
 Flood
Source
Name and
Flood
Profile
Number
 Streambed
Elevation
Unit 3. Flood BCA Module
3-75
Overview of Flood BCA Tool
 Coastal Data:
 FFE and
Diagram
Description
 BFE or 100year elevation
including wave
action
 Flood Source
Name and
Flood Profile
Number
 Stillwater
Elevation
Unit 3. Flood BCA Module
3-76
Overview of Flood BCA Tool
 Total size of
building
(square feet)
 BRV
(dollars
/square foot)
 Demolition
damage
threshold
Unit 3. Flood BCA Module
3-77
Overview of Flood BCA Tool
RESIDENTIAL
Riverine/Coastal A
 Building Type
 Foundation
Type
 Basement
Coastal V
 Obstruction
Unit 3. Flood BCA Module
3-78
Overview of Flood BCA Tool
NON-RESIDENTIAL
 Structure Type
 Engineered
 Pre-Engineered
 Primary Use of
Building
 Contents Value
 Default changes
based on
primary use of
building
 Displacement Cost
 One-Time
Displacement Cost
Unit 3. Flood BCA Module
3-79
Overview of Flood BCA Tool
 Depth Damage
Functions
 Default/ Library/
Custom
 Displacement Costs
 FEMA Standard
Value:
$1.44/sf/month
 One-time
OR
 Loss of Rent
(rental property)
 Building Contents
Value
 DDF Table populates
after inputs are
entered
Unit 3. Flood BCA Module
3-80
Overview of Flood BCA Tool
 Select other
benefits by adding
columns
 Provide
justification
 Table is
dynamically
generated based
on user-entered
categories
Unit 3. Flood BCA Module
3-81
Overview of Flood BCA Tool
 Expected
Annual
Damages
Report
 Provides annual
damages based
on earlier inputs
 No further action
is required after
this screen
Unit 3. Flood BCA Module
3-82
Overview of Flood BCA Tool
Summary of Benefits
provides a report on:
 Annual Damages
(Before and After
Mitigation)
 Expected Avoided
Damages
 Mitigation Benefits
 Mitigation Cost
 Benefit-Cost Ratio
Unit 3. Flood BCA Module
3-83
Flood BCA Case Study
 Refer to the Case Study in the
Student Manual
 Complete the Flood BCA module
using the Case Study
Unit 3. Flood BCA Module
3-84
Review of BCA Activity
BCR Value Discussion
Unit 3. Flood BCA Module
3-85

Download Report