Floodplain Maps

Question 1

As directed by the National Flood Insurance Act of 1968, FEMA conducts flood studies To determine what 2 things?

Answer 1

Map floodprone areas of the United States. Establish flood risk zones within those floodprone areas.

Question 2

The base flood is a flood that has a _________ of occurring in any year.

Answer 2

1%

Question 3

The base flood is also called the ________- year flood.

Answer 3

100

Question 4

True or False

A 100-year flood will occur only once every 100 years.

Answer 4

False

Question 5

True or False

A 100-year flood could occur 2 times in one year.

Answer 5

True

Question 6

True or False

The 100- year flood might not occur in a 200- year period.

Answer 6

True

Question 7

The base flood could occur two consecutive years in a row.

Answer 7

True

Question 8

On NFIP maps, the base floodplain is called the _______ __________ ________ ____________.

Answer 8

One-percent annual chance flood

Question 9

BFE is the acronym for what?

Answer 9

Base Flood Elevation

Question 10

What are the components of a Flood Insurance Study?

Answer 10

Flood Insurance Study
Flood Insurance Rate Map
Prior to 1986- a separate flood boundary and Floodway map was included

Question 11

For the purpose of a riverine flood study, ___________ is the study of the distribution and circulation of water in the environment, and _____ is the study of fluids in motion and how water will flow through the channel.

Answer 11

Hydrology

hydraulics

Question 12

The rate at which runoff flows downstream is called the flood____________.

Answer 12

Flood Discharge measured in cubic feet per second

Question 13

What probable effect dos increase in urbanization within a community or upstream of it have on the stream discharges within that community?

Answer 13

Increase flood discharge downstream (runoff volume and velocity)

Question 14

What consequence on flood water level of a stream would usually occur when a bridge is constructed over a stream?

Answer 14

the bridge will constrict the stream channel and can elevate the water level behind the bridge

Question 15

To locate the true elevation at a site, surveyors have established ______ marks also know as ______marks.

Answer 15

Reference or bench marks

Question 16

Cross sections describe the _________of the floodplain

Answer 16

profile

Question 17

What is the datum used for your FIS, FIRM, and profiles

Answer 17

NAVD88, NGVD 29

Question 18

Flood profiles are developed by plotting the flood elevations at the ______ _______ and connecting the plotted points

Answer 18

Cross sections

Question 19

To make a floodplain map, the base flood elevations are plotted on a ____ map or a _______map.

Answer 19

topographic or contour

Question 20

The ______ is defined as the stream channel and that portion of the adjacent floodplain that must remain open to permit passage of the base flood.

Answer 20

Floodway

Question 21

A floodway analysis conducted to the minimum NFIP standard allow the fringe to be obstructed until the base flood level is increased by how much.

Answer 21

One foot

Question 22

What causes storm surge?

Answer 22

Air pressure changes and Wind from coastal storms causes the waves to pile up against coast

Question 23

What is wave runup?

Answer 23

The additional sea level elevation created by the toe of waves advancing on the beach.

Question 24

Instead of cross sections, coastal flood engineers survey ________.

Answer 24

Coast line transects.

Question 25

The most hazardous part of the coastal floodplain is the ______ _________ ________ area, which is shown on the map as a _______ Zone.

Answer 25

Coastal High Hazard Area or V Zone

Question 26

What differentiates shallow flooding from riverine flooding.

Answer 26

Where flooding occurs 1-3 feet deep and there is no channel or identifiable flow path. shallow flooding occurs commonly, as sheet flow, ponding or as the result of poor urban drainage.

Question 27

Flood studies that do not identifiy BFEs are called ______ _________.

Answer 27

Floodway maps, or old format FIRMs

Question 28

Prior to 1986 the maps published with an FIS are the _________ and the _________.

Answer 28

Old format FIRM, FBFM, Flood boundary and Floodway map

Question 29

Since 1986, the map published with an FIS is the_______

Answer 29

New format FIRM

Question 30

Is your community's FIRM a flat or Z-fold map

Answer 30

Z fold

Question 31

How many panels does your FIRM have?

Answer 31

Varies

Question 32

What is the map scale of your FIRM?

Answer 32

Varies

Question 33

What does an elevation reference mark look like on a FIRM?

Answer 33

RM 15.2

Question 34

What is an AO zone

Answer 34

Base floodplain with sheet flow, BFE are provided.

Question 35

What is the FIRM effective date for your community?

Answer 35

Looks on the front of the FIRM title block

Question 36

How is a floodway shown on the Flood Boundary and FLloodway Map?

Answer 36

White area bordered by grey shading of 100-year and 500-year flood boundary.

Question 37

How is a floodway shown on the new format FIRM?

Answer 37

Floodways shown as diagonal hatched lines on new format FIRM

Question 38

A Zone C on an old format FIRM is shown as a Zone ____ on the new format FIRM.

Answer 38

zone X

Question 39

CRBS stands for what

Answer 39

Coastal Resource Barrier System

Question 40

What community's floodplains are shown on a countywide FIRM?

Answer 40

All geographic areas of that county

Question 41

Floodways are shown along the _____ toe of a levee on the FIRM.

Answer 41

Landside toe of the dike or Levee

Question 42

Area behind recognized levees are designated as _____ _______.

Answer 42

Zone X

Question 43

The base flood elevation is the elevation of the ___ -year flood or the ___ % annual chance

Answer 43

100-year flood or the 1% annual chance.

Question 44

The Special Flood Hazard Area or SFHA is what the _______ floodplain is called on FEMA maps.

Answer 44

Base floodplain

Question 45

The SFHA is shown on a FIRM as a Zone that begins with the letter ___ or ____.

Answer 45

A or V

Question 46

What are the components of a Flood Insurance Study?

Answer 46

The components of the Flood Insurance Study include: FIS report FIRM Prior to 1986 a separate Flood Boundary and Floodway Map (FBFM) was issued as component of the FIS

Question 47

List 3 things a FIRM is used to determine.

Answer 47

Extent of flood hazard elevation of flooding special flood conditions such as shallow coastal flooding.

Question 48

___ is the study of a watershed's behavior during and after a storm.

Answer 48

Hydrology

Question 49

Most permanent FIR elevation reference marks are reference to what datum?

Answer 49

NAVD88

Question 50

A hydraulic study uses the hydrology, cross section information and stream characteristics to determine the flood _____.

Answer 50

elevation

Question 51

Cross sections are shown on which map?

Answer 51

The FIS flood profiles map

Question 52

Flood profiles are used to determine what?

Answer 52

The flood elevations in the stream channel

Question 53

In riverine situations, the floodplain is divided into two separate parts for floodplain management purposes. These parts are the _______ and the _________.

Answer 53

stream channel and the fringe

Question 54

Based on minimum NFIP standard, if the flood fringe were completely filled, how high could the base flood elevation go up.

Answer 54

One foot

Question 55

What FIRM zone has wave heights greater than three feet?

Answer 55

V zone

Question 56

Instead of using a base flood elevation, some shallow flooding areas are defined using a base flood ______.

Answer 56

Depth

Question 57

An approximate study shows the base _______ but does not show the base flood __________.

Answer 57

flood hazard extent, base flood elevation

Question 58

How many digits are there in the NFIP community identification number

Answer 58

6 digits such as 99009C

Question 59

What is an AH Zone?

Answer 59

Shallow flooding base floodplain due to ponding, includes BFEs

Question 60

What was the problem with the way the floodway was shown on the old format Flood Boundary and Floodway Maps?

Answer 60

Made without detailed studies or hydraulic analysis

Question 61

The new format FIRMs include what three elements?

Answer 61

Floodways, cross sections, simplified flood zone insurance information,

Question 62

Do Q3 Flood Data show base flood elevations if they are available.

Answer 62

Q3 flood data product is FEMA software to use with desktop mapping and GIS. They do NOT include base flood elevations

Question 63

Rivers and coastlines each have its own probability of flooding, how is probability defined?

Answer 63

Probability defines the size of the storm and the odds of that size of flood occurring in any year.

Question 64

How is 100-year flood used by NFIP?

Answer 64

Used to require purchase of flood insurance and regulating new development.

Question 65

What is the recurrence interval calculation for 100 year flood?

Answer 65

1 divided by .01 = 100. One percent annual chance flood

Question 66

What is calculation for 500 year flood?

Answer 66

1 divided by .002 = 500 year flood or .2 percent annual chance flood

Question 67

A flood with a on- percent chance of occurring in a year can be called one of these three terms: .

Answer 67

Base flood 100- year flood one-percent annual chance flood.

Question 68

Define the base floodplain?

Answer 68

The land area covered by the base flood.

Question 69

What is the Special Flood Hazard Area or SFHA

Answer 69

The area covered by the base flood designated by zones | A,AE,AA1-30, AO, AH, V, VE or VE-30 depending on the amount of flood data available.

Question 70

What is the significance of site located in the SFHA?

Answer 70

NFIP floodplain management regulations must be enforced by the community as a condition of participation in the NFIP. Mandatory flood insurance required.

Question 71

Define Base Flood Elevation.

Answer 71

The calculated elevation to which floodwater is expected to rise.

Question 72

What is the chance of flooding in any one year from a 10,25, 50 and 100-year storm?

Answer 72

10%, 4%, 2%, and 1%

Question 73

What is the chance in flooding in 30 years from a 10, 25, 50, and 100-year flood?

Answer 73

96%, 71%, 45%, 26%

Question 74

What were the mapping directives to Federal Insurance Agency under the 1968 National Flood Insurance Act?

Answer 74

Identify all floodprone areas in the US and establish flood- risk zones within the floodprone areas.

Question 75

What is purpose of flood studies?

Answer 75

Analyze the terrain and factors that affect flood hazards.

Question 76

How is the flood study information used?

Answer 76

To draw the maps that delineate the flood plain boundaries.

Question 77

What elements are included in the maps and studies

Answer 77

``` Projected flood elevations Flood velocities Floodway dimensions Insurance rating zones Describe how study was done and how maps were prepared ```

Question 78

What are uses of the flood studies and maps

Answer 78

Flood insurance | Floodplain management

Question 79

What were the initial early maps called.

Answer 79

Flood Hazard Boundary Maps- base on approximate studies

Question 80

What are maps with more detailed studies called?

Answer 80

FLood Insurance Rate Maps or FIRMs. Based on published Flood Insurance Study reports or FIS, also called Detailed Studies.

Question 81

What does the FIS and FIRMS provided for communities

Answer 81

Data needed to adopt and implement more comprehensive floodplain manage the regulations and entire regular phase of the NFIP.

Question 82

What information is contained in the Flood Insurance Study report

Answer 82

Flooding issues narrative Community map and photos Tables with flood Hazard data Flood profiles for recurrence intervals (10-, 50-, 100-and 500- yr flood)

Question 83

What Zone is defined by the Floodway plus the flood fringe?

Answer 83

Zone AE or A1-30

Question 84

How do communities permit development in the flood fringe area?

Answer 84

If structure is elevated or will not cause the base Flood Elevation to rise.

Question 85

How do communities allow development in the Floodway?

Answer 85

Building discouraged due to high Hazard, but is allowed if building does not obstruct flows, or cause BFE to rise more than one foot.

Question 86

How is the floodway boundary extent determined.

Answer 86

Model fill in the edges of the floodplain until the flood water rises one foot.

Question 87

How are surge elevations predicted for a certain recurrence interval?

Answer 87

Based on data from past storms, model include wind speeds, wind direction, and atmospheric pressure to calculate surge elevations.

Question 88

What is the Stillwater Flood Elevation based on?

Answer 88

Historic storm surge elevations not including the waves.

Question 89

How does coastal flood study account for waves?

Answer 89

Study analyzes the wave crest Elevation above Stillwater, wave run up, and wave setup- the additional Elevation over normal surge Elevation.

Question 90

Define shallow flooding

Answer 90

Flooding with an average depth of one to three feet

Question 91

List types of shallow flooding?

Answer 91

Pounding, or urban drainage, sheet flow, coastal flooding from wave run up that is trapped behind dunes or structures

Question 92

what is an AO zone?

Answer 92

Shallow flooding due to sheet flow, usually with established depth.