Unit 5:

The NFIP Floodplain Management Requirements

In this unit

Unit 6 reviews more restrictive standards that may be required or
recommended for your community. Units 7 through 10 provide guidance on
how to administer a program that fulfills the requirements spelled out
in this unit.

This unit reviews the NFIP standards for floodplain development,
including:

-   What maps, base flood elevations and other flood data must be used,

-   When permits are required,

-   Ensuring that new development does not cause increased flooding
    elsewhere,

-   Standards to ensure that new buildings will be protected from the
    base flood, and

-   Additional requirements for certain types of development.

Materials used in this unit

-   ![](media/image1.wmf){width="1.1819444444444445in"
    height="0.7729166666666667in"}Videotape segments: *Federal and State
    Floodplain Management Requirements* and two of the *Best Build*
    series

-   Video cassette player

Contents

A. The NFIP's Regulations 5-[4](#__RefHeading___Toc413558167)

44 CFR 5-[4](#__RefHeading___Toc413558168)

Community types 5-[6](#__RefHeading___Toc413558169)

Video: *Federal and State Floodplain Management Requirements*
5-[7](#__RefHeading___Toc413558170)

B. Maps and Data 5-[8](#__RefHeading___Toc413558171)

NFIP maps and data 5-[8](#__RefHeading___Toc413558172)

When FIRM and ground data disagree 5-[9](#Toc406569203)

Regulating Approximate A Zones 5-[10](#__RefHeading___Toc413558174)

Small developments 5-[11](#__RefHeading___Toc413558175)

Larger developments 5-[12](#__RefHeading___Toc413558176)

Draft revised NFIP data 5-[14](#__RefHeading___Toc413558177)

Advisory flood hazard data 5-[15](#__RefHeading___Toc413558178)

Learning Check #1 5-[16](#__RefHeading___Toc413558179)

C. Permit Requirements 5-[17](#__RefHeading___Toc413558180)

Development permit 5-[17](#__RefHeading___Toc413558181)

Building permits 5-[18](#__RefHeading___Toc413558182)

Small projects 5-[18](#__RefHeading___Toc413558183)

Permits from other agencies 5-[19](#__RefHeading___Toc413558184)

D. Encroachments 5-[21](#__RefHeading___Toc413558185)

Regulatory Floodways 5-[21](#__RefHeading___Toc413558186)

Encroachment review 5-[21](#__RefHeading___Toc413558187)

Streams without floodway maps 5-[24](#__RefHeading___Toc413558188)

Allowable increases in flood heights
5-[25](#__RefHeading___Toc413558189)

Learning Check #2 5-[27](#__RefHeading___Toc413558190)

E. New Buildings in A Zones 5-[28](#__RefHeading___Toc413558191)

Video: *Best Build: Constructing in a Riverine Floodplain*
5-[28](#__RefHeading___Toc413558192)

Buildings 5-[28](#__RefHeading___Toc413558193)

Elevation 5-[29](#__RefHeading___Toc413558194)

Fill 5-[29](#__RefHeading___Toc413558195)

Piles, posts, piers or columns 5-[30](#__RefHeading___Toc413558196)

Walls or crawlspace 5-[30](#__RefHeading___Toc413558197)

How high? 5-[31](#__RefHeading___Toc413558198)

Elevation Certificate 5-[32](#__RefHeading___Toc413558199)

Enclosures 5-[32](#__RefHeading___Toc413558200)

Openings 5-[33](#__RefHeading___Toc413558201)

Use 5-[35](#__RefHeading___Toc413558202)

Floodproofing 5-[36](#__RefHeading___Toc413558203)

How high? 5-[38](#__RefHeading___Toc413558204)

Basements 5-[39](#__RefHeading___Toc413558205)

Anchoring 5-[40](#__RefHeading___Toc413558206)

Flood-resistant material 5-[40](#__RefHeading___Toc413558207)

Accessory structures 5-[41](#__RefHeading___Toc413558208)

Manufactured homes 5-[42](#__RefHeading___Toc413558209)

Elevation 5-[42](#__RefHeading___Toc413558210)

Anchoring 5-[43](#__RefHeading___Toc413558211)

Recreational vehicles 5-[44](#__RefHeading___Toc413558212)

AO and AH Zones 5-[44](#__RefHeading___Toc413558213)

A99 and AR Zones 5-[45](#__RefHeading___Toc413558214)

Learning Check #3 5-[46](#__RefHeading___Toc413558215)

F. New Buildings in V Zones 5-[47](#__RefHeading___Toc413558216)

Video: *Best Build: Constructing a Sound Coastal Home*
5-[47](#__RefHeading___Toc413558217)

Building location 5-[47](#__RefHeading___Toc413558218)

Elevation on piles or columns 5-[48](#__RefHeading___Toc413558219)

Wind and water loads 5-[49](#__RefHeading___Toc413558220)

Certification 5-[50](#__RefHeading___Toc413558221)

Breakaway walls 5-[50](#__RefHeading___Toc413558222)

G. Other Requirements 5-[53](#__RefHeading___Toc413558223)

Subdivisions 5-[53](#__RefHeading___Toc413558224)

Water and sewer systems 5-[53](#__RefHeading___Toc413558225)

Watercourse alterations 5-[54](#__RefHeading___Toc413558226)

Learning Check #4 5-[56](#__RefHeading___Toc413558227)

Unit Learning Exercise 5-[57](#__RefHeading___Toc413558228)

Answers to the learning checks 5-[61](#__RefHeading___Toc413558229)

Learning check #1 5-[61](#__RefHeading___Toc413558230)

Learning check #2 5-[63](#__RefHeading___Toc413558231)

Learning check #3 5-[65](#__RefHeading___Toc413558232)

Learning check #4 5-[67](#__RefHeading___Toc413558233)

Unit Learning Exercise 5-[68](#__RefHeading___Toc413558234)

[]{#__RefHeading___Toc413558167 .anchor}A. The NFIP's Regulations

For a community to participate in the National Flood Insurance Program,
it must adopt and enforce floodplain management regulations that meet or
exceed the minimum NFIP standards and requirements. These standards are
intended to prevent loss of life and property, as well as economic and
social hardships, that result from flooding.

The NFIP standards work -- as witnessed during floods in areas where
buildings and other developments are in compliance with them. Nationwide
each year, NFIP-based floodplain management regulations help prevent
more than \$700 million in structural damage.

This unit focuses on the minimum NFIP criteria. In some instances, more
restrictive state standards may exist, and they must also be met by
communities in the NFIP. They are the subject of the next unit.

[]{#__RefHeading___Toc413558168 .anchor}44 CFR

The NFIP requirements can be found in Chapter 44 of the *Code of Federal
Regulations* (44 CFR). Revisions to these requirements are first
published in the *Federal Register*, a publication the Federal
Government uses to disseminate rules, regulations and announcements.

Most of the requirements relative to your community's ordinance are in
Parts 59 and 60. These are included in Appendix E along with the mapping
regulations of Parts 65 and 70.

Figure 5-1 shows how the regulations are organized. The sections are
referred to in shorthand, such as 44 CFR 60.1---Chapter 44, *Code of
Federal Regulations*, Part 60, Section 1. In this course, excerpts are
shown in boxes:

**44 CFR 59.2(b)** To qualify for the sale of federally-subsidized flood
insurance a community must adopt and submit to the Administrator as part
of its application, flood plain management regulations, satisfying at a
minimum the criteria set forth at Part 60 of this subchapter, designed
to reduce or avoid future flood, mudslide (i.e., mudflow) or
flood-related erosion damages. These regulations must include effective
enforcement provisions.

As noted in Unit 2, when your community joined the NFIP, it agreed to
abide by these regulations. When your community's FIRM was published, it
had to submit its ordinance to FEMA to ensure that it met these
requirements.

**Part 59---General Provisions**

Subpart A---General

1.  Definitions

2.  Description of program

3.  Emergency program

4.  References

Subpart B---Eligibility Requirements

59.21 Purpose of subpart

22. Prerequisites for the sale of flood insurance

23. Priorities for the sale of flood insurance under the regular program

24. Suspension of community eligibility

**Part 60---Criteria for Land Management and Use**

Subpart A---Requirements for Flood Plain Management Regulations

60.1 Purpose of subpart

60.2 Minimum compliance with flood plain management criteria

60.3 Flood plain management criteria for floodprone areas

> \(a\) When there is no floodplain map
>
> \(b\) When there is a map, but not flood elevations
>
> \(c\) When there are flood elevations
>
> \(d\) When there is a floodway mapped
>
> \(e\) When there is a map with coastal high hazard areas

4.  Flood plain management criteria for mudslide (i.e., mudflow)-prone
    areas

5.  Variances and exceptions

6.  Revisions of criteria for flood plain management regulations

7.  Definitions

Subpart B---Requirements for State Flood Plain Management Regulations

Subpart C---Additional Considerations in Managing Flood-Prone, Mudslide
(i.e.,

Mudflow)-Prone, and Flood-Related Erosion-Prone Areas

Figure 5-1. 44 CFR Parts 59 and 60

Many state NFIP coordinators have prepared model flood damage prevention
ordinances to assist communities in meeting the NFIP requirements, so it
is likely that your community adopted an ordinance based on the state
model.

[NOTE:]{.underline} Periodically, the NFIP regulations are revised to
incorporate new requirements or clarify old ones. These changes are
published in the *Federal Register*. Some revisions require local
ordinance amendments. Your community may or may not have made the
amendments needed to stay updated. Before you complete this unit, you
should check with your state NFIP coordinator or FEMA Regional Office to
verify that your ordinance is currently in full compliance with the
latest NFIP requirements.

[]{#__RefHeading___Toc413558169 .anchor}Community types

NFIP regulations identify minimum requirements that communities must
fulfill to join and stay in the program. The requirements that apply to
a particular community depend on its flood hazard and the level of
detail of the data FEMA provides to the community. The specific
requirements are in Section 60.3, and apply to communities as follows:

-   60.3(a) FEMA has not provided any maps or data.

-   60.3(b) FEMA has provided a map with approximate A Zones

-   60.3(c) FEMA has provided a FIRM with base flood elevations

-   60.3(d) FEMA has provided a FIRM with base flood elevations and a
    map that shows a floodway

-   60.3(e) FEMA has provided a FIRM that shows coastal high hazard
    areas (V Zones)

Two important notes:

*The NFIP requirements are minimums.* As noted in 44 CFR 60.1(d), "Any
floodplain management regulations adopted by a State or a community
which are more restrictive than the criteria set forth in this part are
encouraged and shall take precedence."

*These requirements are cumulative.* A 60.3(c) community must comply
with all appropriate requirements of sections 60.3(a) and (b). For
example, 60.3(a) includes basic requirements for subdivisions and
utilities that are not repeated in the later sections. *All* communities
in the NFIP must comply with these subdivision and utility requirements.

For example, a 60.3(c) community must use the base flood elevations
provided on the FIRM. If that community has an approximate A Zone
without a BFE, it must comply with the requirements of 60.3(b) for that
area.

The rest of this unit explores the requirements of 44 CFR 60.3. It is
organized by subject matter, so it will not correspond with the sections
in 44 CFR. Where appropriate, the specific section numbers are
referenced.

You should be able to identify where the requirements discussed in this
unit appear in your ordinance. If you cannot find a specific reference
or if you are not comfortable with your ordinance's regulatory language,
contact your state NFIP coordinator or FEMA Regional Office. FEMA and
your state will expect you to enforce these minimum requirements as
agreed to. If you don't think your ordinance language is clear or up to
date, you should consider an amendment to remove any doubt.

This unit covers the minimum requirements for participation in the NFIP.
As noted, communities are encouraged to enact regulatory standards that
exceed these minimums and that are more appropriate for local
conditions.

![](media/image2.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System (CRS) is a part of the NFIP that rewards
communities that implement programs that exceed the minimums. It is
explained in more detail in Unit 9, Section C. Where provisions that can
receive CRS credit are mentioned in this course, they are highlighted
with the CRS logo.

[]{#__RefHeading___Toc413558170
.anchor}![](media/image1.wmf){width="1.1819444444444445in"
height="0.7729166666666667in"}Video: *Federal and State Floodplain
Management Requirements*

This 19 minute segment summarizes much of the material contained in this
unit. Some of the items discussed, such as substantial improvements and
variances, are discussed in later units.

The segment is part of a series produced by the Commonwealth of
Pennsylvania. There are some references to Pennsylvania agencies and
governmental units, but they should not detract from the information's
usefulness in other jurisdictions.

After viewing the segment, return to the text. You may rewind the tape.

[]{#__RefHeading___Toc413558171 .anchor}B. Maps and Data

Flood maps and flood data were discussed in Units 3 and 4. This section
builds on that information, covering the NFIP requirements as to when
and how a community must use those maps and data.

Basic rule #1: You must use the latest maps and flood data published by
FEMA.

[]{#__RefHeading___Toc413558172 .anchor}NFIP maps and data

A community must adopt and enforce floodplain management regulations
based on data provided by FEMA (44 CFR 60.2(h)). This includes the
floodplain boundaries, base flood elevations, FIRM zones and floodway
boundaries shown on your current Flood Insurance Rate Map, Flood
Boundary Floodway Map and/or Flood Insurance Study.

**44 CFR 60.2(h):** The community shall adopt and enforce flood plain
management regulations based on data provided by the \[Federal
Insurance\] Administrator. Without prior approval of the Administrator,
the community shall not adopt and enforce flood plain management
regulations based upon modified data reflecting natural or man-made
physical changes.

This requirement does not prevent a community from adopting and
enforcing regulations based on data more restrictive than that provided
by FEMA. For example, a community may want to regulate to an historical
flood which was higher than the BFEs shown on the FIRM. However, such
data must be approved by the FEMA Regional Office before it is used.

This requirement also does not prevent a community from using other
technical data to identify and regulate floodprone areas not shown on
FEMA maps. For example, many cities and urban counties map and regulate
areas on small tributary streams that are not shown on the FIRM.

The community always has a say in what the latest maps and data should
be. FEMA will send you proposed revisions to the official FIRM and you
will have time to review them and submit your comments to FEMA before
they are published. If you disagree with the FEMA data, then you should
submit a request for a map revision as noted in Unit 4, Section D,
*Maintaining and Revising NFIP Maps.*

**Annexations:** If a property is in a recently annexed area that does
not show up on your community's map, use the county's map and base flood
elevations (BFEs) to determine the flood protection requirements. In
fact, you should formally adopt the county's FIRM in your ordinance to
strengthen your basis for regulating areas not currently shown on your
FIRM.

**Exceptions:** The basic rule does not cover every situation. Four
occasions where a community may vary from the data provided by FEMA are:

-   When the FEMA data disagree with ground elevations.

-   When the FEMA data are insufficient. This occurs in approximate A
    Zones where base flood elevations and floodway boundaries are not
    provided with the FIRM.

-   When FEMA has provided draft revised data.

-   When FEMA provides "advisory" flood hazard data.

These situations are discussed below.

Note: these situations only apply to the use of flood data for
floodplain management purposes. Insurance agents and lenders must use
the current FIRM when setting insurance rates and determining whether
flood insurance is required. If a person wants to vary from the current
FIRM to obtain different premium rates or to not have to purchase a
flood insurance policy, the FIRM must be officially revised or amended.

[]{#Toc406569203 .anchor}

When FIRM and ground data disagree

The BFEs published in the Flood Insurance Study set the level for flood
protection purposes. The maps are a graphic portrayal of that
information.

Since FEMA usually does not have detailed topographic mapping to use in
preparing the flood maps, the flood boundaries are interpolated. This
can result in inaccuracies in drawing the boundaries on the map.

The BFE in relation to the actual ground elevation sets the floodplain
limits for regulatory purposes. When ground surveys show that a
development site is above the BFE, you should record the data and issue
the permit*.* Then, if the developer or owner wants the property removed
from the Special Flood Hazard Area designation, he or she can request a
Letter of Map Amendment.

It is up to them to apply for a map change, not you. The procedure is
discussed in Unit 4, Section D.

Conversely, if site surveys show that areas considered outside the
100-year floodplain on published maps are in fact below the BFE, you
should require protection of new buildings to the BFE. Even though a
site may be technically outside the mapped SFHA, you are not doing
future occupants any favors by ignoring the known flood hazard.

[]{#__RefHeading___Toc413558174 .anchor}Regulating Approximate A Zones

The second occasion where you may vary from the data provided by FEMA is
in approximate A Zones. Approximate A Zones are those areas not studied
by the detailed hydrologic/hydraulic methods. These areas are shown as
"unnumbered A zones" on the FIRM and "approximate 100-year flood zones"
on the Flood Boundary Floodway Map. The FIS will not contain specific
base flood elevations for approximate study areas nor will there be a
floodway/fringe designation on the FBFM.

**44 CFR 60.3(b)** When the Administrator has designated areas of
special flood hazards (A zones) by the publication of a community\'s
FHBM or FIRM, but has neither produced water surface elevation data nor
identified a floodway or coastal high hazard area, the community
shall:...

**(3)** Require that all new subdivision proposals and other proposed
developments (including proposals for manufactured home parks and
subdivisions) greater than 50 lots or 5 acres, whichever is the lesser,
include within such proposals base flood elevation data;

**(4)** Obtain, review and reasonably utilize any base flood elevation
and floodway data available from a Federal, State, or other source,
including data developed pursuant to paragraph (b)(3) of this section,
as criteria for requiring that new construction, substantial
improvements, or other development in Zone A on the community\'s FHBM or
FIRM meet the standards ...

Regulating development in approximate or unnumbered A Zones is one of
the tougher jobs you'll face, especially in counties that have large
areas of such zones. 44 CFR Section 60.3(b)(4) requires that you make
every effort to use any flood data available in order to achieve a
reasonable measure of flood protection. Further, many states and local
ordinances require a base flood elevation before a permit can be issued
for any development.

Here are some tips in obtaining data needed for unnumbered A Zones.
Whichever method you use, be sure to record on the permit records where
the flood elevation came from. This will help you be consistent with
future development in the same area.

-   Check with your state NFIP coordinator. Some states have regulations
    or guidance on how to obtain regulatory data. Some have repositories
    of data or may help conduct a new study.

-   Check with local flood control, sanitary or watershed districts.
    Like state agencies, they may have their own programs for developing
    new flood data.

-   If a body of water forms a boundary between two communities, the
    community on the other side may have a detailed study. Such base
    flood data are valid for both sides of a body of water.

-   Ask the U.S. Army Corps of Engineers, U.S. Department of
    Agriculture/Natural Resources Conservation Service, or U.S.
    Geological Survey if they have knowledge of any flood studies,
    unpublished reports, or any data that may pertain to the area in
    question.

-   If the property is along a stream that is near state highway
    structures such as bridges or culverts, the state highway department
    may have done a flood study to properly size the structure.

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-   If the property is on a river with a power-generating dam, the dam
    owner may have had to conduct a study for federal licensing.

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-   See if your engineer or the developer will conduct a study to
    calculate BFEs.

Data obtained from one of these other sources should be used as long as
they:

-   Reasonably reflect flooding conditions expected during the base
    flood,

-   Are not known to be technically incorrect, and

-   Represent the best data available.

The FEMA publication *Managing Floodplain Development in Approximate
Zone A Areas: A Guide for Obtaining and Developing Base (100-Year) Flood
Elevations* provides information on a number of methodologies for
developing BFEs in approximate A zones. These methodologies range from
detailed methods that produce BFEs and perform floodway analyses similar
to those developed for a Flood Insurance Study to simplified methods
that can be used in isolated areas where more costly studies cannot be
justified.

If your community has approximate A Zones that are likely to be
developed, you should get a copy of this document and have your engineer
review it. (The guide includes the Quick-2 software for computing flood
elevations.)

[]{#__RefHeading___Toc413558175 .anchor}Small developments

If the project is an isolated building, such as a single-family home in
an undeveloped area, it may not make economic sense to conduct a study
to determine the BFE. In these cases, you may want to use a less
expensive alternative to determine the flood protection level.

There are two possibilities:

-   Use historical records or the [flood of record]{.underline} (the
    highest known flood level for the area). It may be that a recent
    flood was close to the base flood. If records of the recent flood
    can be used, base your regulatory flood elevations on them (or add a
    foot or two to the historical flood levels to provide a margin of
    error). Before you do this, get a second opinion from your state
    NFIP coordinator, FEMA Regional Office or other agency that is
    familiar with the flood data you want to use.

-   Require protection to at least five feet above grade.

These methods are not as good as requiring protection to a BFE. However,
they may be more appropriate for small projects. The second approach
will result in lower flood insurance rates than if the building had no
protection, but the rates are not as favorable as they would be if a BFE
were calculated. Examples of the possible rates are discussed in Unit 9,
Section B.

[]{#__RefHeading___Toc413558176 .anchor}Larger developments

You are encouraged to discuss the flood hazard as early as possible in
discussions with subdividers and developers of large areas. If a
subdivision of planned unit development will be partially in the
floodplain, there may be ways to avoid building in the flood hazard
area, which can save the developer the cost of a flood study.

**44 CFR 60.3(b)(3):** \[Communities must\] Require that all new
subdivision proposals and other proposed development (including
proposals for manufactured home parks and subdivisions) greater than 50
lots or 5 acres, whichever is the lesser, include within such proposals
BFE data.

Any subdivision that meets this threshold must be evaluated to determine
if the proposed site is in an approximate A Zone and whether BFEs are
required. If BFEs are required, the developer must conduct the required
study (the community, state or other agency may provide assistance).
While the study must provide BFEs, you may want to require a floodway
delineation and inclusion of other data needed to ensure that the
building sites will be reasonably safe from flooding.

![](media/image3.wmf){width="3.420138888888889in"
height="2.2680555555555557in"}BFE data are required for the affected
lots in the subdivisions shown in Figure 5-2 and Figure 5-3. Figure 5-2
shows a 76-lot subdivision with several lots clearly affected by an
approximate Zone A area. The subdivision depicted in Figure 5-3 is only
12 lots, but BFEs are required because the subdivision covers more than
five acres and clearly shows buildable sites affected by an approximate
Zone A area.

Figure 5-2: Proposed 76-lot subdivision

![](media/image4.wmf){width="3.129861111111111in"
height="2.2895833333333333in"}

Figure 5-3: Proposed 6.7-acre subdivision

![](media/image5.wmf){width="3.370138888888889in"
height="2.2354166666666666in"}In Figure 5-4*,* the entire approximate
Zone A area is to be left as open space. If the planned subdivision
shows the floodplain is contained entirely within an open space lot, it
may not be necessary to conduct a detailed engineering analysis to
develop BFE data.

Figure 5-4: Proposed 76-lot subdivision

**44 CFR 65.3**: As soon as practicable, but not later than six months
after the date such information becomes available, a community shall
notify the Administrator of \[map\] changes by submitting technical or
scientific data in accordance with this part.

When a developer prepares a detailed flood study in an approximate A
Zone, you must submit the new flood information to FEMA within six
months. The community can pass that cost on to the developer by
requiring that he or she submit of a Letter of Map Revision as a
condition of approving the development.

![](media/image2.png){width="1.3in" height="1.0034722222222223in"}CRS
credit is provided if BFEs, floodways and related regulatory data are
provided in areas not mapped by the NFIP. This credit can be found in
Activity 410, Section 411, of the *CRS Coordinator's Manual* or the *CRS
Application*.

[]{#__RefHeading___Toc413558177 .anchor}Draft revised NFIP data

The third situation where a community may vary from the official FEMA
data is when FEMA has sent some preliminary data to the community for
review. Communities are required to "reasonably utilize" the data from a
draft or preliminary FIRM or flood insurance study.

Four scenarios are possible:

-   Where the original FIRM shows an A or V Zone with *no* BFEs: Use the
    draft information. In the absence of other elevation or floodway
    data, the draft information is presumed to be the best available.

-   Where the original FIRM shows an AE or VE Zone *with* a BFE or
    floodway and the revision *increases* the BFE or *widens* the
    floodway: The draft revised data should be used. However, if the
    community disagrees with the data and intends to appeal, the
    existing data can be presumed to be valid and may still be used
    until the appeal is resolved.

-   Where the original FIRM shows an AE or VE Zone *with* a base flood
    elevation or floodway and the revision *decreases* the BFE or
    *shrinks* the floodway: The existing data should be used. Because
    appeals may change the draft data, the final BFE may be higher than
    the draft. If you were to allow new construction at the lower level
    as shown in the draft, the owners will have to pay higher flood
    insurance premiums.

-   Where the original FIRM shows a B, C or X Zone: NFIP regulations do
    not require that the draft revised data be used. However, you are
    encouraged to use the draft data to regulate development, since
    these areas are subject to a flood hazard.

If the community intends to appeal preliminary data, it must be done
during the official appeals period. Otherwise, you will have to wait for
the new map to become official and submit a request for a map amendment
or revision.

For more information on this issue, see *Use of Flood Insurance Study
(FIS) Data As Available Data*, FEMA Floodplain Management Bulletin 1-98.

**CLOMRs:** The above four scenarios are also relevant for a Conditional
Letter of Map Revision or CLOMR. Note the *conditional* part of a CLOMR.
A CLOMR provides that *if* a project is constructed as designed, the
BFEs can be revised or modified (or the property in question can be
removed from the SFHA) *[after]{.smallcaps}* the as-built specifications
are submitted *[and]{.smallcaps}* the final LOMR is issued.

A permit should not be based on a lower BFE proposed by a CLOMR until
the final LOMR is issued. However, you can issue a permit for that part
of the work not dependent on the changes that will result from the LOMR
and condition the full permit upon receipt of the final LOMR.

[]{#__RefHeading___Toc413558178 .anchor}Advisory flood hazard data

Sometimes FEMA issues advisory data after a major flood where it was
found that the FIRM and/or flood insurance study underestimated the
hazard. This information is provided so communities can ensure that
reconstructed buildings are protected from the true hazard, not the one
shown on the FIRM.

When you receive such advisory information, you should "reasonably
utilize" it. If your community agrees with the information, the
ordinance should be revised to adopt it. If it disagrees with the data,
you should be ready to explain why the community is not requiring
construction and reconstruction to be protected. You and your community
are not helping residents if you allow them to rebuild without
protection from a known hazard.

For more information on this issue, see *Use of Flood Insurance Study
(FIS) Data As Available Data*, FEMA Floodplain Management Bulletin 1-98.

[]{#__RefHeading___Toc413558179
.anchor}![](media/image6.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #1

1.  What publication has the NFIP requirements for communities?

2.  Most of the requirements relative to your community's ordinance are
    in 44 CFR Parts \_\_\_\_ and \_\_\_\_ .

3.  Does your ordinance comply with the latest NFIP requirements?

4.  Which part of 44 CFR 60.3 covers the requirements for areas with a
    FIRM, but no base flood elevations?

5.  What is "Basic rule #1" for using maps and data?

6.  What map do you use if recently annexed areas do not show up on your
    community's FIRM?

7.  If you find information that shows the ground to be higher than the
    BFE, can a bank use that data when determining whether a flood
    insurance policy must be purchased?

8.  Site E is in the approximate A Zone of Dean Lake. A developer wants
    to build a small commercial building on a 3 acre site. Where do you
    get a base flood elevation for Site E?

9.  A developer downstream of Dean Lake wants to build a 40 acre
    subdivision that crosses Ireland Creek. You need a base flood
    elevation before you review the plans. What options do you tell the
    developer he has?

10. A restudy was performed on the Josias River. The preliminary study
    will not be final for another five months. It shows a new BFE at
    Site N that is two feet higher than the BFE in your current FIS.
    Which one do you use to determine the flood protection level for a
    new home at Site N?

[]{#__RefHeading___Toc413558180 .anchor}C. Permit Requirements

Permits are required to ensure that proposed development projects meet
the requirements of the NFIP and your ordinance. Once a person applies
for a permit, you can review the plans and make sure the project
complies.

Basic rule #2: A permit is required for all [development]{.underline} in
the SFHA shown on your FIRM.

The first step, therefore, is to get people to apply for a permit.

[]{#__RefHeading___Toc413558181 .anchor}Development permit

**44 CFR 59.** Definitions: \"Development\" means any man-made change to
improved or unimproved real estate, including but not limited to
buildings or other structures, mining, dredging, filling, grading,
paving, excavation or drilling operations or storage of equipment or
materials.

The NFIP requirements are keyed to "development" in the floodplain.
"Development" means "any man-made change to improved or unimproved real
estate." This includes, but is not limited to:

-   Construction of new structures

-   Modifications or improvements to existing structures

-   Excavation

-   Filling

-   Paving

-   Drilling

-   Driving of piles

-   Mining

-   Dredging

-   Land clearing

-   Grading

-   Permanent storage of materials and/or equipment

-   

**44 CFR 60.3(a)(1)** \["60.3(a) communities" that do not have a FIRM
must\] Require permits for all proposed construction or other
development in the community, including the placement of manufactured
homes, so that it may determine whether such construction or other
development is proposed within flood-prone areas;

If you are a 60.3(a) community, you do not have a FIRM. Consequently,
you must require a permit for all development projects throughout your
community.

You must review each project's location to determine if it has a flood
risk. If it does, the best way to protect a new building from flood
damage is to obtain a BFE for the site and require that the building be
elevated or protected to or above that BFE.

[]{#__RefHeading___Toc413558182 .anchor}Building permits

Most communities have long had a system for issuing building permits,
but few have a permit system for "development." Regulating all
development in floodplains is essential because fill or other material
can obstruct flood flows just as structures can.

Because a "building permit" often covers only construction or
modifications of buildings, this course uses the term "development
permit." You should check your permit system to ensure that in the
floodplain, permits are being required for *[all]{.smallcaps}* projects
that meet the definition of development, not just "building" projects.
Make sure you regulate the following in addition to the tradition
building projects:

-   Filling and grading.

-   Excavation, mining and drilling.

-   Storage of materials.

-   Repairs to a damaged building that do not affect structural members.

-   Temporary stream crossings

-   Activities by other government agencies, such as roads, bridges and
    school buildings

If your building permit system does not require permits for these
activities, you need to revise your system, enact a new type of
"development permit" or otherwise ensure that people apply for a permit
for these non-building projects.

[]{#__RefHeading___Toc413558183 .anchor}Small projects

You have some discretion to exempt obviously insignificant activities
from the permit requirement, such as planting a garden, farming, putting
up a mailbox or erecting a flagpole. You may also want to exempt routine
maintenance, such as painting or reroofing.

The key is whether the project will present a new obstruction to flood
flows, alter drainage or have the potential to be a substantial
improvement. These determinations can only be made by the permit
official, not the builder, so make sure your exemptions are clear. There
should be no possibility of a misunderstanding resulting in construction
of a flood flow obstruction or a substantial improvement without a
permit.

Some communities specifically exempt small projects in their ordinances.
This is the recommended approach, as it avoids challenges that the
permit official arbitrarily decides what projects need permits. Check
with your state coordinating agency and/or FEMA Regional Office before
you do this. You may be able to exempt projects (other than filling,
grading or excavating) valued at less than, say, \$500.

[]{#__RefHeading___Toc413558184 .anchor}Permits from other agencies

44 CFR 60.3(a)(2) requires all NFIP communities to ensure that other
federal and state permits have been obtained. You should not issue your
local permit until you are certain that the other agencies' requirements
are met.

Some communities allow their permit officials to issue the local permit
on the condition that other required permits are obtained. However, this
is not as effective as holding the local permit until the applicant can
show that the other agencies have issued or will issue their permits.

Otherwise, the project may get under way before you are sure that it
meets all legal requirements.

To implement this requirement, you're encouraged to develop a list of
what permits are required in your jurisdiction. Your state NFIP
coordinator should be able to help.

These development activities may require a state permit:

-   Construction in the coastal zone.

-   Construction in floodways or other designated areas.

-   Stream crossings or projects that affect navigable rivers.

-   Installation of septic systems.

-   Subdivision standards or subdivision plat or lot filing
    requirements.

-   Manufactured housing (mobile home) park or tie-down requirements.

-   Public health facilities, such as hospitals and nursing homes.

-   Alteration of sand dunes.

-   Operating a landfill or hazardous materials storage facility.

The more common federal regulations that may require a permit include:

-   U.S. Army Corps of Engineers Section 404---permits for wetlands
    filling

-   U.S. Army Corps of Engineers Section 10---permits for work in
    navigable waterways

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-   U.S. Coast Guard---permits for bridges and causeways that may affect
    navigation.

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-   U.S. Fish and Wildlife Service---consultations required under
    Sections 7 and 10 of the Endangered Species Act of 1973.

You should also check with your county; sewer, sanitary or flood control
district; water management district; and any other local or regional
agency that may regulate certain types of development in the floodplain.

[]{#__RefHeading___Toc413558185 .anchor}D. Encroachments

Once a permit application is received and the proposed project is ready
for review, the next job is to ensure that the project will not impose
flood problems on other properties.

Basic rule #3: Development must not increase the flood hazard on other
properties.

This is more of a concern in riverine situations where a project may dam
or divert flowing water onto other properties or increase flood flows
downstream. To prevent this, communities adopt floodways to designate
those areas where flood flows are most sensitive to changes brought by
development.

Communities must regulate development in these floodways to ensure that
there are no increases in upstream flood elevations. For streams and
other watercourses where FEMA has provided BFEs, but no floodway has
been designated, the community must review developments on a
case-by-case basis to ensure that these increases do not occur.

[]{#__RefHeading___Toc413558186 .anchor}Regulatory Floodways

**44 CFR 59.1** Definitions: \"Regulatory floodway\" means the channel
of a river or other watercourse and the adjacent land areas that must be
reserved in order to discharge the base flood without cumulatively
increasing the water surface elevation more than a designated height.

As explained in Unit 3, Section B, the floodway is the central portion
of a riverine floodplain needed to carry the deeper, faster moving
water. Buildings, structures and other development activities---such as
fill---placed within the floodway are more likely to obstruct flood
flows, causing the water to slow down and back up, resulting in higher
flood elevations.

A floodway map is included with most riverine Flood Insurance Studies.
The community officially adopts its "regulatory floodway" in its
floodplain management ordinance.

[]{#__RefHeading___Toc413558187 .anchor}Encroachment review

All projects in the regulatory floodway must undergo an encroachment
review to determine their effect on flood flows and ensure that they do
not cause problems. Development projects in the flood fringe by
definition do not increase flood heights above the allowable level, so
encroachment reviews are not needed.

**44 CFR 60.3(d)(3):** \[In the regulatory floodway, communities must\]
Prohibit encroachments, including fill, new construction, substantial
improvements, and other development within the adopted regulatory
floodway unless it has been demonstrated through hydrologic and
hydraulic analyses performed in accordance with standard engineering
practice that the proposed encroachment would not result in any increase
in flood levels within the community during the occurrence of the base
flood discharge.

The objective of this requirement and the floodplain management
ordinance to ensure that the floodway is reserved to do its natural job:
carrying floodwater. The preferred approach is to avoid all development
there.

Once your community adopts its floodway, you must fulfill the
requirements of 44 CFR 60.3(d). The key concern is that each project in
the floodway must receive an [encroachment]{.underline}
[review]{.underline}, i.e., an analysis to determine if the project will
increase flood heights or cause increased flooding downstream. Note that
the regulations call for preventing [any]{.smallcaps} increase in flood
heights. This doesn't mean you can allow a foot or a tenth of a foot --
it means zero increase.

Projects, such as filling, grading or construction of a new building,
must be reviewed to determine whether they will obstruct flood flows and
cause an increase in flood heights upstream or adjacent to the project
site.

Projects, such as such as grading, large excavations, channel
improvements, and bridge and culvert replacements, should also be
reviewed to determine whether they will remove an existing obstruction,
resulting in increases in flood flows downstream.

Your community may conduct the encroachment review, or you may require
the developer to conduct it. Most local permit officials are not
qualified to make an encroachment review, so most require that this be
done by an engineer at the developer's expense.

As the permit reviewer, it is the community's job to ensure that an
activity will not cause a problem. You have two options for doing this:
For every project you could require the applicant's engineer to certify
that there will be no rise in flood heights or you can make the
determination for minor projects.

**Encroachment certification:** To ensure that the encroachment review
is done right, you may want to require the developer to provide an
encroachment certification. This is often called a "no-rise"
certification because it certifies that the development project will not
affect flood heights. An example of a form developed by the North
Carolina state coordinating agency is shown in Figure 5-5.

The certification must be supported by technical data, which should be
based on the same computer model used to develop the floodway shown on
the community\'s map.

**"NO-RISE" CERTIFICATION**

This is to certify that I am a duly qualified registered professional
engineer licensed to practice in the State of

It is further to certify that the attached technical data supports the
fact that proposed (Name of Development) will not impact the 100-year
flood elevations, floodway elevations, or floodway widths on (Name of
Stream) at published sections in the Flood Insurance Study for (Name of
Community) dated (Study Date) and will not impact the 100-year flood
elevations, floodway elevations, or floodway widths at unpublished
cross-sections in the vicinity of the proposed development.

Attached are the following documents that support my findings:

Date:

Signature:

Title: {SEAL}

Figure 5-5: Example no-rise certification

Although your community is required to review and approve the
encroachment review, you may request technical assistance and review
from the FEMA Regional Office or state NFIP Coordinator. If this
alternative is chosen, you must review the technical submittal package
and verify that all supporting data are included in the package before
sending it to FEMA.

**Minor projects:** Some projects are too small to warrant an
engineering study and the certification. Many of these can be determined
with logic: a sign post or telephone pole will not block flood flows. A
driveway, road or parking lot at grade (without any filling) won't cause
a problem, either.

Building additions, accessory buildings, and similar small projects can
be located in the [conveyance shadow]{.underline}. This is the area
upstream and downstream of an existing building or other obstruction to
flood flows. Flood water is already flowing around the larger
obstruction, so the addition of a new structure will not change existing
flood flow.

Determining the limits of the conveyance shadow is illustrated in Figure
5-6. Small structures located completely within the shadow can be
permitted without the engineering analysis needed for a no-rise
certification.

Note: Just because a small structure can be located in the conveyance
shadow, it is still preferable to keep all development out of the
floodway. Don't forget: all buildings must be elevated or otherwise
protected from the base flood.

![](media/image7.png){width="5.483333333333333in"
height="2.3881944444444443in"}

Figure 5-6. Determining the conveyance shadow

[]{#__RefHeading___Toc413558188 .anchor}Streams without floodway maps

If your community is subject to 44 CFR Section 60.3(c), you have a FIRM
with base flood elevations but no mapped floodway. The following applies
to you.

**44 CFR 60.3(c)(10):** \[Communities must\] Require until a regulatory
floodway is designated, that no new construction, substantial
improvements, or other development (including fill) shall be permitted
within Zones A1-30 and AE on the community\'s FIRM, unless it is
demonstrated that the cumulative effect of the proposed development,
when combined with all other existing and anticipated development, will
not increase the water surface elevation of the base flood more than one
foot at any point within the community.

For the purposes of administering your ordinance, you should treat the
entire riverine floodplain as a floodway. You should require the same
encroachment certification to ensure that a development project will not
obstruct flood flows and cause increased flooding on other property.
This approach is recommended for all other riverine floodplains without
a mapped floodway.

In riverine floodplains where no floodway has been designated, the
review must demonstrate that the *cumulative* effect of the proposed
development, when combined with all other existing and anticipated
development:

-   Will not increase the water surface elevation of the base flood more
    than one foot at any point within the community, and

-   Is consistent with the technical criteria contained in Chapter 5
    (Hydraulic Analyses) of the Flood Insurance Study: Guidelines and
    Specifications for Study Contractors, FEMA-37, 1995.

This review must be required for all development projects that may
create a one-foot increase in flood flows, such as bridges, road
embankments, buildings and large fills.

[Note:]{.underline} In some states, floodways are mapped based on
allowing flood heights to increase by less than one foot. In those
states, the encroachment certification must be based on that more
restrictive state standard, not the FEMA standard that allows a one-foot
rise.

[]{#__RefHeading___Toc413558189 .anchor}Allowable increases in flood
heights

In some situations, it may be in the public interest to allow increase
in flood heights greater than those allowed under the NFIP regulations.

For example, it would be hard to build a flood control reservoir without
affecting flood heights. Because a dam would have a major impact on
flood heights, there needs to be a way to permit such projects,
especially those that are intended to reduce flooding.

However, when the project will change the flood level, maps must be
changed to reflect the new hazard.

**44 CFR 60.3(d)(4)** Notwithstanding any other provisions of § 60.3, a
community may permit encroachments within the adopted regulatory
floodway that would result in an increase in base flood elevations,
provided that the community first applies for a conditional FIRM and
floodway revision, fulfills the requirements for such revisions as
established under the provisions of § 65.12, and receives the approval
of the Administrator.

If your community proposes to permit an encroachment in the floodway or
the floodplain that will cause increases in the BFE in excess of the
allowable level, you're required to apply to the FEMA Regional Office
for *conditional* approval of such action prior to permitting the
project to occur.

As part of your application for conditional approval, you must submit:

-   A complete application and letter of request for conditional
    approval of a change in the FIRM or a Conditional Letter of Map
    Revision (CLOMR), along with the appropriate fee for the change
    (contact the FEMA Regional Office for the fee amount).

-   An evaluation of alternatives which, if carried out, would not
    result in an increase in the BFE more than allowed, along with
    documentation as to why these alternatives are not feasible.

-   Documentation of individual legal notice to all affected property
    owners (anyone affected by the increased flood elevations, within
    and outside of the community) explaining the impact of the proposed
    action on their properties.

-   Concurrence, in writing, from the chief executive officer of any
    other communities affected by the proposed actions.

-   Certification that no structures are located in areas which would be
    affected by the increased BFE (unless they have been purchased for
    relocation or demolition).

-   A request for revision of BFE determinations in accordance with the
    provisions of 44 CFR 65.6 of the FEMA regulations.

Upon receipt of the FEMA conditional approval of the map change and
prior to approving the proposed encroachments, you must provide evidence
to FEMA that your community's floodplain management ordinance
incorporates the post-project condition BFEs.

[]{#__RefHeading___Toc413558190
.anchor}![](media/image6.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #2

1.  What is basic rule #2 on what needs a permit in the floodplain?

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11. Define "development" as the term is used in your ordinance.

12. Does your community only require building permits? If so, does
    someone who wants to fill a vacant lot need a permit from the
    community?

13. The State in which Flood County is situated requires a permit from
    the state Department of Environmental Protection for development on
    primary sand dunes. A permit applicant wants to build on one near
    Site F. Department staff informs you that based on the plans they
    have seen, they will have to deny the state permit. Should the Flood
    County permit officer issue a floodplain development permit?

14. What is Basic rule #3 as it relates to encroachments in riverine
    floodplains?

15. An encroachment review should review projects in a floodway for what
    two things?

16. A farmer wants to build a dairy barn in the floodway. Will he need
    to provide you with a "no-rise" certification before you can issue
    the permit?

17. The same farmer wants to build a small addition onto his farmhouse
    (also in the floodway). Can this be designed so he won't have to pay
    for an engineer's encroachment review?

18. In a riverine AE Zone with a base flood elevation, what must a
    developer show in order to demonstrate that he is meeting Basic Rule
    #3?

19. Does your state have a more restrictive standard than allowing flood
    heights to increase by one foot?

[]{#__RefHeading___Toc413558191 .anchor}E. New Buildings in A Zones

[]{#__RefHeading___Toc413558192
.anchor}![](media/image8.wmf){width="1.2645833333333334in"
height="0.8090277777777778in"}Video: *Best Build: Constructing in a
Riverine Floodplain*

Before continuing, please view the 23-minute video segment on
construction techniques along rivers and streams. Called *Best Build II:
Constructing in a Riverine Floodplain*, it is on the second videotape
included in the course materials. Do not rewind the tape.

*Note:* The NFIP rules have changed since this video was made. It shows
a garage door being used as an opening to allow water under the elevated
building. This is no longer allowed -- all openings must be permanent or
automatic. Allowable openings could include vents in garage doors, but
cannot include doors that need a person present to open them.

Basic rule #4: New, substantially improved or substantially damaged
buildings must be protected from damage by the base flood.

[]{#__RefHeading___Toc413558193 .anchor}Buildings

In this course, the term "building" is the same as the term "structure"
in the NFIP regulations. Your ordinance may use either term.

**44 CFR 59.1** Definitions: \"Structure\" means, for flood plain
management purposes, a walled and roofed building, including a gas or
liquid storage tank, that is principally above ground, as well as a
manufactured home.

The term "building" or "structure" does not include open pavilions,
bleachers, carports and similar structures that do not have at least two
rigid walls and a roof.

How to determine if a building is substantially improved or
substantially damaged is discussed in Unit 8. In this unit, consider the
term "building" as an all-encompassing term that includes substantial
improvements and repairs of substantial damage to a building.

Residential and nonresidential buildings are treated differently. A
residential buildings must have a higher level of protection---if it is
to be built in the floodplain, it must be elevated above the BFE.
Nonresidential buildings, on the other hand, may be elevated or
floodproofed.

[]{#__RefHeading___Toc413558194 .anchor}Elevation

**44 CFR 60.3(c)(2)** \[Communities must\] Require that all new
construction and substantial improvements of residential structures
within Zones A1-30, AE and AH zones on the community\'s FIRM have the
lowest floor (including basement) elevated to or above the base flood
level...

In Zones A1-A30, AE and AH, all new construction and substantial
improvements of residential structures must be elevated so that the
lowest floor (including the basement) is elevated to or above the BFE.
This can be done in one of three ways:

-   Elevation on fill.

-   Elevation on piles, posts, piers or columns.

-   Elevation on walls or a crawlspace.

[]{#__RefHeading___Toc413558195 .anchor}Fill

![](media/image9.png){width="3.0097222222222224in"
height="4.504861111111111in"}NFIP regulations allow fill to be used, but
restrictions apply in floodways where fill would cause an increase in
flood heights.

Many communities also limit the use of fill in the flood fringe to
protect flood storage capacity or require compensatory storage, which is
discussed in Unit 6, Section C.

Where fill is the method of choice, it should be properly designed,
installed in layers and compacted. Simply adding dirt to the building
site may result in differential settling over time.

The fill should also be properly sloped and protected from erosion and
scour during flooding. To provide a factor of safety for the building
and its residents, it is recommended that the fill extend 10 -- 15 feet
beyond the walls

before it drops below the BFE. **Figure 5-7. These two new buildings**

**elevated on fill were not damaged by**

**this 100-year flood.**

[]{#__RefHeading___Toc413558196 .anchor}Piles, posts, piers or columns

![](media/image10.png){width="4.040277777777778in"
height="2.748611111111111in"}Piles, piers, posts or columns are
appropriate where there is deeper flooding and fill is not feasible.
Where flooding is likely to have high velocities or to create waves,
elevation with no lower area enclosure is preferred. As illustrated in
Figure 5-8, this permits unrestricted flow of floodwater under buildings
and causes little, if any, impact on flood heights.

Figure 5-8. Elevation on piers

[]{#__RefHeading___Toc413558197 .anchor}Walls or crawlspace

The third elevation technique is to build on solid walls. In shallower
flooding areas, this elevation technique is the same as creating a
crawlspace---a foundation of solid walls that puts the lowest floor
above the flood level.

When solid walls are used, care must be taken to ensure that hydrostatic
or hydrodynamic pressure does not damage the walls. As discussed in Unit
1, Section B, these water pressures can break a solid wall.

There are two ways to prevent this:

-   Stem walls can be used on two sides parallel to the flow of water.
    The other two sides are kept open (Figure 5-9). This minimizes the
    obstruction to floodwaters and lessens pressure on the foundation.

-   The walls can have openings large enough to allow floodwaters to
    flow in and out, preventing differential pressures on the walls.
    This is discussed in more detail in the later section on enclosures.

![](media/image11.png){width="4.090277777777778in"
height="2.752083333333333in"}

![](media/image12.png){width="4.290277777777778in"
height="2.752083333333333in"}Figure 5-9: Building elevated on parallel
stem walls.

Figure 5-10: Building elevated on crawlspace with openings.

[]{#__RefHeading___Toc413558198 .anchor}How high?

NFIP regulations require that the lowest floor of a building must be
elevated above the BFE. Note three things about this minimum
requirement:

1.  The term "[lowest floor]{.underline}" includes a basement because
    all usable portions of a building must be protected from flood
    damage.

**44 CFR 59.1.** Definitions: \"Lowest Floor\" means the lowest floor of
the lowest enclosed area (including basement). An unfinished or flood
resistant enclosure, usable solely for parking of vehicles, building
access or storage in an area other than a basement area is not
considered a building\'s lowest floor; provided, that such enclosure is
not built so as to render the structure in violation of the applicable
non-elevation design requirements of section 60.3.

> ![](media/image13.png){width="3.0902777777777777in"
> height="2.5034722222222223in"}2. The minimum requirement is to elevate
> to the BFE. In the next unit, we will discuss freeboard, an extra
> margin of protection that requires the lowest floors to be one or more
> feet above the BFE.
>
> 3\. In A Zones, under the minimum NFIP requirement, the lowest floor
> is measured from the top of the floor (Figure 5-11). However, it is
> recommended that buildings on elevated foundations, such as piles or a
> crawlspace, have supporting beams or floor joists above the BFE to
> protect them from flood damage.
>
> Figure 5-11. In A Zones: the top
>
> of the floor is the reference level

[]{#__RefHeading___Toc413558199 .anchor}Elevation Certificate

Because most new buildings built in the floodplain are residences,
elevating them is one of the most important requirements of the NFIP. To
ensure that a building is elevated above the BFE, the lowest floor is
surveyed and a surveyor's elevation certificate is obtained and kept by
the local permit office. This is discussed in more detail in Unit 7,
Section G.

[]{#__RefHeading___Toc413558200 .anchor}Enclosures

Enclosures are areas created by a crawlspace or solid walls below the
BFE. They deserve special attention for two reasons:

-   The walls of enclosed areas are subject to flood damage from
    hydrostatic and hydrodynamic forces.

-   People are tempted to convert floodable enclosures into areas that
    can sustain damage in a flood.

Does an enclosure under an elevated floor just go to waste? It need not.

NFIP regulations allow certain uses in enclosures below the BFE because
they are subject to minimal flood damage. Three uses are allowed:

-   building access

-   vehicle parking

-   storage.

The floodplain regulation requirements can be easier to accept if owners
and builders are encouraged to think about the enclosed lower areas as
usable space. If a building has to be elevated, say, five feet above
grade, the owner should be encouraged to go up eight feet. This allows
the lower area to be used for parking---and provides three extra feet of
flood protection.

However, if the lower area is enclosed, there is a tendency for the
owner to forget about the flood hazard and convert the enclosure to a
bedroom or other finished room. This must be prevented.

The lower area on an elevated building must be floodable---it must be
built of flood-resistant materials (see the next section on what
materials are acceptable). Not allowed are finishings such as carpeting,
paneling, insulation (both cellulose and fiberglass) and gypsum
wallboard (also known as drywall and sheet rock).

Utilities that serve the upper level also must be protected from flood
damage. Consequently, a furnace cannot be put in an enclosure unless it
is above the BFE. This is explained in more detail in *Engineering
Principles and Practices for Flood Damage-Resistant Building Support
Utility Systems*, which is due to be published in late 1998.

The lower area must provide access to the upper level. A stairway can
easily be designed that provides access yet is resistant to flood
damage. Installing an elevator is tricky, but there are ways to design
and install an elevator that will face minimal flood damage, as
explained in *Elevator Installation for Buildings Located in Special
Flood Hazard Areas*, FIA-TB-4, FEMA 1993.

[]{#__RefHeading___Toc413558201 .anchor}Openings

As noted in Unit 1, solid walls can collapse if floodwaters get too
deep. To prevent this, the enclosure must have openings to allow
floodwaters to enter and leave, thus automatically equalizing
hydrostatic flood forces on the walls.

You can be sure the openings are adequate by using one of two methods.

The first method is to require the builder to have the design certified
by a registered professional engineer or architect.

**44 CFR 60.3(c)(5)** \[Communities must\] Require, for all new
construction and substantial improvements, that fully enclosed areas
below the lowest floor that are usable solely for parking of vehicles,
building access or storage in an area other than a basement and which
are subject to flooding shall be designed to automatically equalize
hydrostatic flood forces on exterior walls by allowing for the entry and
exit of floodwaters. Designs for meeting this requirement must either be
certified by a registered professional engineer or architect or meet or
exceed the following minimum criteria: A minimum of two openings having
a total net area of not less than one square inch for every square foot
of enclosed area subject to flooding shall be provided. The bottom of
all openings shall be no higher than one foot above grade. Openings may
be equipped with screens, louvers, valves, or other coverings or devices
provided that they permit the automatic entry and exit of floodwaters.

The second method is to have the design meet or exceed the following
three criteria:

1.  The bottom of the openings must be no higher than one foot above
    grade (see Figure 5-12).

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20. The openings should be installed on at least two walls of the
    enclosure to ensure that at least one will work if others get
    blocked or plugged.

21. Provide a minimum of two openings having a net area of not less than
    one square inch for every square foot of enclosed area that is
    subject to flooding. If the area of the enclosure is 1,000 square
    feet, the area of the openings combined must total at least 1,000
    square inches.

> A standard crawlspace vent for block walls is 8" x 16" or 128 square
> inches (see Figure 5-12). To determine how many would be needed,
> divide the square footage of the floor area by 128.

Example 1: [1,280 square foot house]{.underline} = 10 10 vents will be
needed

128 square inches/vent

Example 2: [2,000 square foot house]{.underline} = 15.62 16 vents will
be needed

128 square inches/vent

Openings may be equipped with screens, louvers, valves or other
coverings or devices to keep animals out of the enclosure. However, any
covering must permit the automatic flow of floodwater in both
directions.

The opening sizes in the previous examples and in Figure 5-12 are based
on standard crawlspace vents, which most building codes require to be
installed in a crawlspace for ventilation purposes. Often these are
located close to the floor in order to circulate air around the floor
joists.

![](media/image14.png){width="5.5in" height="2.915277777777778in"}

Figure 5-12. Opening location in solid foundation wall

Such vents are well above the ground in an elevated house and would not
meet the NFIP requirement that the bottom of the opening be within one
foot of grade. However, NFIP requirements and building codes can be
satisfied by the same vents if they meet the three criteria listed
above.

Garage doors cannot be used to satisfy this requirement because they do
not permit the automatic flow of floodwaters. However, garage doors may
have vents in them that meet the above criteria.

Openings are not required for stem wall foundations that have been
backfilled for pouring of a concrete floor slab.

For further guidance, refer to *Openings in Foundation Walls*, FIA-TB-1
(FEMA 1993).

[]{#__RefHeading___Toc413558202 .anchor}Use

Enclosed areas must be floodable and used only for parking vehicles,
storage or entry to a living area---uses that are subject to little
flood damage.

The type of storage permitted in an enclosed lower area should be
limited to that which is incidental and accessory to the principal use
of the structure. For instance, if the structure is a residence, the
enclosure should be limited to storage of lawn and garden equipment,
snow tires, and other low damage items which can be conveniently moved
to the elevated part of the building.

The interior portion of an enclosed area should not be partitioned or
finished into separate rooms, except to enclose storage areas.

If a building is elevated eight feet or more, regulating the use of the
enclosure presents special problems. Over time, the owner may forget the
flood hazard and want to convert the floodable area into a finished
room. Such an action would increase the flood damage potential for the
building and violate the conditions of the building permit.

However, because the room is hidden behind walls, it can be very hard
for the permit office to catch such a conversion. You should carefully
check new building plans for signs, such as roughed in plumbing and
sliding glass doors, that indicate that the owner may expect to finish
the area in the future.

One way to help prevent conversions is to have the owner sign a
nonconversion agreement. An example developed by the North Carolina
State NFIP Coordinator is in Figure 5-13*.*

[]{#__RefHeading___Toc413558203 .anchor}Floodproofing

Nonresidential buildings must be elevated or floodproofed. If they are
elevated, they must meet the same standards as for residential buildings
that were just reviewed. Elevation is the preferred method because it is
more dependable. Elevated commercial and industrial buildings can often
be designed so that they can continue to operate during a flood reducing
or eliminating business disruptions.

**44 CFR 59.1.** Definitions: \"Flood proofing\" means any combination
of structural and non-structural additions, changes, or adjustments to
structures which reduce or eliminate flood damage to real estate or
improved real property, water and sanitary facilities, structures and
their contents.

**44 CFR 60.3(c)(3**) \[Communities must\] Require that all new
construction and substantial improvements of non-residential structures
within Zones A1-30, AE and AH zones on the community\'s firm (i) have
the lowest floor (including basement) elevated to or above the base
flood level or, (ii) together with attendant utility and sanitary
facilities, be designed so that below the base flood level the structure
is watertight with walls substantially impermeable to the passage of
water and with structural components having the capability of resisting
hydrostatic and hydrodynamic loads and effects of buoyancy;

**44 CFR 60.3(c)(4)** \[Communities must\] Provide that where a
non-residential structure is intended to be made watertight below the
base flood level, (i) a registered professional engineer or architect
shall develop and/or review structural design, specifications, and plans
for the construction, and shall certify that the design and methods of
construction are in accordance with accepted standards of practice for
meeting the applicable provisions of paragraph (c)(3)(ii) or (c)(8)(ii)
of this section, and (ii) a record of such certificates which includes
the specific elevation (in relation to mean sea level) to which such
structures are floodproofed shall be maintained with the official
designated by the community under §59.22(a)(9)(iii);

This DECLARATION made this \_\_\_ day of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_,
19\_\_, by \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
("Owner") having an address at
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ .

WITNESSETH:

WHEREAS, the Owner is the record owner of all that real property located
at \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ in the City
of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ in the County of
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, designated in the Tax Records as
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

WHEREAS, the Owner has applied for a permit or variance to place a
structure on that property that either (I) does not conform, or (2) may
be noncompliant by later conversion, to the strict elevation
requirements of Article \_\_\_\_\_\_\_ Section \_\_\_\_\_\_\_ of the
Floodplain Management Ordinance of \_\_\_\_\_\_\_\_\_\_\_\_\_\_
("Ordinance") and under Permit Number \_\_\_\_\_\_\_ ("Permit").

WHEREAS, the Owner agrees to record this DECLARATION and certifies and
declares that the following covenants, conditions and restrictions are
placed on the affected property as a condition of granting the Permit,
and affects rights and obligations of the Owner and shall be binding on
the Owner, his heirs, personal representatives, successors and assigns.

UPON THE TERMS AND SUBJECT TO THE CONDITIONS, as follows:

1\. The structure or part thereof to which these conditions apply is:
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
.

2\. At this site, the Base Flood Elevation is \_\_\_\_\_\_\_ feet above
mean sea level, National Geodetic Vertical Datum.

3\. Enclosed areas below the Base Flood Elevation shall be used solely
for parking of vehicles, limited storage, or access to the building. All
interior walls, ceilings and floors below the Base Flood Elevation shall
be unfinished or constructed of flood resistant materials. Mechanical,
electrical or plumbing devices shall not be installed below the Base
Flood Elevation.

4\. The walls of the enclosed areas below the Base Flood Elevation shall
be equipped and remain equipped with vents as shown on the Permit.

5\. Any alterations or changes from these conditions constitute a
violation of the Permit and may render the structure uninsurable or
increase the cost for flood insurance. The jurisdiction issuing the
Permit and enforcing the Ordinance may take any appropriate legal action
to correct any violation.

6\. Other conditions:
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

In witness whereof the undersigned set their hands and seals this
\_\_\_\_\_\_\_ day of \_\_\_\_\_\_\_\_\_\_\_\_\_\_, 19 \_\_.

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ (Seal)

Owner

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ (Seal)

Witness

Figure 5-13: Example Nonconversion agreement

For the purposes of regulating new construction, floodproofing is
defined measures incorporated in the design of the building so that
below the BFE:

-   Walls are watertight (substantially impermeable to the passage of
    water),

-   Structural components can resist hydrostatic and hydrodynamic loads
    and effects of buoyancy, and

-   Utilities are protected from flood damage.

Most floodproofing is appropriate only where floodwaters are less than
three feet deep, since walls and floors may collapse under higher water
levels.

A registered professional engineer or architect must prepare the
building plans and certify the floodproofing measures, preferably using
the FEMA Floodproofing Certificate form. This is discussed in more
detail in Unit 7, Section G.

Floodproofing techniques that require human intervention are allowed but
should be discouraged. [Human intervention]{.underline} means that a
person has to take some action before the floodwater arrives, such as
turn a valve, close an opening or switch on a pump. There are many
potential causes of failure for these techniques, including inadequate
warning time, no person on duty when the warning is issued, the
responsible person can't find the right parts or tools, the person is
too excited or too weak to install things correctly, and/or the
electricity fails.

Before you approve plans for a building that relies on human
intervention to be floodproofed, you should make sure that there are
plans and precautions to keep such problems from occurring. Techniques
that rely on human intervention should only be allowed in areas with
adequate warning time and in situations where there will be someone
present who is capable of implementing or installing the required
measures.

More information on floodproofing can be found in FEMA's Technical
Bulletin 3-93, *Non-Residential Flood­proofing Requirements and
Certification for Buildings Located in Special Flood Hazard Areas*
(FIA-TB-3. 1993)

[]{#__RefHeading___Toc413558204 .anchor}How high?

The minimum NFIP requirement is to floodproof a building *to the BFE*.
However, when it is rated for flood insurance, one foot is subtracted
from the floodproofed elevation. Therefore, a building has to be
floodproofed *to one foot above the BFE* to receive the same favorable
insurance rates as a building elevated to the BFE. Unit 9, Section B,
discusses this in more detail.

[]{#__RefHeading___Toc413558205 .anchor}Basements

The definition of the "lowest floor" includes [basements]{.underline}
and the definition of "basement" includes any floor level below grade.

**44 CFR 59.1** Definitions: \"Basement\" means any area of the building
having its floor subgrade (below ground level) on all sides.

Note that "walkout basements," \"daylight basements\" or \"terrace
levels\" are usually subgrade on only three sides, with the downhill
side at or above grade. Thus, they are not considered basements for
either floodplain management or flood insurance rating purposes (but
they are still the lowest floor of a building for floodplain management
and insurance rating purposes). If these areas are used only for
parking, access, or storage and they meet other ordinance requirements,
they can be regulated as enclosures below an elevated building and not
be considered the lowest floor of the building.

On the other hand, cellars, the lower level of a split-level or bi-level
house, garden apartments and other finished floors below grade are
considered basements under NFIP regulations.

Since the lowest floor of a residential building must be above the BFE,
the only way to build a residential basement in the floodplain is if it
is elevated and surrounded by fill. Floodproofed non-residential
basement are allowed, though.

A few communities have obtained exceptions to the NFIP regulations that
allow them to permit floodproofed residential basements. The soil types
and flooding conditions in these communities allow construction of
floodproofed basements that are not subject to damage by hydrostatic or
hydrodynamic forces.

A community may apply for an exception to allow floodproofed residential
basements if it can demonstrate flood depths are less than five feet,
velocities are less than five feet per second, there is adequate warning
time for the site and it has appropriate construction requirements. This
exception is explained in 44 CFR 60.6(c).

Buildings with floodproofed basements must have their design certified
by a registered engineer or architect and are more difficult to
construct than buildings elevated above the BFE. Improperly designed or
constructed basements can collapse or otherwise fail resulting in major
damage to the structure.

[]{#__RefHeading___Toc413558206 .anchor}Anchoring

**44 CFR 60.3(a)(3)** ...If a proposed building site is in a flood-prone
area, all new construction and substantial improvements shall (i) be
designed (or modified) and adequately anchored to prevent flotation,
collapse, or lateral movement of the structure resulting from
hydrodynamic and hydrostatic loads, including the effects of buoyancy...

Both elevated and floodproofed buildings must be properly anchored to
stabilize them against flood forces. This means anchoring the building
to its foundation and ensuring that the foundation won't move.
Therefore, you need to make sure there is adequate protection against
hydrostatic and hydrodynamic forces and erosion and scour that can
undercut the foundation.

In areas of shallow flooding and low flood velocities, normal
construction practices suffice. Additional anchoring measures, such as
using extra bolts to connect the sill to the foundation or installing
rods to connect the cap to the sill, should be required in three
situations:

-   Where the flood flows faster than five feet per second.

-   In coastal areas subject to waves and high winds.

-   In manufactured or mobile homes.

In some areas it may be necessary to use foundations such as piles or
piers which provide less resistance to floodwaters.

If your community has any of these conditions, you should see if there
are state standards that take these into account, such as state coastal
construction or manufactured housing (mobile home) tie-down regulations.
If not, it is recommended that the builder's architect or engineer sign
a statement saying the design of the building includes "anchoring
adequate to prevent flotation, collapse and lateral movement" during the
base flood.

[]{#__RefHeading___Toc413558207 .anchor}Flood-resistant material

Whether a building is elevated or floodproofed, it is important that all
parts exposed to floodwaters be made of flood-resistant materials
(Figure 5-14).

**44 CFR 60.3(a) (3)** ...If a proposed building site is in a
flood-prone area, all new construction and substantial improvements
shall (ii) be constructed with materials resistant to flood damage...

"Flood-resistant materials" include any building product capable of
withstanding direct and prolonged contact with floodwaters without
sustaining significant damage. "Prolonged contact" means at least 72
hours, and "significant damage" is any damage requiring more than
low-cost cosmetic repair (such as painting).

-   Concrete, concrete block or glazed brick

-   Clay, concrete or ceramic tile

-   Galvanized or stainless steel nails, hurricane clips and connectors
    (in areas subject to saltwater flooding)

-   Indoor-outdoor carpeting with synthetic backing (do not fasten down)

-   Vinyl, terrazzo, rubber or vinyl floor covering with waterproof
    adhesives.

-   Metal doors and window frames.

-   Polyester-epoxy paint (do not use mildew-resistant paint indoors,
    especially on cribs, playpens or toys because it contains an
    ingredient that is toxic)

-   Stone, slate or cast stone (with waterproof mortar)

-   Mastic, silicone or polyurethane formed-in-place flooring. Styrofoam
    insulation

-   Water-resistant glue

-   Pressure treated (.40 CCA minimum) or naturally decay resistant
    lumber, marine grade plywood

Figure 5-14: Flood-resistant materials

For further details on flood-resistant material requirements, refer to
FEMA Technical Bulletin 2-93, *Flood-Resistant Materials Requirements
for Buildings Located in Special Flood Hazard Areas*.

[]{#__RefHeading___Toc413558208 .anchor}Accessory structures

Certain accessory structures may not qualify as "buildings." For
example, open structures, such as gazebos and picnic pavilions that do
not have at least two rigid walls, are not "buildings" and do not have
to be elevated or floodproofed.

In some cases, low-cost accessory buildings may not have to be elevated
or dry floodproofed. These structures would include detached garages,
boathouses, small pole barns and storage sheds. Such structures must
meet these three requirements:

-   The owner must obtain a variance (contact your FEMA Regional Office
    on procedures for this type of variance),

-   The building has the required openings to allow floodwaters in, and

-   The building is [wet floodproofed]{.underline}.

Wet floodproofing involves using flood-resistant materials below the BFE
and elevating things subject to flood damage above the BFE. Items that
can be installed above the BFE include electrical boxes, switches and
outlets. Only the minimum amount of electrical equipment required by
code may be located below the BFE, and that equipment must be flood
damage resistant.

For additional guidance, see *Wet Floodproofing Requirements*, FIA-TB-7,
FEMA 1994, and *Engineering Principles and Practices for Flood
Damage-Resistant Building Support Utility Systems*, (due to be published
in late 1998).

[]{#__RefHeading___Toc413558209 .anchor}Manufactured homes

**44 CFR 59.1** Definitions: \"Manufactured home\" means a structure,
transportable in one or more sections, which is built on a permanent
chassis and is designed for use with or without a permanent foundation
when attached to the required utilities. The term \"manufactured home\"
does not include a \"recreational vehicle\".

A [manufactured home]{.underline} includes a building that is
transportable, a mobile home or a "double wide" under the NFIP
regulations.

[]{#__RefHeading___Toc413558210 .anchor}Elevation

Generally, manufactured homes must meet the same flood protection
requirement as "stick built" or conventional housing. Since they are
usually residential buildings, they must be elevated so the lowest floor
is above the BFE.

**44 CFR 59.1** Definitions: \"Manufactured home park or subdivision\"
means a parcel (or contiguous parcels) of land divided into two or more
manufactured home lots for rent or sale.

**44 CFR 60.3(c)(12**) Require that manufactured homes to be placed or
substantially improved on sites in an existing manufactured home park or
subdivision within Zones A-1-30, AH, and AE on the community\'s FIRM
that are not subject to the provisions of paragraph (c)(6) of this
section be elevated so that either (I) the lowest floor of the
manufactured home is at or above the base flood elevation, or (ii) the
manufactured home chassis is supported by reinforced piers or other
foundation elements of at least equivalent strength that are no less
than 36 inches in height above grade and be securely anchored to an
adequately anchored foundation system to resist floatation, collapse,
and lateral movement.

44 CFR Section 60.3(c)(12) allows for a limited exemption to elevating
to the BFE in pre-FIRM manufactured housing (mobile home) parks. In such
older parks, a newly placed manufactured home chassis may be elevated
only three feet above grade provided it "is supported by reinforced
piers or other foundation elements of at least equivalent strength."

This exemption does not apply to new manufactured housing (mobile home)
parks, expansions to existing parks, to manufactured housing located
outside a pre-FIRM park, or to repairing or replacing a manufactured
home in a pre-FIRM park substantially damaged by a flood.

This exemption is a compromise that tries to balance the flood hazard
against the severe economic impacts on some manufactured home park
owners that would result if elevation to the BFE were required. The
exemption may not be necessary or appropriate for your community,
especially if manufactured home parks are able to meet the requirement
to elevate to the BFE. In other areas, the flood hazard may be so severe
that the exemption may put lives and property at too great a risk. Many
states have not included this exemption in their model ordinances and it
may not be in your regulations.

[]{#__RefHeading___Toc413558211 .anchor}Anchoring

44 CFR 60.3(c)(6) ...\[Manufactured homes must\] be elevated on a
permanent foundation ... and be securely anchored to an adequately
anchored foundation system to resist flotation, collapse and lateral
movement.

A "permanent foundation" means more than a stack of concrete blocks. It
should include a below-grade footing capable of resisting overturning,
the depth needs to account for frost depth and expected scour, the
footing must be sized appropriately for the site's soil bearing
capacity, and the design needs to account for seismic and other hazards.

The following types of permanent foundations should be used:

-   Reinforced piers,

-   Posts,

-   Piles,

-   Poured concrete walls,

-   Reinforced block walls, or

-   Compacted fill.

"Adequately anchored" means a system of ties, anchors and anchoring
equipment that will withstand flood and wind forces. The system must
work in saturated soil conditions. Usually this means over-the-top or
frame tie-downs in addition to standard connections to the foundation.

Most states have manufactured home tie-down regulations. Check with your
state NFIP coordinator to see if your state's regulations also meet the
NFIP anchoring standard. If so, you need only make sure that the state
requirement is met for each new manufactured home installed in your
floodplain.

If not, see FEMA's *Manufactured Home Installation in Flood Hazard
Areas*, FEMA-85, for additional guidance on anchoring.

The anchoring requirement does apply in an existing (pre-FIRM)
manufactured housing or mobile home park. Even if not elevated above the
BFE, the owner must still certify that the anchoring system will still
withstand the forces of a flood over the first floor.

**Evacuation:** In some areas, there is adequate warning time to remove
a manufactured home from harm's way. Protecting such property should not
be discouraged, so FEMA allows an evacuated manufactured home to be put
back on the original site without having to meet the requirements for
siting a new building. An existing manufactured home can be returned
after an evacuation without being elevated provided it is not enlarged
or altered.

[]{#__RefHeading___Toc413558212 .anchor}Recreational vehicles

**44 CFR 59.1** Definitions: \"Recreational vehicle\" means a vehicle
which is:

\(a\) built on a single chassis;

\(b\) 400 square feet or less when measured at the largest horizontal
projection;

\(c\) designed to be self-propelled or permanently towable by a light
duty truck; and

\(d\) designed primarily not for use as a permanent dwelling but as
temporary living quarters for recreational, camping, travel, or seasonal
use.

A recreational vehicle placed on a site in an SFHA must:

-   Meet the elevation and anchoring requirements for manufactured
    homes,

-   Be on the site for fewer than 180 consecutive days, [or]{.smallcaps}

-   Be fully licensed and ready for highway use. "Ready for highway use"
    means that it is on its wheels or jacking system, is attached to the
    site only by quick disconnect type utilities and has no permanently
    attached additions.

The purpose of this requirement is to prevent recreational vehicles from
being permanently placed in the floodplain unless they are as well
protected from flooding as a manufactured home.

[]{#__RefHeading___Toc413558213 .anchor}AO and AH Zones

AO Zones are shallow flooding areas where FEMA provides a base flood
depth. Since there is no BFE, the rules read a little differently.

All new construction and substantial improvements of residential
structures shall have the lowest floor (including basement) elevated
above the highest adjacent grade:

-   At least as high as the depth number specified in feet on the
    community\'s FIRM, or

-   At least two feet if no depth number is specified.

All new construction or substantial improvements of nonresidential
structures shall meet the above requirements or, together with attendant
utility and sanitary facilities, be floodproofed to the same elevation.

AH Zones are sheet flow areas. In AO and AH Zones, adequate drainage
paths are required around structures on slopes to guide floodwater
around and away from proposed structures. (Requiring this throughout the
community is a good idea, as it will prevent local drainage problems
from causing surface flooding.)

[]{#__RefHeading___Toc413558214 .anchor}A99 and AR Zones

An A99 Zone is an SFHA that will be protected by a Federal flood control
project that is currently under construction and which meets specified
conditions.

An AR Zone is an SFHA that used to be a B, C or X Zone that used to be
protected by an accredited flood control system. The system has been
decertified but is in the process of being restored to provide
protection to the base flood level.

When the flood control systems are completed or restored, the areas in
A99 and AR Zones are expected to be remapped and taken out of the SFHA.
Until then, they are treated as SFHA for insurance purposes and there
are some floodplain management requirements.

A99 and AR Zones are special situations---few exist. If you have one,
you should contact your state NFIP coordinating agency or FEMA Regional
Office for guidance on regulatory requirements for you situation.

[]{#__RefHeading___Toc413558215
.anchor}![](media/image6.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #3

1.  What does Basic rule #4 say about new buildings in A Zones?

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```
22. Where would elevation on piles or columns be preferred?

23. Can a basement be considered the "lowest floor?"

24. If a residence is elevated above the BFE in an A Zone, where do you
    measure how high the building is?

25. What can be allowed under the lowest floor of an elevated building?

26. Mr. Jones shows you plans for a house elevated on a concrete block
    crawlspace. The area of the crawlspace will be 1,750 square feet.

```{=html}
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```
a.  How many standard 8" x 16" vents will be needed?

b.  How high can they be above ground level?

c.  Can Mr. Jones put his hot water heater in the crawlspace?

```{=html}
<!-- -->
```
27. Mrs. Smith is elevating a house in the AE Zone 8' above grade. How
    can you make sure that the area below the lowest floor won't be
    improved, finished or otherwise turned into living space?

28. What three things do you need to check for to ensure that a building
    is floodproofed?

29. Can a new home in the flood fringe be floodproofed?

30. What's the NFIP definition of "basement?"

31. If a building is proposed to be located in a riverine floodplain
    with flood velocities of 12 --15 feet per second, what should you
    ask the builder to provide to assure you that the building won't get
    washed away during a flood?

32. The builder of a house to be elevated on concrete columns wants to
    use wood for the stairway. He is concerned that wood will swell and
    warp if it gets wet during a flood. Can a portion of the house below
    the BFE be built of wood?

33. How is a manufactured home outside of a manufactured housing park
    treated differently from a conventional "stick built" home?

34. How is a 600 square foot motor home that is permanently attached to
    a reinforced block wall foundation treated differently from a
    manufactured home?

[]{#__RefHeading___Toc413558216 .anchor}F. New Buildings in V Zones

Zones V1-30, VE and/or V identified on FIRMs designate high hazard areas
along coastlines that are subject to high water levels and wave action
from strong storms and hurricanes. The winds, waves and tidal surges
associated with these storms cause water of high velocity to sweep over
nearby land. Many V Zones are also subject to erosion and scour which
can undercut building foundations.

Basic rule #5: V Zones have special building protection standards in
addition to the requirements for A Zones.

This section identifies only those building protection requirements that
differ from the A Zone criteria. Unless mentioned in this section, all A
Zone standards apply for new and substantially improved buildings in V
Zones.

[]{#__RefHeading___Toc413558217
.anchor}![](media/image8.wmf){width="1.2645833333333334in"
height="0.8090277777777778in"}Video: *Best Build: Constructing a Sound
Coastal Home*

Before continuing, please view the 20-minute video segment on
construction techniques in coastal areas. Called *Best Build I:
Constructing a Sound Coastal Home*, it is on the second videotape
included in the course materials. Do not rewind the tape.

[]{#__RefHeading___Toc413558218 .anchor}Building location

New or substantially improved buildings in V Zones cannot be over water.
They must be located landward of mean high tide. In fact, it's best to
be as far back from the shore as possible in order to avoid the more
dangerous areas subject to waves and erosion.

Avoid areas of sand dunes and mangroves. Human alteration of sand dunes
and mangrove stands within V Zones is prohibited unless it can be
demonstrated that such alterations will not increase potential flood
damage.

Both of these natural features are protected against alteration because
they are important first lines of defense against coastal storms and can
do much to reduce losses to inland coastal development.

Generally, you can assume that any removal or other alteration of a sand
dune will increase flood damage. The burden should be placed on the
permit applicant to demonstrate that this will not occur. This will
require a report by a coastal engineer or geologist.

[]{#__RefHeading___Toc413558219 .anchor}Elevation on piles or columns

All new construction and substantial improvements to buildings in V
Zones must be elevated on pilings, posts, piers or columns.

**44 CFR 60.3(e)(4)** \[The community must\] Provide that all new
construction and substantial improvements in Zones V1-30 and VE, and
also Zone V if base flood elevation data is available, on the
community\'s FIRM, are elevated on pilings and columns so that (i) the
bottom of the lowest horizontal structural member of the lowest floor
(excluding the pilings or columns) is elevated to or above the base
flood level...

Elevation---on fill, solid walls or crawlspaces---and floodproofing are
prohibited because these techniques present obstructions to wave action.
The force of a breaking wave is so great that these types of foundations
would be severely damaged, resulting in collapse of the building.

Construction on piles or columns allows waves to pass under the building
without transmitting the full force of the waves to the building's
foundation. A special case is made for installing breakaway walls
between the pilings or columns, but such walls are not supporting
foundation walls.

![](media/image15.png){width="3.1902777777777778in" height="2.5in"}While
fill is not allowed for structural support for buildings within V Zones
because of the severe erosion potential of such locations, limited fill
is allowed for landscaping, local drainage needs, and to smooth out a
site for an unreinforced concrete pad.

**How high?** Within V Zones, the controlling elevation is the bottom of
the lowest horizontal structural member of the lowest floor. (In
comparison, within A Zones, the controlling elevation is the *top* of
the lowest floor.) This is to keep the entire building above the
anticipated breaking wave height of a base flood storm surge.

Figure 5-15: In V Zones, the lowest floor

is measured from the bottom of the

> lowest horizontal structural member

[]{#__RefHeading___Toc413558220 .anchor}Wind and water loads

The design of the supporting foundation must account for wind loads in
combination with the forces that accompany the base flood. As noted in
the video, cross bracing and proper connections are key to this.

**44 CFR 60.3(e)(4)** ...(ii) \[The community must ensure that\] the
pile or column foundation and structure attached thereto is anchored to
resist flotation, collapse and lateral movement due to the effects of
wind and water loads acting simultaneously on all building components.
Water loading values used shall be those associated with the base flood.
Wind loading values used shall be those required by applicable State or
local building standards. A registered professional engineer or
architect shall develop or review the structural design, specifications
and plans for the construction, and shall certify that the design and
methods of construction to be used are in accordance with accepted
standards of practice for meeting the provisions of (e)(4)(i) and (ii)
of this section.

Posts of wood, steel, or pre-cast concrete are preferred over block
columns and similar foundations that are less resistant to lateral
forces. Pilings are preferred in areas subject to erosion and scour, but
it is critical that they be embedded deep enough (Figure 5-16).

![](media/image16.png){width="4.136805555555555in" height="4.15in"}

Figure 5-16: Piles must be embedded well below the scour depth

![](media/image17.png){width="4.5in" height="3.0631944444444446in"}

Figure 5-17: This house had inadequate pile embedment and cross bracing

[]{#__RefHeading___Toc413558221 .anchor}Certification

A registered professional engineer or architect must develop or review
the structural design, specifications and plans for the construction,
and certify that the design and planned methods of construction are in
accordance with accepted standards of practice for meeting the above
provisions.

You must maintain a copy of the engineer's or architect's certification
in the permit file for all structures built or substantially improved in
the V Zone.

The North Carolina Division of Emergency Management has prepared a
V-Zone certification form (Figure 5-18) to ensure that these
requirements are met. This is provided as an example. Check with your
state NFIP coordinator to see if your state has developed a V Zone
certification form.

[]{#__RefHeading___Toc413558222 .anchor}Breakaway walls

Any walls below the lowest floor in a building in a V Zone should give
way under wind and water loads without causing collapse, displacement or
other damage to the elevated portion of the building or the supporting
pilings or columns.

Any enclosed space below the lowest floor must be free of obstruction,
or constructed with nonsupporting breakaway materials such as open wood
latticework or insect screening. Just as in A Zones, this space is to be
used solely for parking of vehicles, building access or storage, and
must be constructed of flood-resistant material.

**44 CFR 60.3(e)(5)** \[The community must\] Provide that all new
construction and substantial improvements within Zones V1-30, VE, and V
on the community\'s FIRM have the space below the lowest floor either
free of obstruction or constructed with non-supporting breakaway walls,
open wood lattice-work, or insect screening intended to collapse under
wind and water loads without causing collapse, displacement, or other
structural damage to the elevated portion of the building or supporting
foundation system. For the purposes of this section, a breakaway wall
shall have a design safe loading resistance of not less than 10 and no
more than 20 pounds per square foot. Use of breakaway walls which exceed
a design safe loading resistance of 20 pounds per square foot (either by
design or when so required by local or State codes) may be permitted
only if a registered professional engineer or architect certifies that
the designs proposed meet the following conditions:

Solid breakaway wall panels are allowed, as are garage doors that meet
the same breakaway requirements.

The area enclosed by solid breakaway walls should be limited to less
than 300 square feet because:

-   Flood insurance rates increase dramatically for enclosures larger
    than 300 square feet.

-   Larger areas encourage conversion to habitable living areas, which
    are difficult to detect and enforce as violations.

For further information see *Coastal Construction Manual*, FEMA-55
(1986), and *Free-of-Obstruction Requirements for Buildings Located in
Coastal High Hazard Areas*, FIA-TB-5 (FEMA 1993).

![](media/image18.png){width="6.5in" height="6.790277777777778in"}

Figure 5-18: Sample V Zone certification

[]{#__RefHeading___Toc413558223 .anchor}G. Other Requirements

The primary thrust of the NFIP regulations is to protect insurable
buildings and reduce future exposure to flood hazards. However, there
are some additional requirements that help ensure that the buildings
stay habitable and additional flood problems are not created.

[]{#__RefHeading___Toc413558224 .anchor}Subdivisions

As noted in Section B of this unit, once you obtain base flood
elevations for a subdivision or other large development, new buildings
must be properly elevated or floodproofed. These developments must also
be reviewed to ensure their infrastructure is reasonably safe from flood
damage.

**44 CFR 60.3(a)(4)** \[The community must\] Review subdivision
proposals and other proposed new development including manufactured home
parks or subdivisions, to determine whether such proposals will be
reasonably safe from flooding. If a subdivision proposal or other
proposed new development is in a flood-prone area, any such proposals
shall be reviewed to assure that (i) all such proposals are consistent
with the need to minimize flood damage within the flood-prone area, (ii)
all public utilities and facilities, such as sewer, gas, electrical, and
water systems are located and constructed to minimize or eliminate flood
damage, and (iii) adequate drainage is provided to reduce exposure to
flood hazards;

This review applies to subdivisions and other development, such as
apartments, parks, shopping centers, schools and other projects.

If one is floodprone, the builder should:

-   Minimize flood damage by locating structures on the highest ground.

-   Have public utilities and facilities located and constructed so as
    to minimize flood damage.

-   Provide adequate drainage for each building site.

The site plans of new development and proposed plats for subdivisions
can usually be designed to minimize the potential for flood damage while
still achieving the economic goals of the project. For example, lot size
could be reduced and the lots clustered on high ground, with homesites
having views of the floodplain.

[]{#__RefHeading___Toc413558225 .anchor}Water and sewer systems

**44 CFR 60.3(a)(5)** \[The community must\] Require within flood-prone
areas new and replacement water supply systems to be designed to
minimize or eliminate infiltration of flood waters into the systems; and

**44 CFR 60.3(a)(6)** \[The community must\] Require within flood-prone
areas (i) new and replacement sanitary sewage systems to be designed to
minimize or eliminate infiltration of flood waters into the systems and
discharges from the systems into flood waters and (ii) onsite waste
disposal systems to be located to avoid impairment to them or
contamination from them during flooding.

The objective of these requirements is to ensure that a building that is
protected from flood damage can still be used after the flood recedes.

In most instances, these criteria can be met through careful system
design. Manholes should be raised above the 100-year flood level or
equipped with seals to prevent leakage. Pumping stations should have
electrical panels elevated above the BFE.

On-site waste disposal systems should be located to ensure they are
accessible during a flood, and that they will not release contamination
in a flood. The first objective should be to locate the system outside
the flood hazard area, if that is feasible. At a minimum, an automatic
backflow valve should be installed to prevent sewage from backing up
into the building during flooding.

[]{#__RefHeading___Toc413558226 .anchor}Watercourse alterations

**44 CFR 60.3(b)(6)** \[The community must\] Notify, in riverine
situations, adjacent communities and the State Coordinating Office prior
to any alteration or relocation of a watercourse, and submit copies of
such notifications to the \[Federal Insurance\] Administrator;

The community must notify adjacent communities and the appropriate state
agency prior to altering or relocating any river or stream within its
jurisdiction. Copies of such notifications must be submitted to the FEMA
Regional Office.

**44 CFR 60.3(b)(7)** \[The community must\] Assure that the flood
carrying capacity within the altered or relocated portion of any
watercourse is maintained;

Any alteration or relocation of a watercourse should not increase the
community\'s flood risks or those of any adjacent community. This could
happen if the watercourse\'s capacity to carry flood flow is reduced
because a smaller or less-efficient channel is created, or by
modifications to the floodway as a result of the project.

After altering a watercourse, the developer has created an artificial
situation and must assume responsibility for maintaining the capacity of
the modified channel. Otherwise, flooding is likely to increase as the
channel silts in, meanders or tries to go back to its old location.

For any significant alteration or relocation, you should consider
requiring the applicant to have an engineer certify that the flood-flow
carrying capacity is maintained and that there will be no increase in
flood flows downstream.

Federal and state permits may be required for any alteration or
relocation activity. It is recommended that the community require the
submittal and approval of a CLOMR from FEMA for large-scale proposals
(see CLOMR procedures discussion in Unit 4, Section D).

[]{#__RefHeading___Toc413558227
.anchor}![](media/image6.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #4

1.  What does Basic rule #5 say about new buildings in V Zones?

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35. Can a new building be built in the V Zone elevated on a crawlspace?

36. Where is the lowest floor measured in a V Zone?

37. What's the best way for a permit official to be sure that a V Zone
    building will be adequate to resist the wind and water loads?

38. What's the best way to deal with those pesky sand dunes in a V Zone
    development site?

39. If a subdivider makes sure that all building sites are above the
    BFE, does he need to do anything more to meet the NFIP requirements?

40. How can you protect a sewer system from flooding?

[]{#__RefHeading___Toc413558228
.anchor}![](media/image6.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Unit Learning Exercise

1.  In what part of the Code of Federal Regulations would you find the
    definition for "development.?"

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41. Where do I find the NFIP requirements for areas mapped with V Zones?

42. If a community has a FIRM that shows floodways and V Zones, which
    parts of 44 CFR 60.3 must it abide by?

43. If your community follows the requirements of 44 CFR 60.3(d), does
    it have to worry about what's in 44 CFR 60.3(b)?

44. A building officials finds it easier to read an old flood map
    prepared on an aerial photograph by the Corps of Engineers. He
    doesn't want to use the current FIRM because it doesn't show all the
    buildings and features that the photograph does. Can he make permit
    decisions based on the Corps map instead of the FIRM?

45. A developer wants to build in an area mapped as an approximate A
    Zone on Ireland Creek. He conducts a detailed flood study which is
    approved by the Town Engineer. It shows that several lots in the A
    Zone are actually higher than the BFE calculated in the study.

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a.  Can you issue permits for building on those sites and treat them as
    C Zone sites?

b.  Will the buyers of the properties have to buy flood insurance
    policies?

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46. Joe Deerslayer wants to build a small hunting cabin on a lake in an
    approximate A Zone. It will be the only building within two miles.
    There are no known sources of a base flood elevation. The cabin will
    cost less than \$10,000 and he does not want to pay \$2,000 for an
    engineering study to develop a BFE. What can you do to make sure the
    property is protected from flooding?

47. Will a developer in an approximate A Zone have to prepare a detailed
    study to calculate base flood elevations if the development is:

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a.  4 acres?

b.  60 lots?

c.  Reserving all the SFHA as open space?

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48. A restudy was performed on the Rocky River. The preliminary study
    will not be final for another five months. It shows a new BFE at
    Site B that is two feet lower than the BFE in your current FIS.
    Which one do you use to determine the flood protection level for a
    new home at Site A?

49. Does dredging a creek to make it deeper to reduce flood levels need
    a floodplain permit?

50. Does replacing an old manufactured home with a new one on the same
    foundation need a permit?

51. If an old manufactured home is replaced with a new one on the same
    foundation, will the new one have to be elevated above the BFE?

52. If a project will involve filling a wetland, is it likely that a
    federal or state permit will be needed?

53. A builder wants to put a house in the floodway. How much can his
    project increase the base flood elevation (in feet)?

54. Will paving a dirt street in the floodway need an engineer's
    "no-rise" certification?

55. A city councilman complains that the NFIP floodway regulations
    prevent construction of a flood control dam that will protect people
    from flooding. What can you tell him?

56. Does a substantial improvement to an existing building have to meet
    the same requirements as construction of a new building?

57. Can a new nonresidential building be built:

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a.  On fill in the flood fringe?

b.  On fill in the floodway?

c.  On fill in the V Zone?

d.  At grade, but floodproofed in the flood fringe?

e.  At grade, but floodproofed in the V Zone?

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58. A builder wants to build an apartment building on stem walls
    parallel to the flow of water with the lowest floor 8' above grade.
    Can the lower area be used as a parking lot?

59. What's the best record to keep to be sure that a house was elevated
    high enough?

60. How many standard 8" x 16" vents are needed for a building that will
    have a 2,250 square foot crawlspace?

61. Can the owner store garden tools in a floodable crawlspace?

62. A business on the Mississippi River wants to build a floodproofed
    warehouse in the flood fringe. The plans are to have the walls built
    of reinforced concrete up to the BFE. Several garage doors will be
    open at grade to allow trucks in and out, but the design includes
    movable shields that can be put in place before floodwaters arrive.
    There would be no other openings below the BFE. The warehouse will
    have a 24-hour security force that will be trained on how to install
    the shields. The design engineer will certify that the building will
    be floodproofed (with human intervention) up to the base flood
    elevation. Can you approve these plans?

63. A builder wants to build a "bi-level" house where the lowest floor
    is three feet below grade. The lowest floor has large windows and
    includes three bedrooms and a bathroom. Because it is habitable
    space, the owner does not consider this a "basement." Does the NFIP
    consider this a "basement?"

64. The area below a planned elevated house in the V Zone will have a
    260 square foot enclosure to house the entryway and storage closets.
    The builder wants to insulate the area and finish it with wallboard,
    wallpaper and carpeting. He says it's OK because the area is under
    300 square feet. What do you tell him?

65. Where can you find standards for tying down manufactured homes?

66. A new house is planned to be built in an SFHA marked "Zone AO (depth
    3 feet)." How high should the lowest floor be?

67. Why are pilings and posts preferred in V Zones?

[]{#__RefHeading___Toc413558229 .anchor}Answers to the learning checks

[]{#__RefHeading___Toc413558230 .anchor}Learning check #1

1.  What publication has the NFIP requirements for communities?

    Chapter 44 of the Code of Federal Regulations

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68. Most of the requirements relative to your community's ordinance are
    in 44 CFR Parts \_\_\_\_ and \_\_\_\_ .

    59 and 60

69. Does your ordinance comply with the latest NFIP requirements?

    Check with your FEMA Regional Office or State NFIP Coordinator

70. Which part of 44 CFR 60.3 covers the requirements for areas with a
    FIRM, but no base flood elevations?

    44 CFR 60.3(b)

71. What is "Basic rule #1" for using maps and data?

    You must use the latest maps and flood data published by FEMA.

72. What map do you use if recently annexed areas do not show up on your
    community's FIRM?

    The FIRM for the county or the community the property used to be in.

73. If you find information that shows the ground to be higher than the
    BFE, can a bank use that data when determining whether a flood
    insurance policy must be purchased?

    No. Insurance agents and lenders must use the current FIRM when
    setting insurance rates and determining whether flood insurance is
    required. If a person wants to vary from the current FIRM to obtain
    different premium rates or to not have to purchase a flood insurance
    policy, the FIRM must be officially revised or amended.

74. Site E is in the approximate A Zone of Dean Lake. A developer wants
    to build a small commercial building on a 3 acre site. Where do you
    get a base flood elevation for Site E?

    Try these sources (in order of preference):

-   Check with your state NFIP coordinator, local water-related
    districts, the Corps of Engineers, etc. to see if there are any
    existing studies.

-   It is possible that the highway agency did a study of the stream
    when the Turnpike bridge was built.

-   See if the Town Engineer or the developer's engineer will conduct a
    study.

-   Use the flood of record plus a margin of protection

75. A developer downstream of Dean Lake wants to build a 40 acre
    subdivision that crosses Ireland Creek. You need a base flood
    elevation before you review the plans. What options do you tell the
    developer he has?

-   He can conduct a flood study and produce the BFEs at his expense or

-   He can set the A Zone aside as open space and not conduct a flood
    study.

76. A restudy was performed on the Josias River. The preliminary study
    will not be final for another five months. It shows a new BFE at
    Site N that is two feet higher than the BFE in your current FIS.
    Which one do you use to determine the flood protection level for a
    new home at Site N?

    The draft revised data should be used unless the community disagrees
    with the data and intends to appeal it.

[]{#__RefHeading___Toc413558231 .anchor}Learning check #2

1.  What is basic rule #2 on what needs a permit in the floodplain?

    A permit is required for all development in the SFHA.

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77. Define "development" as the term is used in your ordinance.

    Your ordinance should have a definition that reads very much like:
    "'Development' means any man-made change to improved or unimproved
    real estate, including but not limited to buildings or other
    structures, mining, dredging, filling, grading, paving, excavation
    or drilling operations or storage of equipment or materials."

78. Does your community only require building permits? If so, does
    someone who wants to fill a vacant lot need a permit from the
    community?

    Depends on the community. If the answer is not "yes," then you need
    to revise your ordinance and permit procedures.

79. The state in which Flood County is situated requires a permit from
    the state Department of Environmental Protection for development on
    primary sand dunes. A permit applicant wants to build on one near
    Site F. Department staff informs you that based on the plans they
    have seen, they will have to deny the state permit. Should the Flood
    County permit officer issue a floodplain development permit?

    No. The local permit should not be issued until staff are certain
    that the other agencies' requirements are met. If it is just a
    question of time and a state permit is expected to be issued, a
    local permit could be issued conditioned on obtaining a state
    permit. However, if it is clear that the project violates the state
    regulations, a local permit should not be issued until the matter is
    settled.

80. What is Basic rule #3 as it relates to encroachments in riverine
    floodplains?

    Development must not increase the flood hazard on other properties.

81. An encroachment review should review projects in a floodway for what
    two things?

    Whether the project will obstruct flood flows and cause an increase
    in flood heights upstream or adjacent to the project site and

    Whether the project will remove an existing obstruction, resulting
    in increases in flood flows downstream.

82. A farmer wants to build a dairy barn in the floodway. Will he need
    to provide you with a "no-rise" certification before you can issue
    the permit?

    Yes

83. The same farmer wants to build a small addition onto his farmhouse
    (also in the floodway). Can this be designed so he won't have to pay
    for an engineer's encroachment review?

    Yes, if it is located in the conveyance shadow of the farmhouse.

84. In a riverine AE Zone with a base flood elevation, what must a
    developer show in order to demonstrate that he is meeting Basic Rule
    #3?

    He must conduct an encroachment review that demonstrates that the
    cumulative effect of the proposed development, when combined with
    all other existing and anticipated development:

-   Will not increase the water surface elevation of the base flood more
    than one foot at any point within the community, and

-   Is consistent with the technical criteria contained in Chapter 5
    (Hydraulic Analyses) of the Flood Insurance Study: Guidelines and
    Specifications for Study Contractors, FEMA-37, 1995.

85. Does your state have a more restrictive standard than allowing flood
    heights to increase by one foot?

    Depends on the state. Some states have more restrictive encroachment
    standards, such as 0.5' or 0.1'.

[]{#__RefHeading___Toc413558232 .anchor}Learning check #3

1.  What does Basic rule #4 say about new buildings in A Zones?

    New, substantially improved or substantially damaged buildings must
    be protected from damage by the base flood.

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86. Where would elevation on piles or columns be preferred?

    In areas where flooding is likely to have high velocities or waves.

87. Can a basement be considered the "lowest floor?"

    Yes.

88. If a residence is elevated above the BFE in an A Zone, where do you
    measure how high the building is?

    At the top of the lowest floor.

89. What can be allowed under the lowest floor of an elevated building?

    Only building access, vehicle parking, and storage.

90. Mr. Jones shows you plans for a house elevated on a concrete block
    crawlspace. The area of the crawlspace will be 1,750 square feet.

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d.  How many standard 8" x 16" vents will be needed?

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14. 14\. 1,750 divided by 128 = 13.67, rounded up to 14 vents

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e.  How high can they be above ground level?

    The bottom of the vents must be no higher than one foot above grade.

f.  Can Mr. Jones put his hot water heater in the crawlspace?

    No. Unless the water heater can be entirely above the BFE.

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91. Mrs. Smith is elevating a house in the AE Zone 8' above grade. How
    can you make sure that the area below the lowest floor won't be
    improved, finished or otherwise turned into living space?

    Require that the lower area must be kept open or require the owner
    to sign a nonconversion agreement (requiring large openings will
    also help).

92. What three things do you need to check for to ensure that a building
    is floodproofed?

    Below the BFE:

-   Walls are watertight (substantially impermeable to the passage of
    water),

-   Structural components can resist hydrostatic and hydrodynamic loads
    and effects of buoyancy, and

-   Utilities are protected from flood damage.

93. Can a new home in the flood fringe be floodproofed?

    No. Elevation is the only method allowed for new residential
    buildings in the SFHA.

94. What's the NFIP definition of "basement?"

    \"Basement\" means any area of the building having its floor
    subgrade (below ground level) on all sides.

95. If a building is proposed to be located in a riverine floodplain
    with flood velocities of 12 --15 feet per second, what should you
    ask the builder to provide to assure you that the building won't get
    washed away during a flood?

    A statement from an architect or engineer that the design of the
    building includes "anchoring adequate to prevent flotation, collapse
    and lateral movement" during the base flood.

96. The builder of a house to be elevated on concrete columns wants to
    use wood for the stairway. He is concerned that wood will swell and
    warp if it gets wet during a flood. Can a portion of the house below
    the BFE be built of wood?

    Yes, provided it is pressure treated (.40 CCA minimum), naturally
    decay resistant lumber or marine grade plywood

97. How is a manufactured home outside of a manufactured housing park
    treated differently from a conventional "stick built" home?

    They are both treated the same. They must meet the same construction
    and elevation requirements.

98. How is a 600 square foot motor home that is permanently attached to
    a reinforced block wall foundation treated differently from a
    manufactured home?

    They are both treated the same. They must meet the same construction
    and elevation requirements.

[]{#__RefHeading___Toc413558233 .anchor}Learning check #4

1.  What does Basic rule #5 say about new buildings in V Zones?

    There are special building requirements in addition to the building
    protection requirements for buildings in A Zones.

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99. Can a new building be built in the V Zone elevated on a crawlspace?

    No. It can only be elevated on pilings, posts, piers or columns to
    avoid obstructions to the wave action.

100. Where is the lowest floor measured in a V Zone?

     At the bottom of the lowest horizontal structural member.

101. What's the best way for a permit official to be sure that a V Zone
     building will be adequate to resist the wind and water loads?

     Have an engineer certify that the design and planned methods of
     construction are in accordance with accepted standards of practice
     to resist flotation, collapse and lateral movement due to the
     effects of wind and water loads acting simultaneously on all
     building components.

102. What's the best way to deal with those pesky sand dunes in a V Zone
     development site?

     Don't touch them. They provide important flood protection by
     breaking waves during coastal storms. If they are to be disturbed,
     the permit applicant should have an engineer's or geologist's
     report that their removal will not increase flood damage.

103. If a subdivider makes sure that all building sites are above the
     BFE, does he need to do anything more to meet the NFIP
     requirements?

     The subdivider also needs to make sure that:

-   All public utilities and facilities, such as sewer, gas, electrical,
    and water systems are located and constructed to minimize or
    eliminate flood damage, and

-   Adequate drainage is provided to reduce exposure to flood hazards;

104. How can you protect a sewer system from flooding?

     Through careful system design. Manholes should be raised above the
     100-year flood level or equipped with seals to prevent leakage.
     Pumping stations should have electrical panels elevated above the
     BFE.

[]{#__RefHeading___Toc413558234 .anchor}Unit Learning Exercise

1.  In what part of the Code of Federal Regulations would you find the
    definition for "development.?"

    44 CFR 59.1 Definitions

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105. Where do I find the NFIP requirements for areas mapped with V
     Zones?

     44 CFR 60.3(e)

106. If a community has a FIRM that shows floodways and V Zones, which
     parts of 44 CFR 60.3 must it abide by?

     All parts up through 60.3(e)

107. If your community follows the requirements of 44 CFR 60.3(d), does
     it have to worry about what's in 44 CFR 60.3(b)?

     Yes. The requirements are cumulative in Section 60.3.

108. A building officials finds it easier to read an old flood map
     prepared on an aerial photograph by the Corps of Engineers. He
     doesn't want to use the current FIRM because it doesn't show all
     the buildings and features that the photograph does. Can he make
     permit decisions based on the Corps map instead of the FIRM?

     No. The community must use the latest maps and data provided by
     FEMA. If the other map shows a higher BFE and a larger floodplain,
     the community may adopt it in its ordinance as the regulatory
     floodplain and exceed the minimum NFIP requirements. The map must
     be approved by the FEMA Regional Office before this is done.

109. A developer wants to build in an area mapped as an approximate A
     Zone on Ireland Creek. He conducts a detailed flood study which is
     approved by the Town Engineer. It shows that several lots in the A
     Zone are actually higher than the BFE calculated in the study.

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c.  Can you issue permits for building on those sites and treat them as
    C Zone sites?

    Yes, as long as the Town Engineer assures you that the developer's
    study

-   Reasonably reflects flooding conditions expected during the base
    flood,

-   Is technically correct, and

-   Represents the best data available.

d.  Will the buyers of the properties have to buy flood insurance
    policies?

    Yes, unless a map amendment or Letter of Map Amendment (LOMA) is
    issued by FEMA.

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110. Joe Deerslayer wants to build a small hunting cabin on a lake in an
     approximate A Zone. It will be the only building within two miles.
     There are no known sources of a base flood elevation. The cabin
     will cost less than \$10,000 and he does not want to pay \$2,000
     for an engineering study to develop a BFE. What can you do to make
     sure the property is protected from flooding?

     Require that the lowest floor of the cabin be at least five feet
     above grade.

111. Will a developer in an approximate A Zone have to prepare a
     detailed study to calculate base flood elevations if the
     development is:

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d.  4 acres? *No*

e.  60 lots? *Yes*

f.  Reserving all the SFHA as open space? *No*

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112. A restudy was performed on Rocky River. The preliminary study will
     not be final for another five months. It shows a new BFE at Site B
     that is two feet lower than the BFE in your current FIS. Which one
     do you use to determine the flood protection level for a new home
     at Site B?

     When the BFE in the new study is lower than the BFE in the existing
     study, the existing FIS data should be used until the new study is
     final.

113. Does dredging a creek to make it deeper to reduce flood levels need
     a floodplain permit?

     Yes. It is considered development and all development needs a
     permit.

114. Does replacing an old manufactured home with a new one on the same
     foundation need a permit?

     Yes

115. If an old manufactured home is replaced with a new one on the same
     foundation, will the new one have to be elevated above the BFE?

     Yes, unless it is in an existing manufactured home park. Then the
     owner has the option of elevating either above the BFE or 36" above
     grade on reinforced piers.

116. If a project will involve filling a wetland, is it likely that a
     federal or state permit will be needed?

     Yes. The U.S. Army Corps of Engineers requires a Section 404 permit
     for most wetland filling activities. A local permit should not be
     issued until it is clear that the project does not violate Section
     404 rules.

117. A builder wants to put a house in the floodway. How much can his
     project increase the base flood elevation (in feet)?

     Zero. A project in a floodway is not allowed to cause any increase
     in floodwaters.

118. Will paving a dirt street in the floodway need an engineer's
     "no-rise" certification?

     No, as long as the grade of the street is no higher than it was
     before the paving project.

119. A city councilman complains that the NFIP floodway regulations
     prevent construction of a flood control dam that will protect
     people from flooding. What can you tell him?

     The community can apply for a conditional letter of map revision if
     it can provide the following:

-   An evaluation of alternatives which, if carried out, would not
    result in an increase in the BFE more than allowed, along with
    documentation as to why these alternatives are not feasible.

-   Documentation of individual legal notice to all affected property
    owners (anyone affected by the increased flood elevations, within
    and outside of the community) explaining the impact of the proposed
    action on their properties.

-   Concurrence, in writing, from the chief executive officer of any
    other communities affected by the proposed actions.

-   Certification that no structures are located in areas which would be
    affected by the increased BFE (unless they have been purchased for
    relocation or demolition).

-   A request for revision of BFE determinations in accordance with the
    provisions of 44 CFR 65.6 of the FEMA regulations.

120. Does a substantial improvement to an existing building have to meet
     the same requirements as construction of a new building?

     Yes

121. Can a new nonresidential building be built:

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a.  On fill in the flood fringe? *Yes*

b.  On fill in the floodway? *Probably not. It would be hard to show
    that the fill does not cause an increase in flood heights.*

c.  On fill in the V Zone? *No*

d.  At grade, but floodproofed in the flood fringe? *Yes*

e.  At grade, but floodproofed in the V Zone? *No*

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122. A builder wants to build an apartment building on stem walls
     parallel to the flow of water with the lowest floor 8' above grade.
     Can the lower area be used as a parking lot?

     Yes

123. What's the best record to keep to be sure that a house was elevated
     high enough?

     A FEMA Elevation Certificate. Any surveyor's or engineer's record
     of the elevation of the lowest floor meets the NFIP requirements,
     but the FEMA form is recommended.

124. How many standard 8" x 16" vents are needed for a building that
     will have a 2,250 square foot crawlspace?

     18\. 2,250 divided by 128 = 17.57, rounded up to 18.

125. Can the owner store garden tools in a floodable crawlspace?

     Yes, if there is enough warning time to move it.

126. A business on the Mississippi River wants to build a floodproofed
     warehouse in the flood fringe. The plans are to have the walls
     built of reinforced concrete up to the BFE. Several garage doors
     will be open at grade to allow trucks in and out, but the design
     includes movable shields that can be put in place before
     floodwaters arrive. There would be no other openings below the BFE.
     The warehouse will have a 24-hour security force that will be
     trained on how to install the shields. The design engineer will
     certify that the building will be floodproofed (with human
     intervention) up to the base flood elevation. Can you approve these
     plans?

     Yes, assuming there is adequate warning time to install the
     shields, which there probably is on the Mississippi River.

127. A builder wants to build a "bi-level" house where the lowest floor
     is three feet below grade. The lowest floor has large windows and
     includes three bedrooms and a bathroom. Because it is habitable
     space, the owner does not consider this a "basement." Does the NFIP
     consider this a "basement?"

     Yes and the lowest floor (i.e., the basement) must be above the
     BFE.

128. The area below a planned elevated house in the V Zone will have a
     260 square foot enclosure to house the entryway and storage
     closets. The builder wants to insulate the area and finish it with
     wallboard, wallpaper and carpeting. He says it's OK because the
     area is under 300 square feet. What do you tell him?

     It's not OK. Any enclosed space below the lowest floor must be
     built of flood resistant materials and free of obstruction, or
     constructed with nonsupporting breakaway materials such as open
     wood latticework or insect screening.

129. Where can you find standards for tying down manufactured homes?

     Check first to see if there are state regulations. If not, see
     FEMA's Manufactured Home Installation in Flood Hazard Areas,
     FEMA-85.

130. A new house is planned to be built in an SFHA marked "Zone AO
     (depth 3 feet)." How high should the lowest floor be?

     At least 3 feet above the highest adjacent grade.

131. Why are pilings and posts preferred in V Zones?

     They can better withstand the wind and water loads.