Unit 6:

Additional Regulatory Measures

In this unit

This unit begins with a discussion of the problem that arises when
regulations are so restrictive they effectively "take" people's freedom
to use their properties.

It then describes some of the more common regulatory approaches that
exceed the NFIP's minimum standards which result in a better and more
appropriate local floodplain management program. These include:

-   State required regulatory standards,

-   Higher local standards,

-   Regulations that address special flood hazards, and

-   Environmental protection regulations.

Contents

Introduction 6-[4](#__RefHeading___Toc413564431)

A. Taking 6-[5](#__RefHeading___Toc413564432)

B. State Regulatory Standards 6-[9](#__RefHeading___Toc413564433)

C. Higher Regulatory Standards 6-[11](#__RefHeading___Toc413564434)

Location Restrictions 6-[12](#__RefHeading___Toc413564435)

Highly hazardous areas 6-[12](#__RefHeading___Toc413564436)

Subdivision design 6-[12](#__RefHeading___Toc413564437)

Setbacks 6-[14](#__RefHeading___Toc413564438)

Manufactured homes 6-[15](#__RefHeading___Toc413564439)

Natural areas 6-[15](#__RefHeading___Toc413564440)

Low-density zoning 6-[15](#__RefHeading___Toc413564441)

Building Requirements 6-[16](#__RefHeading___Toc413564442)

Freeboard 6-[16](#__RefHeading___Toc413564443)

Foundation standards 6-[17](#Toc406722383)

Safety Requirements 6-[18](#__RefHeading___Toc413564445)

Critical facilities 6-[18](#__RefHeading___Toc413564446)

Hazardous materials 6-[19](#__RefHeading___Toc413564447)

Dry land access 6-[19](#__RefHeading___Toc413564448)

Encroachment standards 6-[20](#__RefHeading___Toc413564449)

Compensatory storage 6-[21](#__RefHeading___Toc413564450)

Stormwater management 6-[22](#__RefHeading___Toc413564451)

Temporary moratorium 6-[23](#__RefHeading___Toc413564452)

Temporary Moratorium 6-23

Learning Check #1 6-[24](#__RefHeading___Toc413564454)

D. Flood Hazards of Special Concern 6-[25](#__RefHeading___Toc413564455)

Coastal erosion 6-[25](#__RefHeading___Toc413564456)

Regulatory standards 6-[25](#__RefHeading___Toc413564457)

Tsunamis 6-[26](#__RefHeading___Toc413564458)

Regulatory standards 6-[26](#__RefHeading___Toc413564459)

Closed basin lakes 6-[27](#__RefHeading___Toc413564460)

Regulatory standards 6-[27](#__RefHeading___Toc413564461)

Uncertain flow paths 6-[28](#__RefHeading___Toc413564462)

Regulatory standards 6-[28](#__RefHeading___Toc413564463)

Dam breaks 6-[28](#__RefHeading___Toc413564464)

Regulatory standards 6-[29](#__RefHeading___Toc413564465)

Ice Jams 6-[29](#__RefHeading___Toc413564466)

Regulatory standards 6-[29](#__RefHeading___Toc413564467)

Mudflows 6-[30](#__RefHeading___Toc413564468)

Regulatory standards 6-[30](#__RefHeading___Toc413564469)

E. Environmental Protection Measures
6-[31](#__RefHeading___Toc413564470)

Strategies 6-[31](#__RefHeading___Toc413564471)

Federal regulations 6-[32](#__RefHeading___Toc413564472)

Wetland protection 6-[32](#__RefHeading___Toc413564473)

Rare and endangered species 6-[33](#__RefHeading___Toc413564474)

On-site sewage disposal 6-[33](#__RefHeading___Toc413564475)

Facilities siting 6-[33](#__RefHeading___Toc413564476)

Water quality regulations 6-[34](#__RefHeading___Toc413564477)

Special designations 6-[35](#__RefHeading___Toc413564478)

Learning Check #2 6-[36](#__RefHeading___Toc413564479)

Unit Learning Exercise 6-[37](#__RefHeading___Toc413564480)

Answers to the learning checks 6-[38](#__RefHeading___Toc413564481)

Learning check #1 6-[38](#__RefHeading___Toc413564482)

Learning check #2 6-[39](#__RefHeading___Toc413564483)

Unit Learning Exercise 6-[40](#__RefHeading___Toc413564484)

[]{#__RefHeading___Toc413564431 .anchor}Introduction

**44 CFR 60.1(d)** The criteria set forth in this subpart are minimum
standards for the adoption of flood plain management regulations by
flood-prone... communities. Any community may exceed the minimum
criteria under this Part by adopting more comprehensive flood plain
management regulations utilizing the standards such as contained in
Subpart C of this part. In some instances, community officials may have
access to information or knowledge of conditions that require,
particularly for human safety, higher standards than the minimum
criteria set forth in Subpart A of this part. Therefore, any flood plain
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.

The NFIP regulatory standards are minimums. They may not be appropriate
for every local situation or unique circumstances.

Therefore, states and communities are encouraged to enact more
restrictive requirements where needed to better protect people and
properties from the local flood hazard.

This unit reviews the more common approaches to this.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}Many
of these more restrictive requirements are eligible for credit under the
Community Rating System (CRS), a program which provides insurance
premium discounts to policyholders in communities with more restrictive
floodplain management programs (see Unit 9, Section C). Where CRS credit
is provided, it is highlighted with this CRS logo.

[]{#__RefHeading___Toc413564432 .anchor}A. Taking

Why not simply tell people that they can't build in the floodplain? If
we did, we wouldn't have to worry about new buildings getting flooded
and the regulations would be simple to administer: Just say "No."

While this regulatory standard appears desirable, it has one fatal legal
problem: It could be a "[taking]{.underline}."

The Fifth Amendment to the Constitution states, "Nor shall property be
taken for public use without just compensation." The Constitution
contains this provision because in England, the king could take property
and use it for his own purpose---such as quartering troops or hunting---
without compensation.

The term "taking" has come to mean any action by a government agency
that relieves a person of his or her property without payment.

Government agencies possess the authority to acquire privately owned
land. Under the power of [eminent domain]{.underline}, they can acquire
land without the owner's agreement provided the acquisition clearly is
for a demonstrably public purpose and official condemnation proceedings
are followed. Some common examples of eminent domain actions are:

-   Purchase of land for roads and public works projects.

-   The development of public park land.

-   Utility acquisition of rights of way for transmission lines, etc.

Courts have ruled that a taking may occur when the government enacts a
law, standard or regulation that limits the use of the land to the
extent that the owner has been deprived of all of his or her economic
interest in using the property. Thus, the government has "taken" the
property under a legal provision known as [inverse
condemnation]{.underline}.

In cases where a court has found a taking, the governmental body has
been required to compensate the property owner. Often, though, the
regulations are retracted as applied to that property.

Usually, courts undertake a complicated balancing of public and private
interests in deciding a taking issue. The courts will consider such
factors as:

-   Regulatory objectives.

-   The harm posed by uncontrollable development.

-   Reasonableness of the regulations.

-   Severity of the economic impact upon the private property owner

-   

Figure 6-1. Selected cases of challenges to land use regulations

![](media/image2.png){width="6.5in" height="8.210416666666667in"}

Very restrictive floodplain regulations and the regulatory standards of
the NFIP have been challenged as a taking in a number of cases. Figure
6-1 summarizes important cases challenging the legality or
constitutionality of NFIP regulations.

Most NFIP criteria are performance standards that do not prohibit
development of a floodplain site provided the performance standards are
met. For example, development in the floodway is prohibited only if it
increases flood heights. Permit applicants who can find a way to develop
in the floodway without increasing the flood problem are permitted to do
so. These performance-oriented standards of the NFIP have never been
ruled as a taking. This is highly significant, given that more than
19,000 communities administer floodplain management ordinances.

Although it may be more costly to build according to the NFIP standards
and, in some instances, it may not be economical to develop a property,
the performance standard is a valid exercise of the police power because
it is based on a legitimate public purpose: preventing flood damage.
Floodway requirements in particular are defensible because they prevent
the actions of one property owner from increasing flood damage to his or
her neighbors.

The NFIP regulatory criteria have not lost a taking case because they
allow any floodprone site to be built on as long as precautions are
taken to protect new structures and neighboring property from flood
damage. The owners are not denied all economic uses of their properties
as long as their construction accounts for the level of hazard.

Some courts have supported regulatory standards that are more
restrictive than NFIP regulations, such as complete prohibitions of new
buildings or new residences in the floodway. These cases tied the
prohibition to the hazard and the need to protect the public from
hazards created by the development.

Things need to be reasonable. For example, a complete prohibition of
development in a shallow flooding area where there is no velocity may
not be considered as "reasonable" by a court.

The rationale does not always have to be tied to property damage. For
example, in upholding the State's prohibition of new buildings in the
floodway, the Illinois Supreme Court noted that while buildings could be
protected, the residents would be surrounded by moving water during
floods, preventing access by emergency vehicles.

> "The prohibition takes into consideration not only the concern about
> preventing further flooding, but also the concern about the need to
> provide disaster relief services and the need for the expenditure of
> state funds on shelters and rescue services for victims of flooding."
> (Beverly Bank v. Illinois Department of Transportation, September 19,
> 1991).

The lesson is that before your community enacts a regulatory provision
that severely restricts the use of property, your community's attorney
should review the provision to be sure it will not be overturned as a
taking. Regulatory standards that are reasonable, tied to the hazard and
support public objectives should be upheld.

[]{#__RefHeading___Toc413564433 .anchor}B. State Regulatory Standards

All states now allow communities to regulate development to the NFIP
standards. Some states also require that their communities regulate to a
higher standard for certain aspects of floodplain management.

This section reviews the more common state requirements. If your
ordinance was based on a state model, you should be compliant with all
state requirements as well as the NFIP standards.

According to a 1995 survey by the Association of State Floodplain
Managers (ASFPM), 24 states have some kind of riverine standards more
restrictive than those of the NFIP. Of those, 10 require that
communities regulate to the higher standard; three states have opted to
implement and enforce the higher standard directly; and 10 states use a
combination of both approaches.

Eight states prohibit buildings or residences from their floodways at
least in some areas. Twelve states allow less than the NFIP's one-foot
rise in the floodway. States are more likely to regulate some or all of
the floodways than the flood fringes, because they require more
technical expertise than those that apply to the fringe and because the
impacts of floodway development are more extensive, often going beyond
local corporate limits.

The ASFPM survey found that 32 states have enacted some regulations
governing shoreline development. For states with ocean or bay coasts,
this regulatory authority is usually implemented under the state\'s
coastal zone management program. All the Great Lakes states have
lakeshore regulatory standards or permit programs, usually administered
as part of state shoreland management programs.

Twenty-three states now have standards for their coastal high hazard
areas that exceed those of the NFIP. Sixteen states regulate areas
subject to coastal erosion. Sixteen states have regulations or standards
to preserve or protect sand dunes and 16 states regulate or set higher
standards for lakeshore areas.

Nineteen states have stricter building construction requirements than
does the NFIP. The most common additional standard is freeboard
(requiring new buildings to be elevated higher than the base (100-year)
flood level). This standard may apply to all buildings in the floodplain
or only to certain types, such as new jails, hospitals, nursing homes,
mobile home parks, or hazardous materials facilities.

-   Here are some other common state regulatory requirements:

```{=html}
<!-- -->
```
-   25 states either directly regulate the handling and storage of
    stormwater in their jurisdictions or establish standards that
    communities must meet.

-   30 states have regulations or standards for the control of erosion
    and sediment.

-   23 have either direct regulations or state standards to restrict or
    prohibit some or all development within a certain distance from
    bodies of water.

-   16 of those have setbacks for coastal and/or lakeshore areas.

-   14 states have special rules for areas that lie below dams or are
    protected by levees.

-   30 states have adopted measures to regulate hazardous materials in
    floodplains

-   29 states have special public health standards that apply to
    floodplains

Twenty-four state governors have issued a directive to their state
agencies on floodplain management. Most of these were implemented to
meet the minimum NFIP requirements but many go beyond them. Five states
have wetlands policy set by executive order, five have orders on hazard
mitigation or disaster recovery, and two states have other resource
protection executive orders that affect floodplains.

For more information on which states have which requirements, see
Floodplain Management 1995: State and Local Programs, Association of
State Floodplain Managers, 1995.

[]{#__RefHeading___Toc413564434 .anchor}C. Higher Regulatory Standards

FEMA has established minimum floodplain management requirements for
communities participating in the NFIP. Communities must also enforce
more restrictive State requirements. However, communities should
seriously consider enacting regulations that exceed the minimum state
and federal criteria.

In fact, the NFIP requires communities to at least consider additional
measures which are found in 44 CFR 60.22, Planning Considerations for
Floodprone Areas. They are summarized in Figure 6-2.

+-----------------------------------------------------------------------+
|                                                                       |
+-----------------------------------------------------------------------+
| (a) The floodplain management regulations adopted by a community for  |
|     floodprone areas should***:***                                    |
+-----------------------------------------------------------------------+
| 1.  Permit only that development of floodprone areas which            |
|                                                                       |
|     i.  is appropriate in light of the probability of flood damage    |
|                                                                       |
|     ii. is an acceptable social and economic use of the land in       |
|         relation to the hazards involved                              |
|                                                                       |
|     iii. does not increase the danger to human life                   |
+-----------------------------------------------------------------------+
| 2.  Prohibit nonessential or improper installation of public          |
|     utilities and public facilities.                                  |
+-----------------------------------------------------------------------+
| (b) In formulating community development goals after a flood, each    |
|     community shall consider:                                         |
+-----------------------------------------------------------------------+
| 1.  Preservation of the floodprone areas for open space purposes      |
+-----------------------------------------------------------------------+
| 2.  Relocation of occupants away from floodprone areas                |
+-----------------------------------------------------------------------+
| 3.  Acquisition of land or land development rights for public         |
|     purposes                                                          |
+-----------------------------------------------------------------------+
| 4.  Acquisition of frequently flood-damaged structures.               |
+-----------------------------------------------------------------------+
| (c) In formulating community development goals and in adopting        |
|     floodplain management regulations, each community shall consider  |
|     at least the following factors:                                   |
+-----------------------------------------------------------------------+
| 1.  Human safety                                                      |
|                                                                       |
| 2.  Diversion of development to areas safe from flooding              |
+-----------------------------------------------------------------------+
| 3.  Full disclosure to all prospective and interested parties         |
+-----------------------------------------------------------------------+
| 4.  Adverse effects of floodplain development on existing development |
+-----------------------------------------------------------------------+
| 5.  Encouragement of floodproofing to reduce flood damage             |
+-----------------------------------------------------------------------+
| 6.  Flood warning and emergency preparedness plans                    |
+-----------------------------------------------------------------------+
| 7.  Provision for alternative vehicular access and escape routes      |
+-----------------------------------------------------------------------+
| 8.  Minimum retrofitting requirements for critical facilities         |
+-----------------------------------------------------------------------+
| 9.  Improvement of local drainage to control increased runoff         |
+-----------------------------------------------------------------------+
| 10. Coordination of plans with neighboring community's floodplain     |
|     management programs                                               |
+-----------------------------------------------------------------------+
| 11. Requirements for new construction in areas subject to subsidence  |
+-----------------------------------------------------------------------+
| 12. Requiring subdividers to furnish delineations for floodways       |
+-----------------------------------------------------------------------+
| 13. Prohibition of any alteration or relocation of a watercourse      |
+-----------------------------------------------------------------------+
| 14. Requirement of setbacks for new construction within V Zones       |
+-----------------------------------------------------------------------+
| 15. Freeboard requirements                                            |
+-----------------------------------------------------------------------+
| 16. Requirement of consistency between state, regional and local      |
|     comprehensive plans                                               |
+-----------------------------------------------------------------------+
| 17. Requirement of pilings or columns rather than fill to maintain    |
|     storage capacity                                                  |
+-----------------------------------------------------------------------+
| 18. Prohibition of manufacturing plants or facilities with hazardous  |
|     substances                                                        |
+-----------------------------------------------------------------------+
| 19. Requirements for evacuation plans                                 |
+-----------------------------------------------------------------------+
| Figure 6-2: NFIP planning considerations (44 CFR 60.22)               |
+-----------------------------------------------------------------------+

Some of the more common approaches taken by communities to better
regulate floodplain development are explained in this section.

[]{#__RefHeading___Toc413564435 .anchor}Location Restrictions

Where the hazard is so severe that certain types of development should
be prohibited, a location restriction provision may be appropriate. Some
communities prohibit some or all development in all or parts of their
floodplains. A common approach is to prohibit particular structures in
the floodway or areas exceeding certain flood depths or velocities.

Because this is the most restrictive higher regulatory provision,
location restriction language has to be drafted carefully to avoid a
taking challenge. Sometimes, a community can tie transfers of
development rights or other benefits to a development that avoids the
flood hazard area. These types of "win -- win" situations benefit
everyone and reduce the potential for challenging the ordinance.

[]{#__RefHeading___Toc413564436 .anchor}Highly hazardous areas

Prohibiting development makes sense in high hazard areas, where people
are exposed to a life-threatening situation even though buildings could
be protected from flood damage. For example, it would be appropriate to
prohibit development at the apex of an alluvial fan or along a narrow
floodplain in a stream valley that is susceptible to flash flooding.

[]{#__RefHeading___Toc413564437 .anchor}Subdivision design

Undeveloped land, still in large tracts, offers the best opportunity to
limit where certain types of development will be located. When a
developer wants to subdivide the land, communities have many tools to
arrange the development so that buildings are kept out of the
floodplain. This has two advantages over simply requiring the buildings
to be protected from flooding:

-   Buildings aren't isolated by floodwaters, putting a strain on local
    emergency services to guard them or evacuate or rescue their
    occupants, and

-   The neighborhood will have waterfront open space and recreation
    areas -- a valuable amenity in most communities.

A housing development can be clustered, as shown in Figure 6-3, so the
developer can sell the same number of homesites as a conventional
subdivision. Check your state laws on whether cluster development can be
mandated or just encouraged during the subdivision review process.

Figure 6-3. Clustering can keep buildings out of smaller floodplains

![](media/image3.png){width="6.5in"
height="8.614583333333334in"}(Source: *Subdivision Design in Flood
Hazard Areas*)

As explained in pages 17-25 of the American Planning Association's
*Subdivision Design in Flood Hazard Areas*, the planner's toolbox
contains other tools for encouraging developers to avoid floodplains. A
density transfer can be used to, say, trade development rights with a
flood-free site. Credits or bonuses can be given to increase the
allowable density if the developer puts building sites on high ground or
does not disturb a wetland.

The [planned unit development (PUD)]{.underline} approach offers
developers flexibility in planning the entire area. For example, a PUD
may have a cluster development with houses closer together than allowed
under normal zoning lot line setbacks.

Subdivision and planning regulations also can mandate that a certain
portion of a development be set aside as open space for recreation or
stormwater management purposes. Developers find that it is cheaper to
put the open space in the floodplain than to put buildings there that
have to incorporate the more expensive floodplain requirements. Linear
parks and greenways that connect the open space areas through a
community are becoming more and more popular and help sell new
developments.

[]{#__RefHeading___Toc413564438 .anchor}Setbacks

Setbacks may be used to keep development out of harm's way. Setback
standards establish minimum distances that structures must be
positioned---set back---from river channels and coastal shorelines.
Setbacks can be defined by vertical heights or horizontal distances.

While floodplain boundaries are defined by vertical measures, horizontal
setbacks also provide protection from flood damage, especially in
coastal areas where the effects of waves decrease further inland.

For coastal shorelines, setback distances act as buffer zones against
beach erosion. In riverine situations, setbacks prevent disruption to
the channel banks and protect riparian habitat. Such setbacks are
frequently created to serve as isolation distances to protect water
quality, and stream and wetland resources.

Setbacks from watercourses have been used to minimize the effect of
non-point sources of pollution caused by land development activities,
timber harvesting and agricultural activities. Solid waste landfills and
on-site sewage disposal systems often are restricted within certain
distances of a body of water.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits setbacks that prevent disruption to
shorelines, stream channels and their banks under Activity 430, Section
431.g.2 in the *CRS Coordinator's Manual* and the *CRS Application*. See
also *CRS Credit for Higher Regulatory Standards* for example regulatory
language.

[]{#__RefHeading___Toc413564439 .anchor}Manufactured homes

Many communities have adopted provisions prohibiting the placement of
manufactured (mobile) homes in the floodway. Check your ordinance. This
used to be a minimum requirement of the NFIP and may still be on your
books.

[]{#__RefHeading___Toc413564440 .anchor}Natural areas

The natural functions and values of floodplains coupled with their
hazardous nature have led communities to promote and guide the less
intensive use and development of floodplains. More and more
municipalities are requiring that important natural attributes such as
wetlands, drainage ways and floodplain areas be set aside as open space
as a condition to approving subdivision proposals.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System provides substantial credit for preserving
floodplain areas as open space. If buildings and filling are prohibited,
credit is found under Activity 420 Open Space Preservation, Section
421.a in the *CRS Coordinator's Manual* and the *CRS Application*. If
the area has been kept in or restored to its natural state, more credit
is provided under Section 421.c.

[]{#__RefHeading___Toc413564441 .anchor}Low-density zoning

When a community prepares its land use plan and zoning ordinance, it
should consider what uses and densities are appropriate for floodplains.
If buildings are not prohibited entirely, the community should zone its
floodplains for agricultural or other low-density use to reduce the
number of new structures.

For example, it's better to have a floodplain zoned for agricultural or
conservation use with a minimum lot size of 20 or 40 acres than to allow
four single-family homes to every acre. In some areas, "residential
estate" zones with minimum lot sizes of two to five acres provide lots
large enough that homes can be built out of the floodplain.

Some states have land use planning laws that require local plans before
enacting a zoning ordinance. Some---including Oregon, Florida, New
Hampshire and Hawaii---mandate that local plans account for floods and
other natural hazards.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System provides substantial credit for zoning
floodplains with low-density uses under Activity 430LZ Low Density
Zoning in the *CRS Coordinator's Manual* and the *CRS Application*.

[]{#__RefHeading___Toc413564442 .anchor}Building Requirements

[]{#__RefHeading___Toc413564443 .anchor}Freeboard

Freeboard is an additional height requirement above the base flood
elevation (BFE) that provides a margin of safety against extraordinary
or unknown risks. This reduces the risk of flooding and makes the
structure eligible for a lower flood insurance rate.

While not required by the NFIP standards, your community is encouraged
to adopt at least a one-foot freeboard to account for the one-foot rise
built into the concept of designating a regulatory floodway and the
encroachment requirements where floodways are not identified.

Other reasons for considering a freeboard are that it:

-   Accounts for future increases in flood stages if additional
    development occurs in the floodplain.

-   Accounts for future flood increases due to upstream watershed
    development.

-   Acts as a hedge against backwater conditions caused by ice jams and
    debris dams.

-   Reflects uncertainties inherent in flood hazard modeling,
    topography, mapping limitations and floodplain encroachments.

-   Provides an added measure of safety against flooding.

-   Results in significantly lower flood insurance rates due to lower
    flood risk.

Freeboard safety factors are common in the design of flood control
projects and floodplain development. Many communities have incorporated
freeboard requirements into the elevation and floodproofing requirements
stipulated by the NFIP. Freeboard requirements adopted by communities
range from six inches to four feet.

When constructing a new elevated building, the additional cost of going
up another foot or two is usually negligible. Elevating buildings above
the flood level also reduces flood insurance costs for current and
future owners.

Figure 9-3 shows the insurance rates for a post-FIRM single-family
dwelling. Note that the higher the building is above the BFE, the lower
the rate. These rates are based on the true or actuarial cost of
insuring a building in the floodplain. By adding one foot of freeboard
above the BFE, the cost for the first layer of coverage is reduced from
45 cents per \$100 of coverage to 26 cents. This shows how the extra
foot reduces the potential for flood damage.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits freeboard under Activity 430, Section
431.a in the *CRS Coordinator's Manual* and the *CRS Application*. See
also *CRS Credit for Higher Regulatory Standards* for example regulatory
language.

[]{#Toc406722383 .anchor}

Foundation standards

Without a safe and sound foundation, an elevated building can suffer
damage from a flood due to erosion, scour or settling. The NFIP
regulations provide performance standards for anchoring new buildings
and foundation and fill placement standards for floodproofed buildings
and V Zones.

However, the NFIP performance standards do not specify how a buildings'
foundations are to be constructed. Especially in areas where an
engineer's certificate is not required by the NFIP regulations, more
specific foundation construction standards would help protect buildings
from flood damage.

One option is to require that a registered professional engineer or
architect certify the adequacy of elevated building foundations and the
proper placement, compaction and protection of fill when it is used in
building elevation. This is an ordinance requirement in the New Orleans
area where subsidence threatens so many buildings.

The national model building codes address building foundations and the
proper placement, compaction and protection of fill. You and your
building department should review how these standards are enforced.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}An
alternative is to require a specific construction standard, such as
requiring the V Zone standard for new structures in coastal AE and AH
Zones. Coastal AE Zones are of particular concern, since they are
subject to wave action of up to three feet in height and the NFIP A Zone
construction standards do not address this hazard.

The Community Rating System credits foundation protection under Activity
430, Section 431.b in the *CRS Coordinator's Manual* and the *CRS
Application*. See also *CRS Credit for Higher Regulatory Standards* for
example regulatory language.

[]{#__RefHeading___Toc413564445 .anchor}Safety Requirements

[]{#__RefHeading___Toc413564446 .anchor}Critical facilities

For some activities and facilities, even a slight chance of flooding
poses too great a threat. These should be given special consideration
when formulating regulatory alternatives and floodplain management
plans.

FEMA defines four kinds of critical facilities:

-   Structures or facilities that produce, use or store highly volatile,
    flammable, explosive, toxic and/or water-reactive materials.

-   Hospitals, nursing homes and housing likely to have occupants who
    may not be sufficiently mobile to avoid injury or death during a
    flood.

-   Police stations, fire stations, vehicle and equipment storage
    facilities, and emergency operations centers that are needed for
    flood response activities before, during and after a flood.

-   Public and private utility facilities that are vital to maintaining
    or restoring normal services to flooded areas before, during and
    after a flood.

A critical facility should not be located in a floodplain. Communities
often prohibit critical or hazardous facilities or uses from the
floodway, the V Zone, or the entire floodplain. While a building may be
considered protected from the base flood, a higher flood or an error on
the builder's or operator's part could result in a greater risk than the
community is willing to accept.

If a critical facility must be located in a floodplain, then it should
be designed to higher protection standards and have flood evacuation
plans. The more common standards---freeboard, elevation above the
500-year floodplain and elevated access ramps---should be required.

According to Executive Order 11988, federal agencies must meet rigorous
alternative site evaluations and design standards before funding,
leasing or building critical facilities in the 500-year floodplain.
Executive Order 11988 is discussed further in Section E of this unit.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits prohibiting critical facilities or
requiring them to be protected from damage by the 500-year flood in
Activity 430, Section 431.e in the *CRS Coordinator's Manual* and the
*CRS Application*. See *CRS Credit for Higher Regulatory Standards* for
example regulatory language.

[]{#__RefHeading___Toc413564447 .anchor}Hazardous materials

While prohibiting or protecting hazardous materials makes sense, it
would be wise to have specific standards in your ordinance. The
following lists were taken from the Corps of Engineers' Flood Proofing
Regulations. The first is of items that are extremely hazardous or
vulnerable to flood conditions so they should be prohibited from the
SFHA or even the 500-year floodplain:

Acetone

Ammonia

Benzene

Calcium carbide

Carbon disulfide

Celluloid

Chlorine

Hydrochloric acid

Prussic acid

Magnesium

Nitric acid

Oxides of nitrogen

Phosphorus

Potassium

Sodium

Sulfur

The following items are sufficiently hazardous that larger quantities
they should be prohibited in any space below the base flood elevation

Acetylene gas containers

Storage tanks

Lumber /buoyant items

Gasoline

Charcoal/coal dust

Petroleum products

Larger quantities of the following items should be prohibited in any
space below the base flood elevation

Drugs

Food products

Matches/sulfur products

Soaps/detergents

Tires

[]{#__RefHeading___Toc413564448 .anchor}Dry land access

Fire prevention, evacuation and rescue operations are common emergency
response activities associated with flooding. The effectiveness and
success of these efforts greatly depend on readily available access.
However, streets and roads are usually the first things to be inundated
in the event of a flood.

To ensure access, some communities have enacted ordinance provisions
requiring that all roads and other access facilities be elevated to or
above the BFE. Some require elevation to within one foot of the BFE so
at least fire and rescue equipment can travel on them during a flood.

While some local officials may feel that this approach is too
restrictive, it is important to note that emergency response personnel
die every year attempting to rescue flood-stranded citizens. Also,
others may die or be seriously injured because they cannot be rescued in
time.

![](media/image4.png){width="4.059722222222222in"
height="2.7493055555555554in"}

Figure 6-4: Four people died in a 1978 flood in this critical facility.

This nursing home in Rochester, Minnesota, was isolated by high velocity
floodwaters. Because there was no dry land access, firefighters could
not rescue the occupants.

Naturally, there are some areas with floodplains so extensive that a
developer cannot be expected to connect his development to high ground.
As with all regulatory standards, you must carefully weigh the local
hazard, the regulation's objectives, and the costs and benefits of
meeting the standard before you draft new ordinance language.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System has credited dry land access provisions under
Activity 430, Section 431.i in the *CRS Coordinator's Manual* and the
*CRS Application*.

[]{#__RefHeading___Toc413564449 .anchor}Encroachment standards

Some states and communities are not comfortable with allowing
development in the flood fringe to increase flood heights by up to a
foot. A one-foot increase in flood heights will increase the potential
for flood damage to floodprone buildings and affect properties that were
otherwise not threatened by the base flood. This is especially true in
flat areas where a one-foot increase can extend the floodplain boundary
by blocks.

These states and communities require floodway mapping and encroachment
studies to allow a smaller surcharge, usually 0.5 or 0.1 foot. Twelve
states require that regulatory maps use a smaller floodway mapping
surcharge than the NFIP's one-foot minimum standard. This results in a
wider floodway, but less potential for increased flood losses due to
future development.

In Minnesota, one watershed district took another regulatory approach,
enacting regulations that restricted encroachments in the flood fringe
to 20 percent of the total floodplain area. In Washington State, some
communities treat higher velocity and deeper flood fringe areas as
floodways and make development in those areas comply with the floodway
construction standards.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits more restrictive floodway mapping
standards under Activity 410 Additional Flood Data, Section 411.c in the
*CRS Coordinator's Manual* and the *CRS Application*.

[]{#__RefHeading___Toc413564450 .anchor}Compensatory storage

The NFIP floodway standard in 44 CFR 60.3(d) restricts new development
from obstructing the flow of water and increasing flood heights.
However, this provision does not address the need to maintain flood
storage. Especially in flat areas, the floodplain provides a valuable
function by storing floodwaters. When fill or buildings are placed in
the flood fringe, the flood storage areas are lost and flood heights
will go up because there is less room for the floodwaters. This is
particularly important in smaller watersheds which respond sooner to
changes in the topography.

For this reason, some communities adopt more restrictive standards that
regulate the amount of fill or buildings that can displace floodwater in
the flood fringe. One simple approach is to prohibit filling and
buildings on fill---all new buildings must be elevated on columns or
flow-through crawlspaces.

Check your statutory authority, because in some states buildings are
allowed only if they are on fill. Some communities prefer buildings on
fill because it provides a safe spot above flood levels outside the
building walls.

Another approach is to require compensatory storage to offset any loss
of flood storage capacity. The developer is required to offset new fill
put in the floodplain by excavating an additional floodable area to
replace the lost flood storage area. This should be done at
"hydraulically equivalent" sites---fill put in below the 10-year flood
elevation should be compensated by removal of soil below that elevation
elsewhere in the floodplain.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits prohibition of fill and compensatory
storage under Activity 430, Section 431.f in the *CRS Coordinator's
Manual* and the *CRS Application*. See *CRS Credit for Higher Regulatory
Standards* for example regulatory language.

[]{#__RefHeading___Toc413564451 .anchor}Stormwater management

A floodplain management program in an urbanizing area must confront the
increase in flood flows caused by development within the watershed. As
forests, fields and farms are covered by impermeable surfaces like
streets, rooftops and parking lots, more rain runs off at a faster rate.
In an urbanized area, the rate of runoff can increase fivefold or more.

Changes in the surface drainage system compound this problem. Stormwater
runoff travels faster on streets and in storm drains than it did under
pre-development conditions. As a result, flooding is more frequent and
more severe (Figure 1-13). Efforts to reduce the impact of increased
runoff that results from new development in a watershed are known as
[stormwater management]{.underline}.

One way to reduce the impact of stormwater from new development is to
require the developer to restrict the rate at which the increased runoff
leaves the property. The developer must build a facility to store
stormwater runoff on the site.

Under [stormwater detention,]{.underline} the stored water is held for
release at a restricted rate after the storm subsides. Under [stormwater
retention,]{.underline} stormwater runoff is held for later use in
irrigation or groundwater recharge, or to reduce pollution.

As an alternative to using a uniform standard for all areas, many
communities regulate development according to a master plan that
analyzes the combined effects of existing and expected development on
stormwater and flood flows in the watershed. Such watershed-specific
regulations may allow different amounts of runoff for different areas in
order to control the timing of increased flows into the receiving
streams.

Instead of requiring developers to build stormwater facilities on-site,
a plan may require them to contribute funds for a regional facility. By
planning the runoff from entire watersheds, this approach can be more
effective in reducing increases in downstream flooding.

Stormwater management also has water quality aspects, and includes
efforts to reduce erosion and the entry of sediment and pollutants into
receiving streams.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits both water quantity and water quality
stormwater management regulations and plans under Activity 450 in the
*CRS Coordinator's Manual* and the *CRS Application*. See also *CRS
Credit for Stormwater Management* for example regulatory language.

[]{#__RefHeading___Toc413564452 .anchor}Temporary moratorium

Following a flood, a number of communities have imposed moratoriums on
rebuilding in the damaged area, effectively prohibiting floodplain
development. Often, temporary measures are put in place after a flood to
allow time to plan for acquisition, relocation, or redevelopment of the
area, or to install flood control projects.

A temporary moratorium should specify when it will be lifted, such as
"within three months or when the plan is completed, whichever is
sooner." An open ended moratorium may be viewed by a court as a taking,
since the owner has no idea when he or she will be allowed to build or
rebuild.

[]{#__RefHeading___Toc413564454
.anchor}![](media/image5.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #1

1.  What NFIP program recognizes local regulatory standards that are
    more restrictive than the minimum NFIP regulations?

2.  If a regulatory requirement prohibits an owner from any use of his
    land, it is referred to by the legal term
    \_\_\_\_\_\_\_\_\_\_\_\_\_\_ .

3.  In how many court cases have the NFIP regulations been overruled as
    unconstitutional?

4.  If a state requirement is more restrictive than the NFIP
    requirements, which set of rules must a community follow?

5.  Does your community's ordinance have any provisions that are more
    restrictive than the minimum NFIP requirements?

6.  Name two higher regulatory standards that can be used to encourage
    building sites completely out of the floodplain?

7.  What is freeboard?

8.  What is the preferred flood protection approach for critical
    facilities?

9.  How does compensatory storage work?

10. What is "stormwater management?"

[]{#__RefHeading___Toc413564455 .anchor}D. Flood Hazards of Special
Concern

The mapping and regulatory standards of the NFIP do not completely
address every flood problem in the United States. Certain floodplains
and flood-related hazards are more destructive and harder to map than
riverine, coastal and shallow flooding.

Unit 1 introduced these flood hazards, so we won't discuss them in
detail here. This section reviews the more common regulatory standards
appropriate to each hazard.

In addition to regulations, communities should address these special
hazards in their planning, public information, hazard disclosure and
flood warning programs.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}More
information on these hazards and the Community Rating System credit for
mapping and managing them is found in *CRS Credit for Special Hazard
Areas*.

[]{#__RefHeading___Toc413564456 .anchor}Coastal erosion

Coastal erosion occurs to properties in the coastal floodplain and to
properties on bluffs above the floodplain. Estimates are that 24 percent
of the Atlantic, Pacific, Gulf of Mexico and Great Lakes coasts face
significant erosion.

Special erosion rate maps are needed to regulate new construction to
protect it from coastal erosion. Normally, 30-, 60- or 100-year erosion
zones are used. Erosion zones are generally calculated by multiplying
the annual rate of erosion times the number of years of protection to be
provided.

The 30-year erosion zone is the area that will likely erode over the
next 30 years. It is measured inland from a known point, such as the
dune or vegetation line. Erosion zones are "moving targets." They can
change each year as the dune or vegetation line moves inland (or
seaward). Erosion rates also vary over the years, moving at a faster or
slower rate than the annual average.

[]{#__RefHeading___Toc413564457 .anchor}Regulatory standards

There are NFIP regulatory performance standards and planning
considerations for erosion-prone areas in 44 CFR 60.5 and 60.24,
respectively. As with 44 CFR 60.3, the NFIP requirements are keyed to
the type of hazard data provided by FEMA. Since there are no FEMA
erosion-prone maps published yet, there are no NFIP requirements for
managing erosion-prone areas. Therefore, Sections 60.5 and 60.24 should
be viewed as advisory.

Several states have erosion management requirements. Their typical
regulatory standards include:

-   All new buildings must be located landward of the 30-year erosion
    zone

-   All larger buildings must be located landward of the 60-year zone

-   Deeper pilings and special foundation provisions

-   Traffic restricted on sand dunes and other protective features

For more information, contact your state's coastal zone management
office. See also FEMA's Coastal Construction Manual.

[]{#__RefHeading___Toc413564458 .anchor}Tsunamis

A tsunami is a wave or series of waves generated at sea or near shore by
an earthquake, volcano or landslide. Tsunamis can move as fast as 1,000
kilometers per hour from their point of origin, usually in the Pacific
Ocean.

Tsunamis pose two special hazards: a short warning time and very deep
flooding.

Tsunamis are hard to recognize at sea but when they reach shallow water,
a wave builds up. The effect is more like a rise in sea level than a
breaking wave. In narrow areas, where water is concentrated, the
resulting water level can be very high, in some areas as much as 20 or
30 feet above normal tides.

Tsunami inundation areas generally are not mapped by FEMA because they
are not considered a normal condition of flooding. However, recent
federal-state efforts have improved the availability of maps and data
for the Pacific states. For more information on tsunami maps, contact
your state's emergency management or coastal zone management office.

[]{#__RefHeading___Toc413564459 .anchor}Regulatory standards

The best regulatory approach is to use an estimated tsunami flood level
or the BFE, whichever is higher. Keeping new buildings out of the area
that lies below that elevation, or protecting them from flood damage
below that elevation, would be appropriate. If not all new buildings can
be prohibited, at least critical facilities and/or high-occupancy
buildings should be prevented from locating in the area that will have
little advance warning of a flood.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}A
community should also tie development of a tsunami-prone area to the
availability of a warning system. Without adequate warning, occupying
such an area can be deadly.

See also *CRS Credit for Management of Pacific and Caribbean Tsunami
Hazards*.

[]{#__RefHeading___Toc413564460 .anchor}Closed basin lakes

Two types of lakes pose special hazards to adjacent development:

-   Lakes with no outlets, like the Great Salt Lake, Utah, Devil's Lake,
    North Dakota, and the Salton Sea, California; and

-   Lakes with inadequate, regulated or elevated outlets, such as the
    Great Lakes and many glacial lakes.

These are referred to as "closed basin lakes." Closed basin lakes are
subject to large fluctuations in elevation which can persist for weeks,
months or years.

Closed basin lakes were formed in almost every part of the United
States:

-   Glaciers scoured out lakes in the northern tier of states and
    Alaska.

-   Tectonic action created lakes with no outlets (playas) in the
    western U.S.

-   Channel migration formed oxbow lakes along the Mississippi and other
    large rivers.

-   Sinkhole lakes formed where there are large limestone deposits at or
    near the surface and adequate surface water and rainfall to dissolve
    the limestone.

[]{#__RefHeading___Toc413564461 .anchor}Regulatory standards

As with tsunamis, the key to regulating these areas is to determine the
appropriate regulatory flood elevation which will likely be higher than
the BFE. The elevation can be determined by studying historical or
geological records, or identifying the elevation of the lowest point
where water can leave.

Areas lower than the regulatory elevation should have construction
standards that protect buildings and their occupants from prolonged
flooding. Other than prohibiting new buildings entirely, the best
approach is to require:

-   Construction of new buildings on fill above the regulatory
    elevation. The fill should be engineered and placed to resist wave
    action.

-   Protection of utilities

-   Access from dry land.

-   Alternatives to septic systems, which won't work under water.

-   Alternatives to on-site wells, which would be polluted when
    floodwater mixes with ground
    water.![](media/image1.png){width="1.3in"
    height="1.0034722222222223in"}

For more information, see *CRS Credit for Management of Areas Adjacent
to Closed Basin Lakes* and *Reducing Losses in High Risk Flood Hazard
Areas: A Guidebook for Local Officials*.

[]{#__RefHeading___Toc413564462 .anchor}Uncertain flow paths

This hazard includes alluvial fans and moveable bed streams. They occur
in hilly or mountainous areas rich in sediments and where precipitation
is not sufficient to carry the sediments downstream as rapidly as they
accumulate. In the United States, these conditions exist primarily in
the arid and semi-arid regions west of the Great Plains, although there
are alluvial fans in Alaska and Appalachia.

Both types of uncertain flow path floodwaters carry large amounts of
sediment which can fill in a channel or move it to a new location.
Regulatory standards must address the three components of the hazard:
velocity of the water, sediment and debris; the volume and movement of
sediment and debris during floods; and the potential for channel
migration during a flood.

[]{#__RefHeading___Toc413564463 .anchor}Regulatory standards

A good study may be able to identify the limits of channel migration and
require new buildings to be set back from that area. A permit applicant
can be required to prepare such a study.

Otherwise, because the characteristics of the hazard is site-specific,
many ordinances simply require the builder to have an engineer certify
that the project will be protected. In alluvial fans, a subdivider can
be required to install debris basins, channels and walls to keep debris
and velocity flows away from houses.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}For
more information, see *CRS Credit for Management of Areas with Uncertain
Flow Paths* and *Reducing Losses in High Risk Flood Hazard Areas: A
Guidebook for Local Officials*.

[]{#__RefHeading___Toc413564464 .anchor}Dam breaks

Almost every state has a dam safety office that has identified high
hazard dams. The designation is based on both the height of the dam and
the amount of development at risk downstream.

Should a dam give way, the area covered by the resulting flood
downstream is called the [dam breach inundation area]{.underline}. Dam
breach analyses may have been done for some of the dams upstream of your
community, in which case you can obtain a map of the area subject to
inundation. (Check with your state dam safety office that the map was
prepared using an approved method.)

Close to the dam, the dam breach inundation area is likely to be larger
than the base floodplain. A regulatory program should encompass such
areas outside the base floodplain. It should also take into account the
lack of warning time a dam break would pose.

[]{#__RefHeading___Toc413564465 .anchor}Regulatory standards

Typical measures include:

-   Prohibiting construction of buildings in the dam breach inundation
    area.

-   Prohibiting siting of critical facilities in the dam breach
    inundation area.

-   Requiring new buildings to be elevated above the BFE or the dam
    breach elevation, whichever is higher.

-   Requiring dam owners to maintain their facilities.

-   Requiring dam owners to establish warning systems if their dams are
    in danger of failing.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}For
more information, contact your state dam safety office or the
Association of State Dam Safety Officials, Lexington, Kentucky.

CRS credit for dam failure regulations is provided in Activity 630 Dam
Safety, Section 631.b of the *CRS Coordinator's Manual* and the *CRS
Application*.

[]{#__RefHeading___Toc413564466 .anchor}Ice Jams

Ice jams form in several ways and at different times in winter and early
spring. Damage from ice jam flooding often exceeds that of clear water
flooding because of higher surface elevations, rapid increases in flood
elevations and physical damage caused by moving ice floes.

[]{#__RefHeading___Toc413564467 .anchor}Regulatory standards

FEMA and the Corps of Engineers have developed an ice jam flood study
methodology (see Appendix 3 of Flood Insurance Study Guidelines and
Specifications for Study Contractors). If your community has a study
done following this methodology, you should adopt the results as your
regulatory flood elevation.

In the absence of such a detailed study, you should use the historic ice
jam flood of record plus a foot or two of freeboard as your building
protection level. Other standards should include requiring new buildings
to be elevated on engineered fill or pilings, and prohibiting new
buildings (or at least requiring them to be on fill) in the floodway or
other defined area subject to ice floes.

For more information, contact the Corps of Engineers, which has ice jam
expertise in its district offices and its Cold Regions Research and
Engineering Laboratory in Hanover, New Hampshire.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}See
also *CRS Credit for Management of Areas Subject to Ice Jam Floods*.

[]{#__RefHeading___Toc413564468 .anchor}Mudflows

Because mudflows may not occur in mapped floodplains, additional mapping
may be required. This requirement can be keyed to steeper slopes or
areas with known unstable soils.

In addition to regulations, communities can undertake public
information, fire control and other programs to prevent mudflow
conditions from developing.

[]{#__RefHeading___Toc413564469 .anchor}Regulatory standards

If the hazard is not already mapped, developers in the identified areas
of steeper slopes or unstable soils should be required to prepare flow
hazard studies. Here are regulatory measures appropriate for areas with
mudflow hazards or potential:

-   Require designs that work with natural flow channels, not cut across
    them.

-   Require engineered foundations on compacted fill or pilings.

-   Avoid locating buildings on or below steep slopes.

-   Require debris basins, channels and walls to keep the debris away
    from houses.

-   Require design, construction and drainage practices that direct
    runoff and debris away from unstable areas.

-   ![](media/image6.png){width="5.5in"
    height="2.3604166666666666in"}Enforce grading and cut and fill
    standards that minimize disruption of natural drainage ways (Figure
    6-5).

Figure 6-5. Los Angeles County's hillside grading guidelines.

For more information, see *Planning for Hillside Development*.

[]{#__RefHeading___Toc413564470 .anchor}E. Environmental Protection
Measures

Flooding may not occur often enough in your area to be viewed as a
problem in need of a solution, making it difficult to obtain the public
and political support needed to carry out local floodplain management
measures designed solely to reduce future flood losses.

Support often can be gained by associating flood loss reduction with
broader community concerns and goals. A larger constituency for managing
the community's floodplains can be built if other interests realize that
their needs can be met through their involvement and support in flood
protection. This, in turn, brings more resources and expertise into
play.

Then, too, designing and packaging funding proposals to meet a number of
community goals can boost your chances of obtaining outside resources.
One approach is to tie the need to manage the floodplain to protect your
community's economic well-being with the need to protect and maintain
the natural resources and functions of the floodplain. These resources
and functions can be of considerable benefit to the community, a benefit
often unrealized or underestimated.

[]{#__RefHeading___Toc413564471 .anchor}Strategies

[Preservation]{.underline} and [restoration]{.underline} are the two
basic approaches to protecting a floodplain's natural resources.
Preservation strategies focus on strict control or prohibition of
development in sensitive or highly hazardous areas. Restoration
strategies focus on actions to improve the quality or functioning of
degraded floodplains.

It is not always possible---or necessary---to make a distinction between
the two strategies.

Unit 1 contained an overview of the tools that can be used to preserve
and protect a floodplain's natural and cultural resources. They include:

-   Floodplain, wetland and coastal barrier regulations.

-   Development and redevelopment policies.

-   Land acquisition and preservation.

-   Information and education.

-   Tax adjustments.

This section focuses on the development controls and regulatory
standards you can use to protect natural resources or minimize harm to
them. These measures, used by all levels of government, are among the
most effective means available for protecting natural resources of
floodplains and reducing flood damage.

[]{#__RefHeading___Toc413564472 .anchor}Federal regulations

Federal regulations and those in many states protect resources by
limiting the ways, location and extent to which these resources may be
modified. Two federal regulations can have far-reaching impact:

-   [NEPA]{.underline}: When a federal agency proposes to fund a project
    located in a flood hazard area, the National Environmental Policy
    Act (NEPA) requires an evaluation of the project's environmental
    impact as part of the decision-making process. The evaluation should
    include the impact on flooding as well as water and air quality.

-   [EO 11988]{.underline}: Executive Order 11988 Floodplain Management
    requires federal agencies to check NFIP maps to see if a proposed
    project will be in a floodplain. If one is, the agency must follow
    an eight-step process to determine whether there is a feasible
    alternative to location in the floodplain. If not, the project must
    include flood damage reduction measures.

In short, Federal agencies must meet the same or more restrictive
development standards as do private property owners under the
community's NFIP regulations.

[]{#__RefHeading___Toc413564473 .anchor}Wetland protection

The federal regulation that local permit officials see most often is the
program established by Section 404 of the Clean Water Act. Jointly
administered by the Corps of Engineers and the U.S. Environmental
Protection Agency, the Section 404 program regulates the discharge of
dredged or fill material into U.S. waters, including adjacent wetlands.

The Section 404(b)(1) guidelines provide extensive environmental
criteria for judging permit applications while emphasizing the need to
prevent avoidable losses of aquatic resources, as well as the need to
minimize adverse environmental impacts.

All coastal states and many inland states have their own wetlands
regulations. Because inland wetlands generally receive less protection
than coastal or "tidal" wetlands, many communities establish regulations
that are more restrictive than the Federal or state programs.

The desire to reduce the cumulative impacts of wetland losses has led
many jurisdictions to adopt a "no net loss of wetlands" policy. No net
loss is addressed either in terms of acreage or the functional value of
the wetlands. Despite these programs and other such efforts, as recent
as 1989 it was estimated that the country was losing 300,000 -- 450,000
acres of wetlands each year.

[]{#__RefHeading___Toc413564474 .anchor}Rare and endangered species

Undeveloped floodplains may contain habitat for rare and endangered
species of plants and animals. On the federal level, the Endangered
Species Act of 1973 directs federal agencies not to undertake or assist
projects that would adversely affect any endangered species.

The Act also requires an "incidental take permit" when it appears that
the habitat of a rare or endangered species will be "taken" or impacted
by a non-federal activity. Communities should coordinate their permit
review with this program which is administered by the U.S. Fish and
Wildlife Service.

Many states have programs to identify rare and endangered species and to
acquire or regulate tracts that are home to them. Some states and
communities have sensitive areas regulations or a similar approach that
protects such habitats.

[]{#__RefHeading___Toc413564475 .anchor}On-site sewage disposal

Most states and municipalities regulate the design, location and
placement of on-site sewage systems. Because the objective of such
programs is to prevent surface and subsurface contamination, there are
many requirements to selecting a proper site and designing a system that
will work in a flood.

Less than desirable locations for on-site systems include areas with
high groundwater tables, impervious soils, certain types of porous
soils, and the potential for flooding. These characteristics often
coincide with floodplains.

Regulations that restrict where septic systems can go often mean that a
property owner cannot build in or near the floodplain.

[]{#__RefHeading___Toc413564476 .anchor}Facilities siting

Stringent government regulations restrict the siting of critical
facilities ---hazardous waste facilities, nuclear power plants,
hospitals, police and fire stations ---in a floodplain area.

States and your community also may have siting regulations that
discourage or prevent dangerous or hazardous development in floodplain
areas. These include storage of hazardous materials, sanitary landfills
and related activities.

[]{#__RefHeading___Toc413564477 .anchor}Water quality regulations

Since the enactment of the Clean Water Act in 1972 and related state
legislation, more care is being given to the regulation of direct
discharges of pollutants into waterways. Federal and state point source
regulations focus on wastewater treatment plants and industrial sites
where polluted water is piped to a stream or lake at a single point.

Non-point sources of pollutants are harder to regulate. If stormwater is
not collected and sent to a wastewater treatment plant, it flows
directly into a body of water. On its way, stormwater collects sediments
from soil erosion as well as road oil, pesticides, lawn treatment
chemicals and other pollutants. There is no treatment facility to clean
this runoff water.

Regulatory approaches for non-point sources include buffer zones or
stream setbacks where there are on-site disposal systems, timber
harvesting, tilling of soil, mining, or development in general. These
requirements are often part of, or complement, state or local stormwater
management regulations.

![](media/image7.png){width="6.5in" height="3.4166666666666665in"}

Figure 6-6: Buffer strips.

Source: *Environmental Management: A Guide for Town Officials*,

Maine Department of Environmental Protection, 1992

[]{#__RefHeading___Toc413564478 .anchor}Special designations

Stream corridors often possess special value for an area, region or
state. These corridors are given special designations---such as a wild
or scenic river---and are afforded an extra level of recognition and
protection.

While such programs are not necessarily regulatory in nature, they do
encourage proper planning and land use control, discourage unwanted
development, and guide federal and state actions.

![](media/image1.png){width="1.3in" height="1.0034722222222223in"}The
Community Rating System credits preserving areas for their natural
functions under Activity 420 Open Space Preservation, Section 421.c.
Credit for prohibiting critical facilities in floodplains and for
prohibiting on-site sewage treatment, landfills and other hazardous use
or threats to public health, is provided in Activity 430 Higher
Regulatory Standards, Sections 431.e and 431.g, respectively. Water
quality regulations are credited in Activity 450 Stormwater management,
Sections 451e. and f.

[]{#__RefHeading___Toc413564479
.anchor}![](media/image5.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Learning Check #2

1.  Is your community subject to any of the following flood hazards of
    special concern?

-   Coastal erosion

-   Tsunamis

-   Closed basin lakes

-   Uncertain flow paths or alluvial fans

-   Upstream dams

-   Ice jams

-   Mudflows

11. If so, have you enacted any additional regulatory provisions to
    better protect future development from damage?

12. Since there are several federal agencies that regulate wetland
    development, protect rare and endangered species, etc., is there any
    need for your community to consider any additional environmental
    protection measures?

13. Name three types of regulations that can protect natural resources
    in your floodplains.

[]{#__RefHeading___Toc413564480
.anchor}![](media/image5.wmf){width="0.5701388888888889in"
height="0.6770833333333334in"} Unit Learning Exercise

1.  Does the NFIP allow communities to enact more restrictive regulatory
    standards?

2.  Can a floodplain regulation ever prohibit new buildings from a
    portion of the floodplain?

3.  Name two types of floodprone areas where many communities prohibit
    development.

4.  What's the advantage of requiring dry land access if buildings are
    protected from flooding?

5.  How could a developer of an 80-acre subdivision reduce the amount of
    runoff that leaves the property during a storm?

6.  Do Federal agencies have to meet any floodplain development rules
    similar to the NFIP requirements?

[]{#__RefHeading___Toc413564481 .anchor}Answers to the learning checks

[]{#__RefHeading___Toc413564482 .anchor}Learning check #1

1.  What NFIP program recognizes local regulatory standards that are
    more restrictive than the minimum NFIP regulations?

    The Community Rating System (CRS)

2.  If a regulatory requirement prohibits an owner from any use of his
    land, it is referred to by the legal term
    \_\_\_\_\_\_\_\_\_\_\_\_\_\_ .

    Taking

3.  In how many court cases have the NFIP regulations been overruled as
    unconstitutional?

    None.

4.  If a state requirement is more restrictive than the NFIP
    requirements, which set of rules must a community follow?

    The more restrictive state requirement.

5.  Does your community's ordinance have any provisions that are more
    restrictive than the minimum NFIP requirements?

    Depends on the community.

6.  Name two higher regulatory standards that can be used to encourage
    building sites completely out of the floodplain?

-   Subdivision design that encourages cluster development on high
    ground

-   Low density zoning that gives owners large lots large enough to
    avoid small floodplains

7.  What is freeboard?

    An additional height requirement above the base flood elevation that
    provides a margin of safety against extraordinary or unknown risks.

8.  What is the preferred flood protection approach for critical
    facilities?

    Keep them out of the 500-year floodplain. The next best approach is
    to protect them to the 500-year flood level.

9.  How does compensatory storage work?

    The developer is required to offset new fill put in the floodplain
    by excavating an additional floodable area to replace the lost flood
    storage area.

10. What is "stormwater management?"

    Efforts that reduce the impact of increased runoff that results from
    new development in the watershed.

[]{#__RefHeading___Toc413564483 .anchor}Learning check #2

1.  Is your community subject to any of the following flood hazards of
    special concern?

-   Coastal erosion

-   Tsunamis

-   Closed basin lakes

-   Uncertain flow paths or alluvial fans

-   Upstream dams

-   Ice jams

-   Mudflows

    Depends on the community.

14. If so, have you enacted any additional regulatory provisions to
    better protect future development from damage?

    Depends on the community.

15. Since there are several federal agencies that regulate wetland
    development, protect rare and endangered species, etc., is there any
    need for your community to consider any additional environmental
    protection measures?

    Probably. Federal programs may not address the particular needs of
    your locality.

16. Name three types of regulations that can protect natural resources
    in your floodplains.

-   Wetland protection regulations

-   Habitat protection regulations

-   Restrictions on on-site sewage disposal

-   Water quality regulations and rules on stormwater runoff (non point
    sources of pollution)

-   Designating unique or valuable areas for special protection

[]{#__RefHeading___Toc413564484 .anchor}Unit Learning Exercise

1.  Does the NFIP allow communities to enact more restrictive regulatory
    standards?

    Yes. ".. any flood plain 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." (44
    CFR 60.1(d))

2.  Can a floodplain regulation ever prohibit new buildings from a
    portion of the floodplain?

    Yes, if the area is sufficiently dangerous and/or there is a clear
    relationship between the prohibition and protecting the public from
    the hazard created by the development.

3.  Name two types of floodprone areas where many communities prohibit
    development.

-   High hazard areas, such as flash flood areas and very deep floodways

-   Natural or sensitive areas, such as wetlands

4.  What's the advantage of requiring dry land access if buildings are
    protected from flooding?

    It protects people by allowing them to evacuate when floodwaters
    come up and allows emergency service vehicles to protect the
    properties during a flood.

5.  How could a developer of an 80-acre subdivision reduce the amount of
    runoff that leaves the property during a storm?

    Include stormwater detention or retention basins to hold or delay
    the runoff from the site.

6.  Do Federal agencies have to meet any floodplain development rules
    similar to the NFIP requirements?

    Yes. The National Environmental Policy Act (NEPA) and Executive
    Order 11988 require Federal agencies to meet the same or more
    restrictive development standards.