Reducing Damage from 

Localized Flooding

A Guide for Communities

FEMA 511 / June 2005

ADVANCE TO TABLE OF CONTENTS
Cover photograph courtesy City of Carencro, Louisiana.
Reducing Damage 

from Localized

Flooding

A Guide for Communities

FEMA 511 / June 2005

Reducing Damage from Localized Flooding: A Guide for Communities i

Table of Contents

Acknowledgements ...................................................................................v

Terminology ........................................................................................... vii

Part I. Introduction

Chapter 1. Background ..........................................................................1-1

The NFIP’s Interest ......................................................1-2

About This Guide ........................................................1-3

How to Use the Guide ................................................1-4

Chapter 2. Localized Flooding ..............................................................2-1

The Problem ................................................................2-1

What Can Be Done ......................................................2-5

Where to Get Help ......................................................2-9

Part II. Community-Level Tools and Techniques

Chapter 3. Community-Level Activities .................................................3-1

The Strategy ................................................................3-1

A Community Plan ......................................................3-2

Building Capabilities ...................................................3-5

Where to Get Help ......................................................3-8

Chapter 4. Regulatory Tools ...................................................................4-1

A Regulatory Floodplain Map ......................................4-1

Land Use Regulations ..................................................4-7

Standards for Subdivisions ........................................4-10

Floodplain Regulations ..............................................4-14

Site Drainage ............................................................4-17

Where to Get Help ....................................................4-20
ii Reducing Damage from Localized Flooding: A Guide for Communities

Table of Contents

Chapter 5. Public Information and Awareness .......................................5-1

Answer Questions .......................................................5-1

Provide Resources for the Public .................................5-3

Deliver Flood Information ...........................................5-4

Educate to Build Community Capability ......................5-6

Where to Get Help ......................................................5-8

Chapter 6. Warning and Emergency Services .........................................6-1

Recognizing the Threat ................................................6-1

Issuing the Warning ....................................................6-3

Responding to the Threat ............................................6-4

Informing the Public ...................................................6-6

StormReady Program ..................................................6-7

After the Flood ............................................................6-8

Where to Get Help ....................................................6-11

Part III. Neighborhood-Level Tools and Techniques

Chapter 7. Area Analysis .........................................................................7-1

The “Area” ..................................................................7-1

Conducting the Analysis ..............................................7-2

Follow-Up Activities ....................................................7-8

Funding .......................................................................7-9

Where to Get Help ....................................................7-12

Chapter 8. Drainage Improvements .......................................................8-1

The Drainage System ...................................................8-1

Modifying the Drainage System ..................................8-6

Maintaining the Drainage System ..............................8-13

Where to Get Help ....................................................8-16

Chapter 9. Redevelopment .....................................................................9-1

Redevelopment Objectives ..........................................9-1

Clearing the Area .........................................................9-7

Reuse of the Area .......................................................9-11

Where to Get Help ....................................................9-16
Reducing Damage from Localized Flooding: A Guide for Communities iii

Table of Contents

Part IV. Site-Specific Tools and Techniques

Chapter 10. Retrofitting .......................................................................10-1

Introduction ..............................................................10-1

Retrofitting Techniques ..............................................10-1

Precautions and Parameters .....................................10-13

Community Support ...............................................10-19

Where to Get Help ..................................................10-21

Chapter 11. Flood Insurance ................................................................11-1

NFIP Flood Insurance ................................................11-1

The Community’s Role ..............................................11-6

Where to Get Help ..................................................11-10

References .................................................................................................................R-1

Appendix A. Sources of Assistance ............................................................................ A-1

Organizations ....................................................................................... A-3

State and Local Entities ......................................................................... A-4

Appendix B. Reference Works and Recommended Reading ......................................B-1

Community-Level Approaches ...............................................................B-1

Regulatory Tools ....................................................................................B-2

Public Information and Awareness ........................................................B-3

Warnings and Emergency Services ........................................................B-3

Area Analysis ........................................................................................B-4

Drainage Improvements ........................................................................B-4

Redevelopment ......................................................................................B-4

Retrofitting ............................................................................................B-5

Index

Reducing Damage from Localized Flooding: A Guide for Communities v

Acknowledgements

This guide was produced with the assistance and expert advice of numerous 

specialists throughout the United States. Thanks are extended to the technical 

reviewers, and to the local, State, and Federal officials who provided valuable 

input through interviews with project staff.

Mike Buchert, City of Tulsa, Oklahoma, Public Works

Dave Canaan, Director of Charlotte/Mecklenburg County, North Carolina, Stormwater Services

Dr. Mow-Soung Cheng, Department of Environmental Resources, Prince George’s County, Maryland

Jack DeCicco, State Farm Insurance Company

Ted DeBaene, Owen and White, Inc., Baton Rouge, Louisiana

Trudi Johnson, CRS Coordinator, Hilton Head Island, South Carolina

Ward Miller, Lake County, Illinois, Stormwater Management Commission

Doug Plasencia, AMEC Earth & Environmental, Inc., Phoenix, Arizona 

Andy Reese, AMEC Earth & Environmental, Inc., Nashville, Tennessee

Joe Tram, Maricopa County Flood Control District, Arizona

Kevin Stewart, Urban Drainage and Flood Control District, Denver, Colorado

Tom Donaldson, National Weather Service, Silver Spring, Maryland

Daisy Sweeny, Regional Repetitive Loss Coordinator, FEMA Region I

Pat Griggs, Regional Repetitive Loss Coordinator, FEMA Region II

Dave Thomas, Regional Repetitive Loss Coordinator, FEMA Region III

Bob Durrin, Regional Repetitive Loss Coordinator, FEMA Region IV

Anna Pudlo, Regional Repetitive Loss Coordinator, FEMA Region V

Greg Solovey, Regional Repetitive Loss Coordinator, FEMA Region VI

Georgia Wright, Regional Repetitive Loss Coordinator, FEMA Region VII
vi Reducing Damage from Localized Flooding: A Guide for Communities

Acknowledgements

Bonnie Heddin, Regional Repetitive Loss Coordinator, FEMA Region VIII

Gregor Blackburn, Regional Repetitive Loss Coordinator, FEMA Region IX

Denise Atkinson, Regional Repetitive Loss Coordinator, FEMA Region X

Dave Carlton, Civil Engineer, FEMA Region X

Clifford E. Oliver, Branch Chief, Risk Assessment, FEMA HQ

Michael Grimm, Community Assistance Section Chief, Risk Assessment, FEMA HQ

Cynthia Pollnow, Project Manager, Risk Assessment, FEMA HQ

Errol Garren, Project Monitor, Risk Assessment, FEMA HQ

Mike Robinson, Risk Assessment, FEMA HQ

Bill Lesser, Risk Assessment, FEMA HQ

Don Beaton, Risk Insurance, FEMA HQ

Mary Chang, Risk Insurance, FEMA HQ

Sheila Donohoe, Risk Reduction, FEMA HQ

Kathleen Wissman, Risk Reduction, FEMA HQ

This guide was prepared by URS Corporation, French & Associates, Ltd., and JLM 

Associates, Inc. under Task Order 269 of the FEMA Hazard Mitigation Technical 

Assistance Program.
Reducing Damage from Localized Flooding: A Guide for Communities vii

Terminology

Throughout this guide, the following terms are used.

A Zone is defined as the Special Flood Hazard Area shown on a community’s Flood 

Insurance Rate Map. The A Zone is the area subject to inundation during a 100-year 

flood, which is the flood elevation that has a 1-percent chance of being equaled or 

exceeded each year. There are several categories of A Zones, including AO (shallow 

sheet flow or ponding; average flood depths are shown); AH Zones (shallow flooding; 

base flood elevations are shown); numbered A and AE Zones (base flood elevations 

are shown); and unnumbered A Zones (no base flood elevations are provided because 

detailed hydraulic analyses were not performed). 

B Zone is defined as an area of moderate flood hazard, usually depicted on Flood 

Insurance Rate Maps as between the limits of the base flood and 500-year flood of 

the primary source of flooding. B Zones may have local, shallow flooding problems. B 

Zones are also used to designate areas protected by levees and base floodplains of little 

hazard, such as those with average flood depths of less than 1 foot.

BFE is the base flood elevation. The base flood is the flood having a 1-percent chance 

of being equaled or exceeded in any given year. (It is also known as the 100-year 

flood.) The BFE has been adopted by the National Flood Insurance Program as the 

basis for mapping, insurance rating, and regulating new construction.

C Zone is defined as an area of minimal flood hazard, usually depicted on the Flood 

Insurance Rate Map as above the 500-year flood level of the primary source of 

flooding. C Zones tend to have local, shallow flooding problems. B and C Zones may 

have flooding that does not meet the criteria to be mapped as a Special Flood Hazard 

Area, especially ponding, localized drainage problems, and streams that drain smaller 

watersheds.

CRS is the abbreviation for Community Rating System, a voluntary program for 

National Flood Insurance Program-participating communities. The goals of the 

CRS are to reduce flood losses, facilitate accurate insurance rating, and promote 

the awareness of flood insurance. The CRS was developed to provide incentives for 

communities to go beyond the minimum floodplain management requirements to 
viii Reducing Damage from Localized Flooding: A Guide for Communities

Terminology

develop extra measures to protect them from flooding. The incentives are in the form 

of premium discounts.

Community means any city, village, town, county, or other local government with 

authority to enact floodplain management measures.

DFE is the acronym for design flood elevation, the specified level to which a structure 

will be protected from floods when it is built or retrofitted.

FEMA is the Federal Emergency Management Agency, the Emergency Preparedness 

and Response Directorate within the U.S. Department of Homeland Security. 

FIRM is the acronym for the Flood Insurance Rate Map, an official map approved 

by the Federal Emergency Management Agency and adopted by the community 

that delineates the Special Flood Hazard Area subject to the community’s floodplain 

management regulations and the insurance risk premium zones. 

Floodplain is used in a general sense to mean the area most prone to flooding, 

mapped or not. The floodplain for a localized flood problem may not be mapped as 

Special Flood Hazard Area on the Flood Insurance Rate Map.

Floodway means the stream channel and that portion of the adjacent floodplain that 

must remain open to permit passage of the base flood. The floodway is delineated on 

the Flood Insurance Rate Map or an accompanying Floodway Map and is subject to 

special development restrictions. 

Localized flooding refers to smaller scale flooding that can occur anywhere in a 

community. This can include flooding in B, C, and X Zones as depicted on the Flood 

Insurance Rate Map. The term is also used to refer to shallow flooding that occurs 

in low-lying areas after a heavy rain, flooding in small watersheds, ponding, and 

localized stormwater and drainage problems anywhere in the community. In this 

guide, “local flooding” and “localized flooding” are used interchangeably.

NFIP is the National Flood Insurance Program.

Repetitive loss refers to an NFIP-insured property where two or more claim payments 

of more than $1,000 have been paid within a 10-year period since 1978. About 20 to 

25 percent of repetitive loss properties are rated as being in B, C, or X Zones.

SFHA is the Special Flood Hazard Area, or the A and V Zones as depicted on the Flood 

Insurance Rate Map. B, C, and X Zones are outside of the SFHA.

Watershed means an area of any size that drains into a lake, stream, or other body of 

water; also known as “basin” or “catchment area.”

X Zone relates to newer Flood Insurance Rate Maps, which show B and C Zones (see 

above) as X Zone. The shaded X Zone corresponds to a B Zone and the unshaded X 

Zone corresponds to a C Zone.

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 1
Reducing Damage from Localized Flooding: A Guide for Communities

Introduction

This guide is intended to help local offices in cities, towns, villages, and counties in 

the United States understand what they can do to reduce the damage, disruption, and 

public and private costs that result from the shallow, localized flooding that occurs 

within their jurisdictions. This is flooding that all too often escapes the attention 

received by larger floods or those that are clearly mapped and subject to floodplain 

development regulations.

Part I of the document introduces the content and goals of the guide. It includes 

Chapters 1 and 2, which: 

Outline the purpose of the guide and how to use it;

Explain what is meant by local or localized flooding;

Lay out the scope of the localized flooding problem as it affects jurisdictions 

throughout the United States;

Give reasons why communities would want to deal with these types of flood 

problems; and

Explore how a community can get started to find and implement remedies 

for its localized flooding problems.

Part I:

Chapter 1. Background

Chapter 2. Localized Flooding

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Part I

Reducing Damage from Localized Flooding: A Guide for Communities 1-1

Background

Most cities, towns, villages, and counties in the United States have one or 

several clearly recognizable flood-prone areas, usually along a river or stream or 

other large body of water. These areas usually are identified as the Special Flood 

Hazard Area (SFHA) on the community’s Flood Insurance Rate Map (FIRM), 

which is provided to the community by the Federal Emergency Management 

Agency (FEMA) when it joins the National Flood Insurance Program (NFIP). 

These flood-prone areas are properly the subject of community, State, and Federal 

initiatives to minimize the flooding and its impacts. The NFIP and communities 

address these flood-prone areas through maps, floodplain management criteria, 

ordinances, and community assistance programs.

However, thousands of communities also have shallow, localized flooding problems 

outside of the SFHA resulting from ponding, poor drainage, inadequate storm 

sewers, clogged culverts or catch basins, sheet flow, obstructed drainageways, sewer 

backup, or overbank flooding from small streams. These kinds of flood events can 

occur anywhere in a community.

If these localized floods occurred infrequently, the problems would be minor. 

However, in some areas localized flooding can be chronic, so that over the years the 

cumulative damage and recurring disruption from localized flooding can be more 

than that caused by flooding on major rivers and streams. The costs of insuring 

buildings that are subject to this repeated damage add up as well.

Local and State officials confirm that localized flooding is a problem. They characterize 

it as “a drainage issue,” “low-level nuisance flooding,” and “headwater flooding.” 

According to one local official, citizens seem to present more complaints about 

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1-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 1. Background

repetitive localized flooding than about deeper, more destructive flooding from 

larger bodies of water.

A community’s floodplain management requirements in the SFHA will protect new 

construction from localized flooding. However, most communities do not have such 

regulations for development outside the SFHA, in areas mapped as B Zones, C Zones, 

or X Zones. If action is not taken, local flooding problems will likely increase over 

time as development in watersheds and in B, C, and X Zones continues without 

sufficient land use and building regulations.

The NFIP’s Interest

Flood insurance is available for all eligible buildings within a community that 

participates in the NFIP. However, the NFIP currently has no floodplain management 

criteria for B, C, and X Zones—those areas that lie outside of the SFHA—and no 

requirements for communities to take action to reduce or prevent losses in these areas. 

The result is significant financial losses for the NFIP, including the cost of insuring 

Photo by Michael Democker © 2003

The Times-Picayune Publishing Co., all rights reserved. Used with permission of the Times-Picayune, New Orleans, LA.

Flood water does not have to be deep to make a costly mess.
Reducing Damage from Localized Flooding: A Guide for Communities 1-3

Chapter 1. Background P A R T I

repetitive loss properties. Here are some statistics that 

show the cost of localized flooding to the NFIP: 

Since 1978 the NFIP has paid over $2.8 billion 

in claims in B, C, and X Zones.

Of that, $1.1 billion was paid for claims 

on repetitive loss properties. 

Between 20 percent and 25 percent of all 

repetitive loss properties are rated as being in B, 

C, and X Zones. 

In some communities, over half of the repetitive 

loss buildings are in B, C, and X Zones. 

About This Guide

Many State and local officials assert that their communities have put forth substantial 

effort to address localized flooding problems with much success. They say that, 

although flood mitigation is not always seen as a good use of funds in lower risk 

areas, communities would benefit from guidance on addressing localized flooding 

problems. They believe that information for both the property owner and local 

officials is important, and that both audiences need to understand the necessity for 

taking action and how reducing flood losses can benefit them and their communities 

in the long term.

This guide is a response to that expressed need. It is meant to help State and local 

officials understand what they can do to reduce the damage, disruption, and 

public and private costs that result from localized flooding that occurs within their 

jurisdictions. 

Accordingly, this document

Supports the premise that State officials, local officials, and residents can do 

something about localized flooding problems;

Focuses on building a community’s capability to minimize its existing 

localized flood problems and avoid future ones; and

Contains ideas and techniques that can work within the existing community 

framework. Nothing has to be reinvented unless the community wants to do 

so. 

This is not a technical manual; there are many excellent technical reference sources 

already available. Instead, this guide outlines the types of actions that can be taken, 

explains why they are important and what their potential benefits are, and points the 

reader in the direction of where to obtain more information and assistance.

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What is Localized Flooding?

In this guide, localized flooding refers to flooding 

outside the scope of criteria that apply to the 

SFHA as depicted on a community’s FIRM. This 

includes areas within and outside the B, C, and 

X Zones. Such floods are often referred to as:

stormwater flooding

nuisance flooding

flooding on small streams

carpet wetters

poor drainage

ponding

•

•

•

•

•

•
1-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 1. Background

How to Use the Guide

This guide is organized into four parts. 

The rest of Part I (Chapter 2) describes the problems that accompany localized 

flooding, gives reasons why communities would want to deal with these types of 

flood problems, and lists general actions that can be taken by the community.

The three parts that follow describe tools and techniques that can be used for different 

types of flood problems. The tools should be selected carefully; certain ideas work 

well in some situations but not in others. Many of the techniques are best applied 

on a small scale, perhaps building-by-building. 

Part II addresses techniques for coping with flooding that are appropriate for 

community-wide action, such as comprehensive planning, regulations, public 

education efforts, and warning systems.

Part III concentrates on the specific neighborhood or block where the flooding takes 

place. Techniques that are appropriate at this scale are described, including conducting 

an area-wide analysis, making improvements to the drainage system, or redeveloping 

flood-prone properties.

Part IV narrows the focus even further, offering techniques that can be used buildingby-building and by individual property owners to reduce potential flood damage 

or how to better cope with it when it does occur. These chapters cover retrofitting 

and flood insurance.

A set of appendices lists sources of technical assistance and advice, along with contact 

information and additional recommended reading.

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 2
Reducing Damage from Localized Flooding: A Guide for Communities 2-1

Localized Flooding 

Localized flood problems sometimes do not get the remedial attention they need, 

partly because they are not the subject of dramatic headlines or stories on the 

nightly news, and partly because they fall outside the scope of many local flood 

protection ordinances, which are geared toward the Special Flood Hazard Area 

(SFHA) depicted on the community’s Flood Insurance Rate Map (FIRM). 

However, as local officials, technical staff, and residents of those areas know, 

this flooding is a significant—and usually recurring—problem.

The Problem

Localized flooding can result from even minor storms. Runoff overloads the 

drainageways and flows into the streets and low-lying areas. Sewers back up; yards 

are inundated. Homes and businesses are flooded, especially basements and the lower 

part of first floors. Localized flooding poses most of the same problems caused by 

larger floods, but because it typically has an impact on fewer people and affects small 

areas, it tends to bring less State or Federal involvement such as funding, technical 

help, or disaster assistance. As a result, the community and the affected residents or 

business owners are left to cope with the problems on their own. Finally, flooding 

of this type tends to recur; small impacts accumulated over time can become major 

problems.

Safety Hazards

People are at risk even in shallow flooding. It is not unusual for children, especially, 

to drown after slipping in shallow water or to be swept into a ditch or storm drain. 

Even adults can be knocked down by just a few inches of moving water.

According to the National Weather Service, almost half of all flood fatalities occur in 

vehicles. Local storms can quickly fill underpasses and cover bridges, and even two 

feet of water can float most vehicles, including large ones. If the water is moving, 

2
2-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 2. Localized Flooding

vehicles can be swept away. Driving at night during a local flood can be especially 

hazardous. 

Emergency workers and other public employees who help in flood response and 

cleanup risk injury and even death themselves.

Water and electricity can lead to a dangerous situation, no matter how shallow the 

water. Damp electrical system components pose a shock hazard, as do the extra tools 

and appliances people use to clean up moist conditions. 

Health Concerns

In addition to the obvious risks of drowning and electrocution, there are many 

less well-known health problems that can be consequences of shallow flooding, 

particularly if it is recurrent. 

Damp conditions can trigger the growth of mold and mildew in flooded 

buildings, especially if the weather is warm and atmospheric humidity high. 

Molds contribute to allergies, asthma, and respiratory infections, especially in 

children, the elderly, and those with weakened immune systems.

Snakes and rodents are forced out of their natural habitat by flood waters and 

move into closer contact with people. 

Gasoline, pesticides, fuel oil, chemicals, and other substances can be brought 

into the area and into buildings by flood waters. They soak into the soil, 

building components, and furniture, and can result in long-term health 

problems.

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Village of Gurnee, Illinois

Children, as well as adults, often do not realize the danger of even shallow flood 

waters.
Reducing Damage from Localized Flooding: A Guide for Communities 2-3

Chapter 2. Localized Flooding P A R T I

Standing water and wet conditions are breeding 

grounds for mosquitoes, which are not only a 

nuisance but also can transmit encephalitis and 

West Nile Virus. 

Any flood experience is a strain on individuals 

and families. Over time, this stress can lead to 

anger, conflicts with others, inability to sleep, 

anxiety, hyperactivity, depression, withdrawal, 

or lethargy. 

The stress is intensified if there is a sense 

that the flood water will be back because the 

problem has not been solved. This can worsen 

pre-existing medical conditions and contribute 

to mental health problems.

Property Damage

Even a few inches of water in the basement or ground 

floor of a building can cause expensive damage. 

Carpeting, wallboard, insulation, mattresses, and 

upholstered furniture must be thrown out and replaced. 

Flooring, studs, and other wooden parts of the building 

must be thoroughly cleaned and dried. Business records, 

photographs, and other papers are often destroyed. 

Many owners find it cheaper to replace flooded 

furniture, cabinets, contents, machinery, equipment, 

and inventory than to try to salvage them. Since these 

areas often flood frequently, the cumulative damage 

can be significant.

Many property owners outside the SFHA do not have 

flood insurance. Property and contents damage from 

flooding is not covered under standard homeowners 

insurance policies. No amount of money can compensate for ruined keepsakes, 

photographs, or family heirlooms.

Even under non-flood conditions, there can be some structural damage if the soils have 

been saturated for a long period or repeatedly over time. Foundations can be gradually 

undermined, wood can rot, and masonry materials can become weakened.

Disruption

Flood waters can block streets, disrupt traffic patterns, and hinder access to homes 

and businesses. This can affect the entire community, not just those whose property 

is flooded. People have to evacuate wet and/or damaged homes, and businesses have 

to close. Cleanup and repairs take time away from normal routines, interrupting 

lives and business operations. These difficulties may be serious enough to close a 

business permanently. All these interruptions, even if short-lived, have ripple effects 

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Even Minimal Risk Zones 

Can Be Dangerous

In 1997, a series of intense thunderstorms 

in Fort Collins, Colorado, resulted in flooding 

throughout the city. The Johnson Mobile Home 

Park, located in an X Zone, was completely 

destroyed, and five of its residents died in the 

flood.

Indiana Department of Natural Resources 

Even shallow flooding results in a major cleanup and 

repair effort. A common approach to cleaning flooded 

wallboard is to cut and remove the lower 4 feet and 

replace those sections and the insulation.
2-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 2. Localized Flooding

throughout a community, its citizens, its commerce, 

and its economy. 

Costs to Local Government

Localized flooding can cause damage to public property, 

particularly if the flooding recurs periodically. Even 

though they are intended to withstand some abuse, 

sidewalks, streets and roads, benches, trash cans, fences, 

public buildings, signs, and other public property suffer 

additional wear and tear from flooding and will require 

repair, replacement, or repainting more frequently than 

normal.

Another cost of flooding is the diversion of local 

government staff and resources. Flood fighting, repairs 

to public buildings, extra trash collections, and cleanup 

of public property are all expenses that are borne by 

the public.

Impacts on the Community

In many instances, residents of the flooded areas complain to their local officials, 

wanting to know why the flooding happens and what is going to be done about it. 

Such dissatisfaction can even culminate in lawsuits against the local government for 

damage resulting from, for example, an undersized storm drainage system.

Areas that are flooded repeatedly show signs of deterioration. Buildings age 

before their time, and streets, sidewalks, and other infrastructure wear out sooner. 

Maintenance becomes harder to carry out. Property owners can be discouraged if 

flooding happens more than once or twice and begin to take shortcuts on some 

repairs, skip them altogether, or even move out and convert the building to a rental 

property, even if it has not been brought back up to its pre-damage condition. Some 

owners of repeatedly flooded properties walk away, letting the mortgage holders 

foreclose and resell or rent out the problem property. These approaches solve the 

current owner’s problem, but just pass the flooding threat on to others.

Repeatedly flooded areas become undesirable places in which to live or work. Property 

values decline and the community’s tax base is diminished.

Shallow stormwater flooding and drainage problems can have a ripple effect 

throughout the community’s economy, social fabric, environment, and quality of life. 

It is a good idea to step back from the situation, take a broad look at other community 

concerns or problems, and decide whether localized flooding is contributing to any 

of them. 

Are property values falling in some areas?

Has a once-attractive stream become a place to dump garbage?

Is the economy periodically disrupted?

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Legal Liability for Flood Problems

When individuals receive damage from flooding or erosion they often file lawsuits against 

governments, claiming that the government 

has caused the damage, contributed to it, or 

(in some instances) failed to prevent or provide 

adequate warnings of the hazard. Such lawsuits 

are expensive for governments not only because 

damage awards are growing but also because of 

attorney and expert witness fees... Courts have 

often held governmental units liable for inadequately maintaining or operating culverts, bridge 

crossings, channelization projects, and dams. 

Kusler (2004)
Reducing Damage from Localized Flooding: A Guide for Communities 2-5

Chapter 2. Localized Flooding P A R T I

Has the fishing declined? 

Have environmental conditions been degraded?

Are stream banks eroding and threatening homes or bridges?

Do more storm sewers need repairs?

All these seemingly unrelated issues may well be influencing, or be influenced by, a 

flooding problem. The advantage is that the solutions to the flood problem can be 

linked with solutions to other, perhaps more visible or popular, local concerns. They 

can even influence how well the community can sustain itself into the future.

What Can Be Done

Most of the time, the areas that receive shallow localized flooding are outside the 

community’s regulatory floodplain and thus are not subject to the zoning regulations 

and building standards that are in place in higher-risk areas. A community may feel 

that it can do only what the National Flood Insurance Program (NFIP) requires and 

that it has no regulatory jurisdiction or the power to enforce floodplain management 

requirements outside the SFHA. However, there are many examples of communities 

throughout the United States that have taken charge of their localized flooding 

problems instead of focusing solely on the SFHA and the minimum NFIP criteria. 

These communities have worked on their own to successfully resolve their localized 

flooding problems by tailoring solutions to their own needs, resources, and desires. 

The vital first step is for community officials and residents themselves to realize that 

they have a problem and that they can resolve it. 

Develop a Strategy

An organized approach is always best, and developing a strategy does not need to be 

a large undertaking. The community’s approach to resolving a localized flood problem 

can be a formal plan, such as a community hazard mitigation plan, or it can be a 

simple decision to take a couple of visible steps in the right direction. Whatever is 

decided, the strategy should address the real needs and desires of the community, 

or at least those of the neighborhoods with flood problems. As detailed in Chapter 

3 and Chapter 7, finding out what those concerns are lays the foundation for a plan 

that can be implemented successfully.

Coordinate with Other Concerns

A remedy for a flooding problem can also be a remedy for some other local concerns, 

and vice versa. Finding ways to combine solutions to these problems can be the key 

to simultaneously improving life in the community and alleviating flooding.

Does the community/neighborhood need a park? A low-lying area converted 

to public space could fulfill that purpose and also provide needed storage for 

stormwater to alleviate flooding of nearby homes or businesses.

Does the community/neighborhood need after-school activities for young 

people? Cleaning accumulated debris out of a stream channel and “adopting” 

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2-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 2. Localized Flooding

Orland Hills Solves its Flood Problems The Village of Orland Hills, Illinois, had a varied 

and widespread flooding and drainage problem that 

affected buildings, yards, and streets throughout 

town. Heavy rains caused water problems several 

times each year. 

The Village has a FIRM, but the mapped SFHA 

is relatively small and 82 percent is preserved as 

open space. The chronic flooding situations faced by 

Orland Hills residents were caused by local drainage 

problems. Regulating floodplain development and 

other traditional flood control approaches would not 

help. 

Accordingly, the Village created a Committee that 

prepared a Flood Protection Plan in 1995. It reviewed problems with maintenance of open ditches 

and detention basins. Many of the problems were 

preventable.

In some areas, weeds and brush have 

been allowed to grow. Rocks placed as rip 

rap on the banks have been moved to the 

channel bottom, apparently by children. 

Figure 2-1 shows where the rip rap has been 

moved to plug a detention basin inlet.

The worst problem in the channel is the 

condition of some of the culverts. As shown 

in the profiles, the culverts are so small 

that they act as dams even when clear. 

Over time, debris collects in them, rip rap is 

moved to block them, and they suffer from 

wear and tear. The pipes under 93rd Avenue have apparently separated, resulting 

in a hole in the overlying fill. Figure 2-2 

shows this culvert and the barricade that 

has been placed over the hole.

Flood Protection Plan, Village of Orland Hills, 

1995, pp. 2-6–2-7.

it can minimize flooding and provide an educational experience for middle 

and high school students.

Have residents or businesses in certain neighborhoods been asking for 

sidewalks? Combining the installation of this infrastructure with drainage 

works can make pedestrians safer and can also direct stormwater to a more 

appropriate location.

Has the downtown area been declining? If it is flood-prone, a project to 

mitigate the flooding could support revitalization efforts, and vice versa.

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Village of Orland Hills Figure 2-1

Village of Orland Hills Figure 2-2
Reducing Damage from Localized Flooding: A Guide for Communities 2-7

Chapter 2. Localized Flooding P A R T I

Village of Orland Hills Figure 2-3

The Plan identified storm sewer backup and yard 

drainage as major causes of the continuing problems. The Plan also noted that many of the problems were caused by the owners themselves:

Over the years, this drainage system 

has been disrupted. Many property owners are not aware of the need to keep their 

easements and swales open. They installed 

sheds, planters, railroad ties, or swimming 

pools in the easements. They built fences 

right on their lot lines to enclose the largest 

part of their properties. Figure 2-3 shows 

this process in one of the newest areas of 

Orland Hills. The low swale in the middle 

of the picture is being encroached upon by 

the new fences.

Early homes in Orland Hills, especially 

homes on crawlspaces, were built at the 

original ground level. Later home builders, 

especially for tri-levels, added fill around 

the lots. This provided positive drainage 

from the lot, protected the lower areas from 

drainage problems, and improved the appearance of the site. 

Now when it rains, the runoff goes 

downhill to the lowest point: the older 

buildings that did not backfill or raise 

their lots. Directing downspouts and sump 

pump discharge pipes toward the property 

line aggravates the problem. Often the first 

property developed becomes the recipient of 

runoff as later builders fill in their lots. An 

example of this is seen in Figure 2-4.

Village of Orland Hills Figure 2-4

The Flood Protection Plan recommended a range of 

activities that have since been implemented:

Tougher enforcement of easement restrictions;

Passage and enforcement of a stream-dumping ordinance;

Initiating a formal drainage maintenance 

program that inspects all ditches and storm 

sewers several times each year and after 

every heavy rain;

Small scale projects to correct local problems, including televising storm sewers and 

rehabilitating broken ones; 

Site visits to determine the causes of local 

flooding problems and to advise property owners about what they can do; and

A public information program that includes 

articles in the Village newsletter, annual letters to residents in problems areas, cable TV 

“crawlers,” and an annual public information 

campaign theme, such as “Don’t forget your 

drainage.”

Since these efforts were started, Village staff 

report that the number of flooding complaints has 

decreased dramatically. They noted that some 

easement and dumping violations were reported by 

neighbors, a sign that the public information activities were paying off.

In 1996, Orland Hills joined the NFIP Community 

Rating System (CRS). Village officials found CRS 

materials helpful in designing their program and the 

annual reporting requirements helpful reminders 

to keep their programs going. They note that there 

are more advantages to the CRS than the direct 

financial reward to the policyholders. Orland Hills is 

currently a CRS Class 5, one of the best in the nation, even though there are only 22 flood insurance 

policies in the Village.

•

•

•

•

•

•
2-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 2. Localized Flooding

Pick an Activity and Do It

Start with an action item listed in the plan or strategy 

that is easy, or inexpensive, or can be added on an 

existing activity. An early success will give people 

a sense of accomplishment and encourage moving 

on to the more difficult or complicated tasks. After 

that, priorities will have to be set by the community 

based on identification of the most visible problems 

and the resources that are available, as well as other 

factors. The area analysis process described in Chapter 

7 offers some ideas of the factors to be considered 

in setting priorities.

Any initiative will fall into one of the three general 

categories of approaches listed below. These are 

based on the scale of the area and number of people 

affected, going from broad to narrow. The rest of this 

guide is organized according to this scheme.

Organize community-wide activities (Part II of 

this guide) to make a broad impact and/or obtain 

wider support. This includes local planning and 

bolstering the capabilities of community staff 

(Chapter 3); and assessing regulations, mapping, 

building standards, zoning, and other techniques 

that apply to the whole community, even if there 

are different provisions for certain areas (Chapter 

4). Public awareness and education campaigns 

(Chapter 5) and flood warning systems and 

emergency services (Chapter 6) also are best 

handled at the community level.

Tackle each neighborhood problem area

individually (Part III). In many cases, several 

homes and/or businesses suffer flood problems 

for the same reason, whether it’s their location 

in a low-lying area or an inadequate storm 

drain or culvert. The local government will probably be the entity to carry 

out neighborhood-level projects or programs, but involving residents as 

much as possible is essential. The area analysis recommended in Chapter 7 

encompasses this idea. Neighborhood associations or even ad hoc groups of 

property owners can be a big help in spreading the word, developing ideas, 

and garnering citizen support for changes such as drainage improvements 

(Chapter 8) and even redevelopment (Chapter 9).

Deal with individual buildings. The flood risk to some flood-prone structures 

cannot be mitigated through a community-wide or neighborhood-level 

approach. These buildings need special attention to make them resistant 

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Solving Localized Flooding—

Value Added

Property and neighborhoods are preserved 

and often improved.

The lives of residents and emergency personnel are protected. Fewer floods mean 

fewer opportunities for injuries and accidents 

to occur.

The health of community residents is safeguarded; unhealthy and stressful situations 

are minimized. 

The economic viability of the community is 

maintained.

Disruption and economic losses from 

flooding are reduced or eliminated.

Business interruptions and permanent 

closures are minimized.

Public (local) costs of flood response 

and recovery are reduced or eliminated. 

Property values and the local tax base 

are preserved. 

Legal liability is minimized. 

Credit for certain activities can be obtained 

under the CRS, resulting in lower insurance 

premiums for all flood insurance policyholders in the community. Even policyholders 

outside the SFHA receive a 5 to 10 percent 

reduction in their premiums. 

Making progress, and especially participating in the CRS, provides both an incentive for 

more organized and permanent local floodplain management, stormwater drainage, 

public awareness, and other activities.

•

•

•

•

•

•

•

•

•

•

•
Reducing Damage from Localized Flooding: A Guide for Communities 2-9

Chapter 2. Localized Flooding P A R T I

to flooding. Another reason to work on a single-building basis is that 

convincing one property owner to take protective measures for his or her 

property may well induce others in the area to follow. Often people are 

hesitant because they don’t know what the finished product will look like 

or because they are unfamiliar with the problem or the techniques that can 

solve it. An individual success can induce others to take action and lead to a 

bigger project, if needed.

Part IV explains the best techniques to use on individual structures, namely, 

retrofitting (changing a building or part of it to make it more resistant to 

flood waters) in Chapter 10, and flood insurance, discussed in Chapter 11.

Join or Advance in the Community Rating System

Under the NFIP Community Rating System (CRS), a community receives a classification 

based upon credit points that are awarded for conducting activities to reduce flood 

losses, such as better mapping, stronger regulations, public information campaigns, 

flood damage reduction projects, and/or flood warning and preparedness programs. 

The credit points earn reductions in flood insurance premium payments for all NFIP 

policyholders in the community, even those outside the floodplain.

But participating in the CRS is not just about saving people money. Belonging to the 

CRS provides an incentive not only to start new flood mitigation activities, but also to 

keep them going. A CRS community must recertify each year that it is continuing the 

activities for which it receives credit. The recertification is a simple procedure, but it 

serves to keep local attention focused on the importance of these ongoing activities. 

Further, in the process of applying for the CRS, a community receives help on and 

feedback about parts of its flood reduction program, which improves staff expertise 

and generates new ideas. Some communities say that the CRS has changed the way 

their programs work, even without budget increases.

Because there are 10 levels (classes) in the CRS, even communities that already 

participate can benefit from undertaking additional flood-related activities. They will 

receive greater premium discounts and can take advantage of the expert assistance, 

information, and contact with other communities.

Where to Get Help

The Community Rating System Web site is http://training.fema.gov/

emiweb/CRS/.

The Web site of the Association of State Floodplain Managers (ASFPM) is 

http://www.floods.org.

Information on the NFIP can be viewed at http://www.fema.gov/nfip/.

Examples of how localities have solved flood problems can be found easily 

on the Web. Search for “mitigation success” or go to http://www.floods.

org/Publications/mitsuccstories/mssiii1.htm.

Additional resources are listed in Appendixes A and B.

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The CRS has made 

the Village think more 

proactively about 

stormwater management, 

instead of just waiting 

for the next big rain. 

— Gary Salavitch, Village of 

Hoffman Estates, Illinois
2-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I Chapter 2. Localized Flooding

The Community Rating System

The CRS rewards communities for what they are 

doing to reduce flood losses and also provides an 

incentive for new flood protection activities. The 

reward is a reduction in flood insurance premium 

rates. A community’s efforts are rated and identified by a CRS classification, with an accompanying 

discount on the annual premiums for policyholders 

in the community (see table below). 

Application. To apply, a community submits 

worksheet pages from the CRS Application that 

show what it is doing and that its activities earn 

at least 500 points. After the activities are verified through a field visit, The Federal Emergency 

Management Agency (FEMA) sets the credit to be 

granted and notifies the community, the State, and 

insurance companies of the rating.

Recertification. Each year the community must 

recertify that it is continuing to perform the activities that are being credited by the CRS, and submit 

documentation in the form of copies of projects 

conducted during the year, progress reports, and 

similar items. 

Community Responsibilities. A community in 

the CRS must:

Designate a CRS Coordinator;

Cooperate with the verification of its credited 

activities;

•

•

Continue to implement its activities, and 

certify each year that it is doing so, with appropriate documentation;

Advise FEMA of modifications to its activities; 

Address any identified repetitive loss issues;

Maintain elevation certificates, other permit 

records, and old FIRMs forever; and

Maintain other records of its activities until 

the next verification visit.

CRS Activities. The CRS credits a range of local 

(and State) activities that operate to reduce flood 

losses, promote flood insurance purchase, and 

facilitate accurate insurance rating. The four main 

categories and 18 creditable activities are listed in 

the box below.

Information. Technical assistance is available 

for communities applying for and participating 

in the CRS. No fees are charged for application, 

publications, or participation. The CRS Application,

the CRS Coordinator’s Manual, and all other CRS 

publications are free and can be obtained by 

calling 317-848-2898 or e-mailing NFIPCRS@iso.

com, or downloaded from http://training.fema.

gov/emiweb/CRS/.

•

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•

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•

Credit Points

CRS 

Class

Credit

SFHA*

NonSFHA*A99/AR 

Zones

4,500+ 1 45% 10% 10%

4,000 - 4,499 2 40% 10% 10%

3,500 - 3,999 3 35% 10% 10%

3,000 - 3,499 4 30% 10% 10%

2,500 - 2,999 5 25% 10% 10%

2,000 - 2,499 6 20% 10% 10%

1,500 - 1,999 7 15% 5% 5%

1,000 - 1,499 8 10% 5% 5%

500 - 999 9 5% 5% 5%

0 - 499 10 0 0 0%

CRS Classifications

* SFHA: the floodplain shown on the community’s FIRM.

CRS Activities

300 Public Information Activities

 310 Elevation Certificates

 320 Map Information Service

 330 Outreach Projects

 340 Hazard Disclosure

 350 Flood Protection Information

 360 Flood Protection Assistance

400 Mapping and Regulatory Activities

 410 Additional Flood Data

 420 Open Space Preservation

 430 Higher Regulatory Standards

 440 Flood Data Maintenance

 450 Stormwater Management

500 Flood Damage Reduction Activities

 510 Floodplain Management Planning

 520 Acquisition and Relocation

 530 Flood Protection

 540 Drainage System Maintenance

600 Flood Preparedness Activities

 610 Flood Warning Program

 620 Levee Safety

 630 Dam Safety

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 3
Reducing Damage from Localized Flooding: A Guide for Communities

Part II

CommunityLevel Tools and 

Techniques

The first part of this guide reviewed the problems created by localized flooding and 

the reasons why a community should take actions to protect people and property 

from the hazard. Chapter 2 noted that actions can be taken at three different levels: 

community-wide, neighborhood, and individual structures.

Part II addresses the broadest of these levels: techniques for coping with flooding 

that are appropriate for community-wide action. First, Part II describes a community 

planning process that will help determine and build support for appropriate flood 

mitigation activities. It will also meet the planning prerequisite for several Federal 

funding programs. Next, various regulations are discussed that a community can 

apply to its flood-prone areas. The usefulness and potential of public information 

campaigns and projects are presented. Finally, Part II explores what a community 

should do to improve its warnings for localized flooding, as well as its preparedness 

for a flood emergency.

Part II:

Chapter 3. Community-Level Activities

Chapter 4. Regulatory Tools

Chapter 5. Public Information and Awareness

Chapter 6. Warning and Emergency Service

Reducing Damage from Localized Flooding: A Guide for Communities 3-1

CommunityLevel Activities

This chapter reviews the three parts to organizing community-level activities: 

3

(1) determining an overall strategy, (2) preparing a more detailed plan, and 

(3) building capabilities to implement flood-protection actions. As used in this 

guide, a “community” is any city, village, town, county, or other local government 

with authority to enact floodplain management measures. 

The Strategy

A community should have an overall strategy that outlines how it will address its 

localized flooding problems. It may be as simple as doing nothing or funding drainage 

improvements in response to complaints. The more the community intends to do, 

the more involved the strategy must become. 

The Document

Many communities have unwritten strategies or strategies that change when leadership 

changes. To be effective, the strategy should be written. A written document provides 

a clear statement that will be consistent over time. It also shows how individual 

actions fit in the bigger picture. The best approach would be a document adopted 

by the governing board, such as a resolution.

A strategy or resolution can be as short as one page. No special format is needed, but 

it should recognize that there is a problem and identify the key policies and actions 

that will be pursued. An example is on pages 3-4 and 3-5. Circulating a draft for 

comments by the appropriate staff will help gain their support and ensure that the 

policies and actions are realistic.

Strategy Statements

Strategy statements will depend on the problems, resources, and the community’s 

level of commitment to take action. Examples include:
3-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 3. Community-Level Activities

All reports of localized flooding problems will be investigated by municipal 

engineering, utility, or public works staff to determine the cause and most 

appropriate solution.

New buildings constructed in flood problem areas must be protected to the 

highest recorded flood level, even if they are not in the Special Flood Hazard 

Area (SFHA) mapped on the community’s adopted Flood Insurance Rate Map 

(FIRM).

Land development regulations will be reviewed to determine if revisions 

would help prevent localized flooding problems or exacerbate existing 

problems in the future.

All residents in areas with localized flooding problems will be encouraged to 

purchase and maintain flood insurance.

All buildings will be constructed with positive drainage away from the 

building.

The rest of the chapters in this book can be used as a checklist to identify actions 

that can be pursued by the community and included in the strategy document. The 

more time spent reviewing what should be done, the more detailed the strategy can 

be. However, there comes a point at which the level of detail is sufficient for the 

community plan to be prepared, reviewed, and adopted. 

Long-Term Strategies 

Some communities have short-term and long-term strategies. Short-term strategies 

might include small-scale drainage modifications and encouraging people to buy 

flood insurance. The long-term strategy could be to prepare a flood mitigation plan 

that sets out a more comprehensive approach to the problem. 

A Community Plan

A community-level plan is more formal and detailed than a strategy statement. It 

summarizes the problem(s), sets goals, reviews alternative actions, and selects those 

actions that will best reduce the problem. It is a systematic and thorough review of 

what can be done. It should take more time and involve more people than a simple 

strategy.

Benefits 

A well-prepared plan will:

Ensure that all possible activities are reviewed and implemented so the local 

problem is addressed by the most appropriate and efficient solutions; 

Ensure that individual activities are coordinated with other community goals 

and activities, preventing conflicts and reducing the costs of implementing 

each activity;

Coordinate local activities with Federal, State, and regional programs;

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Reducing Damage from Localized Flooding: A Guide for Communities 3-3

Chapter 3. Community-Level Activities P A R T I I

The City of Conway, South Carolina, was severely flooded by Hurricane Floyd in September 

1999. The Waccamaw River and its tributaries 

flooded areas that were mapped as X Zones on 

the community’s FIRM. Acting quickly, before 

the waters receded, the City Council passed a 

resolution that spelled out its strategy:

All properties, including those not in the 

SFHA, would be inspected and subject to the 

same reconstruction requirements.

A mitigation plan would be prepared to identify a long-term solution.

Residents would be helped with information 

and financial assistance.

The resolution appears on the next two pages.

•

•

•

Educate residents on flood problems, flood 

insurance, and loss-reduction measures; 

Build public and political support for mitigation 

projects; and

Fulfill planning requirements for State or 

Federal mitigation grant funds.

The Process

Plans can come in a variety of formats and organizational 

styles. The format and organization of a plan is not 

important, but the process of planning is.

The planning process provides a framework within 

which planners, local officials, residents, engineers, 

technical experts, stakeholders, and others can work 

out the details and reach a consensus on what should 

be done. The process works for all types of plans, such 

as comprehensive plans, land use plans, capital improvement plans, neighborhood 

redevelopment plans, hazard mitigation plans, stormwater management plans, and 

floodplain management plans.

Planning Guidance

The Federal Emergency Management Agency (FEMA) has published various guidance 

documents over the years, and they all agree on four basic phases to developing a 

mitigation plan:

Organize for the effort and involve affected parties, especially the public;

Assess the hazard and the community’s exposure to damage by the hazard;

Set goals and review and select appropriate measures to reach those goals; 

and

Adopt, implement, evaluate, and revise the plan 

periodically.

There are four FEMA programs with planning criteria: 

the three major flood mitigation funding programs 

require a plan as an application prerequisite, and the 

Community Rating System (CRS) has credit criteria for 

floodplain management planning. The chart on page 3-6 

shows that the planning process the community uses 

can meet the prerequisites of all these programs. 

These programs have published guidance documents that are listed in the last section 

of this chapter. Furthermore, flood control assistance from the U.S. Army Corps 

of Engineers also has a floodplain management plan requirement. The Corps of 

Engineers’ guidance states that a plan that meets the CRS criteria under Floodplain 

Management Planning, Activity 510, will fulfill this requirement.

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1.

2.

3.

4. One planning effort can meet the community’s 

needs and meet the criteria of several different 

programs, including hazard mitigation grants, 

the CRS, the Natural Resources Conservation 

Service, and the Corps of Engineers’ project 

prerequisite. Planners should review the criteria of each program to ensure that their efforts 

will qualify for all the programs’ benefits.
3-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 3. Community-Level Activities

Resolution by the City of Conway, South Carolina, After 

Flooding from Hurricane Floyd in 1999

floodproofing and relocation) based on building 

conditions, the desires of the property owners, 

and funding sources that are available to assist 

the property owners; and

Assist residents with information on relocation 

and other flood protection measures and help 

them obtain financial assistance.

To implement this policy, be it hereby resolved that:

Every building that has been flooded must have 

an inspection by the Building Official or his duly 

authorized representative before it is repaired or 

reoccupied. If the level of damage is minor, the 

Building Official may issue a letter saying that 

clean up may proceed without a permit. There is 

no fee for such inspection or for the subsequent 

permit to repair or rebuild a flooded building.

A Mitigation Planning Committee is hereby established. Its members shall be:

(The City of Conway citizens’ names have been 

removed, but their representation on the committee 

is the following) 

Chair – banker, floodplain resident and former city manager

Vice-chair – floodplain resident

Floodplain resident

Floodplain resident

Floodplain resident

Council member, floodplain resident

Council member, floodplain resident

Director of Planning

Building official, floodplain resident

Floodplain resident

Grants/special projects coordinator

Floodplain resident

The Mitigation Planning Committee is charged 

with the following:

4.

1.

2.

3.

WHEREAS, properties along the Waccamaw River 

and its tributaries in the City of Conway have been 

severely flooded, are currently uninhabitable, and 

according to the best available information, may be 

substantially damaged;

WHEREAS, the floodplain ordinance of the City 

requires substantially damaged residences to be 

either elevated or demolished and either option can 

place a hardship upon the owners;

WHEREAS, the City Council has discussed various alternative ways to redevelop the area but none 

has yet been reviewed in depth and none has been 

based on full knowledge of the condition of the 

buildings or the desires or financial conditions of 

the owners; and

WHEREAS, several of the redevelopment alternatives reviewed to date may conflict with each other, 

may jeopardize the availability of flood insurance to 

residents, and/or may not be in the long term best 

interests of the residents or the community;

NOW, THEREFORE, BE IT RESOLVED by the City 

Council of the City of Conway that:

It is the policy of the City of Conway to:

Keep the City in good standing in the National 

Flood Insurance Program to ensure that all residents can obtain financial assistance and flood 

insurance to protect their properties from flood 

damage;

Not allow any reconstruction or reoccupation of 

flooded buildings or homes until the City Building Official or his duly authorized representative 

has inspected the site and issued a building 

permit;

Carefully develop a mitigation plan for the affected area after a review of all options (including flood control, reconstruction, elevation, 

1.

2.

3.

(continued on facing page)
Reducing Damage from Localized Flooding: A Guide for Communities 3-5

Chapter 3. Community-Level Activities P A R T I I

Building Capabilities

Once the strategy has been decided or the plan has been drafted, the community 

should prepare to implement it. A formal plan will identify who is responsible 

for each action item, when it will be accomplished, and what will be the source 

of funding. A strategy may not be so specific; however, certain activities should be 

pursued in a strategy.

Assign Staff Responsibilities

An activity identified in a strategy or an action item in a plan will not be implemented 

if no one is responsible for it. The strategy resolution or the mayor should designate 

offices or individual staff members as the lead for each activity. 

In most cases, the responsibility will be obvious: the public works department is 

responsible for drainage maintenance and the planner is responsible for plans. The 

discussion in the following chapters includes typical contacts and responsible offices 

for the various mitigation tools and techniques.

Collect data on building conditions, the desires of the property owners, and funding 

sources for reconstruction and redevelopment in the flooded area;

Recommend reconstruction and redevelopment policies and procedures to be 

followed by the City;

Identify particularly hard hit areas that 

could be designated as target areas appropriate for acquisition, clearance and 

conversion to open space;

Prepare a post-flood hazard mitigation plan 

for the City that designates target areas 

and recommends mitigation measures 

appropriate for the flood hazard facing the 

City; and

Keep the public informed of its deliberations and recommendations.

Upon the advice of the mitigation planning 

committee, the City Council may adopt a 

a.

b.

c.

d.

e.

4.

(continued from page 3-4)

moratorium to prohibit reconstruction of 

buildings in certain target areas until the 

mitigation plan is adopted.

Owners of property in the affected area are 

encouraged to:

Attend public meetings to review the City’s 

mitigation planning activities and recommendations;

Cooperate with the building inspectors in 

order to help determine the condition of 

their buildings and to collect accurate data 

as quickly as possible; and

Assist in the preparation of the mitigation 

plan by providing information on the condition of their buildings and whether they 

are interested in relocating to a flood free 

location.

Passed this 27th day of September 1999.

5.

a.

b.

c.
3-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 3. Community-Level Activities

FEMA 386-3 (2000, p. xi)

The planning requirements and processes that are used for FEMA programs and described in various guidance 

documents coincide as shown in this chart. It should be noted that a CRS publication, Example Plans, provides 

guidance that will meet all three programs’ criteria. It is available at http://training.fema.gov/emiweb/CRS/.
Reducing Damage from Localized Flooding: A Guide for Communities 3-7

Chapter 3. Community-Level Activities P A R T I I

Educate Staff

Although it may be obvious that the planner is responsible for plans, the community’s 

planner may not be familiar with flood mitigation planning. There are many 

publications and training programs, as well as references in this guide, that can help 

educate or train staff on flood protection tools and techniques.

Get Help

A community should not duplicate the efforts of others. Nor should it try to solve 

all its problems by itself. Other government agencies and private organizations may 

be implementing activities that can affect flooding in the community. Many agencies 

and organizations can provide:

Flood hazard data and maps; 

Technical information on flood mitigation tools and techniques; 

Guidance on regulatory requirements;

Advice and assistance in the planning effort;

Staff training;

Implementation of an activity; and/or 

Financial assistance.

The lists in Appendixes A and B give agencies, organizations, and other resources 

that can be consulted for help in planning and conducting local flood mitigation 

activities.

Help can also be hired. A community may turn to a consultant if it concludes that:

It does not have enough staff;

It does not want to hire staff for a short-term project; or 

It wants help from someone with specialized knowledge.

At the end of each chapter of this guide is a section called “Where to Get Help,” 

which lists relevant and helpful agencies and organizations. Those entities should be 

contacted for assistance or for information on qualified consultants who can help 

the community’s efforts. 

Integrate Activities

The best way to ensure that an activity will be implemented is to incorporate 

it into existing programs and activities. If staff members modify their work or 

accept assignments as part of their regular duties, the activity will become part of 

the community’s routine responsibilities. Integrating the flood protection tools 

and techniques into ongoing activities also reduces the financial impact on the 

community. 

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3-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 3. Community-Level Activities

A Planning Success Story

After a flood in 1990, Village officials of South 

Holland, Illinois, were faced with many angry 

residents who were convinced that the Village 

was not doing enough to protect them from 

flooding. The Village formed a Flood Liaison 

Committee so residents and staff would work 

together. 

The Committee spent a year preparing a 

floodplain management plan that reviewed all 

the alternatives and recommended 31 action 

items. The Village began providing technical 

assistance and a floodproofing rebate program 

that has helped fund 450 self-help retrofitting 

projects to protect homes from local flooding. 

Residents are now active participants in the 

Village mitigation program. South Holland has 

since received one of the highest ratings in the 

CRS (Class 5), has received state and national 

awards, and has played a lead role in the initiation of a watershed-wide flood and stormwater 

mitigation planning effort.

The Flood Liaison Committee still meets to 

provide oversight of the staff’s activities and to 

monitor, evaluate and recommend revisions to 

the plan.

Wetmore and Jamieson (1999)

The integration of activities is discussed in the 

chapters that follow. Examples include:

Modifying subdivision regulations to include 

stronger drainage and stormwater management 

standards, rather than adopting a new set of 

regulations;

Adding flood protection topics to water quality 

public information materials instead of creating 

and printing new brochures;

Coordinating park and open space planning 

with floodplain property acquisition efforts, 

using Federal mitigation funds to help expand 

recreation lands; and

Using experienced housing rehabilitation staff 

to provide retrofitting advice and/or administer 

retrofitting financial assistance funds.

Evaluate

A periodic review of activities included in the strategy or 

plan can be helpful. The community should determine if 

the activities are being implemented and, if so, whether 

they are effective. At the same time, the basis for the 

strategy or plan should be evaluated to determine if 

they are still relevant and whether new activities are 

needed.

Periodic monitoring, evaluating, and, if necessary, 

revising the activities recommended by a floodplain 

management or hazard mitigation plan are requirements of the FEMA planning 

programs. They are good measures to include in a strategy. 

Where to Get Help

FEMA’s Planning Resource Page at http://www.fema.gov/fima/planresource.

shtm.

Flood Mitigation Planning—The First Steps, Association of State Floodplain Managers 

(ASFPM), 2001, is a floodplain management planning kit consisting of 

reference materials, masters that can be duplicated for handouts, and a 2-part 

video that explains the 10-step process to the general public. It is designed 

to be shown at the first meeting of a planning committee. Order through the 

ASFPM Web site at http://www.floods.org or call 608-274-0123.

FEMA Regional Offices (see Appendix A).

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Reducing Damage from Localized Flooding: A Guide for Communities 3-9

Chapter 3. Community-Level Activities P A R T I I

State National Flood Insurance Program coordinating office and the State 

emergency management agency’s mitigation office can be located at http://

www.floods.org/StatePOCs/map.asp and http://www.fema.gov/fema/

statedr.shtm, respectively.

American Planning Association at http://www.planning.org.

The Insurance Services Office (ISO) administers the Community Rating 

System on behalf of FEMA. For technical assistance in preparing a floodplain 

management plan, contact NFIPCRS@ISO.com.

Publications and other information about the CRS, including its planning 

components, are available at http://training.fema.gov/emiweb/CRS/.

Regional planning commissions and councils of government often help 

communities with planning or prepare plans for them.

Training courses in floodplain management, flood insurance, the CRS, 

building protection, and other matters are offered by the Emergency 

Management Institute. Tuition is usually free to local government staff. The 

schedule and course descriptions can be found at http://www.fema.gov/

emi/.

If there is a State-level professional association for floodplain managers, 

wetlands managers, stormwater managers, or others, it can be a resource 

for technical training opportunities for local staff. Floodplain management 

associations can be found at http://www.floods.org/StatePOCs/stchoff.asp.

The State emergency management agency can be contacted for technical 

training schedules for local staff.

Three FEMA programs provide financial assistance for flood or hazard 

mitigation planning on a 75%/25% cost share: 

Flood Mitigation Assistance program (FMA)

Pre-Disaster Mitigation program (PDM)

In the PDM grant program, special consideration will be given to 

small and impoverished communities and they may be eligible for a 

90%/10% split.

Hazard Mitigation Grant Program (HMGP).

The State emergency management agency and the FEMA Regional Offices 

have more information about these funding programs. (Note that the Flood 

Insurance Reform Act of 2004 has a special provision under which the 

cost share for mitigating repetitive loss properties may be 90%/10%, but 

regulations to implement this change have not yet been finalized.)

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3-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 3. Community-Level Activities

Many States have prepared their own floodplain management or mitigation 

planning guidance. It is usually found at the State’s emergency management 

or National Flood Insurance Program (NFIP) coordinating office. The user 

should verify that the State guidance includes the latest criteria from the CRS 

Coordinator’s Manual and the Disaster Mitigation Act of 2000.

Additional resources are listed in Appendixes A and B.

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RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 4
Reducing Damage from Localized Flooding: A Guide for Communities 4-1

Regulatory Tools

In almost all cases, it is less expensive and less disruptive for a community to 

prevent flood problems from occurring than to mitigate problems that already 

exist. Regulatory tools can be designed to protect new buildings from flooding 

and to prevent new development from creating new or aggravating existing flood 

problems. The National Flood Insurance Program (NFIP) and its Community 

Rating System (CRS) are good starting points for reviewing regulatory tools.

4

To participate in the NFIP, communities are required to adopt and enforce regulations 

to manage new development in the Special Flood Hazard Area (SFHA) shown on the 

Flood Insurance Rate Map (FIRM). As noted in Chapter 2, significant damage can 

occur in the areas outside the SFHA in the B, C, and X Zones. 

To prevent new development from making its localized flood problems worse, a 

community needs to do more than just enforce its NFIP regulations. The many 

regulatory tools that help minimize flooding and flood damage are discussed under 

the five main sections of this chapter:

Adopting a map showing additional flood-prone areas to be regulated;

Planning and zoning for appropriate development in flood-prone areas;

Setting standards for new subdivisions; 

Setting standards for new buildings in flood-prone areas; and

Regulating site drainage.

A Regulatory Floodplain Map

The first step in managing new construction to protect it from flood damage is 

to determine what areas are subject to regulation. The NFIP has published the 

community’s FIRM, but this should be considered as only a beginning. The regulatory 

floodplain on the FIRM may not adequately identify all of a community’s at-risk 

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4-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 4. Regulatory Tools

areas. There are several reasons why some local flooding areas may be missing from 

the community’s FIRM. 

Smaller problem areas do not show up as SFHAs 

because Federal Emergency Management Agency 

(FEMA) mapping standards focus on larger flood 

problems, such as watersheds larger than 1 square 

mile.

Conditions may have changed since the study was 

conducted to produce the FIRM, which could have 

been as long as 10 or 20 years ago.

When the FIRM was prepared, an area may not 

have been known to have a flood problem or it 

may not have had much development activity, so it 

was not studied.

The study criteria may not have reflected all types 

of flood-related hazards, such as land subsidence.

In short, FIRMs cannot be expected to show every flooding problem in the community, 

especially flooding caused by local drainage or storm sewer problems. However, 

because these problems are more frequent than the major flooding shown on the 

FIRM, and because the drainage or sewer system is a local responsibility, it is likely 

that the community has additional information that could be used to supplement 

the FIRM’s presentation of the community’s flood hazard. 

Communities can do much to provide a better floodplain map and regulatory data. 

This section explains four valuable options for improvement:

Use more accurate elevation contour information to map flood elevations 

provided with the FIRM;

Restudy local flood-prone areas and produce a new regulatory floodplain 

map;

Require permit applicants to provide needed flood data; and

Develop new flood hazard maps and data using more exacting study 

techniques.

More Accurate Contour Map

When a community’s FIRM is prepared, the study contractor uses the best base map 

available at that time. In many cases, it could be a U.S. Geological Survey quadrangle 

map with a 5- or 10-foot contour interval. Since their FIRMs were prepared, many 

communities have developed geographic information systems (GIS), often with more 

recent and more accurate elevation data.

A community should check to see if there is a new base map with more accurate 

topography. This could be the product of recent surveying, analysis of ortho-rectified 

aerial photos, or light detection and ranging (LIDAR) (the use of an airborne laser 

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1.

2.

3.

4.

In Activity 410 (Additional Flood 

Data), the CRS encourages and 

provides credit for several mapping activities:

Providing regulatory flood elevations in X and 

approximate A Zones;

Restudying and remapping areas shown on 

the FIRM;

Requiring developers to produce regulatory 

flood elevations in smaller watersheds; and 

Studying hydrology based on future watershed conditions.

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Reducing Damage from Localized Flooding: A Guide for Communities 4-3

Chapter 4. Regulatory Tools P A R T I I

system to prepare topographic maps). Such a base map 

may have recently constructed roads, bridges, and other 

human-made features, 1- or 2-foot contour intervals, 

or contour information that is more accurate or more 

recent than that used to prepare the FIRM. 

If there is a more accurate and more recent contour map, 

the 100-year flood elevations from the Flood Insurance 

Study’s flood profile should be plotted on it. Such an 

exercise may well reveal that the boundaries of the SFHA 

should be different. Gurnee, Illinois, found this to be 

true, as depicted in the adjacent map.

Many times, such a review finds that the FIRM 

understates the true inundated area and the SFHA 

should be extended into the X Zone. If this is the 

case, it is recommended that the community adopt 

this more accurate map in its floodplain management 

regulations. 

Another approach is to record the high-water marks and 

note the areas flooded if a recent flood extended outside 

the boundaries of the SFHA. That is what the City of 

Conway, South Carolina, did after Hurricane Floyd sent 

the Waccamaw River flooding into its X Zone in 1999. 

The city adopted the area flooded by Floyd as its new 

regulatory floodplain (see page 4-5).

A third approach to capture more of the flood-prone 

areas is to regulate the mapped floodplain plus all 

areas 1 foot higher than the base flood elevation 

(BFE). Development on properties outside the SFHA, 

but within 1 foot of the BFE, would need a floodplain 

permit. If the developer produces accurate ground 

elevation data that show the building site above the BFE, 

the floodplain regulations would not apply. 

A variation on this approach is to regulate to the next 

higher contour line. For example, a site located between 

a BFE of 145 and one of 146 would be mapped at the 

146 contour line. A disadvantage of this method is that 

elevations are not increased by a constant amount (for 

example, 145.1 and 145.9 both round to 146). 

New Flood Study

Using more recent or more accurate elevation data is 

a relatively inexpensive way to get a better flood map 

from existing flood data. Another approach to getting 

a new floodplain map is to conduct a new flood study 

Gurnee, Illinois, put its FIRM flood elevations 

onto a more accurate base map and found these 

differences, identifying other areas that could be 

susceptible to flooding.

New Maps vs. FIRM

Adoption of a different map in the local ordinance is allowed by the NFIP regulations, 

provided the new map covers a larger floodplain 

than the FIRM does. In fact, exceeding the NFIP 

minimum criteria is encouraged by FEMA. However, two things should be noted: 

The community’s map will not affect the current FIRM or alter the SFHA used for setting insurance rates or making map determinations.

Under 44 Code of Federal Regulations 65.3, 

as “soon as practicable, but not later than 

six months after the date such information 

becomes available, a community shall notify 

[FEMA] of the changes by submitting technical 

or scientific data....” The State NFIP Coordinator or the FEMA Regional Office should be 

contacted for instructions on how this is done 

(see contact list in Appendix A).

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4-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 4. Regulatory Tools

to produce new flood data. The new study could either cover the same area mapped 

as SFHA on the FIRM or areas outside the SFHA that have been known to flood or 

have repetitive flood problems.

In the SFHA, the community’s new study must use the same or similar study 

techniques as for a detailed study on a FIRM. These techniques can be expensive, but 

the study may help with activities other than regulations. As noted in Chapters 8 and 

10, a new flood study and watershed model can help greatly when planning drainage 

modifications or selecting a design protection level for a retrofitting project.

Typically, FIRMs do not include the floodplains of streams with a drainage area of 

less than 1.0 square mile in urban areas and even larger drainage areas in rural areas. 

Therefore, if there is a localized flood problem that should be mapped in order to 

guide development regulations, the area will most likely have to be studied by the 

community.

If the area is outside the SFHA, the community can use any technique it prefers. Areas 

not previously studied have no minimum standards. Probably the least-expensive 

approach is to use the flood of record, i.e., to map out the areas that were under 

water during the highest recorded flood. Communities that use this approach usually 

add a safety margin of a foot or two to the flood-of-record’s crest as the basis for a 

regulatory flood elevation. 

It should be noted that using historical floods does not necessarily treat everyone the 

same. In some areas, the historical flood of record may be the 100-year flood, but 

in other parts of a community, it may be the 25-year flood. It is especially difficult 

to be consistent when some areas were developed in the last 10–20 years, so there 

is a relatively short history of known flood problems. 

FEMA encourages a community to provide more 

accurate flood data to revise its FIRM. In fact, the 

Cooperating Technical Partners (CTP) program is a 

formal mechanism through which communities can 

cooperate on new flood studies or provide flood data 

that may differ from FEMA mapping criteria.

FEMA is working to prepare more new flood studies. 

Its Map Modernization Program has a goal of helping 

all communities update their FIRMs by the year 2008. 

Congress is allocating significant additional funding for 

these efforts. In other words, under the CTP program, 

FEMA wants to work more closely with communities 

to better delineate their flood hazard areas, and under 

Map Modernization, FEMA is expected to be able to 

increase its new study effort. 

FEMA has also provided guidance and developed 

software to facilitate flood studies and reduce their cost. 

Managing Floodplain Development in Approximate Zone A Areas can 

be ordered from FEMA or downloaded from its Web 

Cooperating Technical Partners

In conjunction with the Map Modernization 

Program, FEMA establishes partnerships with 

participating NFIP communities to collaborate in maintaining up-to-date flood maps and 

other flood hazard information through the CTP 

program. Under the CTP program, a community 

and FEMA work as partners to more efficiently 

and effectively update flood hazard maps. This 

ensures that local knowledge about flood problems, local sources of data, and local preferences for study priorities are all incorporated into 

the process. The CTP program brings funding 

for eligible activities, such as topographic data 

generation, hydrologic and hydraulic analyses, 

Digital FIRM (DFIRM) creation, and others. More 

information can be found at FEMA’s Web site at 

http://www.fema.gov/fhm/ctp_main.shtm.
Reducing Damage from Localized Flooding: A Guide for Communities 4-5

Chapter 4. Regulatory Tools P A R T I I

Conway Remaps after Floyd

Hurricane Floyd flooded places in the City of Conway, South Carolina, that were outside the mapped 

SFHA of the Waccamaw River and its tributaries. 

The map below shows that many properties in the 

X Zone were flooded with water over 2 feet deep. 

Many flooded property owners did not have flood 

insurance because they were not in the designated 

SFHA.

Conway reviewed the discharges and elevations 

from past floods. The chart below summarizes 

these data, showing that the Hurricane Floyd flood 

in 1999 had practically the same discharge as the 

100-year or base flood used for the city’s FIRM. 

However, the elevation of the flood was 11⁄2 feet 

higher. There had also been a flood in 1928 with 

the same discharge and elevation as in 1999.

* Property where the 1999 flood was over 2 feet on 

the outside wall of the building.

V Properties with a “V” and no address are vacant.

Waccamaw River at Conway

 

Date of Crest 

Estimated

Peak Discharge 

(cubic feet/

second) 

Elevation

(NGVD)*

(feet)

October 1924 15,400 10.45

September 1928 22,000 12.75

September 1945 15,500 10.55

March 1959 8,800 7.75

July 1961 9,600 8.05

February 1973 9,900 8.35

December 1994 8,630 8.00

September 1996 12,000 9.15

February 1998 14,800 9.60

September 1999 22,400 12.55

Base Flood 

(modeled) 22,310 11.10

* National Geodetic Vertical Datum

Conway opted to use the Hurricane Floyd 

flood elevations for its floodplain management 

regulations. The area affected by Floyd became 

the regulatory floodplain. The city subsequently 

requested a revision to its FIRM in order to 

allow the flooded properties to become eligible 

for mitigation funding assistance and to inform 

future purchasers of property of the true flood 

hazard.

Flood Hazard Mitigation Plan,

City of Conway, South Carolina (2000)
4-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 4. Regulatory Tools

site. It includes instructions on using the Quick-2 program, which can help calculate 

a BFE without conducting an expensive on-site flood study.

Permit Requirements

The greatest obstacle to preparing a new flood study is the cost. There is a rationale 

that says that if someone wants to build in a flood-prone area, he or she should bear 

all the costs of developing there, including paying for any needed flood data. The 

NFIP requires that in approximate A Zones (mapped floodplains where FEMA did 

not provide a flood elevation), anyone who develops more than 50 lots or 5 acres 

must provide the needed data.

This rationale is appropriate in all flood-prone areas for all sizes of development. 

Some communities require developers to:

Identify all streams and watercourses that flow 

through or adjacent to the property;

Determine the size of the contributing drainage 

area; and 

If the drainage area exceeds a certain threshold, 

provide the BFE (and in some cases delineate a 

floodway).

An example of this approach is the City of Tulsa, 

Oklahoma. Tulsa requires all development in drainage 

areas as small as 40 acres to conduct a study to show 

the 100-year floodplain and floodway. All areas smaller 

than 40 acres must have a combination of storm sewer 

and overland drainage so that a 100-year storm will not 

cause any building to flood. 

In Prince George’s County, Maryland, developers are 

required to delineate the floodplain for streams that 

drain 25 acres or more. This approach can also be used 

if the community has identified flood-prone areas 

of concern, such as those that have been repetitively 

flooded in the past. If such areas are delineated based on 

available historical data, developers could be required to conduct a study to produce 

a regulatory flood elevation before they are permitted to build there. 

Study Standards

Although the FIRM floodplain boundaries are the regulatory boundaries initially 

provided by FEMA, communities can consider using higher standards when mapping 

a flood-prone area. This would apply to any of the previous conditions: restudying an 

existing SFHA, preparing a new study, or requiring developers to prepare regulatory 

flood data. (Note that a community should modify its ordinance to have the authority 

to require that these higher study standards be used.) 

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Lake County, Illinois, regulates many flood 

problem areas outside the SFHA shown on its 

FIRM. These include:

“Flood table lands,” areas within 2 feet of 

elevation of a floodplain for a stream that 

drains more than 100 acres;

Depressional storage areas with a storage 

volume of 0.75 acre-feet or more for the base 

flood; and

Non-riverine depressional floodplains and 

wetlands of any size.

Permit applicants must have an engineer calculate the BFE in these areas. In non-riverine 

areas, the historic flood-of-record elevation plus 

3 feet can be used instead of conducting the 

detailed study. The full language of the county’s 

Watershed Development Ordinance can be 

found at http://www.co.lake.il.us/smc/regulatory/wdo/.

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Reducing Damage from Localized Flooding: A Guide for Communities 4-7

Chapter 4. Regulatory Tools P A R T I I

The most common higher study standard is known as future-conditions hydrology. 

Under FEMA mapping standards, the flood elevations on FIRMs are based on land 

use conditions existing at the time of the study (which may have been a decade or 

more in the past). If significant development occurs in the watershed, the hydrology 

(i.e., how much water comes from the watershed) will be outdated and will likely 

understate the true flood hazard. 

To prevent studies from becoming outdated as new development alters the 

watershed and the hydrology, communities can take two approaches: (1) require 

that new developments in the watershed include storage basins to store the excess 

stormwater, or (2) conduct studies that are based on future watershed conditions. 

Many communities use both approaches. Stormwater storage basins are discussed 

on page 4-14.

Mapping based on future watershed conditions is especially useful where a community 

does not have regulatory authority over the watersheds outside its corporate limits. 

One of two common approaches is used:

Assume that the watershed is developed according to a long-range land use 

plan; or

Assume that runoff comes from a fully urbanized watershed.

Future-conditions hydrology and other higher standards will usually result in larger 

floodplains and higher flood elevations than are shown on the FIRM. Using such 

data has several benefits:

New construction will be better protected against flood damage;

There will be fewer requests for FIRM revisions; 

Flood insurance rates will be lower for new buildings as a result of higher 

standards; and

The community can receive CRS credit. 

Land Use Regulations

Once the flood-prone areas are shown on a community-adopted map, the community 

can use several techniques to prevent new development in those areas from being 

subject to flood damage and from aggravating existing flood problem(s). Three 

general approaches are covered in the rest of this chapter:

Land use regulations to guide development away from the flood-prone areas;

Regulations on new infrastructure, such as drainage systems; and

Regulations on construction of individual buildings.

There are two basic tools to regulate the use of land: a land use plan and a zoning 

ordinance. These tools designate where low-, medium-, and high-density residential 

development and industrial and commercial development should go. These tools are 

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Anne Arundel County, 

Maryland, has a “48-

inch pipe rule,” which 

requires that the 100-year 

floodplain be delineated 

for a stream if a 10-

year ultimate land use 

discharge cannot be 

conveyed within a 48-

inch reinforced concrete 

pipe at the natural 

ground slope.

Anne Arundel 

County, Maryland,

 Floodplain Ordinance
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used early in the development process, and they should require or at least encourage 

development to avoid flood-prone areas.

Planning and zoning regulations should allow only those land uses that are compatible 

with the natural conditions of the land. For example, in areas where there is no 

infrastructure for sanitary sewers, the regulations should specify a lot size large enough 

for the soil type to accommodate the drain field needed for a septic system.

Use of the land should be tailored to match the land’s hazards, such as reserving floodprone areas for parks, greenways, golf courses, backyards, wildlife refuges, wetlands, 

natural areas, resource conservation areas, or similar compatible uses. Planning and 

zoning regulations should allow developers flexibility to arrange improvements on a 

parcel of land so they can reach their development objectives and avoid the hazardous 

areas at the same time. One way to do this is through the planned unit development 

(PUD) approach discussed on page 4-10.

Plans

Most communities use comprehensive plans or land use plans to guide future 

development. Although it usually has limited authority, the plan sets out what the 

community would like to see happen. It guides other local measures, such as capital 

improvement programs, zoning ordinances, and subdivision regulations.

Plans can reduce future property damage by specifying land uses of open space or low 

density development within areas known to be flood-prone. Unfortunately, flooding 

or other natural hazards are not always considered when many communities prepare 

their plans. But in more and more instances, community plans call for reserving floodprone areas as open space. One example is St. Charles, Illinois (see facing page).

A capital improvement plan will guide a community’s major public expenditures for 

5 to 20 years. Capital expenditures may include flood control projects and drainage 

modifications; acquisition of open space in flood problem areas; and extension (or 

withholding) of sewers, water lines, and other public services into flood-prone 

areas.

Zoning

A zoning ordinance regulates development by dividing a community into zones 

or districts and setting development criteria for each zone or district. Zoning is the 

primary tool for implementing a comprehensive plan’s guidelines for how land should 

be developed. Zoning ordinances can limit development in flood-prone areas, such 

as reserving the SFHA for agricultural uses. 

A zoning ordinance can also require larger lots or lower densities in areas with 

flooding, poor soils, or known drainage problems. This requirement helps to ensure 

that the builder can locate a suitable place on the lot for the structure and reduces 

the total number of people who will be exposed to the hazard. 

On large lots, a lower percentage of the area will have impervious surfaces, and it 

will be easier to preserve natural storage depressions.

As a rule of thumb... 

wetlands, floodplains, 

and slopes... take first 

priority for inclusion 

in the designated 

open space, as they 

represent highly sensitive 

environmental resources 

that are generally 

considered to be 

unbuildable in a legal 

sense, in a practical 

sense, or for reasons of 

common sense. 

 Arendt (1996)
Reducing Damage from Localized Flooding: A Guide for Communities 4-9

Chapter 4. Regulatory Tools P A R T I I

St. Charles’ Comprehensive Plan

The Comprehensive Plan of the City of St. Charles, 

Illinois, was adopted in 1996. Three chapters are 

devoted to natural development factors: geological 

conditions, hydrological conditions, and open space. 

The introduction to this section states:

Many of today’s environmental problems result either from past ignorance of 

the impact of man’s actions or insufficient 

attention to the importance of natural 

systems.... An understanding of this information will enable the community to build 

and maintain a harmony between development and nature. 

Comprehensive Plan, page 5-2.

The plan recommends that permit applications 

be required to include a soil survey and development proposals be reviewed by the Soil and Water 

Conservation District for their impact on natural 

features. 

The chapter on hydrological conditions notes that 

“One of the best ways to prevent losses from flood 

damage is to protect floodplains from development” 

(page 6-6). It then describes the beneficial uses of 

floodplains, such as outdoor recreation, wildlife habitat, and scenic beauty enhancement. This chapter 

includes a map showing all the lots and floodplains 

in the city.

The chapter on open space and recreation builds 

on this goal to preserve floodplains. It identifies the 

benefits of preserving and restoring natural areas 

and the special attention that should be paid to the 

Fox River waterfront. There is also a section on continuity of open space, which recommends corridors 

to protect linear features (like streams) and to link 

parks and other sites. Pursuing these concerns not 

only makes for a more pleasant and safe environment to live in, it also enhances the city’s image 

and character.

All of these concerns come together in one of the 

most important parts of the Plan, the Future Land 

Use Map. As seen in the excerpt below, the city 

intends to overlap the green open space areas with 

the blue watercourses and their floodplains.
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An increasing number of communities have adopted the 

PUD approach. The PUD approach allows adjustment 

of site design standards and land use densities to 

preserve open space and/or flood-prone areas from 

development. In return, the developer is allowed to have 

a higher density in the flood-free area (see example on 

facing page). 

Standards for Subdivisions

Although land use plans and zoning ordinances can help 

steer development away from flood-prone areas, some 

development inevitably will occur in those places. This 

guide recommends that communities use two types of 

regulations for such development: (1) ensure that the infrastructure is free from flood 

damage and does not aggravate flooding, and (2) ensure that individual buildings 

are protected from flood damage. 

“Infrastructure” is a term that encompasses the public works and utilities that serve 

development. These include the streets, water lines, drainage system, storm and 

sanitary sewers, and subdivision layout. The standards recommended here usually 

would be incorporated into the community’s subdivision regulations. Four provisions 

of subdivision regulations are reviewed in this section:

Designing subdivision layouts to keep infrastructure and buildings out of 

flood problem areas;

Setting buildings back from the source of flooding through buffers;

Controlling stormwater runoff; and

Incorporating the “green infrastructure” approach.

Subdivision Layout

Zoning ordinances dictate the density of development in each zoning category (for 

example, a zone of R2 may require a minimum lot size of 0.5 acre). Typically, a 

developer will divide the parcel evenly, so that a 10-acre parcel will have 20 evenly 

spaced half-acre lots. The concept of PUD is illustrated on the following page. 

Subdivision developers should always be encouraged to vary from the traditional 

approaches if by doing so they can avoid building in the flood-prone areas.

Cluster development is an attractive redevelopment option for developers because 

the cost of land clearance, site preparation, and infrastructure is reduced. Sometimes, 

the community will allow higher densities than permitted under the regular zoning 

district as an incentive to keep new construction out of flood-prone areas.

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In Activities 420 and 430LD

(Open Space Preservation and 

Land Development Criteria), the 

CRS encourages and provides 

credit for:

Regulations that preserve floodplains as 

open space;

Regulations that encourage developers to 

set aside floodplains from development; and

Floodplains zoned for lower density development (less than one building per acre).

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Reducing Damage from Localized Flooding: A Guide for Communities 4-11

Chapter 4. Regulatory Tools P A R T I I

PUD: In the standard zoning approach (left), the 

developer considers six equally-sized lots without 

regard for the flood hazard. Two properties are subBuffers 

If the subdivision layout does not keep entire lots out 

of the flood-prone area, buffers can help minimize 

the amount of development exposed to flooding. 

Buffers require certain areas to be kept open and free 

of development. 

A buffer is typically a setback of a specific distance, such 

as 25 or 100 feet, from a channel, floodway, wetland, 

or other water feature. In that area, no cutting, clearing 

of ground cover, or alteration of the natural features is 

allowed, but the rest of the lot can be regraded and built 

on. In the State of Maryland, for example, a 25-foot 

buffer is required next to all wetlands. 

Under such a restriction, buffers help:

Preserve the natural habitat adjacent to the 

water;

Improve the visual appearance of the waterway;

Reduce the potential for disruption or erosion of channel banks; and

Filter runoff to the stream, improving water quality.

Buffers are also a best management practice (BMP) recognized under the National 

Pollutant Discharge Elimination System (NPDES). For further information on NPDES, 

see page 8-5.

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Lake County, Illinois, Stormwater Management Commission

Buffers protect natural areas and filter runoff into 

streams and ponds. They have a spin-off benefit of 

keeping buildings away from sources of floodwater.

ject to flooding and the natural stream is disrupted. On 

the right is an alternative, flexible, PUD approach. The 

floodplain is dedicated as public open space. There are 

seven smaller lots, but 

those abutting the floodplain have the advantage 

of being adjacent to a 

larger open area. Four 

lots have riverfront views 

instead of two. These 

amenities compensate 

for the smaller lot sizes, 

so the parcels are valued 

the same. The developer 

makes the same or more 

income, and the future 

residents are safer.
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Buffers Help Manage Stormwater and Protect Wetlands

The south suburbs of the Chicago area are subject to several types of flood problems. The South Suburban 

Mayors and Managers Association initiated a South Suburban Stormwater Strategy to develop programs to 

reduce the area’s exposure to localized flooding. One of the resulting projects was a model ordinance that 

combined floodplain management, stormwater management, and wetlands protection measures. Section 

11 of the Model Stormwater and Floodplain Management Ordinance of the South Suburban Mayors and 

Managers Association has the following buffer language:

11.1. Buffer Areas Required. Buffer areas shall be required along all streams, lakes, waterways, channels 

and wetlands, except for the following:

(a) Roadside ditches; 

(b) Existing excavated stormwater storage facilities; 

(c) Borrow pits and quarries; 

(d) Leveed waterways; and 

(e) Improvements to existing public roads and utilities.

11.2. Buffer Area Dimensions

11.2.1. Linear Buffers. Linear buffers shall be designated along both sides of all streams and natural 

channels. A minimum buffer of thirty feet on each side of the channel shall be provided.

11.2.2. Water Body Buffers. Water body buffers shall encompass all lakes, wetlands and other non-linear 

bodies of water. A minimum buffer of thirty feet on each side of the channel shall be provided.

11.2.3. Exceptional functional value wetlands shall have a minimum buffer of one hundred (100) feet.

11.2.4. In areas having State or Federal threatened and endangered species present or for Illinois Natural Area Inventory Sites, buffer widths may be modified to meet the terms and conditions specified during consultation with the Illinois Department of Natural Resources (DNR) or United States 

Fish and Wildlife Service, pursuant to State and Federal laws and regulations.

11.2.5. The buffer area for all Waters of the United States shall extend from the ordinary high water 

mark. The buffer area for wetlands shall extend from the edge of the delineated wetland. A property may contain a buffer area that originates from the Waters of the United States on another 

property.

11.2.6. Buffer averaging may be allowed by the [title of permit official], provided the buffer width is at 

least half of the buffer width required by this ordinance or the minimum width required by a Corps 

of Engineers permit, whichever is wider.

11.3. Buffer Requirements

11.3.1. Features of the stormwater management system may be within the buffer area of a development.

11.3.2. Access through buffer areas shall be provided, when necessary, for maintenance purposes. 

11.3.3. Preservation of buffer areas shall be provided by deed or plat restriction.

11.4. Allowed Uses in Buffer Areas

11.4.1. All buffer areas shall be maintained free from development except for the following uses:

(a) Passive recreation, including pedestrian, bicycle, or equestrian trails. 

(b) Construction and maintenance of utilities and stormwater facilities.

11.4.2. Structures and impervious surfaces related to recreational facilities, such as trails and paths, 

may occupy a maximum of twenty (20) percent of the buffer surface area, provided the runoff 

from such facilities is diverted away from the Waters of the United States or such runoff is 

directed to enter the buffer area as unconcentrated flow. Boat docks, boathouses and piers shall 

be allowed and count as a structure when calculating percent of impervious area.

11.4.3. Buffer areas hydrologically disturbed by allowing construction or as part of a revegetation plan 

shall be revegetated using the Native Plant Guide for Streams and Stormwater Facilities in Northeastern Illinois, (NRCS, et al.) as a minimum standard.
Reducing Damage from Localized Flooding: A Guide for Communities 4-13

Chapter 4. Regulatory Tools P A R T I I

Example buffer regulations are on the facing page.

Enforcing buffer requirements is very important. Although many communities 

have excellent enforcement programs while construction is taking place, it must be 

remembered that permanent buffers and easements need to be established and kept 

open forever. Many property owners are not aware that 10 years after the house has 

been built, they still cannot build a shed in the easement or chop down trees in the 

buffer area.

Stormwater Management

Development activities outside the flood-prone area can significantly affect drainage 

and flooding. Stormwater runoff is increased when natural ground cover is replaced 

by urban development. To protect properties from runoff, developers “improve” 

the local drainage system by putting parts of it underground in storm sewers and 

building ditches to carry larger surface flows.

This combination of increased runoff and drainage system modifications may increase 

flooding, overload the downstream drainage system, cause erosion, and impair 

water quality. Today, most communities have stormwater management requirements 

designed to minimize the adverse impacts caused by urban development. Instead of 

building larger pipes and ditches to hurry the water away from a development (and 

onto someone else’s property), subdivision ordinances have 

standards to manage stormwater.

Stormwater management encompasses four objectives: 

Manage stormwater runoff so new development is 

not damaged during a major storm; 

Prevent new development from diverting surface 

flows onto other properties;

Prevent new development from increasing the peak 

flows to the receiving drainage system; and 

Maintain or improve the quality of the water in the 

system. 

To meet these objectives, a community’s subdivision or other development 

regulations should have stormwater management standards. These usually include 

the following:

Locate building sites on higher ground or on human-made building pads so 

stormwater will run away from the building, into swales, or into the street.

Design swales along lot lines to carry water to drainage easements, the street, 

or nearby ditches (see the Orland Hills illustration on page 4-18).

Design storm sewers to carry the runoff from smaller storms without 

causing street flooding. Traditionally, the national standard is for storm 

sewers to carry the 10-year storm. Recently, communities are finding that 

older estimates of the 10-year storm understated the true hazard, so they are 

addressing larger storms.

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In Activity 450 (Stormwater Management), the CRS 

encourages and provides 

credit for regulations that 

require developers to detain or retain excess stormwater runoff and that require 

stormwater management facilities to include features that improve water quality.
4-14 Reducing Damage from Localized Flooding: A Guide for Communities

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Ensure the infrastructure can handle larger storms without damaging 

buildings. For example, the streets or a defined overflow path can be 

designed to handle the runoff that will not fit in the storm sewers, provided 

that emergency access routes are established and maintained.

Design parking lots, rooftops, streets, or storage basins to hold the runoff 

and release it downstream over time, keeping the peak flow to a level at or 

below the peak flow that existed under the pre-development conditions. 

Incorporate water quality provisions in the storage basins. For example, if 

water is held for a period of time, sediment and other pollutants can settle to 

the bottom, and the released water will be cleaner than when it entered the 

basin. These techniques can also help meet the community’s NPDES goals.

Increasingly, communities are incorporating existing natural features into their 

stormwater management plans and including water quality aspects in their drainage 

system design. There is a move away from storm sewers, which are expensive and 

have limited capacity, toward open swales and grassy ditches, which can carry larger 

flows and have the added advantage of filtering and cleaning the water.

Green Infrastructure

As noted at the beginning of this section, infrastructure is a term that encompasses 

the public works and utilities that serve development. Typically, streets and 

drainageways are thought of as essential public features 

that must be included in all new subdivisions and other 

developments. 

The green infrastructure concept views natural areas 

as another form of infrastructure needed both for the 

ecological health of an area and for the quality of life that 

people have come to expect. Many communities have 

realized that open space and green areas are just as vital 

to urban development as are water and sewer lines.

Green infrastructure can include parks, buffers along 

waterways, greenways, farms, backyards, residential 

landscaping, and urban gardens. These areas can have 

multiple uses. Not only do they protect natural functions 

and habitat, but they also act as stormwater storage 

areas, water conveyance areas, and runoff filters. They 

can be excellent parks, trails, and recreational features 

that increase the value of the properties near them. 

Floodplain Regulations

Every community in the NFIP has floodplain management regulations. These 

regulations require that the lowest floor of any new or substantially improved 

residential building be elevated at or above the BFE. Nonresidential buildings can be 

elevated or floodproofed.

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The Maryland Department of Natural Resources is working to identify those undeveloped lands that are most critical to the State’s 

long-term ecological health. These lands, 

referred to as Maryland’s green infrastructure, 

provide the natural foundation needed to support diverse plant and animal populations, and 

enable valuable natural processes like filtering 

water and cleaning the air to take place. Identifying and setting priorities for protection of the 

green infrastructure is an ongoing process. 

A description of Maryland’s green infrastructure, including county-by-county maps, 

can be found at http://www.dnr.state.md.us/

greenways/gi/gi.html.
Reducing Damage from Localized Flooding: A Guide for Communities 4-15

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Stormwater Management in the Butterfield Creek Watershed

part is a master floodplain and stormwater management model ordinance that all the communities 

adopted. Developers are encouraged to preserve 

marshes and wetlands for their flood storage 

capacity and to enhance wildlife habitat and recreational opportunities. Other storage areas have 

been purchased and turned over to park and forest 

preserve districts.

A study by the Natural 

Resources Conservation Service in the 

1980s concluded that 

if all development in 

Illinois’ Butterfield 

Creek watershed were 

required to construct 

storage basins, flood 

heights and erosion 

would still increase 

because of the loss 

of natural water storage areas. Faced 

with repetitive floods, 

streambank erosion, 

and other problems, 

the communities in the 

watershed formed the 

Butterfield Creek Steering Committee to look 

at the causes of the 

problems and possible 

solutions. 

It was concluded 

that the existing open 

areas in the upper 

reaches of the watershed must be preserved in order to provide the 

needed natural stormwater storage. To do this 

required a great deal of cooperation between the 

downstream and upstream communities. Working 

together, the Steering Committee prepared a Vision 

Plan, sought funding support, and received cooperation and money from a variety of agencies. 

The Vision has regulatory measures, corrective 

actions, and a strong recreational element. A key 

Why not enforce these standards in known problem areas that are outside the SFHA 

designated on the FIRM? The standards work in the official floodplain, and they can 

be just as effective in other flood-prone areas. The discussion in the beginning of this 

chapter describes how these other areas can be mapped. The community needs only 

to adopt the new map as part of its floodplain management ordinance.
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P A R T I I Chapter 4. Regulatory Tools

A typical floodplain management ordinance includes the sections listed below. The 

appropriate amendments are shown in red. Additional studies for other areas can 

also be referenced. Note that any revision of the ordinance should be made only after 

reviewing the change with the State or the FEMA Regional Office to ensure that it 

complies with the NFIP.

Section __. Lands to which this ordinance applies

This ordinance shall apply to all the special flood hazard areas (SFHAs) as 

shown on the Flood Insurance Rate Map of the City of Floodville. The SFHA 

shall also include the regulatory floodplain along Oliver Creek as shown on 

the Oliver Creek Flood Study.

Section ___. Basis for establishing the areas of special flood hazard

The SFHAs are identified 

(1) by FEMA in the Flood Insurance Study for the City of Floodville, dated 

January 1, 1995, and

(2) by the Oliver Creek Flood Study conducted by Lightning Engineers, dated 

June 23, 2004,

with accompanying maps and other supporting data adopted by reference 

and declared to be a part of this ordinance. 

Other sections of the floodplain management ordinance adopt the regulatory BFE 

and floodway. Those sections would be similarly amended. If the new area to be 

regulated has not been delineated by a detailed study and there is no calculated BFE, 

other techniques can be used to set a regulatory flood elevation, as described earlier 

in this chapter.

One key factor in the NFIP floodplain management regulations is that they cover 

existing buildings as well as new ones. If an existing building in the SFHA is to 

undergo a substantial improvement (i.e., the cost of the improvement or addition 

equals or exceeds 50 percent of the value of the building), then the building must 

be brought into compliance with the floodplain management regulations.

If the building is damaged (by any cause) so that the cost to repair the structure 

to its pre-damaged condition exceeds 50 percent of the value of the building, then 

it is considered to be substantially damaged. As with a substantial improvement, a 

substantially damaged building must be brought into compliance with the floodplain 

management ordinance.

There is a special funding provision in the NFIP for insured buildings that have been 

substantially or repetitively damaged by a flood. Increased Cost of Compliance (ICC) 

coverage provides for the payment of additional funds (up to $30,000) to help pay 

for the cost to comply with community floodplain management ordinances after a 

flood in which a building has been declared substantially damaged or repetitively 

damaged. 

A community that is serious about reducing its repetitive localized flooding problems 

would benefit by learning the details of ICC coverage. ICC currently is available to 
Reducing Damage from Localized Flooding: A Guide for Communities 4-17

Chapter 4. Regulatory Tools P A R T I I

properties in the SFHA. After regulations pursuant to the Flood Insurance Reform Act 

of 2004 are published, there will be ways for properties outside the SFHA to benefit 

from this provision, too. The community should discuss ordinance language with 

the FEMA Regional Office. Proper enforcement and an informed property owner can 

greatly facilitate the claims process and help provide funding to mitigate the risk to 

the flood-prone building.

Site Drainage 

Inadequate site drainage is a common cause of flood damage to buildings. Conveyance 

of stormwater away from a structure is critical to prevent overland flooding of the 

structure. It can also help prevent basement flooding due to high groundwater 

elevations. 

Three regulatory approaches can prevent future problems caused by inadequate site 

drainage:

Require new subdivisions to account for drainage from each lot;

Require individual buildings to be elevated; and

Enforce drainage easement provisions. 

Subdivision Design

When a subdivision is designed, a separate drainage plan should be prepared 

and reviewed by the community’s engineers. It should include the stormwater 

management provisions discussed above to ensure that excess surface flows are 

properly handled.

A subdivision or other development proposal may also include a separate drainage 

or grading plan. Individual lots should be designed to direct the flow of surface 

water away from the building. Typically, the developer must provide a building pad 

on each lot. The top of the pad must be at a certain elevation or a set number of feet 

higher than the edge of the lot.

Most subdivision regulations require utility or drainage easements to be set aside 

as part of the subdivision plat. Such easements are 5 or 10 feet inside the property 

line and carry restrictions that prohibit construction or obstructions. Stormwater 

flows from the building pad to the easements and into the street or a drainageway. 

An example of a properly designed drainage pattern is shown on the left side of the 

illustration on the following page.

Building Elevation

Some homes have been built at grade. In very flat areas, the first floor may be only 

a few inches higher than the ground. When it rains, the water does not drain away. 

Instead, it ponds or flows into these low structures.

This has been a significant cause of repetitive flooding problems, especially in the 

South where, over the last 50 years, slab-on-grade foundations replaced the earlier 

method of building houses on piers or crawlspaces. Under the old construction 

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The Village of Orland Hills, Illinois, found out the hard way why it is important to keep drainage easements 

open. Some of the problems that occurred are described in the sidebar on Orland Hills in Chapter 2. This 

graphic is based on the Village’s 1995 Flood Protection Plan that explained the problem to the public and 

helped launch more public information and enforcement activities to keep the easements open. The number of violations and drainage complaints has steadily decreased over the years since the Plan has been 

implemented.

method, localized floodwaters flowed under the first floor, causing no damage. With 

the more recent construction techniques, such flooding goes over the slab and into the 

first floor (see the left side of the St. Tammany Parish example on the facing page). 

There are three typical approaches to ensure that new buildings are not built too 

low for the circumstances:

Require positive drainage away from the building. This is a standard 

provision in the model building codes. Section 1803.3 of the International 

Building Code has such a requirement, for example, so this provision may 

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Chapter 4. Regulatory Tools P A R T I I

already be part of the community’s regulations, 

but that does not mean that it is always 

adequately enforced.

Require the lowest floor of new buildings to be 

1 or 2 feet higher than street level (see the right 

side of the St. Tammany Parish example above).

Require the permit applicant to submit a site 

plan that accounts for local drainage from and onto 

adjoining properties and that protects the building and adjoining properties 

from local drainage flows.

Drainage Easements

Most lots have utility or drainage easements that set aside the area that is 5 or 10 

feet inside the property lines. These easements are designed to carry surface water 

away from the buildings and to the street, storm sewer, or other drainage facility (see 

illustration of drainage patterns on facing page). Easements must be kept open to do 

their jobs. Unfortunately, many property owners do not realize (or forget) that the 

easements exist or why they are needed.

When people build fences, garages, sheds, or swimming pools, or plant trees in the 

easement, the drainage pattern is disrupted and surface water will be pushed onto 

other properties. The photograph on the following page shows how a local drainage 

system can become obstructed when property owners forget to keep their easements 

open.

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St. Tammany Parish, Louisiana, had many homes built close to grade in very flat areas. Heavy rains caused 

on-site flooding and did not drain away quickly. Homes like the one on the left were frequently flooded. In 

response, the Parish adopted a requirement that lowest floors be at least 6 inches above the street. Site 

plans for new construction combine elevation of the building pad with improved drainage, so local drainage is 

not a flooding problem in new subdivisions (as shown on the right).

St. Tammany Parish, Louisiana French & Associates

In Activity 450 (Stormwater 

Management), the CRS provides 

credit for all three approaches to 

protect new buildings from local 

drainage problems. 
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For easements to work, the easement restrictions must 

be enforced by the community. Property owners must 

be reminded to obtain permits for sheds, swimming 

pools, fences, and other structures that can alter the 

ground surface. Permit officials need to check the 

easements before issuing a permit and conduct on-site 

inspections for all projects, no matter how small, to 

ensure that they do not encroach on the easements.

A public information program can be an effective tool 

to help enforce these regulations. Property owners 

who are aware of and understand the need for keeping 

easements open are less likely to obstruct them and 

are more likely to advise local officials when they see 

potential problems. As noted on page 2-6, Orland Hills 

used a combination of regulations, public information, 

and drainage modifications to reduce its drainage 

problems.

Where to Get Help 

The following agencies can help with mapping regulatory floodplains:

FEMA 

U.S. Army Corps of Engineers

Natural Resources Conservation Service

State Department of Natural Resources

The following agencies can provide assistance in reviewing the community’s 

regulatory standards and setting new ones:

FEMA 

State National Flood Insurance Program Coordinator

Training and references on these topics can be found through: 

FEMA 

Association of State Floodplain Managers 

State and regional associations of floodplain managers

American Society of Civil Engineers

Additional resources are listed in Appendixes A and B.

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French & Associates

When this subdivision was constructed, the backyards 

were open. Over the years, fences along the lot lines 

have disrupted the drainage system. Stormwater would 

flow away faster if these obstructions were removed.

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 5
Reducing Damage from Localized Flooding: A Guide for Communities 5-1

Public 

Information 

and Awareness

One of the most effective long-term ways a community can cope with localized 

flood problems and prevent future ones from occurring is by educating its 

residents about why such problems occur outside the Special Flood Hazard Area 

(SFHA) and what they can do to help prevent them. 

A community can choose from numerous avenues to build awareness of and 

knowledge about localized flooding and remedies. The following public information 

activities serve community residents, property owners, insurance agents, lenders, and 

real estate agents by advising them about the flood hazard, flood insurance, ways to 

prevent or reduce flood damage to buildings, and the natural benefits and functions 

of floodplains.

Answer Questions

Virtually all communities provide residents with information about flooding and 

preventive measures if they ask for it, perhaps when they inquire whether a property 

is in the floodplain or they request an elevation certificate. National Flood Insurance 

Program (NFIP) communities are required to make public documents available, such 

as the current Flood Insurance Rate Map (FIRM), or permit records, so that residents 

can consult them as needed.

Communities with drainage problems or other types of localized flooding should 

be ready to explain that the issue is more complicated than simply being inside or 

outside the SFHA, or 100-year floodplain. The community’s program for providing 

map information could be expanded to offer information about low-risk areas as 

well as about the 100-year flood. Local staff should provide information about all 

known flood hazards, including those not mapped on the FIRM.

The local staff should be prepared to provide information and advice about:

Safety measures that can be taken by individuals, property owners, drivers, 

and passengers in automobiles;

Flood risk both inside and outside the SFHA;

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Retrofitting techniques to make buildings safer;

Building techniques and standards (or regulations, if applicable) to make a 

new structure resistant to shallow flooding (such as placing utilities above 

the flood level);

Sources of help in taking action to reduce flood damage;

The availability of flood insurance and insurance for sump pump failure and 

sewer backup, even outside the floodplain; and 

Special flood-related problems in the community, such as streambank 

erosion or subsidence.

A community’s technical staff—building department personnel, code enforcement 

officers, public works staff—have expertise and experience in construction. Although 

they cannot assume responsibility for the design or 

construction of a property owner’s project, they can 

answer inquiries about flood protection measures, 

point people in the right direction, explain what won’t 

work, and identify licensed companies or experienced 

contractors who can do the work. Some building 

department or public works staff, such as those of the 

St. Louis, Missouri, Metropolitan Sewer District, visit 

properties on site and offer suggestions. 

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French & Associates

Before a permit is issued, permit officials should review all information known 

about drainage and local flooding problems in the area.

Credit is provided by the CRS 

under Activity 360 (Flood Protection Assistance) for visiting 

a problem site and giving the 

property owner advice appropriate for the situation, such as retrofitting techniques and names 

of qualified contractors.
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Chapter 5. Public Information and Awareness P A R T I I

Provide Resources for the Public 

People who set out to learn more about localized flooding and its possible remedies 

are far more likely to follow through if they find resources within the community 

that help them with their mission. A community can help by making sure that various 

types of information about local flooding are accessible to the public.

The local library is a logical place to start. A community could have a special section 

in the library that includes materials on its local flooding history, flood control and 

drainage projects, success stories, guidance for homeowners, flood maps, and natural 

resources associated with the streams, such as wetlands or wildlife habitat. Interested 

property owners can read or check out handbooks or other publications that apply 

to their situations or log on to the Internet to search for helpful Web sites. 

Some communities participating in the Community Rating System (CRS) already 

have documents on flood risk available in the library, and get CRS credit points for 

doing so. It would be simple to augment this collection with specific information 

about local flooding within the community, action to take, and experts to contact 

for advice.

A community can display its maps showing flood 

risks at various places in town—the city hall, public 

works offices, library, or other visible locations. If 

additional information (beyond what is displayed 

on the community’s FIRM) is shown on these maps, 

the residents are more likely to become interested in 

flooding problems and remedies. The maps should show 

not only the 100-year floodplain but also other features 

relevant to local flooding, such as low-risk flood areas, 

drainage problems, natural zones along waterways, 

or wetlands. They could incorporate aerial photographs that show recognizable 

buildings or landmarks, information about additional hazards (such as landslides); 

flooding outside the SFHA; natural habitat and parks; or zoning and development 

regulations.

Not only can the community Web site be a research tool, but it also can be a quick 

way to stimulate interest or convey ideas to Internet surfers. The Web site could include 

the same sorts of information housed in the local library, but with the advantage of 

being displayed in a more attention-getting format. It is not difficult to provide links 

on the community’s Web site to many different sources of information, both public 

and private, about floods, flood insurance, property protection, and other ways of 

coping with local flooding. 

Mecklenburg County, North Carolina, has an interactive Web site that 

allows people to look up their flood zones, as well as obtain educational 

information (http://maps.co.mecklenburg.nc.us).

The Colorado Foundation for Water Education has an extensive collection 

of articles, educational materials, and links to other sources (http://cfwe.

org/SchoolPrograms/). 

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Under Activity 350 (Flood Protection Information), the CRS 

credits making references and 

technical information available 

through the community’s library 

and/or Web site.
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The city Web site for Fargo, North Dakota, has local information, flood maps, 

links to the flood-related collection of North Dakota State University, and to 

State and Federal agencies and organizations (http://www.ci.fargo.nd.us/

floodemergency.htm). 

The Federal Emergency Management Agency (FEMA) Web site has a wide 

array of helpful information geared toward the public. 

The Louisiana State University Extension Center has an extensive flood Web 

site, a link to the national Extension Disaster Education Network, and online 

shopping options for retrofitting products, contractors, professional services, 

and examples of installations (http://www.louisianafloods.org). 

A community could also provide a mapping Web site, available to the public. This 

can serve several purposes, from enabling users to determine their FIRM zone and 

other property information to displaying the areas that perhaps are not mapped on 

the FIRM but that the community considers prone to localized flooding. This can 

be automated through the community’s geographic information system (GIS), if it 

has one. Users who locate their properties in localized flooding areas could then 

be offered links to other information appropriate to that type of flooding. Palo Alto, 

California, has a Web site that lists all flood-prone properties in the city, and allows 

users to see current stream levels at certain monitoring sites (http://www.city.paloalto.ca.us/cgi-bin/floods.cgi).

Deliver Flood Information

Instead of waiting for residents to try to find out about localized flooding and its 

remedies for themselves, a community can reach out in various ways to its residents, 

businesses, and property owners to help them become aware of and concerned about 

flood problems and what they can do to protect themselves and their property. This 

is also a way of letting people know what the community itself is already doing to 

combat nuisance flooding and drainage problems.

Such efforts on the part of local government or community groups are often called 

“outreach projects,” and they can take almost any form imaginable. Outreach projects 

are designed to encourage people to seek out more information, take steps to protect 

themselves and their property, and help them understand the natural processes and 

benefits of flooding. 

Special outreach projects can be undertaken to reach 

residents subject to local flood problems, or outreach 

projects that are underway or ongoing can be expanded 

to specifically target those people and their particular 

needs. For example, many communities do an annual 

mailing to owners of property in the floodplain, 

reminding them of their flood-prone location, the 

availability of flood insurance, and steps they can and 

should take to protect themselves. Residents outside the 

SFHA but still subject to flooding could be added to this 

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The annual mailing to 

owners of flood-prone 

property has targeted 

the people who need to 

have this information. 

... Connecting with 

the local Association 

of Realtors® has also 

heightened awareness.

 Linda Wheeland

Sangamon County, Illinois

Credit is provided by the CRS 

under Activity 330 (Outreach 

Projects) for different types 

of projects designed to inform 

people about the flood hazard, about flood protection measures, and about the availability of 

flood insurance. The special publication, CRS 

Credit for Outreach Projects, includes many examples of things that communities have done.
Reducing Damage from Localized Flooding: A Guide for Communities 5-5

Chapter 5. Public Information and Awareness P A R T I I

mailing and/or an insert tailored to localized flooding could be included in their 

mailings.

Any of the topics discussed in this guide could be included in outreach projects to 

residents subject to localized flooding, such as measures to protect a property from 

flood damage (retrofitting, grading a yard, correcting local drainage problems, 

moving furniture, using sandbags) and drainage system maintenance (rules against 

dumping in stream channels, how to report violations, and why it is important to 

maintain the drainage system).

Brochures or flyers with pertinent flood information can be mailed directly 

to flood-prone properties, displayed in public places, enclosed in utility bills, 

or distributed door-to-door by scouts or other 

service groups. This is a good way to reach the 

people who need to know, because it can be 

done only in those neighborhoods subject to 

localized flooding.

Presentations can be made by community staff 

or other experts to neighborhood associations, 

civic groups, or business organizations. 

Signs posted in appropriate places in town can 

show the height of the water during previous 

floods, or remind residents that a storm drain 

leads to the river.

Media packets delivered to local radio and 

television stations compile basic flood facts, 

information about protective measures, names 

of local experts willing to be interviewed and/

or quoted, and sound bites to help the media 

convey accurate, helpful, and straightforward 

information, especially during flood or 

hurricane season.

Displays can be set up in public buildings 

showing maps of flood-prone neighborhoods, 

historical flooding, photographs of houses that 

have been retrofitted, and other information. 

This can be expanded to a booth for special 

events in shopping malls, staffed by a person 

who can answer questions.

Awareness campaigns spread the word 

throughout the whole community, and some 

can be tailored to localized flooding problems. 

For example, the Turn Around Don’t DrownTM 

national campaign, which communities can 

use free, has particular applicability to drainage 

problems, because the danger of driving 

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Fred Block

In the spring of 2003 the Illinois communities 

of South Holland, Calumet City, and Lansing

declared Flood Awareness Week and hosted multiple events to raise public and official awareness 

of local flood problems.

One such event was a floodproofing open 

house, held on a mid-week evening at a local 

grade school. It was arranged so that participants first checked in at a registration table, 

viewed a slide show about local flooding, and 

were invited to view a new video, “Keeping Your 

Home Out of Deep Trouble,” in a separate room. 

They then browsed the gymnasium at will, visiting 

multiple booths and exhibits prepared by public 

agencies and private firms involved in various 

aspects of flood loss reduction.

Reponses from the participants were favorable. Most had heard about the open house 

through the local newsletter, and less than half 

had experienced flooding in the past.
5-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 5. Public Information and Awareness

into flooded intersections is its main message. A “stream cleanup day” 

could emphasize keeping waterways clear of debris, to minimize drainage 

problems. A poster contest could feature things people can do to their own 

homes and yards to make them more resistant to flood damage.

Videos can be produced by the community or local organizations, explaining 

how, why, and where local flooding occurs, and what can be done about it. 

The videos can be loaned to groups, shown on local cable TV shows, or used 

as part of presentations made by community staff. An example of a video 

prepared by a community college with local retrofitting examples can be 

viewed at http://www.southholland.org/Resources/flood%20resources.

htm.

Feature articles in newspapers or stories in local newsletters can highlight 

local flooding and send messages about what people can do. These are 

usually more effective if they are issued at the onset of the rainiest season.

Educate to Build Community Capability

Educating the community’s leaders and future residents is an even longer-term 

approach to preventing flood problems. People who have a thorough understanding 

about local floodplain resources and the potential for flooding and damage 

permanently change their attitudes from one of helplessness to one of knowing 

how to take care of the problems. Over time, this education and changed attitude 

result in residents who are able and willing to take responsibility for managing the 

flood hazard. The community will have built the capability to cope with flood risks 

without relying on State or Federal help. This is never more true than with smaller 

watersheds and the localized flooding that results in less-than-disastrous damage. 

More details about building capability among the local government staff can be 

found in Chapter 3.

Local Staff

Training for community staff who deal with flooding, zoning, permits, engineering, 

and public works is readily available through FEMA, the States, and professional 

associations. The national Emergency Management Institute (EMI) in Emmitsburg, 

Maryland, offers numerous courses on its campus, and some courses are offered 

throughout the country to address specific issues. Attending or hosting floodplain 

management workshops and conferences gives local staff members an opportunity to 

learn more about their fields, network with other communities about their programs, 

and trade successes and lessons learned.

Elected Officials

Keeping elected officials informed and knowledgeable about ongoing programs and 

projects is very important. Something as simple as a presentation to City Council every 

few months can keep decision makers abreast of progress. Inviting elected officials 

to be present (and visible) at a stream cleanup or an open house on floodproofing 

gives them an opportunity to deepen their understanding of (and commitment to) 

flood issues in their districts.

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Reducing Damage from Localized Flooding: A Guide for Communities 5-7

Chapter 5. Public Information and Awareness P A R T I I

113 Calhoun Street:

A Center for Sustainable Living

This building in Charleston, South Carolina, is used 

as a learning center to demonstrate various sustainable building techniques, including flood mitigation. 

The 125-year-old building, located in the historic 

downtown district, was already abandoned when it 

was further damaged by Hurricane Hugo in 1989. 

The 113 Calhoun Street Foundation, a private, nonprofit organization established by the South Carolina 

Sea Grant Consortium, Clemson University Extension Service, and the City of Charleston, decided 

to transform it into a real-life example of sensible 

building practices and use it as a demonstration 

project. Funding for floodproofing was obtained from 

FEMA. People can tour the house, and it also is a focal point for hazard-related education and research. 

All renovations and improvements had to comply 

with the historic district rules, but a variance to 

the substantial improvement requirement allowed 

the house to remain close to street level (elevating to the 100-year flood level would have meant 

raising it 4 feet, destroying its historic appearance).

A benefit-cost analysis conducted with FEMA’s 

software showed that raising the structure one 

foot would protect it from shallow, more frequent 

localized flooding. It was calculated that the probability of flood damage would be reduced by 60%.

The original foundation was completely replaced 

with concrete footings reinforced with steel rods. 

This prevents it from floating off its foundation in 

a severe flood. The original brick from the foundation was re-used as a veneer over the concrete 

block to preserve the historic character.

The crawlspace is insulated with non-water-absorbing foam insulation. 

All electric, telephone, and computer outlets and 

furnace, air conditioning, and other ductwork are 

located above the 100-year flood elevation. There 

are no splices or connections below that elevation. 

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Wooden panels, called wainscoting, were installed 

up to the 100-year flood elevation. These panels 

are less water-absorbent than wallboard and can 

be removed after a flood, allowing both the panels 

and the wall space to dry thoroughly. 

Other protection measures for wind, hurricane, and 

other hazards were also incorporated.

More information, including a virtual tour, can be 

found at http://113calhoun.org.

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Photo courtesy of 113 Calhoun Street Foundation
5-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 5. Public Information and Awareness

Children and Youths

Environmental and safety education programs can teach children about flooding, 

the forces of nature, the factors that cause flood problems, and how important 

it is to protect natural drainageways and the many resources of watersheds. Such 

programs operate to influence future property owners 

and elected officials and foster a sense of stewardship 

for the land and water. Educational programs can be 

presented through schools, summer camps, parks and 

recreation departments, conservation groups, and youth 

organizations. 

Sponsoring special workshops for teachers helps 

them learn more about flooding and gives them ideas 

and materials for passing that knowledge on to their 

students.

Professionals

A community whose professionals have an accurate understanding of the flood 

situation and about rules, requirements, and remedies will be closer to resolving its 

flood problems.

For floodplain managers and local ordinance administrators, the Association of State 

Floodplain Managers administers the Certified Floodplain Manager (CFM®) Program 

to ensure that floodplain management staff are trained and that they keep their skills 

and knowledge up-to-date through continuing education. Some States operate their 

own nationally approved certification program for floodplain managers. New Mexico 

and Oklahoma have state laws requiring that all local floodplain administrators be 

accredited.

These certification programs connect their applicants and members with numerous 

training and continuing education opportunities.

Some States license their building inspectors and code officials, and specify the type 

of training, skills, and abilities that are required to effectively perform those roles.

Other professionals, like real estate agents, insurance agents, and surveyors, are links 

between flood information and the public. It is in their best interest to have accurate 

information to pass along to their clients; providing updates, speaking at their regular 

meetings, keeping them in the loop through their publications, and inviting them 

to meetings or workshops is a good informational strategy.

Where to Get Help

Local public information campaigns are underway in many communities, 

sponsored by the county emergency manager, the local chapter of the 

American Red Cross, the utility company, school district, parks department, 

youth groups, and others. Finding a way to combine their projects with 

information that will raise flood awareness is an inexpensive way to get 

started.

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The Milwaukee Metropolitan Sewerage District and the Milwaukee Public Schools have 

a partnership to develop an environmental education curriculum focusing on water quality and 

addressing such issues as floodplain management, flooding, and stormwater runoff.
Reducing Damage from Localized Flooding: A Guide for Communities 5-9

Chapter 5. Public Information and Awareness P A R T I I

The community’s webmaster may accept 

contributions to focus attention on local 

flooding.

The local library may welcome displays about 

flooding, lecture series, and special flood-related 

collections.

The Web sites of most Federal agencies with 

flood mitigation or water resources missions 

have numerous floodplain and flood protection 

references that can be ordered, downloaded, or 

linked to a community’s Web site. 

Many State, Federal, and non-profit Web sites 

have special sections for school children, with 

downloadable materials, posters, and projects. 

Some examples are the National Wildlife 

Federation’s Kidzone at http://www.nwf.

org/kids/; FEMA for Kids at http://www.fema.

gov/kids; or Environmental Kids Club at http://

www.epa.gov/kids/.

The Web sites of cities, such as Fort Collins, 

Colorado, and Tulsa, Oklahoma, are examples of 

sites that provide extensive outreach materials 

to educate their residents about local flooding 

and floodplains.

The StormReady program provides proven 

methods for educating citizens and preparing 

the community to be ready to handle a storm at 

http://www.stormready.noaa.gov.

The CRS publication CRS Credit for Outreach Projects

has lots of ideas and examples for reaching 

people with information about flood problems. 

See http://training.fema.gov/emiweb/CRS/.

Training courses in floodplain management, 

flood insurance, the CRS, building protection, and other matters are offered 

by the Emergency Management Institute. Tuition is usually free to local staff. 

The schedule and course descriptions can be found at http://www.fema.

gov/emi/.

Information about the CFM® Program of the Association of State Floodplain 

Managers can be found at http://www.floods.org.

Project WET (Water Education for Teachers) provides guides and workshops 

for teachers on many water resources issues. See http://www.projectwet.

org/. Educating Young People about Water maintains a catalog of almost 

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Maryland Residents Watch 

Their Streams

The Stream Teams program is a way for 

residents of Prince George’s County to work 

together to protect the over 1,500 miles of 

streams in the county. Stream Teams are 

groups of friends, work colleagues, families, 

school classes, scout troops, church organizations, or others who want to work together 

to protect and restore streams. Each team 

adopts a stream of its choice and agrees to 

carry out one or more activities.

There are three levels of Stream Teams 

involvement, coordinated by the county Department of Environmental Resources. 

A Stream Reporter conducts stream surveys 

by periodically walking along the adopted 

stream, observing and reporting problems 

such as unusual discharges, trash dumps, 

fish kills, algae blooms, sewage leaks, or 

sudden sedimentation. 

Stream Activists do stream cleanups, tree 

plantings, storm drain stenciling, or public 

education.

Stream Water Quality Monitors collect and 

identify certain aquatic insects that are indicators of the water quality in a stream. All 

Stream Teams attend a free half-day training 

workshop.

Additional information may be found at the 

Stream Teams page on the Prince George’s 

County Web site at http://www.co.pg.md.us/

government/agencyindex/der/ppd/community/stream_teams.asp.

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5-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 5. Public Information and Awareness

200 curriculum materials on water resources topics at http://www.uwex.

edu/erc/eypaw/.

The State emergency management agency can be contacted for schedules of 

technical training for local staff.

If there is a State-level professional association for floodplain managers, 

wetlands managers, stormwater managers, or others, it can be a resource 

for technical training opportunities for local staff. Floodplain management 

associations can be found at http://www.floods.org/StatePOCs/stchoff.asp.

Many soil and water conservation districts have staff assigned to help prepare 

and present educational programs.

The Turn Around Don’t DrownTM campaign, sponsored by the Federal 

Alliance for Safe Homes (FLASH) and the National Weather Service, has a 

Web site with safety tips and downloadable brochures, signs, and other 

outreach materials about the danger of driving during flood conditions at 

http://www.nws.noaa.gov/os/water/tadd/.

Funding

Many of the public education and awareness ideas discussed here can 

be added to or integrated with ongoing initiatives, making the cost of 

implementing them fairly low and possibly within the operating budgets of 

many local government agencies.

Floodplain management messages can be included in other publications and 

mailings, for example, articles on flood protection in a citywide newsletter, 

in the water bill, or with the annual tax bill.

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RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 6
Reducing Damage from Localized Flooding: A Guide for Communities 6-1

Warning and 

Emergency 

Services

If people know that flood conditions are likely to occur, they can take steps to 

ensure their own safety and minimize damage to their homes, businesses, and 

personal property. A flood warning system that does the following things can go a 

long way toward reducing losses from localized flooding:

Identifies flooding threats; 

Disseminates information to residents as a warning or advisory; 

Signals the need for emergency services; and 

Promotes public understanding of flood risks. 

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A flood warning and emergency response program focuses on knowing when and 

where it will flood and doing something about it before the flood causes any damage. 

In areas subject to localized flooding, the first component of the system—flood 

threat recognition—would be different from that on larger rivers, but the provisions 

for spreading the warning, educating people, and 

developing community response would be essentially 

the same as for other flood situations.

Recognizing the Threat

Types of Systems

Before a flood warning program can be developed, the 

community must have a system that provides advance 

notice of potential flooding conditions. This is known 

as flood threat recognition. Nationally, flood threat 

recognition is managed by the National Weather Service 

(NWS) and its regional River Forecasting Centers.

6

Communities can obtain CRS 

credit for their flood warning 

system. CRS Credit for Flood 

Warning Programs describes 

the elements of a flood warning 

system that are eligible for credit under Activity 

610 of the CRS:

Flood threat recognition systems; 

Emergency warning dissemination; 

Other response efforts; 

Critical facilities planning; and 

Being a StormReady community.

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6-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

When information from 

radar, remote gauges, 

or the NWS indicate 

that conditions are ripe 

for local flooding, the 

emergency operations 

staff can monitor 

developments and decide 

if a watch or warning is 

appropriate.

French & Associates

The NWS focuses on larger rivers and major threats, such as hurricanes. It cannot 

track every little stream and ditch. It does monitor conditions and issue flood watches 

and warnings, but often only for low-lying areas, not crest predictions on individual 

streams. Therefore, more specific recognition of localized flooding potential is left to 

local authorities. The NWS can, however, provide technical advice and assistance.

A Local System

There are two major types of local flood warning systems: manual and automated. 

Deciding which to choose depends on the characteristics of the watershed, the flood 

loss potential, and the warning time that will be needed for the community to take 

action. 

Manual systems involve a network of residents who collect data by reading rain and 

river gauges or using other observation techniques. When a predesignated condition 

occurs (perhaps the gauge measurement reaches a certain level), the gauge watchers 

contact a community flood coordinator, usually in the emergency management office. 

The flood coordinator may use paper graphs or a computer model to calculate the 

impact of the rain and water levels and obtain a simple flood forecast. 

Automated systems can be faster, more accurate, and more reliable, but are more 

expensive than manual systems. As rain gauges fill with water, they tip over, sending a 

signal to a central monitoring station. Computers record and react to the data provided 

by the automatic rain and river gauges and calculate a flood prediction. 

The amount of damage incurred by localized flooding may not justify the significantly 

greater expense of an automated system. Further, an automated system may not be 
Reducing Damage from Localized Flooding: A Guide for Communities 6-3

Chapter 6. Warning and Emergency Services P A R T I I

effective for localized flooding because there is often 

no identifiable flooding source on which to install a 

stream gauge.

A community and its local NWS office can work 

together to determine what can be done to develop 

advance notice of localized flooding. The collective 

experience of community officials and residents with 

historic flooding and drainage problems can help 

inform hydrologists about the conditions under which 

localized flooding is likely to occur and help them 

advise the community on the most effective type of 

flood warning system and what conditions will warrant 

issuing a warning. 

It may be that the NWS general watches or warnings 

will provide all the advance notice that can be expected. 

If so, rather than invest a lot of effort in gauges, radios, 

and computers, the community could use storm 

spotters, police patrols, and other volunteer weather 

watchers to advise of potential flooding. It should focus 

on preparing an appropriate program for disseminating 

the warnings it does get, teaching people what to do, 

and developing effective community responses.

However, it may be possible and very useful to have a system that predicts that 

low lying areas will flood in the next few hours. Even this general advance notice 

could help residents move cars or close openings. Such a warning system would be 

meteorologically focused, with warnings based on precipitation rates, radar displays, 

the rate of snowmelt known historically to cause flooding, and other factors, rather 

than on gauges of the precipitation and stream flow.

Issuing the Warning

Even though the community’s system for recognizing a threat of localized flooding 

would be different from the system for larger rivers, the procedures for issuing 

the flood warning would be much the same as for other hazards. Once NWS flood 

watches and warnings are received or local information suggests an imminent threat, 

that information needs to be spread among residents, businesses, critical facilities, 

and local government personnel.

A community should determine whether, and when, any areas subject to flooding 

should receive special warnings. For example, some neighborhoods may always be 

the first to be flooded, even if the flood threat to the rest of the community never rises 

to the level of a general warning. Or, if the general NWS warning for the community 

is the best information that is going to be available, perhaps areas subject to localized 

flooding should receive special instructions beforehand.

French & Associates

Before this gauge was installed in Matteson, Illinois, 

two people had died at this underpass. They thought 

the water was shallow enough that they could drive 

through, their cars stalled, and they drowned. The 

gauge is a localized flood threat recognition system that 

enables motorists to see how deep the water is and avoid 

risking their cars and lives.
6-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

A flood warning should advise people what areas are likely to be flooded, what actions 

they should take, what actions they should avoid (using closed streets or dangerous 

intersections, etc.), and what they can expect officials and emergency personnel to 

do. It should also encourage people to pass the word to others, especially those least 

likely to hear the warning and those who might need special help. 

Responding to the Threat

The Community’s Response

After a flood warning is issued, the community sets in motion a previously agreedupon flood response effort. The actions to be implemented should be part of the 

emergency response or emergency preparedness plan administered by the emergency 

manager. Often these plans have a flood annex or separate procedures for floodspecific activities.

The plan should include:

Instructions for emergency services personnel;

Identification of roads that should be closed before flooding begins; 

Identification of routes to be kept clear for flood response and access to 

buildings;

Procedures for residents to exit the flooded (or blocked) areas; and

Identification of critical facilities (hospitals, water treatment plants, etc.) that 

need attention. 

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FEMA News Photo Some roads will be blocked because of flooding.
Reducing Damage from Localized Flooding: A Guide for Communities 6-5

Chapter 6. Warning and Emergency Services P A R T I I

The community should conduct practice drills of its response program at least 

once each year when there is no flood. In addition, an ongoing training program 

will ensure that local staff are always aware of what to do. The staff should also be 

trained to test and maintain warning equipment; response equipment, machinery, 

and supplies; computers, and communications systems.

Site-Specific Responses

The community’s plan should specify the personnel responsible for securing critical 

facilities and providing flood protection for those facilities. Each critical facility should 

have its own flood response plan that its staff implements. Often, these are prepared 

and administered by the facility’s security office, the counterpart to the community’s 

emergency management office.

Raindrops to Response

Tulsa, Oklahoma, is subject to flooding and flash 

flooding, often resulting from severe thunderstorms. 

Tulsa’s system for recognizing flood threats and 

issuing warning information is a cooperative effort 

among the National Weather Service, the news media, the Tulsa Area Emergency Management Agency 

(TAEMA), amateur radio operators, and the City of 

Tulsa. 

Tulsa’s computerized ALERT (Automated Local 

Evaluation in Real Time) system includes 39 rain 

gauges, 19 stream gauges, and seven detention 

gauges that report changes as they happen. A 

hydrologic program develops stream and flood forecasts, which are analyzed by the city’s Department 

of Public Works staff in consultation with TAEMA, 

the Fire Department, and the Police Department, to 

determine appropriate action.

When warranted, flood watches and flood warnings are issued by the Tulsa NWS office. They 

are distributed through the National Oceanic and 

Atmospheric Administration (NOAA) Weather Wire or 

NOAA Weather Radio, and then via other media.

If the amount of rain expected will cause ponding 

and other flooding of small streams and depressions, the NWS may issue a “flash flood warning.” 

But sometimes these events are so localized and 

rapid that a flash flood warning never gets issued. 

On the smaller flooding sources, local rainfall and 

river gauges are needed. When street flooding is 

reported, Public Works staff are sent to the field as 

spotters, who confirm what is occurring and what action needs to be taken.

In addition to the NWS data, TAEMA also maintains a weather sensor system consisting of two 

types of radar, which are used to monitor stream 

water levels and changes in the atmosphere. The 

system is equipped with its own database that 

compiles and analyzes data received from the two 

sensors. A technician analyzes both reports.

When a flood threat is recognized, the next step 

is to notify the public and staff of other agencies 

and critical facilities. Residents receive information through the media. Manual and automated 

telephone systems are used by TAEMA to contact 

city departments and critical facilities such as area 

nursing homes, childcare facilities, and hospitals.

TAEMA may decide to activate the emergency 

warning sirens. Tulsa has 82 warning sirens, each 

of which can be heard for up to a 1-mile radius. A 

three-minute alternating “high-low” tone on the siren 

tells people of impending flooding. Citizens have 

been instructed that, upon hearing the flood siren, 

they should avoid low-lying areas or any place where 

flooding is likely to occur, drive only with caution, 

and access local media for further information. 
6-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

The facility flood response plan should cover the following topics:

Identifying what flood warning message will trigger implementation of the 

plan;

Identifying which people need to be called when the warning is issued, their 

telephone numbers, and where they should report;

Operating or closing a gate valve, including 

how to do it, when to do it, and where it is 

located;

Closing door or window shutters on a 

building or gates in a floodwall, including 

where they are stored, how they should be 

installed, and how they should be fastened or 

locked in place;

Operating a sump pump system;

Operating a generator if the power is 

disrupted, including how to connect or 

disconnect it, how to start it, how to refuel it, 

and what circuits should be charged; 

Maintaining the valves, pumps, and other 

mechanical components;

Reporting to and communicating with the 

community’s emergency manager; and

Listing safety measures, such as:

Evacuating the building when the flood threatens;

Making sure that generators do not injure power company personnel by 

back-feeding into the power lines; and

Ensuring that there is adequate ventilation for generator exhaust.

Informing the Public

Public information before the flood should equip residents with an understanding 

of: 

The procedure for the warnings, signals used, what radio or television 

station to listen to, how much time there will be, and the reliability of the 

warnings;

What to do during a flood warning to minimize risks to health and safety;

What to do during a flood warning to reduce property damage;

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St. Tammany Parish, Louisiana

Cars can be damaged in a small amount of water. Moving 

vehicles to higher elevations before local flooding can 

significantly reduce the cost of flood damage.
Reducing Damage from Localized Flooding: A Guide for Communities 6-7

Chapter 6. Warning and Emergency Services P A R T I I

How to get help from the Red Cross, local emergency services, and other 

organizations; 

How to find out which shelters are open; and

How to obtain supplies, if needed.

It is important to ensure that homeowners are also 

aware of their options for responding to potential flood 

threats. The community should provide information 

about where homeowners can obtain materials for 

sandbags and other mitigation activities. 

Where floodwaters rise quickly, people should be 

advised that sandbagging may be too little too late. 

Instead, they should be advised about other measures 

that can be taken to protect the building. The most 

effective ones (see Chapter 10) are permanent and need 

to be prepared in advance, well before a flood warning 

is given. However, it may be possible on short notice to 

put protective shields on buildings as illustrated on page 

10-5, or to put a few sandbags in crucial places. 

People also need to know the location of some nearby, 

safe parking so they can quickly move their vehicles 

out of danger. This alone can significantly reduce the 

cost of damage. 

Residents should be advised how to develop a family 

response plan. Generally, people are more interested in 

such preparations when they understand that they are 

useful for fires, storms, and other family emergencies 

as well.

StormReady Program

Becoming a designated StormReady community is 

one way to ensure that the community is prepared 

for localized flooding. The StormReady program 

is administered by the NWS to help communities 

become better prepared for storms and other natural disasters. Because it is not 

limited to the problems of riverine or coastal flooding, the StormReady program 

guidance and materials are particularly well-suited to localized flooding problems. 

The Web site, http://www.stormready.noaa.gov, provides guidance for warning 

dissemination and describes proven methods for educating citizens and preparing 

the community to handle a storm.

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The Turn Around Don’t DrownTM program is a 

public education program developed by the NWS 

to help communities educate residents about 

the dangers of walking or driving in flood waters.

http://weather.gov/os/water/tadd/index.shtml
6-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

To be officially StormReady, a community must:

Establish a 24-hour warning point and 

emergency operations center; 

Have more than one way to receive severe 

weather warnings and forecasts and to alert 

the public; 

Create a system that monitors weather 

conditions locally; 

Promote the importance of public readiness 

through community seminars; and 

Develop a formal hazardous weather plan, 

which includes training severe weather 

spotters and holding emergency exercises. 

Being designated as a StormReady community 

by the NWS is a good measure of a community’s 

emergency warning program for weather hazards. 

It is also credited by the CRS. 

After the Flood

Recovery 

After a disaster, communities should undertake activities to protect public health 

and safety and facilitate recovery. Appropriate measures include:

Ensuring that the basic needs of citizens are met, including shelter, food, 

and safe drinking water;

Monitoring for diseases;

Vaccinating residents for tetanus;

Patrolling evacuated areas to prevent looting;

Clearing streets; and

Cleaning up debris and garbage.

Throughout the recovery phase, everyone wants to get back to normal. The problem 

is, “normal” means the way they were before the disaster, exposed to repeated 

damage from future floods. There should be an effort to help prepare people and 

property for the next disaster. It should include three concurrent tasks:

Inspecting damaged buildings and public facilities to identify mitigation 

measures that can be included during permitted repairs;

Conducting public information activities to advise residents about mitigation 

measures they can incorporate into their reconstruction work; and

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FEMA News Photo

The recovery phase of 

a flood is a good time 

for public information 

programs because people 

are more aware of the 

issues and problems caused 

by flooding.

The Red Cross has a great 

deal of information on 

family preparedness.
Reducing Damage from Localized Flooding: A Guide for Communities 6-9

Chapter 6. Warning and Emergency Services P A R T I I

Updating the community’s mitigation plan and applying for assistance made 

available through the disaster programs.

Inspections 

Requiring permits for building repairs and conducting inspections are vital activities 

to ensure that damaged structures are safe for people to re-enter and repair. Even in 

shallow flooding, the foundation may have shifted or been undermined; electrical 

hazards are always a potential danger; and building components that are saturated 

lose their strength and can collapse, injuring people. There is a special requirement 

to do an inspection in the Special Flood Hazard Area and other regulated floodplains, 

regardless of the type of disaster or cause of damage. 

The National Flood Insurance Program (NFIP) requires that local officials enforce 

the substantial damage regulations in their floodplain management ordinances. These 

rules require that if the cost to repair a building in the floodplain equals or exceeds 50 

percent of the building’s market value, the building must be retrofitted to comply with 

the community’s floodplain ordinance. In many cases, this means that a substantially 

damaged building must be elevated to or above the base flood elevation.

There may be pressure from the public and elected officials to waive this regulation 

in order to help people return to normal as fast as possible, even though that means 

exposing people and buildings to the type of flooding that caused the disaster in 

the first place. Further, waiving the requirement is a violation of the community’s 

adopted regulations and its obligations to the NFIP, and can be cause for placement 

on probation or suspension from the program. However, a community can facilitate 

post-disaster reconstruction and make the permit requirements more palatable 

through such techniques as:

Publicizing the need for permits and explaining how to apply for them;

Keeping the permit office open later;

Setting up a permit office in the affected area;

Having permit officials walk through the flooded area and issue permits to 

repair minor damage without all the application paperwork; and 

Waiving the permit fee.

The substantial damage requirement can be very difficult for understaffed and 

overworked offices after a disaster. If these activities are not carried out properly, 

not only does the community miss a tremendous opportunity to redevelop or clear 

out a hazardous area, but it also may be violating its obligations under the NFIP. In 

some areas, mutual aid agreements have been established so building inspectors 

from a community not affected by the disaster can work in the communities that 

were hit the hardest.

The Federal Emergency Management Agency (FEMA) has developed software to help 

local officials make substantial damage determinations. The software comes with 

a manual, Guide on Estimating Substantial Damage Using the NFIP Residential Substantial Damage 

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6-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

Estimator, FEMA 311. Copies can be obtained from the FEMA Regional Office. Training 

sessions and technical assistance may be available after a disaster declaration.

Public Information Activities

People need to recognize that returning to normal may mean returning to a building 

that will be damaged by another flood. The community should inform its residents 

and businesses about the regulatory requirements and the need to clean and rebuild 

carefully. This can be done through news releases and handouts. 

Sometimes, FEMA or the Red Cross will make copies 

of Repairing Your Flooded Home available in bulk quantities, 

or the community can copy and distribute appropriate 

pages.

The messages that should be disseminated should 

cover:

Safety precautions when returning to a damaged 

building;

Which activities require a permit; 

How to apply for a permit;

Which activities do not require a permit (e.g., 

cleanup and emergency repairs to prevent 

further damage);

The substantial damage rule; 

The benefits of Increased Cost of Compliance 

flood insurance coverage (see Chapter 11);

How to determine the need for licensed 

contractors, if licensing is required by the 

community;

How to implement steps 2, 3, and 4 in Repairing 

Your Flooded Home, such as taking pictures for 

insurance and disaster assistance claims before 

throwing things away, and health and safety 

precautions; and

How to include retrofitting measures as part of repairing homes or 

businesses. 

Mitigation Activities

During the recovery phase of a flood, everyone is more sensitive to flooding 

and interested in doing something about it. It is a good time to build awareness, 

educate residents, and get the public involved in mitigation and other community 

activities.

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Repairing Your Flooded Home

This classic handbook from the American Red 

Cross and FEMA guides flooded property owners through the steps they need to take to reenter and re-occupy their homes after the flood 

waters retreat. Lots of illustrations, lists, and 

references to further sources of information 

combine to describe how to clean up, repair, 

and stay safe. Each chapter, listed below, describes one step.

Step 1. Take Care of Yourself First

Step 2. Give Your Home First Aid

Step 3. Get Organized

Step 4. Dry Out Your Home

Step 5. Restore the Utilities

Step 6. Clean Up

Step 7. Check on Financial Assistance

Step 8. Rebuild and Floodproof

Step 9. Prepare for the Next Flood

Hard copies of the book are available from local Red Cross chapters or by writing to FEMA, 

P.O. Box 2012, Jessup, MD 20794-2012.

http://www.redcross.org/services/

disaster/0,1082,0_570_,00.html
Reducing Damage from Localized Flooding: A Guide for Communities 6-11

Chapter 6. Warning and Emergency Services P A R T I I

The community should evaluate how the warning and 

response systems worked during the flood. Information 

should be collected about where flooding occurred and 

which properties were affected. Documenting high 

water marks can help a community make decisions 

about potential regulatory changes. It may be useful to 

use this information to redraw flood hazard maps, as 

Conway, South Carolina did (see Chapter 4). 

Community staff should go with the disaster assistance 

staff as they inspect public facilities and identify 

opportunities for mitigation during reconstruction 

of the facilities. Certain public and private nonprofit 

facilities are eligible for additional funding for approved 

mitigation measures.

The staff should review and update the community’s 

mitigation plan to reflect what is learned about 

the flooding hazard, the lessons learned from the 

community’s flood response, information collected 

during the building inspections, and available 

mitigation funding.

Where to Get Help

The county office of emergency services or 

emergency management is a good source 

of information, and can describe how other 

communities are addressing flood warning 

systems, response, and public education.

The National Weather Service is an essential 

contact on flood threat recognition and 

warning. Each Weather Service Office has a 

hydrologist who can help set up a local flood 

warning program. They can be found at http://www.nws.noaa.gov/

organization.html.

The National Weather Service StormReady Program can be accessed at 

http://www.stormready.noaa.gov.

The local chapter of the American Red Cross can provide recovery assistance 

and should be included in a community’s response and recovery planning. It 

can also provide valuable information on family preparedness. http://www.

redcross.org.

The State Office of Emergency Management can provide guidance on 

warning systems, emergency response planning, and mitigation resources.

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During post-flood rebuilding, it also can be 

possible to incorporate sustainability principles 

into individual buildings or into neighborhoods. 

In Grand Forks, North Dakota, for example, 

people who had to replace their furnaces or 

hot water heaters because their basements 

got wet during the 1997 flood were offered 

rebates by the community and the local utility 

to encourage them to replace the old models 

with more energy-efficient systems. 

More information on redevelopment is given 

in Chapter 9, and the U.S. Department of 

Energy has a large compilation of suggestions 

for similar measures at its “Smart Communities Network” at http://www.sustainable.doe.

gov/disaster/disintro.shtml.

After a flood in 1995, Jefferson Parish, Louisiana, examined the causes of flooding problems in the Dumonde Subdivision. The area 

had been flooded four times in the previous 10 

years. The investigation found two homes and 

a wooden fence that obstructed drainage from 

the subdivision. The Parish applied for and 

received a Hazard Mitigation Grant from FEMA. 

It acquired the properties, cleared the buildings and the fence, and restored the drainage 

system
6-12 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I Chapter 6. Warning and Emergency Services

FEMA has many resources for helping to prepare residents for flooding at 

http://www.fema.gov/hazards/floods/floodf.shtm.

CRS Credit for Flood Warning Programs provides guidance on flood threat 

recognition, warning dissemination, and flood response planning.

Technical assistance and financial help for post-flood mitigation projects 

are available from a variety of sources. The first place to contact is the FEMA 

Disaster Field Office, if a Presidential disaster declaration has been made. The 

next place is the State emergency management agency.

Examples of flood warning and public safety publicity can be found in CRS 

Credit for Outreach Projects.

Additional resources are listed in Appendixes A and B.

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RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 7
Reducing Damage from Localized Flooding: A Guide for Communities

Part III

NeighborhoodLevel Tools and 

Techniques

Part I of this guide notes that actions to solve localized flooding problems can be 

taken at three different levels: at the community level, at the neighborhood level, and 

by individual structure. Part II discusses the community-level approaches.

Part III focuses on the specific neighborhood or block where the flooding takes place. 

Chapter 7 reviews the area analysis, a process that determines whether flood protection 

approaches should be pursued at the area (or neighborhood) level. There are two 

types of area-wide approaches: making improvements to the drainage system, or 

redeveloping one or more parcels. Chapter 8 covers drainage system techniques that 

are appropriate at the neighborhood scale, and Chapter 9 describes redevelopment 

options.

Part III:

Chapter 7. Area Analysis

Chapter 8. Drainage Improvements

Chapter 9. Redevelopment

Reducing Damage from Localized Flooding: A Guide for Communities 7-1

Area Analysis

The “Area”

Delineating Areas

The first step in an area analysis is to determine the boundaries of the area, watershed, 

or neighborhood to be reviewed. There is no standard or optimal size area or typical 

number of buildings involved. An area for analysis can have 1 building or 100 or 

1,000, as long as it is an area of contiguous properties subject to the same source of 

flooding. Areas subject to local drainage problems and flooding outside the mapped 

Special Flood Hazard Area (SFHA) usually will be relatively small.

The ideal approach is to start with the most frequently flooded sites and delineate 

the drainage basin or subwatershed that drains to them. This can be done if adequate 

topographic maps are available. Sometimes, such as in flat areas or neighborhoods 

subject to sewer backup, this can be difficult. 

An important part of an area analysis is to work with the property owners. Therefore, 

the area should be delineated, where possible, to include existing neighborhoods 

or neighborhood organizations, even if this means extending the boundaries of the 

area to be analyzed beyond the drainage basin boundaries.

In order to determine whether one of the neighborhood-level approaches (discussed 

7

in the remaining two chapters of Part III) would successfully resolve localized 

flood problems, an area analysis needs to be conducted. The area analysis is a 

scaled-down plan that focuses on a relatively small portion of the community. If 

it concludes that there are no feasible or appropriate drainage or redevelopment 

projects that would resolve the localized flooding problem, the community would 

pursue protection measures on an individual building basis (covered in Part IV).
7-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

Prioritizing Areas

The community can conduct an area analysis for areas that have requested it or that 

have been flooded recently. Or, it can delineate all localized flood problem areas and 

set priorities to analyze each in turn. It is a good idea to prioritize all action items, 

expenditures, and projects, and document why certain items are given precedence. 

Documenting the prioritization process can help keep planners impartial and justify 

funding for projects. The following factors can be considered when prioritizing 

areas:

Start with areas with properties that are on the Federal Emergency 

Management Agency (FEMA) severe repetitive loss or repetitive loss list and 

are priorities for FEMA mitigation funding programs. Contact your local 

floodplain coordinator or Regional FEMA Office for assistance.

Start with smaller areas that will be easier to analyze. It is a good idea 

to begin a program by tackling the smaller, more manageable problems 

and then move on to the larger problems as procedures and expertise are 

improved.

Start with the areas where the residents are actively requesting assistance 

or that have been recently flooded. These areas are most likely to have 

motivated, interested property owners who will be willing to cooperate with 

the community’s effort.

Start with the areas that have the greatest flooding threat to health and safety, 

such as areas subject to flash floods or fast-moving flood waters. 

Conducting the Analysis

The objective of the analysis is to determine if there is a feasible and appropriate 

way to reduce flood damage at the area or neighborhood level. The analysis can be 

informal or highly organized. In either case, it is important to involve the owners of 

the affected properties. A written report is also recommended, showing the process 

that was followed and the rationale for the conclusions.

The following five steps are suggested:

Advise the neighborhood about the upcoming analysis.

Determine the cause and extent of the problem.

Review alternative area-level approaches.

Contact other parties about their activities and possible coordination of 

efforts.

Document the findings.

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1.

2.

3.

4.

5.
Reducing Damage from Localized Flooding: A Guide for Communities 7-3

Chapter 7. Area Analysis P A R T I I I

Step 1. Advise the neighborhood.

Residents and owners of the properties in the area should be told that the community 

plans to initiate the analysis. This notification can be done through the mail or at a 

public meeting. The notice should include the following:

Review the reasons for the analysis and the process that will be followed.

Request information on the causes and impacts of past flooding. Use a 

form to facilitate review and summary. An example of a request for this 

information is shown on the next page.

Inform residents that all information is voluntary.

Advise that field crews or surveyors will be in the area and include the dates, 

if known. Explain that community staff have identification cards.

Provide the name and telephone number of someone who can answer 

questions.

Provide the date, time, and place of a meeting that will review the results of 

the analysis.

Step 2. Determine the problem.

The community’s engineer should review available 

data, such as:

The community’s Flood Insurance Rate Map 

(FIRM) and Flood Insurance Study;

Other flood studies and reports;

Stormwater management plans;

A topographic map or other source with more 

detailed contour data than the map used to 

prepare the FIRM (see the Gurnee and Conway 

examples in Chapter 4);

Questionnaires and information provided by 

the residents;

Flood insurance claims data that provide the 

location and dates of flood events and the extent 

of damage (see Where to Get Help); and

Field investigations to locate or confirm channel 

obstructions or other reported causes of 

flooding.

A hydrologic and hydraulic study is not necessarily 

warranted at this step, nor are detailed flood elevations 

needed. Step 2 can be performed using engineering 

judgment and staff experience. The product of Step 2 

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FEMA has developed a useful software application to collect information on flood problems 

and building conditions. The National Flood 

Mitigation Data Collection Tool provides a stepby-step process to gather information on each 

building in the area to be analyzed. If the area 

analysis concludes that site-specific approaches should be pursued, the data and the software can be very helpful in determining which 

measures would be most appropriate.
7-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

Village of Gurnee/Lake County, Illinois Stormwater Management Commission

Flood Protection Questionnaire 

Property address: ______________________________________________________________________________

1. Has your home or property ever been flooded or had a water problem? ( ) Yes ( ) No

 If “yes,” please complete this entire questionnaire.

 If “no,” please complete questions 6 – 9.

2. In what years did it flood? _____________________________________________________________________

3. Where did you get water and how deep did it get?

 ( ) In basement: ______________ deep.

 ( ) In crawl space: _____________ deep.

 ( ) Over first floor: _____________ deep.

 ( ) Water kept out of house by sandbagging, sewer valve or other protective measure.

 ( ) In yard only.

4. What do you feel was the cause of your flooding? Check all that affect your building.

 ( ) Storm sewer backup ( ) Sanitary sewer backup

 ( ) Sump pump failure/power failure ( ) Saturated ground/leaks in basement walls

 ( ) Standing water next to house

 ( ) Overbank flooding from _________________________________________ River/Lake

 ( ) Other: ___________________________________________________________________________________

5. Have you installed any flood protection measures on your property?

 ( ) Sump pump ( ) Backup power system/generator

 ( ) Overhead sewers or sewer backup valve ( ) Sewer plug or standpipe

 ( ) Waterproofed walls ( ) Moved things out of the basement

 ( ) Regraded yard to keep water away from building

 ( ) Other: ____________________________________________________________________________________

6. When did you move into the building? ____________________________________________________________

7. What type of foundation does your building have?

 ( ) Slab ( ) Crawlspace ( ) Basement ____________________________________

8. Do you have flood insurance or a sewer/basement flood rider to your homeowner’s insurance? 

 ( ) Yes ( ) No

9. Do you want information on protecting your house from flooding or sewer backup? 

 ( ) Yes ( ) No If yes, please include your full mailing address.

Please include any comments you may have about flooding in your area.

This questionnaire was sent to residents of a flood-prone area in Gurnee, Illinois.

[The reverse side had the Village Hall address and a stamp so the form could be folded and mailed after it was 

filled out.]
Reducing Damage from Localized Flooding: A Guide for Communities 7-5

Chapter 7. Area Analysis P A R T I I I

would be a narrative and/or map. Examples of findings from a community’s investigation 

are listed in the table below. It is important to remember that if a drainage modification 

project looks feasible as an alternative, a hydrologic and hydraulic analysis will be 

needed to make sure the improvement is properly sized. Too often a community goes 

forward with a poorly conceived solution that is destined to fail, is under-sized for 

the job, or worsens flooding elsewhere.

Examples of Flood Problems and Possible Approaches to Resolve Them

Problem Statement Approaches to Investigate

On four occasions in the last 5 years, local storms overloaded 

the ditch along County Road 14 and flooded nearby houses. 

The ditch has filled in with sediment over time and can no 

longer carry flows from a severe storm.

Dredge the ditch

Enlarge the ditch 

Initiate a drainage 

maintenance program

Install an underground 

sewer

•

•

•

•

The storm sewer system was designed and installed in 

1950. At that time, it could handle the 10-year storm from 

the upstream drainage basin. Since then, the basin has 

been urbanized and the amount of runoff has substantially 

increased. The storm sewers have deteriorated over time and 

now surcharge once every 2 years on the average.

Install an upstream storage 

basin

Install larger storm sewers

•

•

Intense storms in June 2000 and July 2001 resulted in 

overland flow over construction sites on Vine and Race 

Streets. Lumber, trash, and other loose items were washed 

into the ditch. The debris caught at the culvert under Broadway 

and plugged the pipe, resulting in a 3-foot backwater which 

flooded eight houses.

Enlarge the culvert

Install a trash rack

Initiate a drainage 

maintenance program

Enforce a construction-site 

housekeeping program

•

•

•

•

The houses at 103, 105, and 107 Elm Street are bi-levels 

with garages below grade. Approximately once each year, 

stormwater runoff flows onto Elm Street to a level higher than 

the sidewalk. The water flows over the sidewalk and down the 

driveways. Only these three properties have been affected.

Improve the storm sewers

Raise the sidewalk

Install an upstream storage 

basin

Acquire the three homes

•

•

•

•

Flood insurance records show damage to 12 houses and one 

business on July 1, 1990, August 3, 1995, July 26, 1999, and 

July 17, 2002. A review of the area shows that there are 15 

similarly situated homes and businesses that either were not 

insured or did not have enough damage to warrant a claim, 

but are likely to have been flooded on these dates. The area 

is very flat and poorly drained. Construction of homes and 

streets in a grid pattern has cut the drainageways that existed 

before development. This is an area that should not have been 

developed without construction of new drainage ditches and 

pumps.

Improve drainage

Acquire the lowest 

properties and redevelop 

the site as a storage basin

•

•
7-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

Step 3. Review alternative approaches.

The objective of the area analysis is to determine if an area- or neighborhood-level 

approach is feasible and appropriate. Chapters 8 and 9 discuss specific techniques under 

these approaches. Here are some examples of neighborhood-level approaches.

Drainage modifications, such as removing obstructions or enlarging culverts, 

ditches or storm sewers, to carry the floodwaters away from the area;

Storage basins to hold the water upstream from the area and/or release it 

over time;

Levees, floodwalls, berms, and other structures to divert floodwaters away 

from flooded properties; 

Better maintenance of the drainage system to remove obstructions to low 

flows; and

Acquisition of some or all of the flood-prone properties and conversion to 

open areas that will not be damaged when flooded or to other appropriate 

uses.

Some approaches will be obvious while others will take some time to investigate. If 

residents have voiced a strong opinion about one or two approaches, these should 

be studied, even if the professional engineer thinks they are not feasible. The success 

of this program depends on local support; resident interests should be pursued and 

the advantages and disadvantages of each approach should be clearly explained.

Examples of approaches that could be explored for different problem scenarios are 

shown in the table on the preceeding page. Although these solutions may appear 

simple, the engineer will need to review their pros and cons and determine if they 

effectively reduce the flood problem and are also 

affordable. 

For example, installing larger storm sewers appears to 

be the answer to overloaded storm sewers. However, 

replacing existing sewers can be very expensive and the 

impact of increased flows onto downstream properties 

would need to be considered. Such an approach may 

be readily ruled out as infeasible by an experienced 

engineer. If so, the analyst needs to provide a rough 

cost estimate, rather than summarily state that it is too 

expensive.

Step 4. Contact other parties.

Other agencies or organizations may have plans that 

could affect the cause or impacts of the flooding. For 

example, if the roadside ditch is along a State or county 

highway, are there plans to work on the road or improve 

the ditch? Key agencies and organizations that should 

be contacted include the following:

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The area analysis process can be abbreviated

if the problem is small or the solutions are obvious. In the first example in the table on page 

7-5, it may be that neighbors and the analyst 

agree that cleaning out the ditch would alleviate the flooding problem. Such a project could 

be conducted by a public works crew in a day. 

All that would be needed is a memorandum 

for the record that explains the problem and 

recommended solution.

The more formal step-by-step process is 

recommended for:

Larger problems; 

Problems that have resulted in resident complaints over the years; 

Problems with no obvious solution; and

Problems that will be expensive or disruptive 

to the neighborhood.

•

•

•

•
Reducing Damage from Localized Flooding: A Guide for Communities 7-7

Chapter 7. Area Analysis P A R T I I I

Drainage, levee, sewer, or sanitary district responsible for flood, drainage, or 

sewer problems;

Local or State street or highway department that may improve a ditch, 

bridge, or culvert or construct a project that will affect drainage;

Parks department or school district that may be interested in expanding open 

space lands or athletic fields;

An adjacent landowner or a developer or economic development agency that 

may be interested in acquiring, clearing, and redeveloping some properties;

State emergency management or State National Flood Insurance Program 

coordinating office, council of government, or regional planning agency 

that would know of ongoing mitigation efforts, funding sources, and their 

priorities; and

Environmental or open space organizations, such as the Nature Conservancy 

or the Trust for Public Land, that might be interested in converting problem 

areas into open space.

The analyst should discuss the findings from Step 3 with the agency or organization 

to determine if there are opportunities for cooperation, coordination, cost sharing, 

or modifying the approach to gain support from the agency or organization.

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French & Associates

Sometimes a minor ditch-clearing project can stop flooding and drainage problems.
7-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

Step 5. Document the findings.

The analyst should prepare a short report that includes the following items:

A summary of the process that was followed;

A summary of residents’ comments and/or a tally of the questionnaires;

The problem statement with a map of the area affected and/or the drainage 

basin, if possible;

The alternatives reviewed and their advantages and disadvantages;

Relevant activities by other agencies and organizations; and

Conclusions and recommendations.

The document should be reviewed, either by another engineer or by the community’s 

upper management. Upper management or an elected official (e.g., the council 

member for the area being analyzed) can verify that the recommendations are 

politically acceptable.

Follow-Up Activities

A draft report will be the likely product at the end of Step 5. Before it is officially 

adopted as the way to reduce flood damage for the area, three follow-up activities 

should be pursued.

Neighborhood Review

Neighborhood support is vital, especially if the proposed project depends on access 

onto private property, obtaining easements, or voluntary sales of property. The analysis 

findings should be reviewed with the residents and 

property owners of the affected area. 

If it is not too long, the document could be sent to 

everyone. An alternative is to send a notice to everyone 

with a Web link to where the document can be read.

There should also be a meeting with the neighbors. 

The author of the analysis can review the problem, the 

alternatives, and the conclusions and recommendations. 

The community can gauge support for the 

recommendations at the meeting. Unanimous support 

may not be necessary, but if there is strong opposition, 

the recommendations may need revision or extra time 

may be needed with the concerned parties.

Detailed Plans

If the recommended project proves appropriate (i.e., it will reduce flood losses and has 

resident support), it should be verified that it is also feasible (i.e., it is cost-effective 

and can be funded). The analyst should have estimated the cost and reviewed cost-

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There may be many cases in which the area 

analysis concludes that there is no appropriate 

or feasible drainage, flood control, or redevelopment project. In these situations, community staff should begin looking at site-specific 

projects, such as retrofitting. 

The meeting to review the findings of the 

area analysis can be used to introduce the 

concept of site-specific approaches and to 

schedule appointments with the property 

owners.
Reducing Damage from Localized Flooding: A Guide for Communities 7-9

Chapter 7. Area Analysis P A R T I I I

effectiveness during Step 3. Some level of hydraulic and hydrologic analysis will 

probably be needed.

For small projects, such as cleaning out a ditch, no further details may be needed. 

For larger projects, a formal cost estimate may need to be prepared. If FEMA funds 

will be sought, a formal benefit-cost analysis (BCA) should be conducted, preferably 

using FEMA software, because it will be required when application is made. The 

community may opt to contract out this work for very large projects. 

Funding

The final activity is to schedule and fund the recommended project. Small projects, 

such as ditch cleaning, may just be a work order for the public works department. 

Larger projects may have to be funded or budgeted individually. 

There are usually four sources of funds for a flood mitigation project: 

Local funds;

State funds; 

Federal funds; or

The benefiting properties.

Typically, larger projects use a combination of sources. For example, most State and 

Federal programs will only fund a percentage of a project’s cost and require a local 

cost-share to make up the difference.

Local Funds

Most communities have operating budgets and capital 

budgets. Operating budgets fund routine activities 

and capital budgets fund one-time-only construction 

projects. Smaller flood mitigation projects can often be 

funded from an operating budget account, while larger 

ones are considered capital improvement projects. 

Typically, operating budgets are funded by taxes, such 

as property or sales taxes. There are usually limits to 

how much can be raised, so flood projects compete 

with other community concerns for the limited funds 

available. 

Capital budgets are often funded by bond issues. Some 

bond issues require a referendum that sets the purpose 

and the amount of funds to be made available. Again, 

there may be a limited amount of money available.

Increasingly, communities are turning to sources other than their limited generalpurpose taxes. Sometimes special revenue sources can be used. For example, if a 

roadside drainage ditch is causing a localized flooding problem, the community 

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The CRS provides credit under 

Activity 540 (Drainage System 

Maintenance), if the community has an ongoing program, 

such as a capital improvements 

plan, “to eliminate or correct problem sites or 

to construct ‘low maintenance’ channels or 

other facilities.” There is no credit for this item 

if the community does not spend money on a 

regular basis on such improvement projects (a 

one-time-only project would not be credited). 

More information can be found in CRS Credit 

for Drainage System Maintenance.
7-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

may be able to use its share of the State gasoline tax to make improvements that also 

reduce street flooding. Projects to relieve or prevent sewer backup are often funded 

by sewer utility revenues.

The most promising new source of local funding is the stormwater utility. Stormwater 

utilities charge each property according to how much it uses the stormwater system 

(i.e., how much stormwater runoff it generates). As with a water or sewer utility, 

everyone pays according to how much they use the system. Unlike some taxes, no 

properties are exempt. Utility bills are sent to all properties, or the stormwater fee 

is included in the water or sewer bill.

Typically, each single-family home pays a base rate, usually $2 to $5 per month. 

Other properties pay according to their “equivalent residential unit” amount of 

impervious surface. A five-acre shopping center with a parking lot would pay more 

than a five-acre lot with one building and a lawn. Often credits are provided for 

good stormwater management practices, so a shopping center with a storage basin 

would pay a lower utility fee.

Stormwater utilities have proven to be a dependable source of funds for both operating 

and capital expenses. A set amount of money is raised each year for flood mitigation 

that is not subject to diversion to other uses. Communities with stormwater utilities 

have greatly improved their stormwater and flood protection programs.

State Funds

Some States have special appropriations to fund local flood protection, acquisition, 

and retrofitting projects. Some examples include:

Washington’s Flood Control Assistance Account Program receives $4 million 

from the State legislature every two years. 

Minnesota’s Flood Damage Reduction Grant Program provides 50% of the 

local cost of flood mitigation projects.

Virginia collects surcharges on insurance policies and places the funds in a 

State mitigation fund.

Florida has several dedicated State funds that can be used for flood 

mitigation, including the Emergency Management Preparedness Assistance 

Trust Fund, the Residential Construction Mitigation Program, and the 

Communities Trust Program.

More information on State programs can be obtained from the State National Flood 

Insurance Program (NFIP) Coordinator. A directory of State NFIP coordinators can 

be found at http://www.floods.org/StatePOCs/map.asp.

Federal Funds

Several Federal agencies can provide funding support for certain types of flood 

protection projects. This section identifies the programs and where more information 

can be obtained.

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Reducing Damage from Localized Flooding: A Guide for Communities 7-11

Chapter 7. Area Analysis P A R T I I I

FEMA has several grant programs for acquisition, retrofitting, and small drainage 

improvement projects. The Hazard Mitigation Grant Program, Flood Mitigation 

Assistance, and Pre-Disaster Mitigation program are explained on pages 9-9 and 

9-10. For more information, contact the FEMA Regional Office (see http://www.

fema.gov).

The U.S. Army Corps of Engineers can help design and fund flood control projects. 

For the local Corps of Engineers district, see http://www.usace.army.mil.

The Department of Housing and Urban Development administers the Community 

Development Block Grant program. Larger cities and counties receive entitlement 

grants; smaller communities apply to their county or State community development 

agency. Funds may be limited to projects that benefit low- and moderate-income 

families or economic development. Block Grant funds can also be used to help cover 

the non-Federal match required by other Federal programs. For more information, 

see http://www.hud.gov/offices/cpd/communitydevelopment/programs/index.

cfm.

Benefiting Properties

A fourth source of funding for a project to reduce flood damage is the owner of the 

property who benefits from the project. In many communities, the property owner

has paid the 25% non-FEMA cost share for an acquisition or retrofitting project. 

Sources of assistance to help these people are summarized on pages 10-20 through 

10-21.

Many communities have the authority to create special service districts or levy special 

assessments. In these situations, owners of the benefiting area pay an additional 

property tax. The additional tax revenue is used to retire the bonds that funded the 

project. Each State has its own procedures for using these tools.

Impact fees are contributions from developers. They are designed to offset the cost 

a new development will add to the community’s expenses. For example, if a new 

subdivision increases the amount of runoff that drains into the community’s storm 

sewer system, the developer might be charged an amount sufficient to pay for 

increasing the capacity of that system. 

In Fairfax County, Virginia, for example, developers are required to contribute to the 

cost of handling the increased stormwater runoff produced by their developments. 

The fees are put into a fund for drainage projects. The fund can pay for a retrofitting 

project where it is shown to be an economical way to handle a drainage problem. 

The project illustrated on page 10-7 was funded under this program.
7-12 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 7. Area Analysis

Where to Get Help

There are no special programs to help fund an area analysis, although such 

work is primarily staff time, which may not need outside funding support.

Federal Emergency Management Agency Regional Offices.

FEMA has a benefit-cost (BCA) helpline at 1-866-222-3580 to answer 

questions regarding the benefit-cost procedures.

Additional resources are listed in Appendixes A and B. 

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RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 8
Reducing Damage from Localized Flooding: A Guide for Communities 8-1

Drainage 

Improvements

Every community has a drainage system, either natural or human-made or, 

more likely, a combination of both. The drainage system carries surface water 

from where it falls (or where the snow melts) through channels to a receiving 

body of water.

This chapter focuses on improvements to local drainage 

systems. In most cases, these improvements will be 

applicable to small streams or areas with stormwater 

drainage problems. The types of drainage projects 

described here are smaller than flood control projects, 

and would not be expected to alter a 100-year flow 

or result in a change in a flood hazard area boundary. 

However, if communities implement the measures 

outlined in this chapter, they will see a reduction in 

overall flooding problems.

The Drainage System

Terminology

The setting for the drainage system is the watershed. 

A watershed is an area that drains into a lake, stream, or other body of water. Other 

names for a watershed are “basin” or “catchment area.” Watersheds vary in size, and 

larger ones can be divided into sub-watersheds.

The boundary of a watershed is a ridge or a divide. Water from rain and snowmelt 

is collected by the smaller channels, or tributaries, which can be natural streams, 

ditches, or swales. Swales are shallow flow areas that may not look like a defined 

channel. These tributaries collect the surface water and send it to larger channels and 

eventually to the lowest body of water in the watershed (main channel). 

Watershed terms.

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P A R T I I I Chapter 8. Drainage Improvements

When there is too much surface water, it flows out of the channel and floods the 

adjacent areas. This scenario can happen along the main channel, where the floodplain 

may be mapped on the community’s Flood Insurance Rate Map (FIRM) as an A Zone. 

Or, it can happen along the smaller upland tributaries, ditches, and swales, which 

may not be mapped on the FIRM, but are shown as a B, C, or X Zone.

What happens in a watershed affects events and conditions downstream. In relatively 

flat areas, shallow, slow-moving flood water may cover large areas of land for days or 

even weeks. In hilly areas after a heavy rain, a flood may come and go in minutes.

Development and Drainage 

If the watershed and its floodplains are undeveloped, water is temporarily stored 

while the channel is overflowing. This allows excess water to filter into the ground 

during and after the rain or snowmelt, reducing the amount of water moving 

downstream. 

The buildings, streets, and parking lots that accompany 

human development replace the natural ground 

cover, which allowed infiltration into the soil, with 

impervious surfaces, which do not allow water to be 

absorbed. Storm sewers and ditches collect surface flows 

and discharge them away from developed sites and into 

downstream systems. 

When rain falls in a natural setting, as much as 85 

percent of it will infiltrate into the ground, evaporate, 

or be absorbed by plants. Human development in the 

watershed and the floodplains changes the natural 

conditions of the ground surface. In an urbanized area, 

as much as 60 percent of it will run off, as illustrated 

on this page.

The result of urbanization is that there is more 

runoff in the watershed, which can increase flooding 

downstream. For example, the amount of runoff from 

a 5-year rainfall on a developed parcel in the Houston 

area can be more than the runoff from a 50-year rainfall 

on the same parcel had it had been left undeveloped; 

this overloads the drainage system. 

Urbanization also changes the timing of flows along 

the tributaries. After a subwatershed develops, the 

peak runoff will leave sooner than it used to, possibly 

arriving at the main channel at the same time as the 

peak arrives from another tributary, causing increased 

flooding downstream.

Note: These represent findings from land use 

conversions in the Chicago area. Actual values 

are site-specific and depend on the initial land use 

condition, soil type, degree of ground saturation, 

and the storm’s duration.

Stormwater runoff increases 

as areas are urbanized
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Chapter 8. Drainage Improvements P A R T I I I

Conveyance 

The drainage system can perform two functions: it carries water away and, during 

times of high water, it may store water until it can be carried away. The drainage 

system therefore contains conveyance systems and may contain storage facilities. 

Traditionally, human alterations to drainage systems 

focused on conveyance. People wanted to move water 

away from a site as quickly as possible. Ditches and 

storm sewers were built to collect the surface water 

more quickly and send it to the larger streams. Natural 

channels were altered to be larger and/or straighter so 

they could carry more water more efficiently. 

Urban or human-made channels are different from 

the natural channels. As illustrated here, human-made 

channels may carry more water, but may need more 

maintenance to provide proper conveyance. To function 

properly, it is necessary that they be kept clean and 

clear.

The urban drainage system also includes storm sewers 

(i.e., pipes) that carry smaller flows underground. 

When storm sewers work, the streets and yards are 

drained quickly. Storm sewers won’t work for storms 

General Channel Types

A human-made drainage ditch or canal is typically 

designed to use less surface area to carry more 

water. These channels need more attention because 

there is no room to carry overflows caused by blockages. They are not intended to have trees or other 

vegetation growing in them. In human-made ditches, 

too much vegetation is considered “debris.”

CRS Credit for Drainage System Maintenance, page 9

A community’s drainage system is usually a combination of natural and human-made channels and 

storage basins.

A natural channel typically has a wider area in 

which to flow. Trees and small log or debris jams 

can be accommodated by minor diversions of flow 

without causing any problems. In fact, vegetation 

and minor obstructions that cause riffles and pools 

are desired in many natural streams because they 

improve habitat and water quality. 

French & Associates

Human-made ditches can carry more water, but they 

may require more maintenance.
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P A R T I I I Chapter 8. Drainage Improvements

greater than their design specification, or when they 

are blocked. Typically, neither the storm sewer nor the 

inlets are designed to handle larger storms, such as the 

100-year event; overflow paths should be provided that 

will protect surrounding buildings from damage.

Blockages can be caused by debris at the inlet, an outlet 

or outfall that is under water, a broken pipe, or debris or 

sediment in the pipe (see diagram for terminology). 

After a watershed is developed, the natural channels in 

urban drainage systems have to carry more water for 

longer periods. As a result, the water scours the channel 

bottom and banks and increases bank erosion. 

In the last 30–40 years, communities have been using storage basins as an alternative 

approach to addressing the problems created by urban drainage channels.

Storage

Under natural conditions, the floodplain provides storage for the drainage system. 

When a stream floods, the water is often stored in the floodplain area outside the 

waterway’s banks. The excess water drains back into the river as the water level goes 

down. 

Today’s drainage systems typically include human-made storage basins, especially in 

the newer areas. Storage basins can be dry or wet. Dry basins are intended to drain 

completely and not to hold any water between storm events. The land may be used 

for other purposes, such as a park or playing field. 

Wet bottom basins have permanent pools of water that function like natural ponds. 

Excess runoff is stored above the permanent water level in the basin and is discharged 

at a reduced rate through an outlet. Some communities prefer wet basins because 

they provide a water amenity, but others may be concerned about the safety hazard 

of having children playing near a body of water.

Communities have built larger basins to reduce flooding in developed areas and 

they require new developments to build basins to store their excess runoff on site. 

As noted in Chapter 4, most communities now require that new developments 

ensure that the peak flows leaving their sites are no greater than they were before 

the development.

A third approach is to incorporate natural storage areas into the design of the 

drainage system. Preserving wetlands and natural depressions has been found to be 

very effective for storing (and filtering) flood waters. See the example of Butterfield 

Creek on page 4-15.

Water Quality

Human activity within a watershed affects how and where stormwater runoff flows 

and also affects the quality of the water. Most stormwater runoff affected by human 

activity eventually ends up in a stream, river, lake, or other water body. There are 

French & Associates

Storm sewer terminology.
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Chapter 8. Drainage Improvements P A R T I I I

many programs to monitor, regulate, and in general protect streams, rivers, and 

lakes from being polluted by contaminated runoff, discharges of pollutants, and 

other sources. 

One program that affects most communities was established under the Federal Clean 

Water Act to ensure that only water of a certain quality is discharged into the waters 

of the United States. The National Pollutant Discharge Elimination System (NPDES) 

regulates the type and amount of pollutants and sediment that a community can 

release from its drainage system into a water body (see below). 

Water quality is not the subject of this guide, but it is important to keep its principles 

and goals in mind when considering the drainage system, because many of the 

techniques for preventing and relieving localized flood problems are the same as 

those for preventing water pollution.

Local Stormwater—Quality and Quantity Intertwined

Under their stormwater programs, communities 

use best management practices, or “BMPs,” that 

are recognized techniques for improving water quality. Some of these are described in this guide as being central to flood mitigation as well. Some BMPs 

for stormwater management are:

Using buffers

Planning

Installing riparian (stream-side) zone protection

Minimizing land disturbance

Maximizing open space

Installing wet ponds

Establishing wetlands

Using filtering practices

Building open channels for storage

Using infiltration measures

Planting vegetation

The NPDES stormwater regulations now apply 

to all stormwater systems that serve more than 

100,000 people and to smaller ones that are 

located in urbanized areas or are designated by the 

state or EPA as being subject to the regulations. 

Construction sites larger than one acre are also 

required to have NPDES permits.

For more information, see http://cfpub.epa.gov/

npdes/.

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Section 402 of the Clean Water Act directed the 

U.S. Environmental Protection Agency (EPA) to 

develop and implement a program to prevent harmful pollutants from being released into the nation’s 

surface water from sources such as wastewater 

treatment plants, agricultural operations, and stormwater drainage. Under the program (the National 

Pollutant Discharge Elimination System (NPDES), 

which is administered by most states on behalf of 

EPA), most communities that operate a storm drainage system must obtain a permit to discharge their 

stormwater drainage into a local water body. To get 

the permit, the community must have a local stormwater management program that includes these 

components, most of which are also fundamental to 

sound management of flood problems:

Public education and outreach on stormwater 

impacts.

Public involvement and participation.

Identification and elimination of illicit discharges 

to storm sewers.

Control of construction site runoff.

Control of stormwater runoff from development.

Reduction of pollutant runoff from local government operations.

The NPDES permit specifies what can be discharged, how the level and type of pollutants in the 

water are to be monitored and reported, and other 

provisions.

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P A R T I I I Chapter 8. Drainage Improvements

Modifying the Drainage System 

Methods for modifying the drainage system focus on 

its two main components: conveyance and storage 

facilities. Because the purpose of drainage ditches and 

storm sewers is to safely convey water downstream, 

modifications to conveyance are recommended only 

where the receiving stream or river has sufficient 

capacity to receive the increased volume of water. To 

minimize the cumulative downstream flood impacts 

that may result from multiple small drainage projects, 

more detention or runoff reduction techniques should 

be considered along with the channel or storm sewer 

improvements. 

Remember that the drainage system serves many 

purposes. Modifying it for one purpose—flood 

protection—can have adverse impacts on its other 

purposes. As noted on page 8-4, a natural stream 

carrying more flow will often result in bank erosion 

and accompanying sedimentation. Water moving out 

of the area too quickly can inhibit the natural process 

of filtering out pollutants. Altering the channel with rock or concrete will damage 

or destroy habitat and the aesthetic value a stream provides to adjacent property 

owners.

Channel Modifications

Four types of channel modifications are usually used to reduce localized flooding: 

channelization, vegetated swales, dredging, and increasing conveyance at stream 

crossings. 

Channelization. Channelization means straightening, deepening, and/or widening 

a ditch or drainageway. It is important to emphasize some concerns about this 

approach.

Channelized streams can cause or worsen flooding 

problems downstream because more water is 

transported more efficiently and often at a faster 

rate. 

Channelization projects destroy habitat (see 

bottom photo, this page).

Channelized streams rise and fall faster than 

natural ones. When the weather is dry, the water 

level in the channel is often too low, which can 

diminish water quality and degrade the streamside and aquatic habitat. 

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This project improved the carrying capacity of the 

channel and protected some of the banks, but had an 

adverse effect on the natural functions of the stream 

and created new maintenance costs for the community.

French & Associates

Channelization project.
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Chapter 8. Drainage Improvements P A R T I I I

Channelized waterways need more frequent maintenance to ensure that they 

keep their carrying capacity (see illustrations on page 8-3 and top photo on 

facing page). 

Vegetated swales. A vegetated swale is an open channel that is used to convey 

stormwater in place of conventional ditches or storm sewers. Swales are also used to 

treat stormwater runoff by using native vegetation to filter pollutants.

Vegetated swales have advantages over traditional concrete-lined ditches or storm 

sewers:

They are less expensive to build (although they may take up more surface 

area);

They are less expensive to maintain;

They more closely preserve the natural hydrologic characteristics of the 

drainageway; and

They clean the stormwater by filtering it through the vegetation.

Drainage system modifications can be combined with wetland creation, vegetated 

swales, infiltration trenches, and other best management practices that increase 

infiltration (reducing runoff) and improve water quality.

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Drainage modifications do not have to be concrete channels. They can include measures to improve infiltration 

and water quality.

French & Associates French & Associates

Dredging. Dredging involves the excavation of the channel bottom. It is often 

requested by residents who believe it will increase channel conveyance, but it poses 

these problems:

Given the large volume of water that comes downstream during a flood, 

removing a foot or two from the bottom of the channel may have little effect 

on reducing flood heights. 

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Dredging is often cost-prohibitive because the dredged material must be 

disposed of somewhere.

Steeper side slopes increase bank erosion.

Unless in-stream and upstream erosion problems are corrected, the dredged 

areas usually fill back in within a few years, and the process and expense 

have to be repeated.

If the channel has not been disturbed for many years, dredging will destroy 

the habitat that has developed.

To protect the natural values of the stream, there are many places where Federal law 

requires obtaining a Section 404 permit from the U.S. Army Corps of Engineers before 

dredging can proceed. This can be a long process requiring advance planning and 

many safeguards to protect habitat (which adds to the cost of the project). In general, 

dredging a length of a channel is usually not recommended, although removing 

siltation at an obstruction, such as a bridge, may be worthwhile.

Stream crossings. Undersized stream crossings are a 

frequent problem in stream systems. An undersized 

culvert or bridge opening constricts flows and causes 

localized backwater flooding. One way to identify such 

places is to check the flood profiles, which are graphic 

portrayals of flood elevations that can be found in the 

community’s Flood Insurance Study or local flood 

studies. Obstructions that back up water appear as stair 

steps on the graph (see illustration).

A common solution to these problems is to enlarge the 

culvert or bridge opening. In some cases, the existing 

culvert may act as a dam and provide flood storage 

upstream of the road. Increasing the culvert openings 

will reduce the flooding upstream; however, it will also 

allow more water downstream. Project plans need to 

ensure that the projects do not make flooding worse 

somewhere else and do not result in scour at the bridge 

or culvert.

As noted on page 2-6, the Village of Orland Hills was 

faced with undersized and deteriorating culverts. After 

a flood in 1996, the Village applied for and received 

disaster assistance funds to repair them. In the process, 

the culverts shown in Figure 2-2 (page 2-6) were 

replaced with larger openings.

Storm Sewers

Storm sewers can be an effective means of conveying local drainage and discharge 

into a receiving stream or a stormwater management facility. Flow capacity in storm 

sewers can be increased by installing new sewers, enlarging pipes, and preventing 

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Adapted from St. Tammany Parish Flood Insurance Study

A profile is a side view of the elevations of a channel 

bottom and the various flood levels. This profile shows 

that on this tributary to Bayou Liberty, the Camp 

Villere Road causes nearly a one-foot increase in flood 

heights during smaller flows at the place where it 

crosses the waterway.
Reducing Damage from Localized Flooding: A Guide for Communities 8-9

Chapter 8. Drainage Improvements P A R T I I I

back flows. Storm sewers are commonly designed to 

handle smaller storms and may not be effective for 

larger storms, such as the 100-year storm. Therefore, 

overland flow paths should be provided that will protect 

surrounding buildings from damage during a large 

storm.

The advantage of converting an open channel to a storm 

sewer is that it creates more useable ground surface. 

It can also reduce maintenance problems, because it 

is harder for debris to get into the pipes and clog the 

flow of water. 

From a flood protection perspective, piping ditches and 

storm sewers has some drawbacks: 

A big problem is that a pipe cannot expand. 

What happens to the water from a 10-year 

storm when a pipe is designed to carry only 

the 5-year flow? A good system design needs to ensure that overflows can be 

diverted to the street and not to buildings.

Pipe openings and storm sewer inlets need to be kept clean so the water can 

get into the pipes. 

Installing pipe is an expensive activity, although it can save maintenance costs 

in the long run and reduce the potential for accidents or injuries that can 

occur in open channels.

Converting an open channel to a storm sewer should be done only if there are 

arrangements for handling potential overflow, either through a swale over the pipe 

or through streets.

Storm sewers are designed to carry runoff from an area to a receiving body of water. 

Sometimes the receiving body of water is at flood stage and the storm sewers back up, 

flooding the area that they are supposed to drain. If an area analysis concludes that 

backflow is one of the causes of localized flooding, a gate or valve can be installed 

to prevent storm sewer backup.

Levees and Floodwalls

Levees and floodwalls protect properties from flooding by keeping high flows 

within the channel, away from development in the floodplain. While dredging and 

channelization may make the channel deeper, levees and floodwalls, in effect, make 

the channel’s banks higher. 

Levees are barriers built of earth, and a floodwall is usually concrete, masonry, or 

sheet piling. Floodwalls perform the same function as levees, except they are verticalsided structures that require less surface area for construction. 

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Although piping a ditch makes more room for surface 

use, where will the excess water go? This pipe can 

carry only a fraction of the water that can be carried 

by the ditch.
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P A R T I I I Chapter 8. Drainage Improvements

Both structures must be properly designed to account 

for large floods, underground seepage, pumping of 

internal drainage, erosion, and scour. Key considerations 

when evaluating use of a levee or floodwall include:

Should fill be removed to compensate for the 

floodwater storage that will be displaced?

Will the structure divert flood flows onto other 

properties? (Because of this hazard, levees and 

floodwalls are not allowed in the regulatory 

floodway in the mapped Special Flood Hazard 

Area.)

How will the project handle drainage of the 

surface flows in the area protected by the levee?

What will it cost to construct?

What will it cost in the future to maintain?

Will people object to having their river access and views restricted?

Will people have a false sense of security? (Although levees may reduce 

damage for smaller, frequent rains, they may also be overtopped or breached 

in extreme conditions and then create more flood damage than would have 

occurred without the levee.)

Levees or floodwalls placed along the edge of a river or stream may degrade the 

aquatic habitat and water quality. They also are likely to push floodwater onto other 

properties upstream or downstream. 

To reduce environmental impacts and provide multiple benefits, a setback levee is 

sometimes used. The area between the levee and the channel can provide open space 

for recreation and provide access sites to the river or stream.

Storage Improvements

Storage improvements should be located upstream of the flood problem area, although 

there are some limitations on what can be done in the drainage system of an already 

built-up area. There are two kinds of storage facilities: regional and on-site. Regional 

basins or reservoirs collect and store the excess runoff from many properties and are 

typically larger than on-site basins. 

On-site storage basins manage the stormwater from the site where it originates. 

These smaller basins are usually constructed when the development is built and 

can be designed to address water quality concerns as well. Chapter 4 discusses 

stormwater management regulations that require such basins. Later in this section, 

on-site features are discussed that individual property owners can implement to 

reduce their runoff.

Regional facilities. Larger regional storage basins are often called reservoirs. Reservoirs 

can be dry and remain idle until a large rain. Or they may be designed so that a lake 

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A small floodwall can protect against smaller, more 

frequent floods.
Reducing Damage from Localized Flooding: A Guide for Communities 8-11

Chapter 8. Drainage Improvements P A R T I I I

or pond is created. The lake may provide recreational 

benefits or water supply. 

In urban areas, some reservoirs are simply humanmade holes, excavated to store flood waters. Some 

communities have converted quarries and sand pits 

to temporary storage basins. If they are built into the 

ground, there is no dam for these basins and no dam 

failure hazard. Wet or dry basins can also double as parks 

or other open spaces.

There are several considerations when evaluating use 

of reservoirs and storage basins:

Floods can threaten the protected area if the 

reservoir’s dam fails;

The expense for management and maintenance 

of the facility;

Reservoirs and basins may fail to prevent floods that exceed their design 

levels, which are typically less than a 100-year event;

Sediment deposition may occur and reduce the storage capacity over time;

Water quality (both positive and negative) can be affected due to altered 

temperature, dissolved oxygen and nitrogen, and nutrients; and

If not designed correctly, in-stream reservoirs may cause backwater flooding 

problems upstream.

On-site storage improvements. Most on-site storage facilities are constructed to meet 

the community’s subdivision or other development regulations. These regulations 

are covered in Chapter 4.

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The Town of Hilton Head Island, South Carolina,

conducted an Island-Wide Drainage Study in 1995 

to identify existing drainage improvement needs. 

The study recommended channelizing the natural 

freshwater creek upstream of Jarvis Creek and 

upgrading the stormwater outfall. According to the 

original drainage plan, the freshwater creek would 

be enlarged to a bottom width of 35 feet and a 

depth of 6 feet. This project would destroy approximately 4 acres of freshwater wetlands.

In 1996, the Town negotiated the purchase of the 

50-acre Jarvis Creek Tract, which is adjacent to the 

existing Jarvis Creek ditch and was privately owned. 

An alternative plan was developed: a 10-acre lake 

would be capable of storing and conveying the 

necessary stormwater. A pump station was installed 

that moved water from the ditch to the lake. From 

the lake, water would flow through a vegetated spillway that discharged into the headwaters of Jarvis 

Creek. 

By selecting this storage approach over the 

channelization project, 3.5 acres of freshwater wetlands were protected and upland habitat and tree 

loss was reduced. In addition to being a drainage 

improvement project, the Jarvis Creek Project was 

designed to be a community park. 

Town of Hilton Head Island

French & Associates

This storage basin adds a water amenity to this office 

park and protects downstream properties from high 

flows.
8-12 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 8. Drainage Improvements

In areas that are already developed, large basins are not likely to be feasible. However, 

some improvements can be made when a parcel is redeveloped, and some can be 

initiated by interested owners that will reduce the amount of runoff leaving an 

individual residential or commercial property. Although such techniques will not 

appreciably diminish runoff from a large storm, their cumulative effect may reduce 

flooding problems for small storm events. They do improve water quality at a local 

level and have the added advantage of raising neighborhood awareness about water 

quality and quantity. Some examples include:

Using open brickwork or porous paving when replacing a driveway or 

parking lot (although proper construction and maintenance are needed to 

keep the surface porous);

Replacing lawns with native plants that have 

deeper roots that improve filtration; 

Installing rain barrels that collect and hold 

rainwater in large receptacles for lawn and 

garden watering. This reduces the owner’s water 

bill and reduces the runoff during and after a 

storm; and

Building rain gardens. These are landscaped 

areas planted with wildflowers and other native 

vegetation that soak up rainwater, mainly 

from the roof of a house or other impervious 

areas. Rain gardens, which incorporate special 

design features, allow approximately 30 percent 

more water to soak into the ground than a 

conventional patch of lawn.

Projects like rain barrels and rain gardens can be a 

valuable part of the community’s effort to reduce 

stormwater runoff and meet its NPDES goals of 

improving water quality. Although an individual 

rain garden may seem insignificant, many collective 

rain gardens and an active rain garden program can 

produce substantial neighborhood and community 

environmental benefits and a constituency interested 

in, knowledgeable about, and committed to improving 

the area’s drainage system. 

Rain gardens yield many benefits:

They increase the amount of water that filters 

into the ground, which recharges local and 

regional aquifers;

They help protect streams and lakes from 

pollutants carried by urban stormwater—lawn 

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Compare the root system of Kentucky blue grass with 

native prairie plants. The value of native ecosystems 

to absorb and hold stormwater can be a useful tool in 

reducing floods in urbanized areas.
Reducing Damage from Localized Flooding: A Guide for Communities 8-13

Chapter 8. Drainage Improvements P A R T I I I

fertilizers and pesticides, oil and other fluids 

that leak from cars, and numerous harmful 

substances that wash off roofs and paved areas;

They enhance the beauty of yards and 

neighborhoods; and

They provide valuable habitats for birds, 

butterflies, and many beneficial insects.

Rain gardens take careful planning and won’t work 

everywhere. The design needs to account for soil types, 

standing water that may breed mosquitoes, potential 

damage by vehicles or children, and similar concerns 

that arise when a new technique is introduced.

Maintaining the Drainage System

A community’s drainage system covers a large area and 

includes storage basins, stream channels, backyards, 

swales, ditches, and culverts. A regular program of 

drainage system inspections can catch problems in the 

system before they turn into major obstructions. Such 

inspections and follow-up work for the whole drainage 

system can be quite daunting, so this section breaks the 

work down into four levels of effort:

Maintaining the public drainage system;

Involving citizens in the process;

Regulating against dumping and other actions that will adversely affect the 

system; and

Maintaining the yard.

Maintaining the Public System

The public part of a drainage system varies from community to community. Normally, 

the larger streams, drainage ditches, and channels on public property are maintained 

by the local government. Storage basins that have been dedicated to the community 

also are part of it. Some communities do not accept maintenance responsibility for 

new storage basins, leaving that up to the property owner. 

Government agencies usually accept responsibility for maintaining bridge openings 

and facilities on public property. However, in most areas, the responsibility for 

drainageway maintenance on private property, where no easements have been 

granted, is with the individual private property owner. This often results in very little 

maintenance being accomplished. A community that wants to improve the care of 

its streams should have a campaign to urge owners to sign easements allowing local 

staff access for inspections and maintenance.

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Prince George’s County, Maryland, Stream 

Teams, a valuable part of the community’s stormwater program, includes a citizen volunteer monitoring program and has held several workshops 

called “Planting a Rain Garden for Community 

Service Day” and “How to Make a Rain Barrel.” 

Both workshops were free and open to the public. Free native flowering plants were given to all 

participants for the Rain Garden workshop and 

a free rain barrel to each participant at the Rain 

Barrel Workshop. 

At a Rain Barrel Workshop, about 15 people 

met in the West Laurel Civic Building for a 30-

minute demonstration. Representatives from the 

state Department of Environmental Resources 

showed the participants how to assemble the 

rain barrel and answered questions.
8-14 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 8. Drainage Improvements

As outlined in the CRS, at a minimum, the maintenance program should:

Inspect the entire drainage system at least once each year;

Check known problem sites during or immediately after heavy storms;

Respond to inquiries or complaints from citizens; and

Remove debris soon after it is found.

“Debris” refers to a wide range of materials that 

may obstruct flows so that a small storm will cause 

an overbank flood. Debris may include tree limbs 

and branches that accumulate naturally, large items 

of trash or lawn waste accidentally or intentionally 

dumped into channels, drainage swales, or storage 

basins. Maintenance of storage basins may also require 

revegetation or repairs of the restrictor pipe, berm, or 

overflow structure. 

All communities are encouraged to have formal 

procedures for maintaining their part of the system. 

Sometimes it is a very fine line that separates debris that 

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Dr. Warren Campbell

A regular inspection and maintenance program can remove debris before it becomes 

an obstruction to stream flows.

In Activity 540 (Drainage 

System Maintenance), the 

CRS encourages and provides 

credit for:

A formal program that inspects channels and 

storage basins and removes debris;

A capital improvements program that provides an annual budget for channel and 

basin improvements; and

Stream dumping regulations.

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Reducing Damage from Localized Flooding: A Guide for Communities 8-15

Chapter 8. Drainage Improvements P A R T I I I

should be removed from natural material that helps form habitat. Therefore, written 

procedures that are consistent with state laws and environmental concerns (such as 

the NPDES guidelines) are especially helpful. 

Guidelines on designing a program, along with model procedures, can be found in 

CRS Credit for Drainage System Maintenance.

Citizen Involvement

An annual inspection by a public agency means that 

for most of the year, the inspection or maintenance 

crew does not see the stream or basin. Involving the 

citizens can be very helpful. While they may not do 

any maintenance (especially removing large logs or 

obstructions), citizens are the eyes and ears of the 

community and can look out for and report problems 

before they cause a flood.

Some communities have organized “stream teams” that 

regularly monitor assigned sections of rivers, streams, 

and canals and report when problems are found. Some 

of these team members are trained to know what to 

remove and what not to touch, so they can do some 

minor work during their inspections. 

Many communities leave storage basin maintenance 

up to the property owner or homeowners association, 

people who are often not knowledgeable about the 

technicalities of basin maintenance and who may 

not have the resources to properly care for them. To 

counteract this, some communities have assumed 

responsibility for inspecting all basins on private 

property. If a problem is found, the owners are required 

to correct it.

Other communities have implemented training programs for homeowners associations 

and other basin owners. Some have published guides for individuals who live along 

a stream and for owners of stormwater facilities.

Regulating Dumping 

An anti-dumping program can reduce drainage problems and the workload of the 

maintenance crews. Nuisance ordinances in many communities prohibit dumping 

garbage or other objectionable waste on public or private property, but dumping 

still occurs. 

Non-objectionable materials, such as grass clippings or tree branches that can kill 

ground cover or obstruct drainage channels, also should be covered by the dumping 

ordinance. A community can schedule regular inspections to catch violations. Sample 

language for an ordinance can be found in CRS Credit for Drainage System Maintenance.

Mandeville’s Drain Team

A group of 38 volunteers formed the City of 

Mandeville, Louisiana, Drain Team. The Drain 

Team assists the Department of Public Works 

by monitoring over 150 miles of drainage 

arteries in their neighborhoods. These citizens 

clean debris from the ditches and catch basins 

during wet and dry weather. Members receive 

yellow rain suits with the City of Mandeville 

insignia on them to help keep them dry while 

monitoring the drainage.

Monthly and quarterly meetings are held with 

these members and with the City staff for regular updates. “You just wouldn’t believe what 

an impact this team has on keeping the water 

flowing during storms. Their biggest job is 

keeping the balls and garbage can lids out of 

the culverts,” said Mr. Glenn Craddock, Assistant Superintendent of Streets and Drainage.

FEMA (2002, pp. 25–26)
8-16 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 8. Drainage Improvements

A dumping enforcement program should include public information materials that 

explain why the rules are in place and what the penalties are. This program is essential 

because many people do not realize the consequences of their actions. They may fill 

in the ditch in their front yard, not realizing that it is needed to drain water running 

off the streets. It may not be clear to them that regrading their yard, filling a wetland, 

or discarding leaves or branches in a stream or ditch can cause flood problems.

Yard Maintenance

Yards are part of the drainage system. Subdivision and building plans should have 

the main structure elevated on a building pad. The side and back yards should be 

preserved as conveyance areas to carry water away from the building and to the storm 

sewers, streets, or receiving ditches or streams. 

Many people do not realize the importance of keeping the yards and swales clear. 

When people build fences, garages, sheds, and swimming pools or plant trees that 

disrupt the drainage patterns, surface water will be pushed onto other properties or 

even flow back and into the owner’s house (see the photograph on page 4-20). 

A local government can do two things to preserve yard drainage. The first is to inform 

the public about the importance of yard maintenance, keeping the drainageways open, 

and reporting problems to the authorities. Most people will not obstruct flows if they 

understand how obstructions can adversely affect them and their neighbors.

The second action is to enforce the dumping regulations and drainage easements. 

Most survey plats show easement boundaries, and public information programs can 

help to educate property owners about the laws against stream dumping and the 

easement regulations and restrictions. 

Where to Get Help

U.S. Army Corps of Engineers (for larger levee and channel modification 

projects).

More information on Corps of Engineers’ 404 permits can be found at 

http://www.nwo.usace.army.mil/html/od-tl/introductionto404.html.

Natural Resources Conservation Service (for larger levee and channel 

modification projects).

Additional resources are listed in Appendixes A and B.

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French & Associates

Stream dumping notice.

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 9
Reducing Damage from Localized Flooding: A Guide for Communities 9-1

Redevelopment

An analysis should be conducted of localized flood problems (see Chapter 7) to 

identify actions that would be appropriate on an area-wide basis. The analysis 

would determine whether a local drainage project is feasible (see Chapter 8), 

whether redevelopment of all or parts of the area would be suitable, or whether the 

localized flood problem should be dealt with on an individual building basis (see 

Chapters 10 and 11).

9

As stated in Chapter 1, the term “floodplain” is used in this guide in a general sense 

to mean the area most prone to flooding, be it mapped or unmapped. The floodplain 

for a localized flood problem may well not be mapped as a Special Flood Hazard Area 

(SFHA) on the community’s Flood Insurance Rate Map (FIRM).

As used in this guide, redevelopment means taking deliberate steps to convert 

the use of a parcel or a neighborhood to a new use that is more compatible with 

environmental factors (including flooding), more economically productive, or more 

beneficial to the community fabric. Redevelopment is more than just flood mitigation. 

It looks to the future and what will happen to the land, and what that will mean to 

the community.

Redevelopment Objectives

A redevelopment project could be pursued for several reasons: 

The area analysis may conclude that a change in use of the area is the best 

way to reduce the localized flood problem. 

A fire, flood, or other hazard may damage buildings and necessitate 

reconstruction.

A change in the local economy, such as the closure of a major employer, 

may trigger a need to redevelop an area to attract or pursue new economic 

opportunities.

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9-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

A flood-prone area may have deteriorated to such a state that buildings need 

to be torn down to correct unsafe or unhealthy conditions. 

For whatever reason buildings are removed or rebuilt, redevelopment is an opportunity 

to remedy a localized flood problem and work toward other community goals. 

Floodplain Management Objectives

There are several floodplain management benefits to clearing a flood-prone area for 

redevelopment: 

After clearing, there will be no buildings subject to flood damage. Existing 

damage-prone buildings will have been moved away or demolished and, 

if replaced, the new buildings should be constructed to be protected from 

flood hazards.

A vacant area will provide more room to carry or store flood waters, 

reducing the hazard upstream and/or downstream.

A reduction in urban use of the area will increase opportunities for riparian 

habitat, i.e., habitat for plants and wildlife that live near or depend on water.

The absence of buildings and other urban features that need protection 

would allow the stream channel to seek its natural course, potentially 

reducing public expenditures on bank stabilization projects.

The greatest floodplain management benefit is to remove the greatest cost of 

flooding—damage to buildings, especially buildings that are repetitively flooded. The 

community can consider buying these buildings and clearing the sites. Additionally, 

there are Federal and State programs to finance buy-outs, and the mechanics of 

participating in an acquisition program are covered later in this chapter.

Acquisition of flood-prone properties is becoming more and more common, but 

a community needs to think beyond a single flood protection objective. It needs to 

consider other factors, including:

What will happen to the current occupants, either residents or businesses?

How will the land be used and maintained after it is cleared?

How will this affect adjacent properties and the rest of the neighborhood?

How will it affect other goals and objectives of the community?

Because of these concerns, an acquisition program should not be initiated without 

considering the full impact of redevelopment on the neighborhood and the 

community. 

Non-Flood Objectives

One of the advantages of choosing redevelopment as a solution to a localized flooding 

problem is that the project can also help meet other needs or objectives for the 

neighborhood and/or the community. 

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Reducing Damage from Localized Flooding: A Guide for Communities 9-3

Chapter 9. Redevelopment P A R T I I I

The community planning process described in Chapter 3 and the area analysis 

(Chapter 7) should include a review of community and neighborhood goals and 

objectives for the area. Broader statements of vision and goals may be found in the 

comprehensive plans, hazard mitigation plans, or regional watershed plans. For 

example, a watershed plan may identify natural areas that are to be preserved by 

acquisition and easements when an opportunity arises.

Opportunities for cooperation and sharing resources with others interested 

in non-flood objectives should be a top priority for community floodplain 

managers. Coordination with other people, goals, and objectives has the following 

advantages:

Avoiding conflicts. Coordination ensures that flood mitigation activities 

do not conflict with other plans for an area. For example, if a community 

wants to increase recreational opportunities, clearing out flood-prone 

structures to create a waterfront park would be a good use of resources. On 

the other hand, if a community is interested in economic development, the 

redevelopment strategy should consider approaches that do not reduce the 

community’s economic base.

Sharing resources. Limited funds and resources may be shared to accomplish 

common goals. As an example, programs that fund park development might 

be used to defray the costs of acquiring flood-prone properties.

Maintaining interest. Concern about flood protection wanes over time, 

particularly during a dry spell. If redevelopment is linked to other 

community initiatives, such as economic development, education, and 

recreation, it has a better chance of reaching completion.

Meeting funding requirements. Many funding programs require applicants 

to coordinate with other agencies, exhaust other sources of funding, or bring 

other agencies in on cost-sharing.

Coordination with Other Objectives

There are several important advantages to coordinating with others to expand a floodmitigation-focused approach into a redevelopment project that benefits everyone. 

The interest groups and organizations presented in this chapter should be contacted 

as plans are formulated. They should be invited to participate in the planning of a 

redevelopment project and, ideally, they will want to contribute time, support, or 

even money because the flood project will advance their objectives as well.

The planning and urban renewal departments of the community are the most 

important offices to bring into the redevelopment process. They probably already 

have plans or concepts of how an area should be redeveloped. Approaching them 

with flood-related redevelopment plans or providing funds to acquire some of the 

properties may be the catalyst for them to activate their own plans.

If the community does not have to make immediate decisions (e.g., if the area has just 

been flooded, and people are waiting to rebuild), time should be taken to integrate 

redevelopment of the area with other community objectives. Coordinating with the 

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9-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

community planning office can help ensure that redevelopment of the area would 

be put in the capital improvement plan, land use plan, repetitive loss initiatives, 

waterfront revitalization plan, or economic improvement program. Other objectives 

may include those discussed below.

Recreation. People with interests in recreation are the most obvious supporters of 

a project to clear and reuse land next to a body of water. Replacing flood-damaged 

buildings with open space or a linear parkway can be very popular and supported 

by many different people who would benefit.

Redevelopment objectives. Establishing parks, ball fields, ice skating rinks, hiking 

and biking trails, picnic areas; dedicating sections for fishing, hunting, bird 

watching, and sightseeing.

People to contact. Parks and recreation department; environmental 

organizations; nearby schools (interested in expanding athletic fields or 

educational opportunities); land preservation organizations (e.g., The Nature 

French & Associates

There is often widespread community support to replace run-down buildings with 

open space and recreational facilities that everyone can enjoy. Transportation 

planners support greenway sites to keep pedestrians and bikers separated from 

vehicular traffic. The Aldridge Creek Greenway is being expanded and extended over 

the years as the City of Huntsville, Alabama, acquires and clears flood-prone homes.
Reducing Damage from Localized Flooding: A Guide for Communities 9-5

Chapter 9. Redevelopment P A R T I I I

Conservancy, The Land Trust Alliance); conservation and outdoor groups 

(e.g., Izaak Walton League, Audubon Society, Boy and Girl Scouts and other 

youth groups); hunting and fishing organizations (e.g., Ducks Unlimited, 

Trout Unlimited); recreational businesses (e.g., marinas, sporting goods 

stores).

Fish and wildlife. Preserving open space and restoring waterways, ponds, and 

wetlands are prime goals of the supporters of fish and wildlife. Clearing development 

back from streams, wetlands, and shorelines protects important habitat.

Redevelopment objectives. Expanding habitat; improving water quality (e.g., 

filtering runoff from parking lots or industrial areas through wetlands, 

grass, and/or planted open spaces); reducing or eliminating the need for 

channelization and other alterations to habitat.

People to contact. State fish and wildlife agencies; U.S. Fish and Wildlife Service; 

Federal and State environmental protection agencies; Natural Resources 

Conservation Service; parks departments; land preservation organizations; 

conservation and outdoor groups; hunting and fishing organizations.

Economic development. Some of the strongest community concerns are those that 

relate to the local economy: jobs, business survival and expansion, tax base, and 

viability of shopping areas. In many communities, the economic base was founded 

on or is dependent upon the waterfront. 

Sometimes, economic development is seen as contrary to good floodplain 

management—why put businesses in a hazardous area? Coordinating with 

development interests assumes that new development will meet (or preferably 

exceed) the National Flood Insurance Program (NFIP) requirements for floodplain 

development. For example, the areas of deepest flooding can be preserved as open 

space while new buildings are elevated 1 or 2 feet above the regulatory flood 

elevation.

Redevelopment objectives. Redeveloping or reusing vacant or abandoned 

businesses; improving the appearance of the neighborhood adjacent to 

businesses and stores; improving access to parking and services along the 

waterfront; providing open space, picnic tables, and other recreational 

opportunities for employees; improving facilities that would attract tourists; 

retrofitting certain types of commercial structures, such as garages and car 

washes, to resist flood damage and support nearby businesses. 

People to contact. Local and State economic development and job training 

agencies; chambers of commerce and business or manufacturers’ 

organizations; real estate organizations; U.S. Economic Development 

Administration; community development and planning offices; recreational 

businesses (e.g., marinas, sporting goods stores, restaurants, hotels); utility 

companies; others that serve business and industry.

Housing. If the local flood problem area includes houses, the floodplain manager 

need only remember that every homeowner and renter wants a better place to live. 
9-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

Residents and the organizations that work to improve housing can be vital allies to 

a redevelopment project. 

Residents can even provide financial support for a project. Well-insured flood victims 

have used their claims payments and Increased Cost of Compliance payments (see 

page 11-6), their own labor, and/or additional funds to meet the non-Federal match 

of an acquisition project. Homeowners will work hard to replace their flood-damaged 

or deteriorating homes with new and better ones. 

Redevelopment objectives. Removing vacant, abandoned, or dilapidated housing; 

bringing housing up to safe and sanitary conditions; providing affordable 

housing; improving recreational opportunities for nearby homes; improving 

property values; providing housing adjacent to amenities, such as parks, 

greenways, and natural areas. 

People to contact. Community development, 

planning, and code enforcement offices; local 

housing authorities; neighborhood associations; 

and builders or developers associations.

Historic preservation. Historic features include buildings, 

museums, archeological sites, historic landscapes, and 

collections. These features are irreplaceable. Most 

people responsible for their preservation or restoration 

recognize that if these features were hit by a flood or 

other disaster, a valuable community and educational 

asset would be destroyed. Even minor problems, such 

as a flooded basement, high humidity, or loss of power, 

can severely damage delicate or aged materials. 

Every application for Federal Emergency Management 

Agency (FEMA) acquisition funding requires a historic 

preservation review, so involving the appropriate 

personnel early in the planning is beneficial and 

practical.

Redevelopment objectives. Protecting historic 

properties; improving and opening areas 

surrounding a historic site (to help it conform to 

its original setting).

People to contact. Local historical societies; 

museums; school and university history 

departments; parks and recreation departments; 

State historic preservation office.

Public works. Repetitive flooding can contribute to 

deterioration and maintenance problems for streets 

and other components of an area’s infrastructure. Water, 

gas, sewer, and power lines are sometimes broken due 

to settling of the organic soils found in flood-prone 

Rebuilt Areas Produce Many Benefits

Frankfort, Kentucky, developed a flood hazard mitigation plan to cover areas that were 

not scheduled to be protected by a planned 

floodwall. The areas included residential, commercial, and industrial uses as well as historic 

buildings. The high-velocity floodway has been 

cleared. 

Funding support came from the Federal 

Emergency Management Agency, the U.S. Department of Housing and Urban Development, 

the Kentucky Housing Corporation, Frankfort 

Housing Redevelopment, Inc., and Habitat for 

Humanity. The last three groups helped obtain 

replacement housing for those whose properties were bought out.

There were several important spin-off benefits from the project:

Reduction in the number of buildings exposed to flooding;

Increased open space and recreation opportunities;

Improved housing for residents relocated 

from substandard homes;

Improvements to non-flood-prone houses 

that were purchased and improved to meet 

safety criteria as replacement homes;

Training programs for the youths who helped 

rehabilitate replacement homes; and

Increased property values of the surrounding 

area.

Association of State Floodplain 

Managers (1996, p. 35)

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Reducing Damage from Localized Flooding: A Guide for Communities 9-7

Chapter 9. Redevelopment P A R T I I I

areas and wetlands. Public works, street, and highway 

departments are faced with repairs and are under 

pressure to upgrade roads and bridges to provide 

continued access to flooded areas. Public works staff are 

often supportive of redevelopment plans to reduce the 

amount of their infrastructure in a flood-prone area.

Redevelopment objectives. Lowering maintenance 

and replacement costs; reducing work during 

a flood; creating alternative transportation 

modes (such as bikeways and trails); reducing 

exposure of the sanitary sewer system to inflow 

and infiltration.

People to contact. Local public works, streets, water, and sewer departments; 

utility companies; regional or metropolitan sanitary districts; community 

development, economic development, and planning office.

Clearing the Area

Removing structures and infrastructure from a flood-prone area is one approach to 

acquiring land for redevelopment. If open space or growth control is a community 

objective, then purchasing land, clearing it, and keeping it undeveloped is appropriate. 

If flood-prone properties are to be acquired, then several steps should be taken to 

ensure the desired outcome, whether it’s open space or redevelopment. The properties 

should be assessed for repetitive losses and their proximity to other potential buyout properties. It is advantageous to purchase contiguous properties to provide more 

options for re-use. Once the properties are identified, damage-prone buildings should 

be removed and the area maintained as publicly owned open space or redeveloped, 

as discussed later in the chapter.

Many communities today have ongoing buy-out programs to gradually acquire floodprone lots throughout their jurisdictions, as the opportunities arise.

Acquisition Funding 

The biggest hurdle to redeveloping a flood-prone area is the cost of acquiring the 

properties. Several possible funding sources can be pursued.

Community general funds. The Village of Gurnee set aside funds in its 

operating budget to acquire one or two properties each year as they came up 

for sale (see photos on next page).

Community capital budget. A capital budget is often funded by a bond issue 

or special tax. It is used for permanent improvements to the community, 

such as drainage projects and parks acquisition. 

Environmental or open space organizations. The Nature Conservancy, 

the Trust for Public Lands, and other, more local, organizations are often 

interested in acquiring land for open space preservation. 

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In the 1970s, Baltimore County, Maryland, set 

aside $5 million to enlarge and improve floodprone bridges. The county planners calculated 

that it would be cheaper to purchase and clear 

the flood-prone buildings served by the bridges 

than to replace the bridges. The County subsequently implemented a nationally recognized 

acquisition program and saved money in the 

process.
9-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

Adjacent property owners. A factory, a school district, or another property 

owner interested in expanding may provide financial support. The land could 

be reused for parking or athletic fields to support the owner. If the nearby 

owner is considering redevelopment or expanding in a different direction, 

the flood-prone area might help meet regulatory requirements, such as the 

open space lot ratio or stormwater detention.

Private developer. Depending on the location, a private developer may well 

be interested in purchasing, clearing, and redeveloping an area. It may not 

become open space, but the new development should take the flood hazard 

into account.

State and Federal grants. Community development, open space, parks, 

natural resources, and housing agencies may have funds that can be used for 

different purposes, such as acquiring land needed for a public purpose. The 

most commonly used funds are those from FEMA, which are discussed in 

the next section.

FEMA Funding

Three FEMA programs can fund acquisition of floodplain properties: the Hazard 

Mitigation Grant Program, Flood Mitigation Assistance, and the Pre-Disaster Mitigation 

program. All three are managed by the State, usually the emergency management 

agency. In addition to Federal requirements, States may also set additional priorities 

for use of the funds. Eligibility requirements for these programs may change, so 

contact your local administrator for current requirements. 

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Over the years, the Village of Gurnee, Illinois, acquired and cleared homes in this repetitively flooded area. 

Some were purchased with funds from FEMA, but others were purchased by the Village when they were put 

up for sale by the owners. One area is now a public park for all residents to enjoy.

French & Associates French & Associates
Reducing Damage from Localized Flooding: A Guide for Communities 9-9

Chapter 9. Redevelopment P A R T I I I

Recipe for a Successful Acquisition Project

There are several sources of funds to purchase 

and clear flood-prone property. Getting the money 

is only half the job. The community needs to coordinate with many different parties and do some 

work on its own. Here are the key ingredients.

Commitment by the leadership. The community 

has to be ready to commit staff time and political support for what may be a long and involved 

process. 

Commitment by the staff. If the staff has the 

necessary expertise and can handle the workload, some services can be done in-house. 

Otherwise, some communities will need to contract out services, such as project management, 

appraisals, legal services, and/or demolition.

Property owner involvement. A successful 

mitigation project requires active and willing 

property owner participation. Even though they 

may have experienced recent damage, property 

owners may not always like the idea of selling 

and moving. Mitigation funds from FEMA are 

strictly limited to voluntary participation. The 

process should include a signed statement from 

each property owner that his or her participation 

is voluntary. 

Informed public. The community should have an 

effective communication plan and be committed 

to making it work. It is not just the owners of 

flood-damaged homes who are affected. Nearby 

residents and others throughout the community will be interested and will need to be kept 

informed.

Lots of data. The community will need to collect 

data about each property. Owners should sign 

documents to allow access for the purpose of 

appraising property values and estimating damage. A title search must be conducted to ensure 

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that the title to the property is clear of encumbrances such as ownership issues, probate, or 

contractor liens.

Clear and fair procedures. The community must 

establish the basis for deciding property values 

and the amount of money property owners will receive. A licensed appraiser is needed to prepare 

fair market valuations. Experience shows property owners will talk to each other about their 

offers, so it is important that clear policies are 

established up front and applied uniformly. When 

owners believe the appraisals are not accurate, 

they need to be able to appeal the decision 

about their own appraisal. 

Adjusted purchase price. If FEMA funds are 

involved, flood insurance and disaster assistance 

payments to the owners need to be deducted 

from the purchase price if the money was not 

used to repair the building. This prevents what is 

called “duplication of benefits.” If an owner wants 

to remove items after the appraisals have been 

made, the value of the items is deducted from 

the purchase price.

Demolition and clearance. FEMA rules require 

that acquired buildings be demolished within 

90 days of closing. Communities have found it 

more efficient to clear several lots at the same 

time. Wells have to be capped and septic tanks 

handled according to state regulations.

Paperwork. Required paperwork includes records of meetings with the owners, copies of 

the appraisals, title insurance policies, warranty 

deeds, closing statements, and the checks for all 

disbursements. The state will perform a field inspection before approving final disbursement. All 

paperwork must be in order and kept until FEMA 

closes out the project.

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Hazard Mitigation Grant Program (HMGP). HMGP funds are made available after 

a Presidential disaster declaration. The amount of funding available varies based on 

the total amount of expected Federal disaster assistance (the costlier the disaster, the 

more HMGP funds there will be). Eligible projects may be funded throughout the 

State, not just in the damaged area.
9-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

Flood Mitigation Assistance (FMA). FMA funds come from fees paid by NFIP 

policyholders and are used to reduce flood damage and repetitive losses to buildings 

insured under the NFIP. Each year a certain amount is set aside for planning grants, 

project grants (e.g., acquisition of property), and technical assistance grants. FMA 

funds are allocated to the States and territories based on certain criteria, such as the 

number of repetitive flood loss properties and number of flood insurance policies. 

Pre-Disaster Mitigation (PDM) program. Annual appropriations provide the funding 

for the PDM program. There is no State allocation or formula to distribute the funds. 

States and communities throughout the country can apply, but they compete with all 

other applicants from across the country. Projects that potentially have the greatest 

impact on reducing future losses are the most likely to receive the funds. 

All three programs provide up to 75 percent of the eligible costs for acquisition 

and other mitigation projects. The non-Federal share can be from a variety of other 

local, State, or private funding sources. The Community Development Block Grant 

can also be used as a match. Property owners may contribute their own money or 

their insurance claim payment (see Increased Cost of Compliance coverage in Chapter 

11) to help offset the cost of the project. A portion of the non-Federal match may 

be covered by in-kind or donated services.

All three programs have the following application requirements:

The applicant must show that the benefits of the project exceed the costs 

(FEMA’s benefit-cost analysis software is the best resource);

The applicant must conduct an environmental review and obtain historical 

preservation clearance; and

The community must have adopted a FEMA-approved mitigation plan 

(discussed in Chapter 3).

Clearing the Buildings

If there are buildings on any lots purchased through public acquisition projects funded 

by grant programs, including the FEMA programs, all of them must be cleared off 

the site within a certain time frame.

Deteriorated structures, especially if they are 

abandoned, are health and safety concerns, and if 

the parcel has been converted to public ownership, 

it poses a liability for the local government. It is 

preferable to raze those buildings that have suffered 

repeated flooding and/or have been seriously 

damaged. 

Buildings that are in usable shape may or may not 

be demolished, depending on the future use of the 

property and their location in relation to the expected flood water. However, these 

buildings may be obstructions to the flow, can inhibit drainage, and will take up 

space that might be better used as stormwater storage or for vegetation. 

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In Activity 520 (Acquisition and 

Relocation), the CRS credits 

acquiring, relocating, or otherwise 

clearing buildings from the floodplain. The community must document that the property will stay vacant.
Reducing Damage from Localized Flooding: A Guide for Communities 9-11

Chapter 9. Redevelopment P A R T I I I

Some communities have moved the acquired building to a flood-free site and 

converted the structure to public housing on the new site. In other cases, the building 

owner moves the structure, sometimes to a new lot or sometimes to a part of the 

lot that is above the flood level.

The cost of relocating a building will depend on its size and construction type. It is 

easier and less expensive to move smaller, wood frame buildings on crawlspaces or 

basements than heavy structures made of brick with irregular shapes. Local house 

moving companies can estimate the cost and feasibility of moving a building. Some 

funding programs, such as the FEMA programs listed above and Increased Cost of 

Compliance (see Chapter 11), can help pay to relocate a structure.

Reuse of the Area

Redevelopment projects need to keep the flood hazard 

in mind when reuse of the area is being considered. 

The most popular use (and the use required by some 

Federal funding programs) is open space. Other uses 

compatible with the hazard are possible.

Public Open Space

If the area is being redeveloped as a park, preserve, 

greenway, or other public use, it will likely be owned 

by a parks or recreation agency. It is in the interest of 

the owning agency to keep it in a compatible open 

space use.

Smaller structures can be relocated and reused

relatively easily, provided past flooding has not 

caused permanent damage or created health 

hazards. It is recommended that the walls be 

stripped and new, clean, insulation and wallboard 

be installed after the move.

Hollis Kennedy House Movers Lake County, Illinois, Stormwater Management Commission

One inexpensive way to clear an acquired structure 

that is not a candidate for relocation is to offer the 

structure to the fire department for training and 

practice.

In Activity 420 (Open Space), 

the CRS credits keeping vacant 

flood-prone lands open by keeping the land publicly owned, 

keeping it as a private preserve, or regulating new development on the 

parcel. More credit is provided if the parcels 

are preserved in an undisturbed (or restored) 

natural state.
9-12 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

Parks. Parks are one of the best uses of flood-prone areas. Even with minimal 

investment, such natural areas provide opportunities for passive recreation as well 

as hiking, jogging, horseback riding, bird watching, and photography. 

Greenways. A hiking or biking trail can greatly enhance the benefits derived from 

park lands. Planning such a trail will benefit from input from environmental and 

recreational interests who can help develop a safe, environmentally sensitive alignment. 

Many communities now have networks of greenways that incorporate trails, and it 

may be possible to link newly cleared flood-prone areas with them.

Public facilities. Other recreational facilities, including sports fields, golf courses, 

boat ramps, picnic and camping grounds, fishing docks, and open-air amphitheaters, 

Greenways

In an increasingly urban nation, greenways provide much-needed space for outdoor recreation 

and offer accessible alternatives to those who 

don’t live near traditional parks. 

A greenway is ideally suited to such popular outdoor activities as jogging, walking, biking, fishing, 

and canoeing. 

Greenways provide safe, alternative, non-motorized transportation routes for commuters going 

to work and children traveling to and from school. 

Greenways offer ideal possibilities for joint-use 

partnerships along corridors with sewer, utility, 

and fiber-optic lines and railroad interests. 

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In rapidly urbanizing areas, a greenway offers 

visual relief; its wooded breaks can frame and 

distinguish neighborhoods in an otherwise undifferentiated urban sprawl. 

Greenways are community amenities with an economic value. They enhance the quality of life and 

can increase the value of surrounding properties. 

Greenways have been shown to draw tourists and 

have been the catalyst behind new commercial 

development and the revitalization of former town 

centers. 

Flink and Searns (1993, pp. 1-2)

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The Village of Gurnee, Illinois, included a greenway 

as part of its flood mitigation plan.

Greenways offer recreation and transportation 

opportunities for everyone in the community.

French & Associates French & Associates
Reducing Damage from Localized Flooding: A Guide for Communities 9-13

Chapter 9. Redevelopment P A R T I I I

are compatible with shallow flooding and have the 

potential to generate income for the community. 

The land could also be used for flood storage, either 

by keeping the overbank areas open or using the 

site as a storage basin for the watershed that drains 

to it.

Private Open Space 

In some cases, the flood-prone land may stay in 

private ownership, for example, when:

The community (or a nonprofit group such 

as the Nature Conservancy) purchases the 

development rights or an easement to keep 

an area open, but does not purchase full 

title to the property;

The area is redeveloped by a private 

developer;

Adjacent property owners want the site 

for parking or other private use that is 

compatible with flooding;

The community has purchased and cleared 

lots and deeded them over to adjacent owners for maintenance; or

The owner moves the structure to higher ground but does not want to part 

with the waterfront land.

These cases are often much less expensive than acquiring the entire property, but the 

community does not have complete control over the parcel. There is always a concern 

that owners will be tempted to build something inappropriate on their lots. 

If the community acquired the lot or helped fund the acquisition, it has a right to 

attach an easement to the deed. Easements are legal restrictions to preserve some or 

all of a parcel as open space, as a drainageway, for public access, or other purposes. 

A usual condition of the easement is that the property owner may still develop and 

use the property as long as the easement’s provisions are observed. 

If the community did not fund the acquisition, it may still negotiate with the owner 

for an easement. The community may be able to offer a property tax break or even 

purchase the easement. 

As noted in Chapter 4, a community needs to enforce the provisions of these 

easements to ensure that they fulfill their purpose. As the years go by (particularly 

if flood problems do not recur), property owners tend to forget that there is an 

easement attached to the lot.

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In conjunction with a stormwater management 

project (described in Chapter 8), the Town of Hilton 

Head Island, South Carolina, purchased a 55-acre 

tract on which it created a lake for water storage, 

preserved wetlands, and created a park. Responses to a questionnaire distributed to the Town’s 

residents a few years before had identified the 

need for a park and revealed the kind of amenities 

that would be most used.

The park is designed as a passive recreation 

area with trails and picnic areas. Little vegetation 

was removed to construct the park infrastructure, 

and the walking trails were designed to go around 

trees, so that they would not have to be cut down. 

A boardwalk was constructed to leave the site in its 

natural condition and teach visitors about wetland 

mitigation through the interpretative signs along 

the trail. The undisturbed wetlands and the wetland 

mitigation area are protected permanently through 

restrictive covenants.
9-14 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

New Buildings for Redevelopment

In general, it is best to avoid having buildings in floodprone areas. However, in many instances of localized 

flooding, the water is likely to be shallow and slow 

moving, and measures can be taken to avoid the risk of 

flood damage. It may be feasible and desirable to allow 

new construction in order to redevelop the flood-prone 

area to meet community needs. Particularly if drainage 

modification (as described in Chapter 8) can alleviate 

the flood problem, carefully putting the property to 

a new use can result in a revitalized neighborhood 

that can include new buildings and other community 

benefits.

If new buildings are allowed in a cleared area, it is 

essential that they be protected from flooding. A good 

rule of thumb is to require any new buildings to meet 

the floodplain management standards required for the 

SFHA (as specified in the community’s ordinance) even 

though the area to be developed lies outside the SFHA. It 

is especially important to avoid placing structures in the 

portion of the area needed to convey the flood flow. 

At the same time, a community needs to consider 

carefully what type of development and activities 

are appropriate for a given flood-prone area. Before 

specific redevelopment decisions are made, relevant 

ordinances, regulations, and land use plans that 

affect the neighborhood should be reviewed. Note 

that properties acquired with funds from FEMA and many other State and Federal 

programs restrict future use of the land to open space or similar uses that limit the 

redevelopment options. 

Some background work may already have been done toward the decision. Has the 

area been targeted for special area preservation? Urban renewal? Is there a long-term 

transportation plan that will affect the neighborhood? What other restrictions are 

there on the property’s use?

With advice, encouragement, and a periodic reminder about flooding, a private 

property owner may redevelop the area for a new use on his or her own. In a 

commercial area, sometimes redevelopment with flood protection measures can be 

economically worthwhile. However, the businesses will have to understand that they 

may be closed sometimes when the streets are flooded and access is cut off.

Some ideas for new construction in a redeveloped localized flood problem area 

are:

Sustainable Redevelopment

Ideally, the future use of a redeveloped floodprone area should keep in mind key local 

concerns and couple them with long-term considerations of sustainability. This means that 

any redevelopment should take into account 

social, economic, and environmental factors 

and also look to the future to be sure costs 

are not deferred to future generations. In the 

long run, this will make for a redevelopment 

effort that meets with a broader range of support, makes fewer adverse impacts on people 

or the environment, and pays for itself in terms 

of revenue or benefits. 

The specific concerns will be somewhat different for each community, but any redevelopment of flood-prone property should strive for 

as many of these characteristics as possible:

Be economically viable;

Offer amenities to the neighborhood or community;

Allow for natural movement and/or temporary storage of flood waters; and

Yield benefits to the ecosystem, such as 

protection of vegetation or habitat.

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Reducing Damage from Localized Flooding: A Guide for Communities 9-15

Chapter 9. Redevelopment P A R T I I I

Minimize buildings in the most flood-prone area and avoid any area needed 

for conveyance of flow. Use the lowest land for open space, streets, parking, 

or storage basins (as illustrated on page 4-11).

Instead of single-family homes throughout the area, build townhouses or 

cluster the development on the safest ground.

For the community, redeveloping in this manner can reduce losses caused by a 

localized flooding problem, reduce public expenditures by keeping the land privately 

owned, and bring revenue from property taxes. 

Reusing the Buildings

In some cases, buildings in areas subject to localized flooding can continue to be 

used, even if they have been damaged. Although repeated flooding tends to cause a 

structure to deteriorate, certain building materials and types of structures withstand 

the effects of flood water better, particularly if, as in the case of most localized flood 

problems, the water does not get very deep and recedes fairly quickly.

Reusing the building has the two obvious advantages of avoiding the expense and 

trouble of moving or demolishing it and of continuing to obtain economic benefit 

from the building, especially in the case of a commercial property. This could be 

important to a business that has a substantial investment in the structure or that may 

lose customers if it moves to a new location.

If the localized flood problem can be at least partially relieved by a drainage 

modification project (Chapter 8), then there is even more likelihood that a use for 

the building can be maintained. An extra precaution on the part of the owner would 

be to make alterations to the building (Chapter 10) or to the parcel to foster proper 

drainage and infiltration of stormwater so that the building’s continued presence and 

use does not contribute to drainage problems in the future.

Another option is to put flood-prone buildings to a different use, one that is less 

susceptible to flood damage. It is easy to see that a supermarket would be vulnerable 

in a flood-prone area, while a farm equipment dealer’s 

inventory would be less prone to damage from shallow 

flooding. Retrofitting the building (see Chapter 10) 

can make this an even more viable alternative. This has 

the advantage of preserving sales tax revenues for the 

locality and income for the landowner.

A community needs to consider whether any buildings 

in the target neighborhood have historical value. The 

local historical society or State historical preservation 

office can help make that determination. There may 

be opportunities to create a real community asset in a 

restored structure that is pertinent to local history (see 

page 5-7 for an example). Preservation societies and 

other nonprofit groups can be enlisted to assist with 

restoration plans and work.

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After several floods damaged buildings in the 

Mississippi River floodplain, the Village of 

Thebes, Illinois, cleared out most of its floodplain. The village purchased one gas station 

on the edge of the flood-prone area. It was wet 

floodproofed and converted into a community 

building to serve the newly cleared park. The 

structure provided a meeting space, restrooms, 

and a garage for park maintenance equipment.

Funding was secured from several sources, 

including FEMA, the Community Development 

Block Grant, and the state Division of Water 

Resources.
9-16 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I I I Chapter 9. Redevelopment

Where to Get Help

The Federal Emergency Management Agency has information about, 

technical expertise with, and funding programs for acquisition and 

relocation. See http://www.fema.gov.

The U.S. Army Corps of Engineers has references on and experience with 

relocating houses. See http://www.usace.army.mil/inet/functions/cw/

cecwp/NFPC/nfpc.htm.

Many organizations have Web sites with ample ideas, success stories, and 

links to possible funding sources:

American Planning Association at http://www.planning.org.

Association of State Floodplain Managers at http://www.floods.org.

American Greenways Program at http://www. conservationfund.

org/?article=2471&back=true.

Land Trust Alliance at http://www.lta.org/.

The Nature Conservancy at http://nature.org/.

American Trails at http://www.americantrails.org/.

The Trust for Public Land at http://www.tpl.org/.

The Waterfront Center at http://www.waterfrontcenter.org/.

Additional resources are listed in Appendixes A and B.

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RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 10
Reducing Damage from Localized Flooding: A Guide for Communities

Part IV

Site-Specific Tools 

and Techniques

Part IV of this guide narrows the focus to techniques that can be applied to one 

house at a time, and even by individual property owners, to reduce potential flood 

damage or better cope with it when it occurs. This part covers retrofitting and flood 

insurance.

Part IV:

Chapter 10. Retrofitting

Chapter 11. Flood Insurance

Reducing Damage from Localized Flooding: A Guide for Communities 10-1

Retrofitting

This chapter outlines retrofitting techniques and some of the precautions that 

should be followed before they are implemented. Retrofitting a building is 

implemented by the building’s owner, but the community also has an important 

role, which is discussed in the last section of this chapter.

10

Introduction

Retrofitting is defined as making changes to an existing structure to reduce or 

eliminate the possibility of flood damage. As a flood mitigation technique, retrofitting 

can have several advantages:

It can be implemented on a building-by-building basis.

It can be relatively inexpensive.

It can be the most cost-effective approach for certain types of structures 

subject to shallow flooding.

It can be implemented by the individual building owner; it does not have to 

wait for government funding.

It can improve the market value of the property.

Properly designed, it would not disrupt the neighborhood or natural streams.

It retains the tax base and community integrity.

Retrofitting Techniques

This section presents six retrofitting techniques: 

Elevation;

Barriers;

Yard improvements;

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10-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

Dry floodproofing; 

Sewer backup protection; and

Wet floodproofing.

They are listed in order from what is generally considered the most effective and 

dependable technique—elevation—to the least desirable—wet floodproofing. For 

each technique, this section will explain how the retrofitting method works, where 

it should and should not be used, and its advantages and disadvantages.

There are two other ways to mitigate flood damage to a building that are not covered 

in this chapter. The most effective way to permanently protect a building from 

flooding is to relocate it out of the floodplain, which is discussed in Chapter 9. The 

other way is called “emergency measures,” which means waiting for the flood and 

then moving things out of the way. Emergency measures are temporary and are not 

considered a dependable mitigation approach. They are discussed under “Site-Specific 

Responses” in Chapter 6.

Elevation 

If a building is to remain in place, elevating it to prevent flood waters from reaching 

vulnerable areas is considered the most effective retrofitting technique. The structure 

typically is raised so that the lowest floor is at or above the design flood elevation 

(DFE).

Raising a building above the flood level on an open 

foundation (e.g., piles, piers, or posts) is an effective 

on-site property protection method. Water flows under 

the building, causing little or no damage to the structure 

or its contents.

Alternatives are to elevate on continuous foundation 

walls (creating an enclosed space below the building) 

or on compacted earthen fill. Although elevating on 

compacted fill is sometimes the most desirable elevation 

solution, it is a complicated alternative. The building 

has to be temporarily moved so the fill can be placed 

and properly compacted; the building is then moved 

back to the site. This process may make elevating on fill 

more costly than elevating on an open foundation or 

continuous foundation walls. 

The ease with which an elevation project can be 

accomplished usually depends on the building’s construction type. A large or rambling 

masonry building is more difficult to elevate than a smaller, compact wood-frame 

structure. The type of foundation is the most important factor—the contractor 

must use equipment to raise the building off its foundation. There are four types of 

foundations:

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French & Associates

This compact wood frame house on a crawlspace only 

had to be elevated 2 feet to be 1 foot above the 100-year 

flood level in this shallow, repetitively flooded area. 

The cost to the owner was under $10,000 in 1985. 
Reducing Damage from Localized Flooding: A Guide for Communities 10-3

Chapter 10. Retrofitting P A R T I V

Crawlspace construction (easiest to elevate);

Piers, posts, and pile construction;

Basement construction; and

Slab-on-grade construction (hardest to elevate).

One of the difficulties with elevation is that when newly 

created lower levels are used for storage, the stored items 

can be damaged by flooding. If the building is elevated 8 feet or more, the owner 

may be tempted to convert the lower area into a habitable living space, complete with 

carpet, insulation, and furniture, which can increase the cost of a flood and negate 

the benefits of the elevation project.

One way to help prevent conversions is to have the owner sign a nonconversion 

agreement. The owner and the Recorder of Deeds sign the form indicating that the 

restrictions on the enclosure have been recorded on the deed to the property. Since 

the deed follows the property, future homebuyers are informed of the restrictions. 

Advantages of elevation

Elevation is the most dependable way to protect the structure and 

contents; everything subject to damage is above the flood level.

If the property is in the Special Flood Hazard Area (SFHA), elevation is 

the only way to bring a substantially improved or substantially damaged 

building into compliance with the National Flood Insurance Program 

(NFIP) regulations.

Elevation can reduce flood insurance premiums.

Elevation techniques are well known, and qualified contractors are often 

readily available.

Elevation does not require the additional land that may be needed for 

floodwalls or levees.

Disadvantages of elevation

Elevation can be expensive, especially for buildings on slab foundations.

The appearance of the structure may be adversely affected.

Stairs may be required to access the building. 

Elevation is not appropriate in areas with high-velocity water flow, fastmoving ice or debris flow, or erosion, unless special measures are taken.

Some zoning ordinances and subdivision covenants prohibit buildings 

above a certain height.

Owners may lose their basements.

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The design flood elevation, or DFE, is the 

specified level of protection to which a structure will be protected by the retrofitting project. 

Selecting the DFE is discussed on page 10-16.
10-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

Barriers 

When properly designed and constructed, local barriers, such as floodwalls and levees, 

can be effective devices for repelling flood waters. Both levees and floodwalls can 

hold back flood waters, but they differ in their design and construction, appearance, 

and application. Levees are embankments of compacted soil, and floodwalls are built 

of concrete, masonry, or steel. 

The sides of a levee are sloped to provide stability and resist erosion, thus the width 

is usually 6 to 8 times its height. As a result, the taller the levee, the more space is 

required. Since a floodwall does not rely as much on its mass to resist flood forces, 

it requires less space than a levee of similar height.

A floodwall or levee can surround an entire structure or, depending on the flood 

levels, topography, and design preferences, it can protect isolated structure openings 

such as doors, windows, and basements. In some shallow flooding areas, this may 

be all that is needed to protect a vulnerable portion of the structure. An example is 

shown in the photos at the top of the facing page.

The costs of floodwalls and levees can vary greatly depending on the height, length, 

availability of construction materials, labor, access closures, and the interior drainage 

system. Maintenance of the barrier must also be performed on a scheduled basis to 

monitor and address settling or cracking that may occur over time. Other concerns 

are tree roots and burrowing animals that build tunnels through or under the levee 

or wall.

French & Associates

The owner who built this low floodwall landscaped it with stones and grading to 

minimize its visual impact. The design depends on human intervention to close the 

driveway opening.
Reducing Damage from Localized Flooding: A Guide for Communities 10-5

Chapter 10. Retrofitting P A R T I V

Although this neighborhood is in an X Zone, these two typical homes have experienced repeated floods. 

Heavy local rains fill the streets with water once or twice a year. The water rises above the curbs and sidewalks and pours down the driveway to the sunken garages.

The owner on the left raised the driveway retaining wall, cut grooves in it, and placed a board in the 

grooves when rains threatened the house. The board has rubber gaskets and hangs on the wall in the 

background. The owner of the house on the right opted to raise the retaining walls and the sidewalk to act 

as a permanent barrier to street flooding. 

The photo on the left was taken in the 1980s. Since that time, the owner has abandoned the approach 

that relies on human intervention and has also raised the sidewalk in front of his driveway.

Marsha Hilmes Robinson

This house has a barrier around the stairwell that protects it from shallow and short-duration flooding. This barrier 

requires several precautions, explained later in this chapter: a structural investigation is needed to ensure the walls 

will withstand the water pressures, and warning time is needed to slide the board into place (an example of human 

intervention).

Marsha Hilmes Robinson

French & Associates French & Associates
10-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

Cost, complexity, and space requirements generally limit localized levees and 

floodwalls to a height of 6 feet. Keep in mind that levees, floodwalls, and any other 

measure, can always be overtopped by a flood higher than expected. Overtopping 

allows water into the protected area, and the resulting damage to the structure can 

be as great as if it had not been protected at all. 

Another important design consideration is the effect that a levee or floodwall can have 

on other properties, because they divert water away from the protected structure. 

Such barriers must be kept out of the conveyance portion of the overbank area and 

back from required property line setbacks and drainage easements.

Advantages of barriers

Barriers can protect multiple structures.

Occupants usually do not have to leave the structure during 

construction.

Barriers are usually less expensive than elevating or relocating the entire 

structure.

Property inside the barrier will be protected from inundation without 

significant changes to the structure.

Disadvantages of barriers

Barriers may require land to construct. 

They must be maintained to be reliable.

Depending on the size, they can be very expensive.

Barriers will not reduce flood insurance premiums. 

Overtopping or failure eliminates any protection provided.

Barriers may have openings, thus human intervention may be required.

They may restrict access to the structure.

Interior drainage must be provided.

Yard Improvements

Shallow flooding can often be kept away from a structure if some simple improvements 

are made to the yard. Sometimes structures are built at the bottom of a hill or in a 

natural drainageway or storage area, so that water naturally flows toward them. 

One solution is to regrade the yard. If water flows toward the building, a new swale 

or wall can direct the flow to the street or a drainageway. Filling and grading next to 

the building can also direct shallow flooding away. Although water may remain in 

the yard temporarily, it is kept away from the structure. When these types of drainage 

modifications are made, care must be taken not to adversely affect the drainage 

patterns of adjacent properties.

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Reducing Damage from Localized Flooding: A Guide for Communities 10-7

Chapter 10. Retrofitting P A R T I V

Fairfax County Stormwater 

Management Division

This house in Fairfax 

County, Virginia, has a 

patio lower than the rest 

of the yard. Localized 

flooding flowed across 

the yard, onto the patio 

and into the house. The 

County helped the owner 

raise the stairwell and 

grade the site so water 

flows away from the 

house.

Former level of patio

Often water flows to a low entry point, such as a basement stairwell or patio door. 

A low wall or regrading around this point can keep water away, as illustrated in the 

photos to the right. If the water level does not recede within a few hours, an internal 

drainage system with a pump may be needed to handle seepage.

A related common problem results from disruption of the local drainage system. 

In most cases, subdivisions are designed for surface water to flow away from the 

structure to the lot line. A 5- or 10-foot easement on the lot line is designed to keep 

the area open, so water can flow to the front yard and into a drainage ditch or storm 

sewer or to a drainage swale in the back yard (as discussed on page 8-16).

Over time, the swales along the lot lines or in the back yard may get filled in. Property 

owners build fences, garages, sheds, swimming pools, and other obstructions up to 

the lot line. The photos on page 2-7 illustrate this problem. These drainage problems 

can be fixed by removing the obstructions and restoring the swales so they will carry 

water away from the building.

Advantages of yard improvements

They are very effective when dealing with shallow flooding.

They are low cost. Many projects can be built by the owner. 

Removing one obstruction may reduce flooding on several lots.

Disadvantages of yard improvements

Adjacent owners must cooperate and be instructed on the need not to 

build new obstructions.

They will not affect flood insurance premiums.

Dry Floodproofing

Dry floodproofing involves sealing the exterior of a building to prevent the entry 

of flood waters. Unlike a barrier, dry floodproofing relies on the structure to hold 

waters out. Dry floodproofing a building involves:

Using sealants or plastic membranes to prevent seepage of flood water 

through the walls;

Installing watertight shields over doors and windows; and

Installing measures to prevent sewer backup.

Because most structures were not designed or built to withstand water pressures, 

dry floodproofing is appropriate only for structures that face low-level flooding. The 

general rule is that this measure should not be used if a flood could exceed 2 or 3 

feet in depth, unless a thorough investigation is made by a structural engineer.

Because dry floodproofing depends on plastic membranes and sealants, there is 

always the threat of seepage during a flood. Therefore, it may not be reliable if flood 

waters recede slowly.

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10-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

W.A. Wilson Consulting Services

This house on a slab was dry floodproofed. The first 

1.5 feet of the brick walls were covered with plastic 

sheeting, which was covered with facing brick to 

protect it from debris impact and damage by sunlight. 

A steel gate with rubber gaskets provides access at the 

doorway.

French & Associates

The original design for this apartment building had 

the air conditioner below the center window for each 

unit. After repetitive shallow floods poured through 

the air conditioners on the lowest floor, the owner 

hired an engineer. The engineer concluded that if the 

air conditioners were moved up and the hole sealed, 

the structure could withstand the water pressures that 

accompany flooding. The modification is an excellent 

example of dry floodproofing.

The rate of rise of flood waters and the amount of warning time for the site is also 

important, because dry floodproofing often relies on human intervention to put the 

shields and closures in place.

Advantages of dry floodproofing

Dry floodproofing may be less expensive than other retrofitting 

methods.

It does not require the extra space needed for barriers. 

It retains the structure in its present environment.

Dry floodproofing can avoid significant changes in appearance.

It can reduce flood insurance premiums for non-residential structures.

Disadvantages of dry floodproofing

Dry floodproofing is not dependable for deep flooding, so it is usually 

not recommended for buildings with basements.

It is not dependable for long-duration flooding.

If design loads are exceeded, walls may collapse, floors may buckle, and 

the structure may even float, potentially resulting in more damage than 

would occur if the house were simply allowed to flood.

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Reducing Damage from Localized Flooding: A Guide for Communities 10-9

Chapter 10. Retrofitting P A R T I V

Dry floodproofing may be subject to leakage, which could damage the 

structure and its contents.

It usually requires human intervention and adequate warning time for 

installation of protective measures.

Using this technique requires periodic maintenance.

It will not reduce flood insurance premiums for residential structures.

It does not protect a structure from the force of flowing water, erosion 

and scour, the impact of ice and other floodborne debris, or wave 

action.

Sewer Backup Protection 

In many urban areas, sewer backup is the major cause of repetitive flooding. As 

illustrated below, a typical house has a sanitary sewer that drains toilet waste, laundry 

tubs, and, in some cases, the floor drain to the sanitary sewer main in the street. 

Clean stormwater and groundwater are handled by downspouts, footing drains, and 

sump pumps.

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Typical basement drain and sewer arrangement.

Note: The floor drain may or may not be connected to the sanitary sewer line.

Down

Spout

Down

Spout

Sump

Pump

Outfall

Footing

Drain Footing

Drain

Sump With

Sump Pump

Service

Line 

Sanitary

Sewer

Floor

Drain

Footing
10-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

Sammy Says: Don’t cause your own flood! Keep your sewer lines clear.

Keep out roots from trees and shrubs with root killer.

Make sure your yard clean-out vent will keep debris out.

Don’t pour dangerous liquids down the drain (motor oil, paint, pesticides, poisons, epoxies, 

etc.).

Don’t pour grease, fat, or cooking oil down the drain. They solidify later.

Don’t flush large solids, such as diapers, down the toilet.

•

•

•

•

•

Sewer backups can be caused by events not related to storms or flooding. Individual service lines can be 

plugged by grease, waste, tree roots, breaks in the pipe, or saturated ground. Proper maintenance can 

prevent most of these problems. This public information warning is from Lansing, Illinois, and is designed 

to encourage people to take steps to protect themselves from flooding. Lansing has a variety of materials 

displaying its flood protection mascot, Sammy Sandbag.

Often flooding is caused by these two sewer systems being interconnected. In older 

cities, some sanitary sewage and stormwater systems drain to a combined sewer 

system. In newer areas, some downspouts, footing drains, and sump pumps have 

been illegally connected to the sanitary sewer service. During a heavy rain, stormwater 

enters the sanitary sewers, overloading the main lines and causing the sewage to back 

up into basements and other low areas of buildings.

There are four main approaches to protect a structure against sewer backup: floor 

drain plugs, floor drain standpipes, backup valves, and overhead sewers. The first 

two devices keep water from flowing out of the lowest opening in the building, the 

floor drain. They typically cost less than $25; but if water becomes deep enough in 

the sewer system, it can flow out of the next-lowest opening in the basement, such 

as a toilet or laundry tub.

Backup valves and overhead sewer lines are more secure, but are also more expensive 

($3,000–$5,000). A backwater protection valve allows sewage to flow out while 

preventing backups from flowing into the building. 

An overhead sewer acts like a standpipe but without the shortcomings. A sump is 

installed under the basement floor to intercept sewage flowing from basement fixtures 

and the basement floor drain. An ejector pump in the sump pushes sewage up above 

the flood level. From there it can drain by gravity into the sewer service line. Plumbing 

fixtures on the first floor continue to drain by gravity to the service line.

In the unlikely event that the sewers back up above ground level, a check valve in the 

pipe from the ejector pump keeps it in the pipes. Backed-up sewage is enclosed in 

the sewer pipes and doesn’t overflow laundry tubs or basement toilets. Hydrostatic 

pressure is kept in the pipes outside the building walls, so if a break were to occur, 

it would be easier to fix than if the pipe burst under the building.

Floor drain float plug.
Reducing Damage from Localized Flooding: A Guide for Communities 10-11

Chapter 10. Retrofitting P A R T I V

Adapted from Metropolitan St. Louis Sewer District

Called a “grinder pump,” this is a variation on the backup valve and overhead 

sewer. The Metropolitan St. Louis, Missouri, Sewer District has funded the 

installation of many such pumps to prevent sewer backup in its service area.

Pump discharge to

yard clean-out

Sewage

backed up

in sewer

lines

6" lateral to

MSD sewer

6" lateral

Basement

Sewage flows to grinder pump which forces

sewage above level of sewer backup

During a power outage, the ejector pump will not work unless a backup generator 

is provided. An outage would only limit the use of the facilities in the basement that 

need the pump. The upstairs plumbing would still work, and the sewer would still 

be prevented from backing up.

Advantages of sewer backup protection

The floor drain plug and standpipe are inexpensive ways to prevent 

sewer backup.

The automatic sewer backup valve and overhead sewer are almost 100-

percent dependable and require no human intervention.

Disadvantages of sewer backup protection

The floor drain plug and standpipe need to be removed to allow any 

spillage on the floor to drain. This requires someone to put it in place 

when it rains (human intervention).

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10-12 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

The floor drain plug and standpipe do not stop backup from coming 

out of the next-lowest opening, like a laundry tub or toilet.

The floor drain plug and standpipe do not reduce the hydrostatic 

pressure on the sewer lines. If the line under the floor is not cast iron, it 

may break under pressure. 

Sewer backup can equalize hydrostatic pressures on the basement 

walls and floor, preventing them from collapsing due to outside water 

pressures. Therefore, although stopping stopping sewer backup keeps 

sewage out, it may also increase the risk of structural damage.

The sewer backup valve and overhead sewer require periodic 

maintenance, something that is easy to forget because they are often 

placed out of sight.

Wet Floodproofing

Wet floodproofing is a term that covers various ways to protect a structure, its utilities, 

and its contents, while allowing flood waters to enter the structure. Wet floodproofing 

is the complement of dry floodproofing—the latter keeps water out, but at risk of 

damaging the structure from water pressures (see the 

photograph of the basement floor on the left). Wet 

floodproofing prevents such damage by letting the water 

in, so the pressures will be the same on both sides of 

the walls and floors.

Wet floodproofing is usually one of the most costeffective means of reducing exposure to flood damage. 

Virtually any activity to reduce the number of things 

exposed to water damage is a wet floodproofing 

measure. This can be as simple as picking the television 

set up and setting it on a table or rolling up the carpet in 

the basement and taking it upstairs. A tall water heater 

installed on the floor can be replaced by a shorter, fatter 

one on a pedestal (see the photograph).

All construction and finishing materials in the areas 

of the structure that can get wet must be resistant 

to damage caused by direct and possibly prolonged 

contact with flood waters. Since areas used for living 

space contain materials that are easily damaged by 

water, such as furniture, appliances, and carpeting, 

wet floodproofing is practical only for those portions 

of a structure that do not need to be finished. It is 

generally used on enclosures below elevated buildings, 

basements, crawlspaces, garages, and utilities and 

service equipment inside and outside the building. 

Wet floodproofing requires human intervention in 

most cases. To reduce this need, the interior finishes 

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French & Associates

This basement floor in the photograph on the left 

buckled when the building was surrounded by flood 

waters. It is testament to the pressure water puts on a 

structure. If the basement had been wet floodproofed, 

the flood water allowed into the building would have 

equalized the pressures on the outside, and this damage 

would not have happened. The photograph on the 

right is an example of a wet floodproofed garage, i.e., 

an area that can be flooded with little or no damage to 

the structure or contents. Note the elevated water heater 

and unfinished walls. (In this case, gypsum wallboard 

is required under the local fire code.)

French & Associates
Reducing Damage from Localized Flooding: A Guide for Communities 10-13

Chapter 10. Retrofitting P A R T I V

can be changed to improve their resistance to flood damage. Gypsum wallboard can 

be removed, and epoxy or other impervious paints can be applied to the walls and 

floors to reduce the likelihood of contaminants seeping into concrete. This will also 

make cleanup easier after the flood. See the various measures that were taken to wet 

floodproof the demonstration house in South Carolina shown on page 5-7.

Advantages of wet floodproofing

Wet floodproofing reduces the potential of structural damage by 

minimizing flood forces on the structure due to standing water and 

buoyancy.

Many wet floodproofing actions can be accomplished for a minimal 

cost.

Disadvantages of wet floodproofing

Wet floodproofing usually requires human intervention and, therefore, 

warning time.

It does not reduce the cost of flood insurance for residential structures.

It is most effective when the building is constructed of flood-resistant 

materials, e.g., concrete or block floors and walls.

The wet floodproofed area will be inundated by dirty floodwater and 

will need to be cleaned, sanitized, and dried out.

Precautions and Parameters 

The retrofitting measures presented in the previous section will not work everywhere. 

There are certain technical precautions and design parameters that affect whether 

and how a measure should be used.

Precautions

There are some limitations to all retrofitting measures and some precautions that apply 

only to some of them. The following should be understood before the community 

or the property owner undertakes a project.

Safety. The property will still be subject to flooding after the building is retrofitted. 

It should not be occupied during a flood. Even if the structure is high and dry or 

protected by a barrier, entering or exiting the structure presents a safety hazard. 

Riding out the flood may sound safe, but the occupants should consider the possibility 

of an emergency and whether an ambulance can get to the building through the 

flooded streets.

Human intervention. Human intervention means that the retrofitting measure 

needs someone to take action in order for it to work. Examples include closing an 

opening, relocating contents, or turning on a pump. Other examples are seen on 

page 10-5 in the pair of photos at the top, and the bottom left photo. Projects that 

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10-14 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

do not need human intervention are illustrated on pages 10-2, 10-5 (bottom right 

photo), 10-7, and 10-8.

Retrofitting measures that require human intervention should be avoided. One reason 

elevation is the most desired retrofitting approach is because it does not need human 

intervention. During a flood, no one needs to do anything to make it work. Property 

owners can go to sleep at night or they can go on vacation without worrying about 

something that needs to be done during a thunderstorm. 

Passive retrofitting that requires no human intervention is not, unfortunately, always 

possible. Building or funding constraints may dictate some human intervention in 

the design. Although not the most dependable approach, a measure that uses human 

intervention may be the most economical one and, if the required actions are taken 

when needed, it can be effective. 

Work done by the owner. Some of the retrofitting measures, such as building a levee 

in the backyard and moving furniture upstairs, may be simple and straightforward 

enough for the owner to manage. However, some measures may not be as easy as 

they appear. A contractor, or even an architect or engineer, is recommended for the 

more complicated projects, such as elevation and dry floodproofing a structure. The 

community should also publicize where local codes require an engineer, a licensed 

plumber, or other professionals.

Level of protection. One of the most important steps in the process of retrofitting 

a structure is determining the level of protection. This process is more challenging 

for structures located in B, C, and X Zones where flood data are not available from 

the Flood Insurance Study or Flood Insurance Rate Map (FIRM). Ways to determine 

flood elevations are discussed in Chapter 4.

The specified elevation to which a structure is going to be protected through 

retrofitting (the DFE) is not necessarily the same as the regulatory flood elevation. 

If the property is located in a regulated floodplain (either the SFHA or a floodplain 

adopted in the community’s ordinance) and the project will be a substantial 

improvement, then the design must comply with the regulations. In this case, the 

design protection level must be at or above the regulatory flood elevation.

However, if the project will not be a substantial improvement or it is not in a regulated 

floodplain, then the owner or designer is free to determine the DFE. Protecting to 

the 100-year flood level is highly recommended. However, there may be instances 

where protection to a lower level is more practical. An example would be a large 

masonry commercial structure on a slab foundation. The cost to elevate it could be 

hundreds of thousands of dollars, but the cost to dry floodproof the first 3 feet (the 

maximum height recommended) could be only $10,000 or $20,000.

It must be remembered that the DFE can always be exceeded by a higher flood. In general, the cost of 

retrofitting increases as the design protection level increases. In choosing the level of 

protection, the community and the owner must consider not only how much they 

are willing to pay, but also the level of risk they are willing to accept. Depending on 

the retrofitting technique and the level of protection, there will be some residual risk 

of flooding. No retrofitting technique completely eliminates that risk. 
Reducing Damage from Localized Flooding: A Guide for Communities 10-15

Chapter 10. Retrofitting P A R T I V

Other hazards. Although the focus of this chapter is retrofitting structures affected by 

flooding, the community and the owner should consider that retrofitting a structure 

influences how that structure reacts to other hazards. For example, an elevated building 

may be more at risk to wind damage or shaking from an earthquake.

Flood Insurance

In the SFHA, flood insurance rates for new buildings are based on the building’s 

exposure to flooding by the base flood. Retrofitting a building outside the SFHA will 

not affect the owner’s insurance premiums. If the building is in the SFHA, there are 

three instances in which the retrofitting project will affect flood insurance rates.

If a building in the SFHA is elevated above the base flood elevation, the 

owner can submit an Elevation Certificate to receive lower rates. The table 

shows how much lower the premium can be for an elevated building 

compared to the cost of insurance for an older (pre-FIRM) building that 

benefits from the subsidized rate. 

If a non-residential building in the SFHA is dry floodproofed to or above the 

base flood elevation, the owner can submit the certificate needed to receive 

lower rates. 

If the building is in the SFHA and the project is a substantial improvement, 

then the building must be protected to the base flood and the rates would be 

reduced accordingly.

1.

2.

3.

Example NFIP Flood Insurance Premiums

(as of May 1, 2005)

Annual premium for $150,000 in building coverage and $60,000 in contents 

coverage for a one-story house with no basement and a $500 deductible.

Note that premiums are lower in CRS communities.

Policy/Building Exposure Premium

Outside the SFHA: 

Standard Flood Insurance Policy $794

Within the SFHA:

Pre-FIRM (“subsidized”) rate $1,372

Post-FIRM (actuarial) rates

2 feet above base flood elevation $400

1 foot above base flood elevation $577

At base flood elevation $924

1 foot below base flood elevation $3,288
10-16 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

It can be seen that protecting a pre-FIRM structure (one built before the date of the 

original FIRM for the community) to a level 2 feet above the base flood can save 

the owner about $1,000 annually in reduced insurance premiums. However, if the 

project is a substantial improvement in the SFHA and the building is not protected 

to the base flood elevation, the owner may be required to pay over $3,000 annually 

in flood insurance premiums. 

It should be remembered that even if the current owner does not want insurance 

(e.g., if he or she thinks that the project will protect the building from all floods), 

future owners may need to purchase a policy as a condition of a mortgage. The 

current owner has an incentive to make sure that a future owner can afford the 

required flood insurance.

Design Parameters 

There are many different factors that affect whether a building should be retrofitted 

and what measure to use. Because of this, a building contractor and a design 

professional, such as an engineer or architect, would be helpful. The owner and the 

design professional need to consider important characteristics before a measure is 

selected and detailed plans are prepared. Many of these conditions vary greatly from 

one building to another, so gaining as much information about these characteristics as 

possible will help the design professional determine the most appropriate retrofitting 

techniques.

Building condition and type. A dilapidated structure may not be worth protecting. A 

foundation that has settled and cracked will present problems if the building is to be 

elevated or dry floodproofed. As noted above, certain types of buildings are easier to 

retrofit than others. Buildings on crawlspaces are the most cost-effective to elevate, 

but generally they cannot be dry floodproofed because the floor is not watertight.

Design protection elevation. As stated earlier, the owner or designer has some 

flexibility in setting the DFE. If the protection level is less than 3 feet deep over the 

floor, dry floodproofing becomes feasible, although it may not result in protection 

to the base flood elevation. 

If the owner would like Federal financial assistance to retrofit, he or she must show 

that the benefits of the project exceed the cost. This is done using a benefit-cost 

program that compares the long-term risk and potential for damage to the cost of 

the project. To do this, the program needs an accurate elevation of the lowest floor, 

which is compared to the elevation of the 10- and 100-year floods. 

Therefore, if financial assistance is sought, it may be worthwhile to conduct a study to 

calculate the various flood elevations before selecting the DFE. (See also the discussion 

on setting a regulatory flood elevation in Chapter 4.)

Buildings in an SFHA that are being substantially improved (or have been substantially 

damaged) must be elevated to or above a DFE that is at least as high as the base flood 

elevation (BFE) and possibly higher, depending on the local ordinance. Even if the 

proposed modification is not a substantial improvement, it makes little sense not to 

elevate to at least the BFE even if it is not required. Usually it will not cost much more 

and will yield the added benefit of post-FIRM insurance rates, which are usually lower 

For more about 

designing a retrofitting project, 

designers should 

consult Engineering Principles 

and Practices for 

Retrofitting Flood 

Prone Residential 

Buildings (FEMA 

259).
Reducing Damage from Localized Flooding: A Guide for Communities 10-17

Chapter 10. Retrofitting P A R T I V

than pre-FIRM rates. In localized flooding areas where there is no readily available 

BFE, other types of retrofitting could be designed to a DFE that may be lower than 

the BFE. Owners and designers should bear in mind the precautions and parameters 

noted above when selecting a DFE.

Hydrodynamic forces. Hydrodynamic forces include velocity and debris that can 

batter a structure. Higher velocities can cause erosion and scour a levee or the 

soil supporting the building. Debris can include trees, portions of flood-damaged 

buildings, mobile homes, storage tanks, and in cold climates, sheets or chunks of 

ice. The potential for debris to damage the structure is difficult to predict, but some 

data on velocities can be found in the Flood Insurance Study. If there are no studies, 

the forces can be estimated from previous floods. 

In most localized flooding situations, velocity and debris are usually a minimal 

concern. However, the owner and designer need to consider special precautions 

if velocities exceed 5 feet per second or if there is a history of higher velocities or 

debris during previous local floods. 

Warning time and rate of rise. How fast a flood rises determines whether human 

intervention measures are feasible. In areas of steep topography, in places with a 

high degree of urbanization and impervious surfaces, or in small drainage areas, 

floodwaters can rise very quickly with little or no warning. If there is a fast rate of 

rise but no public warning, measures dependent on human intervention should be 

avoided. (Flood warning systems are covered in Chapter 6.)

There are ways to close openings and turn on pumps without human intervention. 

Doorways can be kept closed rather than open, as is done with the gate shown on 

page 10-8. Pumps can be activated when a sensor gets wet. These passive measures 

work, but they can increase the cost of the project and add to the likelihood of 

problems when the flood comes.

Flood duration. Floods of long duration may hinder access to the structure, but more 

importantly for retrofitting, they may affect the amount of time the water is interacting 

with the structure. Long periods of inundation are more likely to cause significant 

damage than short ones. Certain retrofitting techniques, such as dry floodproofing, 

may be inappropriate in long-lasting flooding due to the increased chance of seepage, 

wicking, or other moisture damage caused by prolonged exposure to flood waters. 

Regulations. Local building codes and floodplain regulations are critical parameters in 

the design of a retrofitting project. (Refer to Chapter 4 for a more detailed discussion 

of regulations.) Here are some common constraints that must be checked:

Barriers are prohibited in the regulatory floodway and on drainage easements 

where they can divert flood waters onto other properties.

If the project is a substantial improvement in the regulatory floodplain, a 

residential building will have to be elevated and a nonresidential building 

will have to be elevated or dry floodproofed.

Zoning ordinances often have restrictions on the height of buildings, 

especially in residential areas. For example, the zoning ordinance may 

prohibit a house to be built more than 30 feet high. If a two-story house is 

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10-18 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

already 28 feet high, it would be difficult obtain a permit to elevate it much 

higher. 

Barriers may be prohibited if the regulations include a compensatory storage 

requirement or prohibit bringing new fill into the floodplain.

Some building codes require that if an older building has electrical work, 

all the wiring and the service must be brought up to the current electrical 

code. While this is an excellent requirement, it adds more expense to a 

floodproofing project.

Regulatory standards that are not NFIP requirements may be amended by the 

community. It may be appropriate to modify a flood protection requirement in order 

to facilitate protecting a building from flooding. For example, some communities’ 

compensatory storage requirements exempt floodwalls that are constructed within 10 

feet of the building, thereby permitting a flood protection measure while minimizing 

the amount of lost flood storage. 

Owner preference. A project to alter a building will not succeed without the support 

of the property owner(s). Owners should agree to a project only after they review 

these concerns and receive satisfactory answers:

How much will the project cost? 

How will the construction project affect them?

How secure will they be from future flood damage?

What are their responsibilities in the project?

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French & Associates

This library was built on flood-prone land donated by a developer. After flooding in 1986, 1987, 1989, and 

1990, the library was relocated. The building was given to the fire department for a headquarters and training 

facility, and the village built this levee. The levee surrounds the building and has no openings requiring human 

intervention. The top is 2 feet above the 100-year flood.
Reducing Damage from Localized Flooding: A Guide for Communities 10-19

Chapter 10. Retrofitting P A R T I V

How will the project affect the appearance of their property?

It is important for the owners to understand that no project will provide total security 

from any future flood. A project can fail for a variety of reasons, such as:

The flood exceeded the project’s design level;

The owners did not properly maintain the project after it was constructed; or

The owners failed to take the appropriate actions during the flood, such as 

installing a closure, or they were away when the home flooded.

These last two items underscore the need for owners not just to agree to the project, 

but also to understand their long-term responsibilities to ensure that the measure 

will work when it’s needed.

The owners’ concern about how their homes and businesses will look after the 

project is completed is the most common reason for delays in projects, particularly 

elevation projects. There are many ways the designer can improve the appearance 

of the building, especially with landscaping. One example is the attractive floodwall 

on page 10-4.

The primary thing to remember about owners’ preferences is that if the owners 

do not like the looks of a proposed project, the building may never be retrofitted. 

Similarly, if the owners are publicly displeased with the finished project, it may be 

hard to convince others of the merits of a similar retrofitting project. 

Community Support 

Usually, retrofitting measures are considered the responsibility of the property owner. 

However, local governments should have some involvement in all strategies that can 

reduce flood losses. Additionally, the community can play various roles in encouraging 

and supporting these projects. These opportunities are covered in more detail in the 

U.S. Army Corps of Engineers’ Local Flood Proofing Programs.

Government Facilities

One of the first duties of a local government is to protect 

its own facilities. Fire stations, water treatment plants, 

and other critical facilities should be a high priority 

for retrofitting. This also sets an example and provides 

models for private property owners.

Public Information

The next step in supporting property protection 

measures is providing basic information to property 

owners. Owners need information about measures they 

can take, and they need to see examples, preferably from 

nearby neighborhoods or towns. Public information 

activities that can promote and support property 

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In Activities 330 and 350 

(Outreach Projects and Flood 

Protection Information), the 

CRS provides credit for distributing technical information on 

property protection to citizens through newsletters, presentations, displays, library references, Web sites, and other means. Activity 

360 (Flood Protection Assistance) encourages 

and provides credit for community visits to 

flood-prone properties and for giving the owner 

site-specific advice on retrofitting and other 

protection measures.
10-20 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 10. Retrofitting

protection are discussed in Chapter 5. They are also eligible for credit under the 

Community Rating System.

Financial Assistance

The local government can be a pass-through and administrator for State or Federal 

funding programs, or it can contribute its own funds to allow for more locally 

appropriate arrangements. Financial assistance can range from full funding of a 

project to helping residents find money from other sources. 

Some communities assume responsibility for situations that arise from an inadequate 

public sewer or drainage system—sewer backups, street flooding, and other problems. 

Rather than face loss of staff time, legal costs, and ill will over assigning blame, 

the Metropolitan St. Louis, Missouri, Sewer District fully funds the sewer backup 

prevention measures shown on page 10-11.

Two community-supported programs are low-interest loans and rebates. These 

approaches do not fully fund a protection project, but they decrease costs to the 

community treasury and increase the owner’s commitment to the project. Often, 

small amounts of money act as a catalyst to pique the owner’s interest and get a selfprotection project underway (described in the box on the facing page).

The more common outside funding sources are listed below. Unfortunately, some 

are available only after a flood or disaster declaration. 

Three Federal Emergency Management Agency (FEMA) programs, discussed 

in the acquisition section in Chapter 9, fund retrofitting and acquisition 

projects: Pre-Disaster Mitigation, Flood Mitigation Assistance grants, and the 

Hazard Mitigation Grant Program. 

After a flood or other type of disaster that warrants a Presidential disaster 

declaration, damaged public and nonprofit properties can be eligible for 

funds that help pay for retrofitting measures that mitigate against future 

damage as part of funding repairs and reconstruction. However, the amount 

of assistance will be reduced by the amount of flood insurance that the 

public agency should be carrying on the property.

A Presidential disaster declaration may also trigger funds for limited home 

repairs and unmet needs for disaster victims. Sometimes these programs 

include wet floodproofing measures, such as replacing a flooded furnace in 

the basement with a furnace at a higher, flood-free, level.

Community Development Block Grants are provided to larger cities 

and counties; smaller communities can apply to the State community 

development agency.

The U.S. Army Corps of Engineers will support elevation projects as part of a 

larger flood protection program. The Corps works with the community, not 

directly with the property owner.

Flood insurance claims can include Increased Cost of Compliance (ICC) 

funding. This provision increases a flood insurance claim payment to help 

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Reducing Damage from Localized Flooding: A Guide for Communities 10-21

Chapter 10. Retrofitting P A R T I V

underwrite a flood protection project required 

by code as a condition to rebuild the flooded 

building. It can also be used to help pay the 

non-Federal portion of a cost-shared retrofitting 

project.

After a disaster declaration, the Small Business 

Administration may provide disaster loans 

for non-governmental properties. There is a 

provision for additional funds for retrofitting.

Where to Get Help

Two helpful resources for making floodresistant modifications to houses are Homeowner’s 

Guide to Retrofitting: Six Ways to Protect Your House from 

Flooding, Federal Emergency Management Agency, 

FEMA 312, 1998, which is available at http://

www.fema.gov/hazards/hurricanes/rfit.shtm and 

Engineering Principles and Practices for Retrofitting Flood Prone 

Residential Buildings, Federal Emergency Management 

Agency, FEMA 259, 1996.

FEMA’s retrofitting publications can be found at http://www.fema.gov/

hazards/floods/whatshouldidoprotect.shtm.

The Regional Office is the best place for information about FEMA mitigation 

funding.

The Corps of Engineers’ National Nonstructural/Flood Proofing Committee’s 

Web site, http://www.usace.army.mil/inet/functions/cw/cecwp/NFPC/

nfpc.htm, lists retrofitting references. The Corps’ District offices may be able 

to provide technical advice on retrofitting measures. 

The most extensive retrofitting Web site is Louisiana State University’s (LSU) 

Extension Center, http://www.louisianafloods.org. In addition to listing 

LSU’s many publications, the site offers advice on floodproofing and flood 

insurance, and a link to the national Extension Disaster Education Network. 

There are also links to online shopping for retrofitting products, contractors, 

and professional services, and to examples of installations.

Additional resources are listed in Appendixes A and B.

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Property Protection Rebates

The Village of South Holland, Illinois, has a rebate program to help property owners fund retrofitting projects to protect against surface and 

subsurface flooding. If a project is approved, 

installed, and inspected, the Village will reimburse the owner 25% of the cost up to $2,500. 

About 650 floodproofing and sewer backup 

protection projects have been completed under 

this program. Perhaps not surprisingly, contractors have become some of the best agents to 

publicize this program.

Lexington-Fayette Urban County, Kentucky, 

has had a rebate program since 1992. It 

funds up to 50% of the cost of a project. It has 

distributed nearly $1,250,000 to protect 340 

homes from surface flooding.

RETURN TO TABLE OF CONTENTS ADVANCE TO CHAPTER 11
Reducing Damage from Localized Flooding: A Guide for Communities 11-1

Flood Insurance

Flood insurance is essential in helping people repair, recover, rebuild, and even 

install some retrofitting measures. Flood insurance has many advantages, 

especially for people in areas prone to shallower, localized flooding problems.

Homeowners, renters, businesses, and the local government can all purchase 

flood insurance, whether the property lies within the designated flood zones 

on the community’s Flood Insurance Rate Map (FIRM) or lies outside of 

them, in an area subject only to localized flooding.

Because localized flooding is unlikely to reach conditions severe enough for 

a Presidential disaster declaration, aid from the State or Federal government 

will be limited. In the absence of a disaster declaration, insurance may be 

the only source of assistance to help owners of damaged property pay for 

cleanup and repairs.

Besides paying for flood damage, insurance payments can be used to cover 

part of the cost of mitigation measures required by the community’s 

regulations (such as elevating the building above the base flood elevation). 

Increased Cost of Compliance (ICC) coverage of up to $30,000 may be 

provided (in addition to the claim payment for flood damage up to the limits 

of the policy) to elevate, floodproof, demolish, or relocate the property.

Coverage is available for the contents of a home or business as well as for the 

structure.

Renters can buy contents coverage, even if the building owner does not buy 

coverage for the structure itself.

NFIP Flood Insurance 

Most standard homeowners insurance policies do not cover a property for damage 

caused by flooding. However, a business or homeowner can insure a building for 

damage by surface flooding through the National Flood Insurance Program (NFIP), 

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11
11-2 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 11. Flood Insurance

as long as the community in which the building is located participates in the 

program. 

Flood insurance coverage is provided for buildings and their contents damaged 

by a “general condition of surface flooding” in the area. Flood insurance can be 

purchased for any eligible building in the community, even those outside the Special 

Flood Hazard Area (SFHA) shown on the community’s FIRM. Residents in B, C, and 

X Zones can purchase coverage and can be eligible for the less-expensive Preferred 

Risk Policy discussed below. 

Under the NFIP rules, a “building” is a walled and roofed structure that is mostly 

above-ground and fixed to a permanent foundation (even a manufactured home). 

“Flooding” is a general and temporary condition during which the surface of 

normally dry land is partially or completely inundated, affecting two properties or 

at least two acres in the area. 

Community participation in the NFIP allows local insurance agents to sell a separate 

flood insurance policy under rules and rates set by the Federal Emergency Management 

Agency (FEMA). Any local property insurance agent may sell a policy through one of 

the “Write Your Own” insurance companies or a direct policy through FEMA. Both 

approaches result in the issuance of a Standard Flood Insurance Policy that meets all 

the requirements and nationally uniform rates determined by FEMA. Some sample 

premiums are shown in the table on the facing page.

Under the NFIP, building coverage is limited to $250,000 for residential dwellings 

and $500,000 for non-residential buildings. Contents coverage is available for up to 

$100,000 for a residence and $500,000 for a business.

Preferred Risk Policies. Preferred Risk Policies can be obtained for most residential or 

commercial buildings in B, C, or X Zones that have not had multiple flood insurance 

claims or disaster assistance payments. The policy offers different levels of building 

and contents coverage (contents-only coverage for renters) for a fixed premium. A 

sample rate is shown in the table on the facing page.

The Preferred Risk Policy has the same provisions as the Standard Flood Insurance 

Policy, and also includes the additional ICC coverage, as explained on page 11-6. 

Claims. If an insured property is flooded, the property owner contacts his or her 

insurance agent. The agent arranges for an adjuster to review the damage and work 

with the insured to settle the claim. Property owners always work through their 

insurance agents; they do not deal directly with FEMA. Note that policy coverage 

details can change from year to year, and a purchaser should carefully read the policy 

when it is issued and renewed.

Building Coverage

For NFIP flood insurance, a building is defined as a walled and roofed structure. 

This includes manufactured homes, as long as they are principally above ground and 

affixed to a permanent site. Detached garages on a residential property are covered 

under the building coverage for up to 10% of the policy limits.
Reducing Damage from Localized Flooding: A Guide for Communities 11-3

Chapter 11. Flood Insurance P A R T I V

Building coverage is for the structure itself and all the things that usually stay with 

the building when it changes ownership, including:

Utility equipment, such as a furnace, air conditioner, or water heater;

Permanent flooring materials installed over unfinished flooring;

Built-in appliances; and

Wallpaper and paneling.

Coverage for items of property in a building enclosure below the elevated floor of 

an elevated post-FIRM building or in a basement is limited to a specific list of items 

described in the policy.

Contents Coverage

Contents coverage for flooding may be purchased separately from the building policy. 

If flood insurance is in force for a particular building because it was required by 

the lender when the mortgage was received, contents coverage may not have been 

purchased at that time, and the property owner should check to verify what coverage 

is in place. Insurance coverage is not required by most lenders for properties outside 

the SFHA, but some lenders do require it to protect their interest in the structure. 

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Example NFIP Flood Insurance Premiums

(as of May 1, 2005)

Annual premium for $150,000 in building coverage and $60,000 in 

contents coverage for a one-story house with no basement and a $500 

deductible.

Note that premiums are lower in CRS communities.

Policy/Building Exposure Premium

Outside the SFHA: 

Standard Flood Insurance Policy $794

Preferred Risk Policy $264

Within the SFHA:

Pre-FIRM (“subsidized”) rate $1,372

Post-FIRM (actuarial) rates

2 feet above base flood elevation $400

1 foot above base flood elevation $577

At base flood elevation $924

1 foot below base flood elevation $3,288
11-4 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 11. Flood Insurance

FEMA News Photo

Local flooding, with shallow, slow-moving floodwaters, damages carpeting, 

furniture, and other contents as much as it damages the structure. Contents 

coverage is highly recommended in areas subject to localized flooding.

Contents coverage is for the removable items inside the building, such as furniture, 

household items, and clothing. Renters can buy contents coverage, even if the owner 

does not buy structural coverage on the building.

Certain contents are not insurable or are subject to coverage limits, such as:

Jewelry, artwork, furs, and similar items (coverage is limited to $2,500);

Money or valuable papers;

Animals and livestock; and

Licensed vehicles.

Other Coverage

The standard NFIP policy also provides coverage for other expenses or damage related 

to a flood. These include certain costs associated with the removal of debris and 

measures taken to protect the property, such as sandbagging, purchasing pumps, 

and/or expenses related to removing insured items to safety.

Waiting Period

Policy owners should be aware that in most cases there is a 30-day waiting period 

after the purchase of an NFIP policy before it goes into effect. This rule encourages 

people to keep a policy in force at all times, rather than wait until there is a flood 

threat. A community should publicize the availability of flood insurance so residents 

can have their insurance protection in place by the time a flood comes. 

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Reducing Damage from Localized Flooding: A Guide for Communities 11-5

Chapter 11. Flood Insurance P A R T I V

About the Mandatory Purchase of Flood Insurance Requirement

to purchase a flood insurance policy on the building. Federal regulations require building coverage 

equal to the amount of the loan (excluding appraised value of the land) or the maximum amount 

of insurance available from the NFIP, whichever is 

less. The maximum amount available for a singlefamily residence is $250,000. Government-sponsored enterprises, such as Freddie Mac and Fannie 

Mae, have stricter requirements.

The mandatory purchase requirement does not 

affect loans or financial assistance for items that 

are not covered by a flood insurance policy, such 

as vehicles, business expenses, landscaping, and 

vacant lots. It does not affect loans for buildings 

that are not in an SFHA, even though a portion of 

the lot may be within the zone. While not mandated 

by law, a lender may require a flood insurance policy 

as a condition of a loan for a property in any zone 

on a FIRM.

If a person feels that an SFHD form incorrectly 

determines that the property is within the SFHA, 

he or she may request a Letter of Determination 

Review from FEMA. This must be submitted within 

45 days of the determination. More information can 

be found at http://www.fema.gov/fhm/fq_gen11.

shtm.

Note that even if a property is not in the SFHA 

or if FEMA issues a letter confirming that status, 

the lender may still require a flood insurance policy. 

Many areas of known local flooding are not in the 

SFHA, and having flood insurance is highly recommended. People in areas of local flooding should 

discuss building coverage, contents coverage, and 

Preferred Risk Policies with their insurance agents.

The Flood Disaster Protection Act of 1973 and 

the National Flood Insurance Reform Act of 1994 

made the purchase of flood insurance mandatory 

for federally backed mortgages on buildings located 

in SFHAs. It also affects all forms of Federal or 

federally related financial assistance for buildings 

located in SFHAs. The SFHA is the base (100-year) 

floodplain mapped on a FIRM. It is shown as one or 

more zones that begin with the letter “A” or “V.” 

The requirement applies to secured mortgage 

loans from financial institutions, such as commercial lenders, savings and loan associations, savings banks, and credit unions that are regulated, 

supervised, or insured by Federal agencies such 

as the Federal Deposit Insurance Corporation and 

the Office of Thrift Supervision. It also applies to all 

mortgage loans purchased by Fannie Mae or Freddie Mac in the secondary mortgage market.

Federal financial assistance programs affected 

by the laws include loans and grants from agencies 

such as the Department of Veterans Affairs, Farmers Home Administration, Federal Housing Administration, Small Business Administration, and the 

Department of Homeland Security’s FEMA. 

Lenders are required to complete a Standard 

Flood Hazard Determination (SFHD) form whenever 

they make, increase, extend, or renew a mortgage, 

home equity, home improvement, commercial, or 

farm credit loan to determine if the building or 

manufactured (mobile) home is in an SFHA. It is the 

Federal agency’s or the lender’s responsibility to 

check the current FIRM to determine if the building 

is in an SFHA. Lenders may read the FIRM themselves or they may use a flood zone determination 

company to provide the SFHD form.

If the building is in an SFHA, the Federal agency 

or lender is required by law to require the recipient 

Mandatory Purchase Requirement

Although having a flood insurance policy is always a good idea, owners or renters 

of buildings subject to localized flooding that are outside the SFHA as shown on the 

community’s FIRM are not required to have insurance as a condition of receiving 

Federal assistance, including federally backed mortgages. However, if the area is 

remapped and a building previously outside the SFHA becomes included within it, 
11-6 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 11. Flood Insurance

the mandatory purchase requirement (see previous page) will be triggered if the 

mortgage is refinanced or the owner takes out a home improvement loan.

ICC Coverage

There is a special coverage provision in the NFIP for insured buildings that have been 

substantially or repetitively damaged by a flood. ICC coverage provides up to $30,000 

to pay for the cost to comply with floodplain management regulations after a flood. 

If the building has been declared by the State or community to be substantially 

damaged or is repetitively damaged (as defined in the policy) the ICC coverage may 

be triggered. This payment is in addition to the damage claim payment that would be 

made under the regular flood insurance policy coverage. However, the total payments 

combined can not exceed the policy’s amount of coverage.

Although a building subject to shallow localized flooding may be unlikely to be 

substantially damaged, it could become repetitively damaged by floods. In certain 

cases, an ICC claim can be paid if the building is repetitively flooded and has had 

two or more claims averaging 25 percent or more of the building’s value within a 

10-year period, provided the community requires that the property comply with its 

floodplain management ordinance. 

ICC will pay up to $30,000 to help cover elevation, relocation, demolition, and (for 

nonresidential buildings) floodproofing. ICC is available for any flood insurance claim 

and, therefore, is not dependent on the community’s receiving a disaster declaration.

Coverage under the ICC does have limitations:

It covers only damage caused by a flood;

The building’s flood insurance policy must have been in effect during the 

flood;

ICC payments are limited to $30,000 per structure; and

Claims must be accompanied by a substantial or repetitive damage 

determination made by the local floodplain administrator.

A community that is serious about reducing its repetitive local flooding problems 

should learn the details of ICC coverage. Proper enforcement and an informed property 

owner can greatly facilitate the claims process and help fund mitigation measures 

for flood-prone buildings. 

The Community’s Role

NFIP flood insurance is available only in communities that participate in the NFIP. 

Communities must enforce their floodplain management regulations on new 

development in the SFHA (as discussed in Chapter 4) and stay in compliance with 

FEMA’s rules and regulations. Failure to fully enforce these regulations could result 

in the community’s residents having to pay a $50 probation surcharge or, if the 

community is suspended from the program, losing their flood insurance policies.

A community can help protect properties subject to localized flooding in the following 

ways:

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Reducing Damage from Localized Flooding: A Guide for Communities 11-7

Chapter 11. Flood Insurance P A R T I V

It can participate in the Community Rating 

System (CRS) to lower the cost of insurance for 

its residents and businesses. The CRS is discussed 

in Chapter 2.

It can encourage its citizens and businesses 

to purchase flood insurance coverage. Local 

public information activities are discussed in 

Chapter 5.

It should purchase insurance on its own public 

buildings.

Insurance for Public Property 

If a local government’s public buildings or facilities lie 

in any area that is prone to flooding, flood insurance 

should be obtained. Policies are available for public 

property through the NFIP, and local governments have 

other options as well.

A local government can set a good example for the 

rest of the community by obtaining flood insurance for its public buildings and 

facilities, even if they are not in the SFHA. Furthermore, a community with an array 

of public buildings both in and out of the floodplain should insure all of them. If a 

major flood occurs and many public buildings are damaged, the claims paid on the 

insured structures and contents will free up other local government funds that will 

be needed to repair and rebuild things that were not insurable. Furthermore, Federal 

disaster assistance will be reduced by the amount of insurance that the community 

should have had on its flood-prone buildings.

Larger local governments often self-insure against flooding simply by absorbing 

the cost of the damage. The expense of repair and rebuilding then comes out of 

the community’s general fund. This avoids annual outlays in premium payments. 

However, if many properties or facilities are exposed to damage, self-insurance can 

be a major drain on the local treasury. Some communities essentially self-insure for 

part of the anticipated losses by specifying a higher deductible on their commercial 

property insurance policy, or by purchasing coverage on properties in flood-prone 

areas but not on others.

NFIP Insurance

Flood insurance is available under the NFIP for public buildings and contents 

anywhere in the community, just as it is for privately owned buildings. In general, 

there is an overall per-building limit for non-residential buildings of $500,000 for 

the structure and $500,000 for the contents.

Commercial Insurance Policies

Local governments can purchase commercial property insurance policies or join a 

local government insurance pool to protect their public buildings from perils such 

as flood, earthquake, and hail. Such policies have a couple of advantages:

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A community that participates 

in the CRS earns reduced 

premiums for its residents who 

buy NFIP coverage, even those 

who are out of the designated 

SFHA. More than 1,000 communities across 

the United States now participate in the CRS. 

Their flood insurance policyholders outside the 

mapped SFHA receive reductions in their annual premiums of 5–10 percent, while policyholders in the SFHA receive reductions of up to 

45 percent. 

Under Activity 330 (Outreach Projects), CRS 

credit is provided to communities that carry out 

local public information and awareness programs that explain flood insurance to property 

owners.
11-8 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 11. Flood Insurance

The community can obtain more coverage than 

under the NFIP.

The policy can be customized to meet the needs 

of the local situation, with special endorsements, 

varying deductibles, and other provisions.

Communities should verify the specific coverage and 

limitations of their policies. Many local agencies find 

out too late that their “all risk” insurance policies or 

government pools do not cover flooding. Further, many 

such policies have a deductible of $500,000, based on 

the assumption that the policy holder will get NFIP 

coverage for smaller flood losses.

Basements 

There is limited coverage for basements under NFIP 

flood insurance policies. The NFIP defines “basement” 

as “any area of the building, including any sunken 

room or sunken portion of a room, having its floor 

below ground level (subgrade) on all sides.” This includes the below-grade floors 

of bi-level and tri-level homes.

In general, flood damage to the walls and floor of the basement area is covered by 

the standard flood insurance policy; this usually is the most expensive damage to the 

basement. However, flood insurance coverage for basements is limited in two ways: 

(1) what is covered, and (2) when it is covered.

In the basement or subgrade levels of a house, NFIP flood insurance will 

cover damage only to specific items needed for the operation of the building, 

such as the furnace, water heater, electrical components, and sump pumps. 

If the policy has contents coverage, the following items are covered if they 

are located in a basement: clothes washer, dryer, food freezer, or portable 

air conditioning unit. There is no coverage for finishings such as wallpaper, 

carpeting, furniture, or other contents located in a basement. 

Flood insurance covers basement damage only when there is a general 

condition of surface flooding in the area, and the flood is the proximate 

cause of the damage. Damage that occurs when water gets into the basement 

from some other cause, such as sump pump overflow or sewer backup not 

caused by a general condition of flooding, is excluded from coverage. 

Sump Pump Failure

Many buildings in areas prone to localized flooding have sump pumps to automatically 

remove water that collects around the building foundation. Unfortunately, the pump 

may malfunction, or the electricity could go out, especially during a storm. NFIP 

flood insurance covers damage to the sump pump as a result of flooding, but does 

not cover water damage caused by sump pump failure (except in cases in which 

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1.

2.

Insurance Affects Disaster Assistance

It should be noted that Federal law expects 

public agencies to be fully insured as a condition of receiving Federal disaster assistance, 

and that such assistance will be reduced by the 

amount of insurance that the community should 

have had on its flood-prone buildings. 

For example, if a city hall in the SFHA suffered $600,000 in flood damage to the structure, Federal disaster assistance will assume 

that the city had $500,000 in flood insurance 

coverage (the maximum coverage available 

under the NFIP for a non-residential building). 

The amount of disaster assistance would be 75 

percent of the remaining $100,000. This would 

not affect public buildings outside the SFHA. 
Reducing Damage from Localized Flooding: A Guide for Communities 11-9

Chapter 11. Flood Insurance P A R T I V

Flood Insurance Coverage for Basements

Heat pumps; 

Nonflammable insulation in a basement; 

Pumps and tanks used in solar energy 

systems; 

Stairways and staircases attached to the 

building, not separated from it by elevated 

walkways; 

Sump pumps;

Water softeners and the chemicals in 

them, water filters, and faucets installed 

as an integral part of the plumbing system; 

Well water tanks and pumps; 

Required utility connections for any item 

in this list; and 

Footings, foundations, posts, pilings, 

piers, or other foundation walls and 

anchorage systems required to support a 

building. 

 Clean-up. (Article III. Section A.8.) 

Coverage under personal property (contents) coverage is limited to the following items, if installed 

in their functioning locations and, if necessary for 

operation, connected to a power source: 

Air conditioning units, portable or window type; 

Clothes washers and dryers; and 

Food freezers, other than walk-in, and food in any 

freezer. (Article III. Section B.3.)

9.

10.

11.

12.

13.

14.

15.

16.

17.

b.

a.

b.

c.

The NFIP has limited coverage for basements and 

the below-grade floors of bi-levels, split levels, split 

foyers, and other buildings that have their lowest 

floor below ground level. The NFIP defines “basement” as “any area of the building, including any 

sunken room or sunken portion of a room, having 

its floor below ground level (subgrade) on all sides.” 

(Article II of the Standard Flood Insurance Policy, 

May 1, 2005.)

Coverage under building or structural coverage is 

limited to: 

Any of the following items, if installed in their 

functioning locations and, if necessary for operation, connected to a power source: 

Central air conditioners; 

Cisterns and the water in them; 

Drywall for walls and ceilings in a basement and the cost of labor to nail it, 

unfinished and unfloated and not taped, 

to the framing; 

Electrical junction and circuit breaker 

boxes;

Electrical outlets and switches; 

Elevators, dumbwaiters, and related 

equipment, except for related equipment 

installed below the base flood elevation 

after September 30, 1987; 

Fuel tanks and the fuel in them; 

Furnaces and hot water heaters; 

a.

1.

2.

3.

4.

5.

6.

7.

8.

there is general flooding in the area and that flooding is the proximate cause of the 

damage).

However, several private insurance companies offer coverage for water damage to a 

structure and its contents incurred if a sump pump fails. Each company has different 

amounts of coverage, exclusions, deductibles, and arrangements. Most such policies 

will not pay for damage from surface flooding that would be covered by the NFIP.

Sewer Backup

During heavy rains, stormwater may overload a community’s sanitary or storm sewer 

system. If the water levels in the receiving streams are high, the storm sewers cannot 

drain. The water backs up, usually into basements and other low-lying areas (see 

Chapter 10 for more information and illustrations).
11-10 Reducing Damage from Localized Flooding: A Guide for Communities

P A R T I V Chapter 11. Flood Insurance

Policies under the NFIP can cover damage from sewer 

backup (even in the basement) if there are also general 

flood conditions in the area that caused the house 

and/or basement to get wet. If there is not a general 

condition of flooding in the area, an NFIP policy will 

not cover this damage. As noted on the previous page, 

there is still limited NFIP coverage for certain items in 

a basement, regardless of the cause of the flood.

However, several private insurance companies offer 

coverage for damage to a structure and its contents when 

sewer lines or a septic tank back up. Policy details will 

vary from company to company, but most of them will 

not pay for damage from surface flooding that would 

be covered by the NFIP. Each company has different 

amounts of coverage, exclusions, deductibles, and 

arrangements. Some endorsements on a homeowner’s 

insurance policy are free; on others, the costs can range 

up to about $75. 

Where to Get Help

Local insurance agents have information on 

both the National Flood Insurance Program and 

private insurance for sump pump failure, sewer 

backup, and other related coverage.

The State NFIP Coordinator can provide contacts 

for insurance and for the Community Rating 

System.

The community’s risk manager or finance office can provide information on 

whether community properties are adequately insured.

The NFIP may be contacted directly at 1-800-CALL-FLOOD. This number can 

also refer callers to agents in the area who sell flood insurance.

The NFIP Web site at http://www.fema.gov/nfip/ has useful information, 

answers to questions, lists of insurance agents, links to and order forms for 

publications, and public information materials.

Information on the NFIP Preferred Risk Policy for residential buildings can 

be found at http://www.fema.gov/nfip/prphome.shtm and for businesses at 

http://www.fema.gov/nfip/prpbus.shtm.

The CRS Resource Center Web site has a collection of CRS materials, 

publications, and links to other insurance-related information at http://

training.fema.gov/emiweb/CRS/.

Additional resources are listed in Appendixes A and B.

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Sewer backups can be costly, but 

sewer backup insurance is not!

All insurance companies writing homeowner policies in Virginia offer special coverage for damage 

resulting from backups of drains and sewers, 

and this additional protection is available at very 

reasonable rates. For information on obtaining 

sewer backup coverage, contact your insurance 

company. 

The Town’s insurance carrier rarely approves 

claims resulting from sewer backups unless negligence in maintaining the system can be shown. 

Therefore, residents are encouraged to protect 

their property by obtaining sewer backup insurance.

The Town of Vienna, Virginia, has this notice 

on its Web site, letting residents know about 

the availability of sewer backup insurance and 

also that claims against the Town are not likely 

to result in payments. The notice is accompanied by links to sites that offer advice about 

preventing damage from sewer backup.

http://www.ci.vienna.va.us/Town_

Departments/backup_ins.htm

RETURN TO TABLE OF CONTENTS ADVANCE TO REFERENCES
Reducing Damage from Localized Flooding: A Guide for Communities R-1

References

Arendt, Randall G. 1996. Conservation design for subdivisions. Washington, D.C.: Island 

Press.

Association of State Floodplain Managers and U.S. Environmental Protection 

Agency. 1996. Using multi-objective management to reduce flood losses in your watershed.

Madison, WI: ASFPM.

Bannerman, Roger. 2003. Rain gardens: a how-to manual for homeowners. Madison: 

Wisconsin Department of Natural Resources.

Federal Emergency Management Agency. 2000. Getting started: building support for 

mitigation planning. FEMA 386-1. Washington, D.C.: FEMA.

Federal Emergency Management Agency. 2002. Promoting mitigation in Louisiana.

Washington, D.C.: DHS/FEMA.

Flink, Charles A., and Robert M. Searns. 1993. Greenways: a guide to planning, design, 

and development. Washington, D.C.: Island Press.

Kusler, Jon A. 2004. No adverse impact: floodplain management and the courts. Madison, WI: 

Association of State Floodplain Managers. Available from World Wide Web: 

(http://www.floods.org).

Morris, Marya. 1997. Subdivision design in flood hazard areas. Planning Advisory 

Service Report No. 473. Chicago: American Planning Association and Federal 

Emergency Management Agency. Copies can be ordered for $32 from 

American Planning Association, 122 So. Michigan Ave., Suite 1600, Chicago, 

IL 60603, (312) 431-9100. pasreports@planning.org.

National Flood Insurance Program. 2003. “Is the CRS worth it? Illinois officials 

respond.” NFIP/CRS Update (Fall): 5-6.

U.S. Army Corps of Engineers. 1985. Guidelines on community local flood warning and 

response systems. Washington, D.C.: National Technical Information Service.

U.S. Department of Homeland Security/FEMA. 2002. Promoting mitigation in 

Louisiana. Washington, D.C.: DHS/FEMA.

Wetmore, French and Gil Jamieson. 1999. “Flood mitigation planning: the CRS 

approach.” Natural Hazards Informer 1 (July).
Reducing Damage from Localized Flooding: A Guide for Communities A-1

Appendix A

Sources of Assistance 

This is a list of contact information for the principal agencies 

and organizations that have expertise, information, and written 

materials about the techniques and tools for dealing with local 

flood problems as discussed in this guide.

Department of Homeland Security/Federal Emergency Management Agency

http://www.fema.gov

Benefit-Cost helpline

1-866-222-3580

The Community Rating System

http://training.fema.gov/emiweb/CRS/

Cooperating Technical Partners Program

http://www.fema.gov/fhm/ctp_main.shtm

FEMA Regional Offices

http://www.fema.gov/regions/

FEMA For Kids

http://www.fema.gov/kids

National Flood Insurance Program

1-800-CALL-FLOOD

http://www.fema.gov/nfip/

Planning Resource Page 

http://www.fema.gov/fima/planning.shtm

Preparing for flooding

http://www.fema.gov/hazards/floods/floodf.shtm

Retrofitting publications

http://www.fema.gov/hazards/floods/whatshouldidoprotect.shtm

Training courses

http://training.fema.gov/emiweb/ 

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A-2 Reducing Damage from Localized Flooding: A Guide for Communities

Appendix A. Sources of Assistance

National Weather Service

http://www.noaa.gov or http://hydrology.nws.noaa.gov

StormReady program

http://www.stormready.noaa.gov

Turn Around Don’t DrownTM campaign

http://www.nws.noaa.gov/om/water/turnaround.shtml

Rivers, Trails, and Conservation Assistance Program, National Park Service

http://www.nps.gov/rtca/

List of funding sources

http://www.nps.gov/ncrc/programs/rtca/helpfultools/ht_funding.html

Small Business Administration

http://www.sba.gov

State emergency management agency hazard mitigation offices

http://www.fema.gov/fema/statedr.shtm

State National Flood Insurance Program Coordinating Offices Directory

http://www.floods.org/StatePOCs/map.asp

U.S. Army Corps of Engineers

http://www.usace.army.mil

National Nonstructural/Flood Proofing Committee

http://www.usace.army.mil/inet/functions/cw/cecwp/NFPC/nfpc.htm 

U.S. Department of Agriculture

Agricultural Extension Services

http://www.csrees.usda.gov

Natural Resources Conservation Service

http://www.nrcs.usda.gov or http://www.nrcs.usda.gov/programs/

watershed

U.S. Department of Energy 

Smart Communities Network

http://www.sustainable.doe.gov/disaster/disintro.shtml

U.S. Environmental Protection Agency

http://www.epa.gov

National Pollutant Discharge Elimination System program

http://cfpub.epa.gov/npdes/

Environmental Kids Club

http://www.epa.gov/kids/

U.S. Geological Survey

http://www.usgs.gov

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Reducing Damage from Localized Flooding: A Guide for Communities A-3

Appendix A. Sources of Assistance

Organizations

American Greenways Program

http://www.conservationfund.org/?article=2471&back=true

American Planning Association

http://www.planning.org

American Rivers

http://www.americanrivers.org

American Society of Civil Engineers 

http://www.asce.org

American Red Cross

http://www.redcross.org

American Trails

http://www.americantrails.org/

Association of State Floodplain Managers

http://www.floods.org

National Association of Flood and Stormwater Management Agencies

http://www.floods.org/StatePOCs/stchoff.asp

Certified Floodplain Manager Program

http://www.floods.org/Certification/certprog.asp

Mitigation Success Stories

http://www.floods.org/Publications/mit%20succ%20stories/mssiii1.htm

Land Trust Alliance

http://www.lta.org/

National Association of Flood and Stormwater Management Agencies

http://www.nafsma.org

National Wildlife Federation

http://www.nwf.org

Kidzone

http://www.nwf.org/kids/

Nature Conservancy

http://nature.org/

The Trust for Public Land

http://www.tpl.org/

Financing alternatives

http://www.tpl.org

The Waterfront Center

http://www.waterfrontcenter.org/

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A-4 Reducing Damage from Localized Flooding: A Guide for Communities

Appendix A. Sources of Assistance

State and Local Entities

Local planning office

Local emergency services office

Local building department

Regional planning commissions and councils of government

Soil and water conservation districts

State office of emergency management 

County emergency manager

Local chapter of the American Red Cross

Utility company and cooperatives 

School district

Park department

Youth groups

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Reducing Damage from Localized Flooding: A Guide for Communities B-1

Appendix B

Reference Works and 

Recommended Reading

The following are citations to all documents recommended in 

the text of this guide, supplemented by other materials useful in 

approaching local flood problems. It is organized by topic. Some 

references are listed under more than one topic.

Community-Level Approaches

Association of State Floodplain Managers. 1987. Reducing losses in high risk flood 

hazard areas: a guidebook for local officials. FEMA 116. Washington, D.C.: Federal 

Emergency Management Agency.

Association of State Floodplain Managers and U.S. Environmental Protection 

Agency. 1996. Using multi-objective management to reduce flood losses in your watershed.

Madison, WI: ASFPM. This publication reviews the 10-step planning process 

and coordination of a hazard mitigation plan with other community goals 

and objectives. It includes examples, references, and lists of sources of 

assistance. It is particularly detailed on integrating flood protection activities 

with other community activities. To order, call ASFPM: 608-274-0123.

Association of State Floodplain Managers. 2001. Flood mitigation planning—the first 

steps. Madison, WI: ASFPM. This floodplain management planning kit consists 

of reference materials, masters for handouts, and a 2-part video that explains 

the 10-step process to the general public. It is designed to be shown at the 

first meeting of a planning committee. Order through the ASFPM Web site, 

http://www.floods.org or call 608-274-0123.

Association of State Floodplain Managers. 2003. No adverse impact: a toolbox for 

common sense floodplain management. Madison, WI: ASFPM. Available from World 

Wide Web: (http://www.floods.org).

Federal Emergency Management Agency. 2000. Planning for a sustainable future: the 

link between hazard mitigation and livability. FEMA 364. Washington, D.C.: FEMA. 

Available from World Wide Web: (http://www.fema.gov/fima/planresource.

shtm). A 40-page illustrated overview of hazard mitigation principles, 

including a list of Federal technical assistance and funding sources. 
B-2 Reducing Damage from Localized Flooding: A Guide for Communities

Appendix B. Reference Works and Recommended Reading

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2003. Example plans. Washington. D.C.: FEMA. 

Available from World Wide Web: (http://training.fema.gov/emiweb/CRS/

index.htm). Click on “Resources.” This 60-page document reviews the 

10-step CRS credit criteria for floodplain management plans and identifies 

additional actions needed to also qualify as a FEMA-approved hazard 

mitigation plan. 

Federal Emergency Management Agency. “How-to” guides for mitigation 

planning, available from World Wide Web: http://www.fema.gov/fima/

resources.shtm.

Getting started: building support for mitigation planning (FEMA 386-1)

Understanding your risks: identifying hazards and estimating losses (FEMA 386-2)

Developing a mitigation plan: identifying mitigation actions and implementation strategies

(FEMA 386-3)

Bringing the plan to life: implementing the hazard mitigation plan (FEMA 386-4)

Incorporating historic resources into mitigation planning (FEMA 386-6)

Integrating manmade hazards into mitigation planning (FEMA 386-7)

Federal Interagency Floodplain Management Task Force. 1996. Protecting floodplain 

resources: a guidebook for communities. FEMA 268. Washington, D.C.: Federal 

Emergency Management Agency.

Wright, J.M., and J.L. Monday. 1996. Addressing your community’s flood problems: A 

guide for elected officials. Madison, WI: Association of State Floodplain Managers, 

and the Federal Emergency Management Agency. This 38-page booklet 

provides a useful explanation of the importance of planning, along with 

recommendations and first person testimonials. It is excellent background 

reading for elected officials. To order, call ASFPM: 608-274-0123.

Wetmore, French and Gil Jamieson. 1999. “Flood mitigation planning: the CRS 

approach.” Natural Hazards Informer 1 (July).

Regulatory Tools

Arendt, Randall G. 1996. Conservation design for subdivisions. Washington, D.C.: Island 

Press.

Association of State Floodplain Managers. 1987. Reducing losses in high risk flood 

hazard areas: a guidebook for local officials. FEMA 116. Washington, D.C.: Federal 

Emergency Management Agency.
Reducing Damage from Localized Flooding: A Guide for Communities B-3

Appendix B. Reference Works and Recommended Reading

Association of State Floodplain Managers. 2003. No adverse impact: a toolbox for 

common sense floodplain management. Madison, WI: ASFPM. Available from World 

Wide Web: (http://www.floods.org).

Federal Emergency Management Agency. 1995. Managing floodplain development in 

approximate zone A areas: a guide for obtaining and developing base (100-year) flood elevations.

FEMA 265. 1995. Available from World Wide Web: (http://www.fema.gov). 

Includes the computer program QUICK-2: Computation of Water Surface 

Elevations in Open Channels, Version 1.0. 

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2002. CRS credit for stormwater management.

Washington, D.C.: FEMA. Available from World Wide Web: (http://training.

fema.gov/emiweb/CRS/index.htm). Click on “Resources.”

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2002. CRS credit for higher regulatory standards.

Washington, D.C.: FEMA. Available from World Wide Web: (http://training.

fema.gov/emiweb/CRS/index.htm). Click on “Resources.” 

Federal Emergency Management Agency. 2003. Guidelines and specifications for flood 

hazard mapping partners. Washington, D.C.: FEMA. Available from World Wide 

Web: (http://www.fema.gov).

Kusler, Jon A. 2004. No adverse impact: floodplain management and the courts. Madison, WI: 

Association of State Floodplain Managers. Available from World Wide Web: 

(http://www.floods.org).

Morris, Marya. 1997. Subdivision design in flood hazard areas. Planning Advisory 

Service Report No. 473. Chicago: American Planning Association and 

Federal Emergency Management Agency. Copies can be ordered for $32 

from American Planning Association, 122 South Michigan Ave., Suite 1600, 

Chicago, IL 60603, 312-431-9100. pasreports@planning.org.

Public Information and Awareness

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2002. CRS credit for outreach projects. Washington, 

D.C.: FEMA. Available from World Wide Web: (http://training.fema.gov/

emiweb/CRS/index.htm). Click on “Resources.”

Warnings and Emergency Services

Denver Office of Emergency Management, Urban Drainage and Flood Control 

District. 2003. Flood Protection Handbook. Denver, CO: City and County of Denver.

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2002. CRS credit for flood warning programs.

Washington, D.C.: FEMA. Available from World Wide Web: (http://training.

fema.gov/emiweb/CRS/index.htm). Click on “Resources.” 
B-4 Reducing Damage from Localized Flooding: A Guide for Communities

Appendix B. Reference Works and Recommended Reading

National Science and Technology Council, Committee on Environment and 

Natural Resources. 2000. Effective disaster warnings, report by the Working Group 

on Natural Disaster Information Systems Subcommittee on Natural Disaster Reduction.

Washington, D.C.: NSTC. 

U.S. Army Corps of Engineers. 1985. Guidelines on community local flood warning and 

response systems. Washington, D.C.: National Technical Information Service.

Area Analysis 

Federal Emergency Management Agency. 2001. Understanding your risks: identifying 

hazards and estimating losses. FEMA 386-2. Washington, D.C.: FEMA.

Federal Emergency Management Agency. 2003. “Mitigation BCA toolkit.” 

Washington, D.C.: FEMA. This compact disk has FEMA benefit-cost analysis 

software, guidance documents, and case studies. 

Federal Emergency Management Agency. 2005. “National Mitigation Data 

Collection Tool.” Washington, D.C.: FEMA. This software is an aid to 

choosing appropriate mitigation measures for a flood-prone property, 

with information on risk, building construction, and costs. Available from 

NFIPCRS@iso.com.

Drainage Improvements

Association of State Floodplain Managers. 2003. No adverse impact: a toolbox for 

common sense floodplain management. Madison, WI: ASFPM. Available from World 

Wide Web: (http://www.floods.org).

Bannerman, Roger. 2003. Rain gardens: a how-to manual for homeowners. Madison: 

Wisconsin Department of Natural Resources.

Federal Emergency Management Agency. National Flood Insurance Program/

Community Rating System. 2002. CRS credit for drainage system maintenance.

Washington, D.C.: FEMA. Available from World Wide Web: (http://training.

fema.gov/emiweb/CRS/index.htm). Click on “Resources.”

Federal Emergency Management Agency. 2002. Promoting mitigation in Louisiana.

Washington, D.C.: DHS/FEMA.

Price, Thomas N., and Dennis W. Dreher. 2000. Urban Stormwater Best Management 

Practices for Northeastern Illinois: Course Notebook. Chicago: Northeastern Illinois 

Planning Commission.

Sacks, Alvin M. 1994. Residential Water Problems. Washington, D.C.: Home Builder 

Press.

Redevelopment

Federal Emergency Management Agency. 1998. Property acquisition handbook for local 

communities. FEMA 317. Washington, D.C.: FEMA.
Reducing Damage from Localized Flooding: A Guide for Communities B-5

Appendix B. Reference Works and Recommended Reading

Federal Emergency Management Agency. 2000. Planning for a sustainable future: the 

link between hazard mitigation and livability. FEMA 364. Washington, D.C.: FEMA. 

Available from World Wide Web: (http://www.fema.gov/fima/planresource.

shtm). A 40-page illustrated overview of hazard mitigation principles, 

including a list of Federal technical assistance and funding sources. 

Federal Emergency Management Agency. 2000. Rebuilding for a more sustainable future: 

an operational framework. FEMA 365. Washington, D.C.: FEMA. 

Federal Insurance Administration. 1991. Answers to questions about substantially damaged 

buildings. FEMA 213. Washington, D.C.: Federal Emergency Management 

Agency.

Flink, Charles A., and Robert M. Searns. 1993. Greenways: a guide to planning, design, 

and development. Washington, D.C.: Island Press.

Monday, Jacquelyn L. 2002. “Building back better: creating a sustainable 

community after a disaster.” Natural Hazards Informer 3. Boulder, CO: Natural 

Hazards Research and Applications Information Center. Available from 

World Wide Web: (http://www.colorado.edu/hazards/informer/infrmr3/

informer3.pdf).

National Wildlife Federation. 1998. Higher ground: a report on voluntary property buyouts 

in the nation’s floodplains. Washington, D.C.: NWF. Available from World Wide 

Web: (http://www.nwf.org).

Natural Hazards Research and Applications Information Center. 2001. Holistic 

disaster recovery: ideas for building local sustainability after a natural disaster. Boulder, CO: 

Natural Hazards Center. Available from World Wide Web: (http://www.

colorado.edu/hazards/holistic_recovery/).

Schwab, Jim; Kenneth C. Topping; Charles C. Eadie; Robert E. Deyle; and Richard 

A. Smith. 1998. Planning for post-disaster recovery and reconstruction. PAS Report No. 

483/484. Chicago, IL: American Planning Association. 346 pp.

Retrofitting

Federal Emergency Management Agency. 1996. Engineering principles and practices for 

retrofitting flood-prone residential buildings. FEMA 259. Washington, D.C.: FEMA.

Federal Emergency Management Agency. 1998. Homeowner’s guide to retrofitting: 

six ways to protect your house from flooding. FEMA 312. Washington, D.C.: FEMA. 

Available from World Wide Web: (http://www.fema.gov/pdf/hazards/

hurricanes/guide.pdf).

Federal Emergency Management Agency. 1999. Protecting building utilities from flood 

damage. FEMA 348. Washington, D.C.: FEMA. Available from World Wide Web: 

(http://www.fema.gov/hazards/floods/lib06b.shtm).

Federal Emergency Management Agency. 2000. Above the flood: elevating your floodprone house. FEMA 347. Washington, D.C.: FEMA.
B-6 Reducing Damage from Localized Flooding: A Guide for Communities

Appendix B. Reference Works and Recommended Reading

Federal Emergency Management Agency’s Technical Bulletin series. Available 

from World Wide Web: (http://www.fema.gov/fima/techbul.shtm).

Federal Insurance Administration. 1993. Openings in foundation walls. FIA-TB-1. 

Washington, D.C.: Federal Emergency Management Agency.

Federal Insurance Administration. 1993. Flood-resistant materials requirements. FIATB-2. Washington, D.C.: Federal Emergency Management Agency.

Federal Insurance Administration. 1993. Non-residential floodproofing—requirements 

and certification. FIA-TB-3. Washington, D.C.: Federal Emergency Management 

Agency.

Federal Insurance Administration. 1993. Wet floodproofing requirements for structures 

located in Special Flood Hazard Areas in accordance with the National Flood Insurance Program.

Technical Bulletin 7-93. Washington, D.C.: Federal Emergency Management 

Agency.

Louisiana State University Cooperative Extension Service. 1999. Floodproofing 

resources. Baton Rouge, LA: LSU.

Sacks, Alvin M. 1994. Residential water problems. Washington, D.C.: Home Builder 

Press.

U.S. Army Corps of Engineers’ National Flood Proofing Committee references. 

Available from World Wide Web: (http://www.usace.army.mil/inet/

functions/cw/cecwp/NFPC/nfpc.htm).

U.S. Army Corps of Engineers. National Flood Proofing Committee. 1984. Flood 

proofing systems & techniques. Washington, D.C.: Corps of Engineers.

U.S. Army Corps of Engineers. National Flood Proofing Committee. 1996. Flood 

proofing techniques, programs, and references. Washington, D.C.: Corps of Engineers.

U.S. Army Corps of Engineers. National Flood Proofing Committee. Floodproofing 

– how to evaluate your options, U.S. Army Corps of Engineers National Flood 

Proofing Committee. 1993. Washington, D.C.: Corps of Engineers.

U.S. Army Corps of Engineers. Local flood proofing programs. 2005. Washington, D.C.: 

Corps of Engineers. Available from World Wide Web: (http://www.nwo.

usace.army.mil/nfpc/docs/Local_FP_Program_February_2005.pdf).
Reducing Damage from Localized Flooding: A Guide for Communities

Index

A

A Zone vii, 4-4, 4-5, 8-2

acquisition 7-9, 7-10, 9-2, 9-6 through 9-15, 10-20, B-5

anxiety 2-2 [See also safety hazards]

approximate A Zone 4-4, 4-6

area analysis 2-8, 7-1 through 7-12, 8-7, 9-1, 9-2

ASFPM [See Association of State Floodplain Managers]

Association of State Floodplain Managers (ASFPM) 2-8, 3-8, A-2, A-3, B-1, B-2, B-3

automated system for flood warning 6-3

B

B Zone vii, 1-2

backup valve 7-4, 10-10 through 10-12

base flood elevation (BFE) vii, 4-5, 4-6, 4-14, 10-16, 11-1

base map 4-2

basement 7-4, 9-11, 10-3, 10-5 through 10-7, 10-9 through 10-15, 11-3, 11-8, 11-9, 11-10

basin [See watersheds]

benefit-cost analysis 5-7, 7-9, 7-12, 9-10, 10-16, B-2, B-4

berm 7-6

BFE [See base flood elevation]

buffers 4-10, 4-11 through 4-12, 8-5

building codes 10-17

building coverage 10-15, 10-16, 11-2, 11-3

building standards 2-5, 2-8

buy-out [See acquisition]

C

C Zone viii, 1-2

capital improvement plan 3-3, 4-8, 9-4

catchment [See watersheds]

CDBG [See Community Development Block Grant]

Certified Floodplain Manager (CFM) program 5-8, A-3

CFM [See Certified Floodplain Manager program]

channelization 2-4, 8-3, 8-6, 8-7, 9-5

cleanup 2-2 through 2-4, 6-8 through 6-10, 10-13, 11-1

cluster development 4-8, 4-11

commercial insurance policies 11-7

Community Development Block Grant (CDBG) 7-11, 9-10, 10-20 
Index

Reducing Damage from Localized Flooding: A Guide for Communities

Community Rating System (CRS) vii, 2-8 through 2-10, 3-8, 4-1, 4-7, 4-10, 4-13, 4-18, 5-3, 

5-4, 5-9, 6-1, 7-9, 8-14, 8-15, 9-10, 9-11, 10-15, 10-19, 10-20, 11-3, 11-7, A-1, B-2, 

B-3, B-4

compensatory storage 8-10, 10-18

comprehensive plans 3-3, 4-7, 4-9, 9-3

contents coverage 10-15, 11-1 through 11-5

Cooperating Technical Partners (CTP) program 4-4, A-1

Corps of Engineers [See U.S. Army Corps of Engineers]

covenants 9-13, 10-3

crawlspace 5-7, 9-11, 10-3

critical facilities 6-1, 6-4 through 6-6, 10-19

CTP [See Cooperating Technical Partners program] 

culvert 1-1, 2-4, 2-6, 7-5, 7-7, 8-6, 8-8, 8-13

D

dams 2-3, 8-7, 8-8, 8-11

debris 2-5, 2-6, 5-5, 6-8, 7-5, 8-3, 8-11, 8-14, 8-15, 10-3

design flood elevation (DFE) 10-2, 10-16 through 10-18

design parameters 10-16

detention 2-4, 4-13, 4-14, 8-4, 8-10, 8-11

development regulations 3-2, 4-2, 4-10, 4-14, 5-2, 8-9

development rights 9-13

DFE [See design flood elevation] 

disaster assistance 2-1, 6-9, 8-8, 9-10, 10-21, 11-2, 11-6, 11-8

disaster declaration 9-10, 10-20, 10-21, 11-1

Disaster Mitigation Act (DMA) of 2000 3-6

drainage 2-6, 2-7, 4-1, 4-2, 4-6 through 4-8, 4-10, 4-13 through 4-20, 5-1, 5-5, 7-1, 7-5, 

7-6, 7-7, 7-9, 8-1 through 8-16, 9-13, 9-15, 10-6 through 10-7

dredging 7-5, 8-7, 8-8

drowning 2-1, 2-2 [See also safety hazards]

dry floodproofing 10-2, 10-7 through 10-9

dumping 2-4, 5-5, 8-13 through 8-16

E

easements 2-5, 4-11, 4-17 through 4-20, 7-8, 8-13, 9-13, 10-6, 10-7, 10-17

ecosystem 8-12, 9-13

education [See public awareness]

ejector pump 10-10, 10-11

electrocution 2-2 [See also safety hazards]

elevation 4-14, 4-17, 4-19, 5-7, 6-9, 10-1 through 10-3, 10-14 through 10-16, 10-18, 

10-19, 11-3

Elevation Certificates 2-10

elevations 4-2 through 4-5

Emergency Management Institute (EMI) 3-9, 5-6, 5-9

emergency operations center 6-5 [See also critical facilities]

EMI [See Emergency Management Institute]

EPA [See U.S. Environmental Protection Agency]

erosion 2-5, 4-11, 4-13, 4-15, 5-2, 8-4, 8-7, 8-9, 10-3, 10-17
Index

Reducing Damage from Localized Flooding: A Guide for Communities

F

fatalities 2-1 [See also safety hazards]

Federal Emergency Management Agency (FEMA) viii, 1-1, 3-3, 3-6, 3-8, 3-9, 4-2, 4-3

through 4-7, 4-16, 5-4 through 5-7, 6-10, 7-2, 7-3, 7-10, 7-11, 9-5, 9-8 through 

9-14, 10-20, 10-21, 11-2, A-1, B-1 through B-6

FEMA [See Federal Emergency Management Agency]

FEMA mapping standards 4-6, 4-7

fill 8-10, 10-2, 10-18

financial assistance 2-1, 3-5, 3-8, 4-4, 4-5, 5-7, 6-11, 7-9 through 7-11, 9-2, 9-7 through 

9-10, 10-20 

fire station [See critical facilities]

FIRM [See Flood Insurance Rate Map]

FIS [See Flood Insurance Study]

Flood Insurance Rate Map (FIRM) viii, 1-1, 1-3, 2-6, 3-2, 4-1 through 4-7, 4-16, 5-1, 5-3, 

7-3, 8-2, 9-1, 10-15 through 10-17, 11-2 through 11-5

Flood Insurance Study (FIS) 4-3, 4-12, 7-3, 8-8, 10-14, 10-17

flood maps 4-3, 4-4, 4-5, 5-2

Flood Mitigation Assistance (FMA) 3-6, 7-11, 9-10, 10-20

flood mitigation plan 3-3, 9-10, B-1, B-2

flood of record 4-3 through 4-6

flood profile 4-3, 8-8

flood watches 6-3 through 6-5

floodplain vii, 1-1, 1-2, 3-8, 4-1 through 4-5, 4-14 through 4-16, 5-1 through 5-3, 8-2, 9-1, 

9-2, 9-15

floodproofing 3-8, 5-4 through 5-7, 10-2, 10-7 through 10-12, 10-16, 11-6, B-6

floodwall 6-6, 7-6, 8-9, 8-10, 9-6, 10-4 through 10-6, 10-18

floodway vii, 4-11, 4-16, 8-10, 10-17

floor drain plug 10-9, 10-10

funding [See financial assistance]

future-conditions hydrology 4-7

G

grants [See financial assistance]

green infrastructure 4-11 through 4-15

greenway 4-14, 9-4, 9-12, 9-13, A-3, B-5

groundwater 4-18, 10-9

H

habitat 4-8, 4-11, 4-14, 4-15, 5-3, 8-6, 8-8 through 8-13, 9-2, 9-5, 9-14

Hazard Mitigation Grant Program (HMGP) 3-8, 7-10, 9-9, 10-20

hazard mitigation plan 2-5, 3-4 through 3-6, 3-8, 9-4, 9-6, B-1, B-2

health [See safety hazards]

historic preservation 5-7, 9-4, 9-5

HMGP [See Hazard Mitigation Grant Program]

homeowners association 5-5, 8-15, 9-6

homeowners insurance 2-3, 11-1, 11-10

human intervention 10-4 through 10-6, 10-9 through 10-14

hurricanes 3-4, 3-5, 4-5, 5-7, 6-3

hydrology 4-3 through 4-9

hydrostatic pressure 10-8, 10-11, 10-12
Index

Reducing Damage from Localized Flooding: A Guide for Communities

I

ICC [See Increased Cost of Compliance]

incentives vii, 2-8, 2-9, 2-10, 10-16

Increased Cost of Compliance (ICC) 4-16, 6-10, 9-10, 9-11, 10-20, 11-1, 11-6

infrastructure 2-6, 2-8, 4-7, 4-10, 4-13, 4-14, 9-6, 9-7

inspections 4-20, 6-9, 8-13 through 8-15

L

lawsuits 2-4, 2-8

lenders 5-1, 11-3, 11-5

levees 7-6, 8-9, 8-10, 10-4, 10-18

liability 2-4, 2-8, 9-10

local flooding [See localized flooding]

localized flooding viii, 1-1, 1-3, 2-1 through 2-9, 4-1, 5-1, 6-1 through 6-3, 6-6, 7-1, 9-15, 

11-1

low-interest loans 10-20

M

mandatory flood insurance purchase requirement 11-5

manufactured homes 11-2

Map Modernization Program 4-4

mildew 2-2 [See also safety hazards]

mitigation 2-5, 2-9, 3-3 through 3-8, 5-5, 5-7, 6-9, 7-3, 7-9, 9-1, 9-2, 9-9, 9-10, 10-1, 

10-2, 11-1, 11-6, A-3, B-1 through B-5

mold 2-2 [See also safety hazards]

mosquitoes 2-2, 8-13 [See also safety hazards]

N

National Flood Insurance Program (NFIP) viii, 1-1 through 1-3, 2-5, 2-9, 3-9, 4-1, 4-3, 4-14, 

4-16, 5-1, 6-9, 6-10, 7-10, 9-10, 10-3, 10-15, 11-1 through 11-10, A-1

National Pollutant Discharge Elimination System (NPDES) 4-11, 8-5, 8-12, A-2

National Weather Service (NWS) 2-1, 6-1 through 6-8, A-2

neighborhood 2-6, 5-5, 7-1 through 7-8, 8-12, 9-1, 9-2, 9-12, 10-1

neighborhood associations 5-5, 8-15, 9-6

NFIP [See National Flood Insurance Program]

nonresidential buildings 10-15, 11-2

NPDES [See National Pollutant Discharge Elimination System] 

nuisance flooding 1-1, 1-3, 5-3

NWS [See National Weather Service]

O

on-site storage 8-10 through 8-12

open space 2-5, 3-5, 3-8, 4-11 through 4-14, 7-8, 8-5, 8-11, 9-3 through 9-13

outreach projects [See public awareness]

overhead sewers 10-9 through 10-12

P

parks 2-6, 3-7, 4-13, 7-5, 8-3, 8-8, 8-9, 9-3 through 9-13

PDM [See Pre-Disaster Mitigation program]

piers, post, and pile construction 4-19, 10-3
Index

Reducing Damage from Localized Flooding: A Guide for Communities

plan 2-5, 3-1 through 3-8, 4-8, 6-4 through 6-6, 7-1, 7-8, 9-3

planned unit development (PUD) 4-8, 4-11

planning guidance 3-3, 3-6

police station [See critical facilities]

political support 3-3, 9-9

pollutants 4-11, 8-4, 8-5, 8-11 [See also National Pollutant Discharge Elimination System]

ponding vii, 1-1, 1-3

ponds 8-4, 8-10, 8-11

positive drainage 2-7, 3-2, 4-17, 4-18, 8-16

Pre-Disaster Mitigation (PDM) program 3-6, 7-10, 9-10, 10-20

Preferred Risk Policy 11-2, 11-10

protective shields 6-7, 10-15

public awareness 5-3 through 5-8, 6-1, 6-3, 6-7, 8-12, 8-13, 10-19, 10-20, 11-7

public education [See public awareness]

public information [See public awareness]

PUD [See planned unit development]

R

rain gardens 8-12, 8-13, B-4

real estate agents 5-1, 5-4, 5-8

rebate 3-8, 6-11, 10-21

reconstruction [See redevelopment]

recovery 6-8, B-5

Red Cross 5-8, 6-7, 6-8, 6-10, A-2, A-3

redevelopment 2-8, 3-3 through 3-5, 6-9, 6-11, 7-1, 9-1 through 9-16

regrading 8-12, 10-5 [See also redevelopment]

regulations 1-1, 1-2, 2-5, 2-8, 3-2, 4-1 through 4-20, 5-2, 6-9, 8-5, 8-13 through 8-15, 

9-11, 10-3, 10-17, 11-5, 11-6

relocation 3-4, 9-7, 9-8, 9-12, 11-6

repetitive flooding, repetitive flood losses 1-3, 2-1, 2-6, 2-10, 4-4, 9-2, 9-15, 11-16

retrofitting 1-4, 2-8, 3-8, 5-3, 6-9, 7-11, 9-6, 10-1 through 10-21, 11-1, B-5, B-6

revitalization 2-6, 9-5, 9-14 [See also redevelopment]

riparian zones, riparian areas 8-5, 9-2

rip-rap 2-6

runoff 2-7, 4-6, 4-10 through 4-14, 5-8, 7-6, 7-10, 8-4 through 8-13

S

safety hazards 2-1, 2-2, 2-8, 6-5 through 6-9, 7-2, 8-4, 9-7, 9-10, 10-13 [See also anxiety, 

drowning, electrocution, fatalities, mildew, mold, mosquitoes, stress]

sandbags 6-7, 11-4

sanitary sewers 4-8, 4-10, 9-8, 10-9 through 10-12

SBA [See Small Business Administration]

scour 8-8, 8-9, 10-9, 10-17

sediment 4-14, 7-5, 8-5, 8-6

seepage 8-9, 10-7, 10-17

setbacks 4-10, 4-11, 10-6

sewer backup 2-7, 7-4, 7-7, 8-8, 10-9 through 10-12, 11-9, 11-10

SFHA [See Special Flood Hazard Area]

shallow flooding 2-1, 2-2, 5-2, 6-6, 9-14, 10-1, 10-4, 10-5

slab-on-grade construction 4-19, 10-3

Small Business Administration (SBA) 10-21, 11-5, A-2
Index

Reducing Damage from Localized Flooding: A Guide for Communities

Special Flood Hazard Area (SFHA) viii, 1-1, 1-2, 2-1, 2-3, 2-5, 2-6, 2-8, 3-2, 4-1 through 

4-5, 5-1 through 5-3, 6-9, 7-1, 8-10, 9-1, 10-3, 10-7 through 10-16, 11-2 through 

11-7

Standard Flood Insurance Policy 10-15, 11-2

standpipes 7-4, 10-10, 10-11

State NFIP Coordinator 4-3, 11-10

storage improvements 8-10

StormReady 5-9, 6-1, 6-7, 6-8, A-2

storm sewers 1-1, 2-4, 2-5, 4-2, 4-14, 4-19, 7-5, 7-6, 8-6, 8-9, 8-12, 10-10, 11-9

stormwater management 4-11 through 4-14, 7-4, 8-2, 8-4, A-3

stormwater storage 4-7, 8-4

stream crossings 8-6, 8-8

stress 2-3 [See also safety hazards]

structural damage 2-3, 10-9, 10-12, 10-13

subdivision layout 4-10, 4-17, 4-18

subdivision regulations 3-8, 4-10, 4-18

substantial damage, substantial improvement 3-4, 4-14, 4-16, 6-9, 6-10, 10-3, 10-14, 11-6, 

B-5

sump pump failure 5-2, 11-8, 11-9

surcharge 7-5, 11-6

surveyors 5-8, 7-3

swales 2-7, 4-13, 4-14, 8-1, 8-6, 8-7, 8-13, 8-14, 10-7

T

tax base 2-4, 2-8, 9-15, 10-1

topographic map 7-3

training 3-7, 3-9, 5-6, 5-8, 6-5, 9-11, A-1 [See also public awareness]

tributaries 4-5, 8-1, 8-2, 8-8

U

urbanization 8-2

U.S. Army Corps of Engineers 3-3, 4-20, 7-11 8-7, 8-16, 9-16, 10-20, 10-21, A-2, B-4, B-6

U.S. Environmental Protection Agency (EPA) 5-9, 8-5, A-2

V

vegetation 8-3 through 8-8, 8-10 through 8-13, 9-12, 9-13

W

warning systems 2-8, 6-1 through 6-8

waterfront 9-12, A-3

water quality 5-8, 8-4, 8-6

watersheds viii, 1-2, 3-8, 4-4, 4-7, 4-15, 5-6, 6-3, 7-1, 8-1 through 8-4, 9-3, 9-11 

[See also drainage]

Web sites 2-9, 3-8, 5-9, 5-10, 6-11, 6-12, 9-16, 10-21, 11-10, A-1 through A-3

wet floodproofing 10-2, 10-12, B-5

X

X Zones viii, 1-2, 1-3, 2-3, 3-3, 4-3, 4-5, 8-2, 10-5, 10-14, 11-2
Index

Reducing Damage from Localized Flooding: A Guide for Communities

Y

yard drainage 2-7, 8-12, 10-6

yard improvements 10-1, 10-6, 10-7

Z

Zone A [See A Zone]

zoning 2-5, 2-8, 4-1, 4-8, 4-10, 5-3, 10-3, 10-18

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