FEMA-165

MAY 1989

A luvial Fans:

Hazards and Management

I---C -11~4- 411r, - -

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Aerial view of the Magnesia Spring Canyon alluvial fan flood of July 1979, which caused over

$7 million in damage, and one death

FEDERAL EMERGENCY MANAGEMENT AGENCY

Federal Insurance Administration

Office of Loss Reduction

February 1989
ALLUVIAL FAN HAZARDS dI THE UNITED STATES

Flood hazards in the American West are often greatly underestimated due to the dry conditions, lack of rainfall and absence of defined watercourses. Ironically, western floods are

quite severe and powerful, exhibiting unpredictable flow paths

and high velocities that usually occur with little advance

warning time. These floodscan cause considerable erosion in

some areas while depositing large amounts of sediment and

debris in others.

With rapid growth continuing throughout the West (particularly

in many major metropolitan areas) hillside building sites have

become more popular as the supply of prime developable land

becomes depleted. This has resulted in an increasing amount

of development occurring in floodplain areas called alluvial

fans.

within participating communities to purchase insurance to

cover flood losses affecting structures and their contents.

- Figure 1.

Dense developmenton alluvialfansin theSouthMountaln area of Phoenix,

Arizona. Note the numerous branching channels.

Alluvial fans are triangular orfan-shaped, gently-sloping landforms which typify the floodplain management dilemma facing

many western states today: fans provide attractive development sites due to their commanding views and good local

drainage, yet harbor all the severe flood hazards which

endanger arid western communities.

Development pressure on alluvial fan areas is intensifying,

creating a critical need to provide guidance to communities,

developers and citizens on how to safely accommodate growth

while protecting life and property from flood hazards. To

address this need, the Federal Emergency Management

Agency (FEMA) has designed this brochure to increase awareness of alluvial fan flood hazards, and to provide general

guidance on the techniques and strategies for minimizing

losses from these hazards when building and developing.

FEMA is the agency which administers the National Flood

Insurance Program (NFIP), which enables property owners

Figure 2.

Damaged homes on a fan In Ocotillo Wells, California, which lies in eastern

San Diego County. Tropical Storm Kathleen caused extensive flooding

September9-11, 1976, there andthroughout Riverside andimperialcounties to the north and east. The channel braiding shown in the photo is

typical of alluvial fan flooding, and thus Itis difficult to predlct the location

of floodflows.

Where Are Alluvial Fans Found?

In the United States, alluvial fans are typically found along the

base of mountain fronts in the western states of California,

Arizona, Nevada, Colorado, Utah, Idaho, New Mexico, Wyoming, Montana, Oregon and Washington. Here, the infrequent

but intense storms typical of arid and semi-arid climates

combined with abrupt changes in topography create the nec1

I N I a 06 M -, t I IM i ON I WHIEN, 0 I WI A
-Cd

essary conditions forfan formation. Differences in climate and

geology have produced mostly active fans in regions such as

Nevada and California, and inactive fans in southern Arizona.

Active fans exhibit braided channels and erratic flowpaths

typical of ayoungfanformation. Fans in southern Arizonatend

to exhibit more predictable channels and flood paths due to

their geologically older setting. It has been estimated that 15

to 25 percent of the arid West is covered by fans.

How Are Alluvial Fans Formed?

Alluvial fans build up over the course of geologic time through

this general sequence:

1. Rock and soil are eroded from the mountain watershed;

2. These sediments are transported through stream channels via storm-generated floodwaters;

3. The floodflow which has been confined in mountain

ravines emerges onto the wide, flat valley slope, and

progressively loses velocity while depositing sediment

as it travels downf an.

The sediment deposits are generally narrow and steep at the

head of the valley, broadening as they spread out onto the

valley floorin awedge or conical shape. The natural processes

responsible for fan formation have frequently been observed

to occur in a specific sequence and range of location along the

length of the fan. For the sake of illustration, these processes

will be presented in a generalized fashion to portray the

formation of the "idealized" alluvial fan. In reality however,

wide variations in the physical characteristics of each fan

system affect the actual location, extent and severity of these

flood processes. Variations occur between areas exhibiting

differences in climate and geology, as well as among fans

within the same valley.

FORMATION OF AN "IDEALIZED"

ALLUVIAL FAN

1. Streamrflow from intense rainstorms

emanates from the confined channel of a

mountain canyon and proceeds onto the

relatively flat valley below. The canyon

outlet forms the APEX of the fan, which

represents the point of highest elevation on

the fan.

2. Flow leaving the apex spreads onto the

uppermost portion of the alluvialfan surface

via a single high-velocity channel. This

singular channel will either follow a preexisting path cut from past flood events,

possibly deepening the channel in a process called entrenchment, or cut a new path

downslope. Flood hazards in this CHANNELIZED ZONE of the upper fan region

can be severe due to the high velocity of

flow, the presence of debris from the watershed, and the unpredictable location of

flowpaths.

3. As the single channelflow encountersthe flatterslope ofthe

mid-fan area, it widens and becomes shallower, losing velocity and depositing sediment and debris. Materials that become

deposited into previously-cut channels can backfill the old

streambeds, leading to the abrupt development of new channels in a process called avulsion. The erosion/deposition processes include channel braiding, where singular flows split and

rejoin as channels are alternately cut and filled with sediment.

These BRAIDED ZONE processes occur erratically, creating

random, unpredictable flow patterns.

4. Toward the base of the fan, called the TOE, watervelocities

are further reduced as the fan surface becomes more uniform,

its slope flattens and water infiltrates the soil surface. In this

portion of the fan, SHEET FLOW (shallow, overland flow) is

common, though flow velocities may remain high. Adjacent

fans which have formed along mountain fronts tend to converge near their bases, producing alluvial APRONS, or zones

of coalescence.

2

1. APEX

4. SHEET FLOW

ZONE

fgure 3
How Are Alluvial Fans Identified?

The gentle, imperceptible slopes and extensive size of many

fans can sometimes make their identification in the field

difficult. As a result, many homeowners do not realize that the

panoramic views of the valley below are due to their elevated

location on an alluvial fan. The initial identification of the

presence and extent of fans within the community is therefore

Figure 4.

This U.S. Geological Survey topographic quadrangle map has been enhanced to show the concentric contour pattern typical of alluvial fans.

Depicted here are two alluvial fans In Wenatchee, Washington.

best accomplished through the use of topographic maps or

aerial photos. Topographic maps (such as those produced by

the U.S. Geological Survey) reveal concentric semicircular

contours that bow downslope, as shown on the figure above.

The use of soil survey maps (such as those developed by the

Soil Conservation Service) can also indicate the presence of

alluvial (water-transported) soils which often comprise fan

formations. In confirming the location and extent of alluvial

fans, the final detailed interpretation of maps, air photos and

field data should be made by a professional geologist, hydrologist, and/or engineer.

What Are The Flood Hazards Associated With Alluvial

Fans?

Alluvial fan floods do not exhibit the more predictable behavior

and well-defined boundaries normally found in most riverine

floods. The behavior and path of flood water in any individual

flood event as it proceeds from the apex to the toe is a direct

result of the flood processes previously illustrated. These

processes vary as a function of the flow's sediment content

and velocity, the fan's slope, soil and vegetative cover, and

types and amount of fan development.

Alluvial fan flows are subject to lateral migration and sudden

relocation during the course of a flood, and may not even follow

the same path in subsequent floods; in any flood event,

however, a part of the fan will always be subject to flocd

hazards. Thus, it is generally not appropriate to utilize the

location of past flow paths in the prediction of future hazards.

The full range of hazards that may be encountered on fans

include:

* high-velocity flow (as high as 15-30 feet per second),

producing significant hydrodynamic forces (pressure

against buildings caused by the movement of flowing

water)

* erosion/scour (to depths of several feet)

* deposition of sediment and debris (depths of 15-20 feet

have been observed)

* debris flows/impact forces

* mudflows

* inundation, producing hydrostatic/buoyant forces (pressure against buildings caused by standing water)

* flash flooding (little, if any, warning times)

An often-overlooked "hazard" is the tendency to underestimate boththe potential and severity of alluvialfanflood events.

The infrequent rainfall, gently-sloping terrain, and often long

time spans between successive floods contributeto asense of

complacency regarding the existence of possible flood hazards. Though the intense rainstorms which produce fan floods

occur randomly, they nevertheless can develop very rapidly at

any time, and can recur with any frequency.

3

I 3  W-10
Figure 5.

High-velocity flows battered homes in Ocotillo Wells, California

during the September 1976 flood caused by Tropical Storm Kathleen.

Figure 6.

Fast-moving floodwaters caused scour, erosion

and structural damage to numerous Rancho

Mirage, Califomia homesin September 1976and

in July 1979.

Figure 7

Large volumes of sediment can be deposited by floodwater

during the course of an alluvial fan flood event.

4

"am
Figure 8.

Four successive days of flooding in August 1982 caused debris and water

damage In Ouray, Colorado. Thirty-five homes and businesses were damaged, andnumerousbridges weredestroyed. Shown here is debris deposited

by Portland Croek. (Courtesy of Dave Vince, City of Ouray)

Figure 9.

Inundation of homes by shallow flooding can

cause extensive interior damage.

5
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A Word About Debris Hazards ...

In the case of geologically younger, or active fans, the natural

processes which, over time, formed the fan continue to act

upon its surface in a somewhat random fashion. Thus, the

entire fan surface represents a potential site for flood, sediment and debris deposition and scour, and is a dangerous

location upon which to build.

In geologically older regions, alluvial fan processes tend to

follow more predictable patterns, and floodflows may remain

within defined channels as theydischarge downslope. Fans or

portions of fans which are no longer subject to these flows are

considered inactive, and may be regarded as less hazardous

construction sites.

Regardless of whether a fan is active, inactive, or both, there

is always some degree of unpredictability of the flood hazard

on all fans.

Debris flows can result from the presence of a large percentage (up to 70-90% of flow by weight) of fine sediment such as

silt and clay in steeply-flowing floodwaters. This enables the

muddy flow to transport sand, gravel, boulders, and dislodged

timber and brush from the mountain watershed onto a fan's

surface. Conditions favoring the formation of debris flows are:

avail able unconsolidated silt, clay and larger rock in the basin

watershed (due to minimal vegetation), heavy or sustained

rainfall in the basin, and the presence of steep basin and fan

slopes. Fans which have been created from repeated debris

flow activity are called debris fans, and are composed of

deposits of rock, soil and vegetation from the upstream watershed. Debris fans are found in areas where mountain systems

are subject to tectonic forces of uplift. Colorado, Utah, Wyoming, Montana, and parts of California, Nevada and Arizona

contain the bulk of debris fans and flows.

Figure 10.

Development on a debris fan in Georgetown, Colorada Note the structures'proximity to the steep mountain slope above. (Courtesy

of the Colorado Geological Survey)

6

Active vs. Inactive Fans
Figure 11.

Debris flow damage In Glenwood Springs, Colorado in July 1977. Property

damage to homes andpublic facilities and cleanup costs totalled approximately $2 million. (Courtesy of the Colorado Geological Survey)

Figure 12.

Boulders several feet in diameter may be transported by sedimentladen flood flows. This debris was deposited south of Sierra Vista,

Arizona in June 1988 following heavy rains in the Huachuca Mountains.

Figure 13.

This small debris basin was constructed In 1984 on Cascade Creek in

Ouray, Colorado after several instances where debris blocked the

channel and worsened flooding conditions. The basin allows debris to

settle out of moving floodwaters. (Courtesy of Dave Vince, City of

Ouray)

7

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MANAGING DEVELOPMENT ON ALLUVIAL FANS

It must be stressed that any development activity sustained on the active portion of an alluvial fan disrupts and

alters the natural flood processes which perpetuate Its

formation, and subjects any structure situated on the fan

to unpredictable, erratic hazards during flood events.

Furthermore, any new construction can redirectflood and

debris flow to adjacent properties and thereby increase

flood hazards In other areas. A comprehensive approach

is therefore needed to manage development on fan areas

such that the entire fan's natural flood processes and

resulting hazards are taken Into account. The development and implementation of a comprehensive approach

is best handled on the local government level through

planning, zoning and building permit processes. Through

these processes, future development can be planned and

its effects on flood hazards adequately addressed.

How Should a Community Manage Development on Alluvial Fans?

A comprehensive or master planning approach to managing

growth on an alluvial fan considers fan conditions from apexto

toe while guidingfuture developmentinacoordinated manner.

The keystone of this planning process is the community's

selection of flood/debris hazard management tools. The

choice of tools will depend upon the nature and location of the

hazards, and the location, timing, size and density of existing

and future development. These tools can be structural (levees, basins, channels) or nonstructural (zoning, public acquisition, subdivision regulations, building standards). The fan

management plan may be incorporated as aseparate element

within the community's existing comprehensive plan, or may

stand alone as a separate document. The planning process

incorporates the following steps:

should be mapped, as should the location of previous and

potential debris flow paths. If the community has had its alluvial

fan areas studied and mapped while preparing its Flood

Insurance Rate Map (FIRM), some of this data may already be

available. The FIRM will delineate the flood having a one

percent chance of occurring in any given year (the 100-year

flood), which can serve as the basis of more detailed hazard

analysis and mapping.

2. PLAN FUTURE DEVELOPMENT. Identify the areas of the

fan which require immediate flood protection, taking into

accountthe location and density of existing development. Establish the location, timing, and amount of future development

in light of the delineated hazards. Development in the most

hazardous portions of the fan should be restricted.

3. CHOOSE FLOOD MITIGATION TOOLS. Analyze the

range of flood management/control tools available in consideration of identified hazards, present and planned density and

location of development, cost to locality, and public acceptance. This is accomplished through the establishment of

community goals, and through coordination among local

government officials, planners, engineers, residents, and the

development community. The most widely-used alluvial fan

flood management tools are presented in the next table.

4. ENFORCE REGULATIONS. Ensure the effective application and operation of the selected flood management tools by

adopting and enforcing regulatory controls:

a. Zoning ordinances, subdivision regulations and open

space/land acquisition plans can be used to prohibit or

otherwise limit growth in high hazard areas, and would

allow the safe passage of flood waters;

1. IDENTIFY THE HAZARDS. Using qualified geologists,

hydrologists and engineers, conduct a detailed study of individual watershed and fan characteristics in orderto determine

the severity and location of hazards to be expected on each

fan. Where appropriate, active and inactive portions of the fan

b. Building codes can help ensure safe residential construction;

c. Maintenance/inspection requirements can help guarantee the effective operation of structural flood control

measures;

5. EDUCATE CITIZENS. Communities should initiate public

awareness programs on alluvial fan hazards, install flood

warning systems (where practical), and encourage the purchase of federal flood insurance.

This comprehensive planning approach Is most effective

when implemented as early as possible during fan development. A community can then exercise maximum control over future desired density levels and have the most

flexible choice of flood management tools. It Is also best

utilized on a multi-community or regional scale, especially when multiple fans occupy range-fronts which may

span several jurisdictions.

8
ALLUVIAL FAN FLOOD MAMAGEMENT

TOOLS

(Based on Size and Density of Planned

Development)

Whole Fan Protection

Levees

Channels

* Detention basins

* Debris basins/fences/deflectors/dams

Design Considerations: Whole-fan protection includes largescale structural measures appropriate for use on extensivelydeveloped fans, and which are most cost-effective in highdensity situations. Structures must be designed to intercept

upstream watershed flow and debris at the apex and to

transportwater and sediment around the entire urbanized fan.

Structures must be designed to withstand scour, erosion,

sediment deposition, hydrostatic forces, impact and hydrodynamicforces, and high flow velocities. Continual maintenance

is essential for optimal operation, and can be costly. These

structures are most often funded through federal and state

sources, but can also be financed through special regional

districts, local governments, or developers.

Subdivision or Localized Protection

* Drop structures to reduce flow velocity

* Debris fences

* Local dikes, channels

* Site plans to convey flow

* Street design/alignment to convey flow

* Elevation on armored fill

Design Considerations: These are smaller-scale measures

that can be used throughout moderate-density fans to safely

trap debris, and to route water and sediment around orthrough

individual residential developments. Protection elements must

prevent formation of new flow paths and/or the relocation of

existing paths; flood control structures must resist high velocities, erosion, deposition, hydrodynamicand hydrostaticforces.

The most effective strategy includes a combination of elements; the entire protection plan must be coordinated with

other similarly-scaled efforts to avoid adverse impacts to

adjacent property. These measures can be financed privately

by developers.

Figure 15.

Shown here is the channelization of Flamingo Wash adjacent to new

construction near Las Vegas, Nevada. Gabions (rock-filled baskets enclosed with wire mesh) help stabilize the channel sideslopes. Walls

provide some additional flood protection.

Figure 14.

This concrete channel was designed to carry floodwater downslope in

Palm Desert, California. -

9
E- _1m .

- t 4m&IA- --h :t

Single Lot/Structure Protection

* Elevation on properly designed foundations (piles, columns or armored fill)

* Floodwalls and berms

* Reinforcement of uphill walls, windows and doors against

debris impact

Design Considerations: These measures are most costeffectively implemented at low development densities, but

should be considered for all structures on fans. Owners of

existing structures should consider retrofitting their homes to

protect against future flood hazards; new lots should be

planned with adequate open space to accommodate flow

paths. Velocity/scour, sedimentation and debris impact must

be addressed in the design of elevated foundations and of

floodwalls. Floodwalls should not be solely relied upon for

protection, but as a supplement to elevated foundations.

These measures are usually financed by the homeowner.

Figure 16.

This home in Palm Desert, California has been elevated on till. Utilities

(shown against the left side of the house) have also been raised to

minimize potential flood damage.

The choice of the appropriate measure(s) will ultimately depend upon the community's development plan and the level

and extent of protection desired.

What Factors Should Be Considered When Building On A

Single Lot?

It is recommended that single lot development only proceed

within the framework of a comprehensive plan for the alluvial

fan, which has identified the fan's flood hazards, design

requirements for the safe construction of individual sites, and

how each site would fit into a coordinated approach. If such a

comprehensive plan has not been developed, then the following general steps should be undertaken to minimize the

potential flood risk for any proposed structure:

1. AVOID THE MOST HAZARDOUS AREAS OF THE

FAN.

2. Consult with local planning, building, and engineering

officials to discuss the potential hazards specific to the

site, regulations in effect which would specify methods

of construction, and any permits required for building in

a flood hazard area.

3. Using the expertise of local engineers, determine the

depth and velocity of the 100-year flood flow which

would affectthe site, including the possible effects of any

debris hazards. 6 r!gS -, -

4. ELEVATETHE @

STRUCTURE

so that the lowestfloor(including basement)

isat orpreferably above) the

determined

flood depth.

The most effective methods of

elevating structuresonfans are

to use piles or -I

columns, or to

elevate on ar--________

mored fill.

5. Flood walls can

also be used to Figure 17.

divert flow Thishomeis underconstruction on an active alluvialfan below the McDowellMountainsin around elevated Scottsdale, Arizona.

structures

where expected flood flows are of minimal depth and

velocity, wherethere is no potential for debris hazards or

increased damage to adjacent structures.

6. Avoid the placement of windows and doors on the uphill

side of the structure to keep debris and flood water from

entering the building. If such openings must be used,

theyshould bereinforcedtostrengthenresistanceagainst

debris and hydrodynamic forces.

10
Fill: SINGLE STRUCTURE PROTECTION

Piles, Columns, or Posts:

* Minimize the structure's exposure to flood hazards

* Eliminate obstructions to natural flow paths

* Do not significantly affect flood flow hydraulics

* Size and number of piles must be adequate to provide

structural support to building; must be embedded to

sufficient depth, and be adequately anchored to both the

structure and to subsoil/bedrock to withstand scour and

erosion

Figure 18.

A home elevated on columns, Illustrating how the area below the first floor

should be limited to parking, access, or storage. Utilities and mechanical

equipment should also be elevated above ground at least to the depth

indicated on the FIRM.

* Should only be used in low to moderate velocity/depth

conditions

* Must be armored above and below grade to withstand

scour, erosion, and debris impact and to protect the

structure's foundation

* Should be oriented parallel to expected flood flow to

reduce debris damage, to avoid defledting flow to adjacent or downstream property, and to minimize obstruction to flow

* Can be landscaped

Figure 19.

This home has been elevatedon earth fiiandlandscaped. The vegetation

helps to stabilize the fill to protect It from erosion.

Floodwalls or Berms:

* Should only be used in very low velocities/depths (sheet

flow velocity of less than 5 feet per second/depth of less

than 3 feet); should only be used near toe of fan or where

large sedimentation and debris loads are not likely

* Should be able to resist erosion at base and below grade

* Should be oriented to avoid diversion of hazards to

adjacent or down stream property

* Can be effective when used as supplemental protection

for elevated structures

Since flood hazards threatening an individual site on an alluvial

fan are highly unpredictable, the methods used to safeguard a

structure will depend upon conditions unique to the location of

the site itself. It is therefore imperative to consult closely with

local engineering experts to determine the site's particular

physical conditions and expected flood and debris hazards.

Figure 20.

Floodwalls, such as this example In Phoenix, Arizona, should be constructed parallel to the expected flow direction to minimize the diversion

of hazards onto adjacent property.

MEMEM

-1"
10 X 1* 

How Does the P/PIP Address Development On Alluvial

Fans?

The NFIP identifies alluvial fan hazards on FIRMs as Zone AO

and provides information on flood depths and velocities. AO

zones are Special Flood Hazards Areas (SFHA) subject to

inundation by 1 00-year sheet-type flow, which are sometimes

associated with high velocities. If the community's FIRM

identifies AO zones with depths and velocities, construction

within those alluvial fan areas are subjectto certain regulations

(in addition to those which apply to all SFHA's) found in

Chapter 44 of the Code of Federal Regulations, Part 60.3:

* Elevate lowest floor (including basement) above the

highest adjacent grade to at least as high as the depth

number specified on the FIRM. (It is recommended,

however, thatthe depth of flow assumed for a particular

site should take into consideration local topographic

anomalies when determining the elevation of any flood

protection measure.) Mechanical and utility equipment

must also be placed above the depth of flooding.

* Provide adequate drainage paths around structures on

slopes, to guide floodwater around and away from

proposed structures. Do not deflect floodflow onto

adjacent properties.

As part of the FIRM revision process, FEMA will review the

development plans submitted by owners of projects who

request the removal of their property from the SFHA. To

ensure thatthese projects are in fact protected from alluvialfan

flood hazards, FEMA's review criteria require that the construction include elements which: do not cause the disturbance of natural flood processes on the fan; allow forthe safe

collection, passage, and disposal of flood-related water, sediment and debris without negative impact to adjacent property;

address erosion, scour, deposition, impact and hydrostatic

forces; provide that the design and maintenance of project

elements be coordinated with the local jurisdiction and/or

agency responsible for flood control within the community.

With knowledge of local conditions and inthe interestof safety,

state and community officials may set higher standards for

construction in f loodplain areas. As with all f looding situations,

FEMA encourages local jurisdictions to adopt floodplain

management measures which are more tailored to the

community's particular flood problems. This is especially

important for communities prone to alluvial fan flood hazards,

where each fan presents a unique set of flood conditions.

It should be noted that the provisions of Section 60.3 are

minimum requirements; buildings constructed according to

these rules alone will not provide adequate protection against

high velocities ordebris loads unless additional measures are

undertaken.

The unique qualities of each fan formation and its attendant

hazards requires individualstudy andstrategicplanning using

the guidance of government officials, engineers, hydrologists,

and geologists. It is hoped that this publication has offered

sufficient information regarding the importance of guiding

development on alluvial fans to provide the impetus for local

knowledge and expertise. Intensified commitment to offset

currentandfuture flood losses on fans willgreatly complement

the work of professional groups and public agencies as they

begin to develop management and construction standards for

these special arid west flood hazards.

12
Figure 21.

Portion of a Flood Insurance Rate Map (FIRM) panel for unincorporated

San Diego County, California showing areas subject to 100-year food

hazards on the Henderson Canyon alluvial fan.

Figure 22.

Flooding hit the community of Borrego Springs near the base of the

Henderson Canyon alluvial fan In northeastern San Diego County when

Tropical Storm Doreen crossed the area in 1977. This photo faces

southward across Montezuma Road, and shows the large amounts of

sediment deposited during this flood. The location of this damage is

shown in the FIRM, Figure 21. In consideration of the frequency of flood

events andthe potential for developmentin the larger Borrego Valley area,

a flood management plan is being finalized bySan Diego Countywhich will

prescribe structural and nonstructural flood control measures for alluvial

fans in the county.

13
APPENDIX A

For Further Information:

For information pertaining to hazard identification mapping and floodplain management, contact the Natural and Technological

Hazards Division of the appropriate FEMA Regional Office, or the state NFIP coordinators listed below:

FEMA REGIONAL OFFICES

Region VI: (Arkansas, Louisiana, New Mexico, Oklahoma,

Texas)

Federal Regional Center

Room 206

800 N. Loop 288

Denton, TX 76201-3698

(817) 898-9127

Region Vil: (Colorado, Montana, N. Dakota, S. Dakota, Utah,

Wyoming)

Federal Regional Center

Building 710

P.O. Box 25267

Denver, CO 80225-0267

(303) 235-4830

Region IX: (Arizona, California, Hawaii, Nevada)

Building 105

Presidio of San Francisco

San Francisco, CA 94129

(415) 923-7175

Region X: (Alaska, Idaho, Oregon, Washington)

Federal Regional Center

130 228th Street, Southwest

Bothell, WA 98021-9796

(206) 487-4682

NFIP STATE COORDINATORS

ARIZONA

Arizona Department of Water Resources

Engineering Division

15 South 15th Avenue

Phoenix, AZ 85007

Ms. Terri Miller

(602) 255-1566

CALIFORNIA

California Department of Water Resources

P.O. Box 942836

Sacramento, CA 94236-0001

Mr. A. Jean Brown

(916) 445-6249

COLORADO

Colorado Water Conservation Board

State Centennial Building, Room 721

1313 Sherman Street

Denver, CO 80203

Mr. Brian Hyde

(303) 866-3441

IDAHO

Idaho Department of Water Resources

Engineering Division

1301 N. Orchard

Boise, ID 83706

Mr. Lotwick Reese

(208) 334-7887

MONTANA

Montana Department of Natural Resources and Conservation

Floodplain Management Section

1520 East 6th Avenue

Helena, MT 59620

Mr. John Hamill

(406) 444-6646

NEVADA

Nevada Division of Emergency Management

2525 South Carson

Capitol Complex

Carson City, NV 89710

(702) 885-4240

NEW MEXICO

New Mexico State Engineer's Office

Design and Construction Section

Bataan Memorial Building

Santa Fe, NM 87503

Mr. Don Lopez

(505) 827-6140

OREGON

Oregon Department of Land Conservation and Development

1175 Court Street, N.E.

Salem, OR 97310

Mr. Jim Kennedy

(503) 378-2332
UTAH

Utah Office of Comprehensive Emergency Management

1543 Sunnyside Avenue

Salt Lake City, UT 84108-0100

(801) 533-5271

WASHINGTON

Washington Department of Ecology

Shorelands and Coastal Zone Management Program

Mail Stop PV1 1

Olympia, WA 98504

WYOMING

Wyoming Emergency Management Agency

P.O. Box 1709

Cheyenne, WY 82003

Mr. Grant Sorenson

(307) 777-7566

Mr. Jerry Louthain

(206) 459-6791

16
V 4rA

APPENDIIX B

FEMA Publications:

The following publications are free of charge and can be

obtained by writing to:

Federal Emergency Management Agency

P.O. Box 70274

Washington, D.C. 20024

ATTENTION: Publications

FEMA-13, Flood Emergency and Residential Repair Handbook-Outlines for the homeowner actions that can be taken

before and after a flood to help reduce damage and speed

repairs.

FEMA-15, Design Guidelines for Flood Damage Reduction-General information on flooding and how to properly

design and build in floodplain areas.

FEMA-54, Elevated Residential Structures-Properdesign

and construction methods for elevated buildings.

FEMA-1 14, Design Manual for Retrofitting Flood-prone

Residential Structures-Presents floodproofing techniques

that can be used for existing residential structures.

ACKNOWLEDG EMENTS

The Office of Loss Reduction wishes to thank the following for

their information, advice and photographic materials used

during the preparation of this publication:

Arizona Department of Water Resources

Association of State Floodplain Managers

California Department of Transportation

Cochise County, Arizona Department of Public Works

Colorado Water Conservation Board

Colorado Geological Survey

Federal Emergency Management Agency-Federal

Insurance Administration-Oftice of Risk Assessment

Federal Emergency Management Agency-Natural

and Technological Hazards Division-Regions 6, 8, 9,

and 10

Michael Baker, Jr. Engineers

City of Ouray, Colorado

Pima County, Arizona Transportation and Flood

Control District

San Diego County, California Flood Control District

Tudor Engineering Company

FEMA-1 16, Reducing Losses In High Risk Flood Hazard

Areas: A Guidebook for Local Officials-A guidebook to

help local governments improve theirfloodplain management

programs for high risk flood hazard areas.

FIA-2, Questions and Answers on the National Flood

Insurance Program-This pamphlet is intended to acquaint

the public with the National Flood Insurance Program. it is

designed for readers who do not need a detailed history or

refined technical or legal explanations, but do need a basic

understanding of the Program and the answers to some

frequently asked questions.

FIA-14, Guide to Flood Insurance Rate Maps-This guide

will help you read and understand a Flood Insurance Rate Map

(FIRM). It contains illustrations and a step-by-step example of

how to use a FIRM.