Erosion management program recommendations for Hawaii Submitted to: Hawaii Coastal Zone Management Program, Office of State Planning

[From the U.S. Government Printing Office, www.gpo.gov]

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EROSION MANAGEMENT PROGRAM
RECOMMENDATIONS FOR HAWAII

Submitted to:
HAWAII COASTAL ZONE MANAGEMENT PROGRAM
OFFICE OF STATE PLANNING

July 1990

Century Square 1188 Bishop Street, Suite 2512, Honolulu, Hawaii 96813
TELEX:7431404 MCI: OCEANIT Ph: (808)531-3017 FAX: (808)526-1519

C2A4

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EROSION MANAGEMENT PROGRAM
RECOMMENDATIONS FOR HAWAII

Submitted to:
HAWAII COASTAL ZONE MANAGEMENT PROGRAM
OFFICE OF STATE PLANNING

Prepared by:
Oceanit Laboratories, Inc.
Honolulu, Hawaii
and
Jan Naoe Sullivan, Esq.
Honolulu, Hawaii

July 1990

The preparation of this report was financed in part by the CoastaL Zone Management Act of 1972, as amended,
administered by the office of Ocean and Coastal Resource Management, NationaL oceanic and Atmospheric
Administration, United States Department of commerce, through the office of state PLanning, state of Hawaii.

Century Square 1188 Bishop Street, Suite 2512, Honolulu, Hawaii 96813
TELEX.- 7431404 MCI.- OCE-ANIT Ph.- (808) 531-3017 RAX. (808) 526-1519

EXECUTIVE SUMMARY

The Hawaii Coastal Zone Management (CZM) program, through the

Office of State Planning (OSP) , requested Oceanit Laboratories,

Inc. to support the development of an Erosion Management Program

(EMP) by analyzing relevant information and recommending program

guidelines and objectives. Additionally, we were requested to

recommend a suitable method for the collection of coastal

information (e.g., erosion rates), which would later become an

integral part of the EMP.

Hawaii's land-use process is commonly referred to as "complex."

This holds true for coastal activities. The present management

program i's geared to address coastal erosion concerns as a tangent

to a land-use process. However, coastal erosion is not only a

land-use issue, but a resource management issue. Analysis of

Hawaii's existing programs that manage activities related to

coastal erosion revealed that the current regulatory scheme

operates in a piecemeal fashion that gives rise to various

problems, including: inconsistent management strategies; 'lack of

uniform policy guidelines for dealing with illegal or non-

conforming structures and encroachment of state-owned land; complex

and unresponsive regulatory processes with overlapping regulatory

functions between agencies; and lack of comprehensive planning.

Planning for erosion management is further impeded from a lack of

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data on coastal erosion phenomena and land-use activities in the

coastal zone, which hinders the effective execution of regulatory

efforts.

Recommended actions include coordinating federal, state and county

erosion management funding to develop a comprehensive data

collection program; develop a comprehensive erosion management

plan; and consolidate jurisdiction over the shoreline area to place

the bulk of the regulatory powers in a separate agency or division,

e.g., "Office of Beaches."

Many other states and countries have regulatory authorities that

handle erosion problems. However, each program is uniquely

designed to address their erosion problems, which directly reflect

on socio/economic values. In places where erosion represents a

large economic loss, proportional monies are spent on the problem.

The recommended EMP mission for Hawaii is "conserve beaches and

minimize erosion," which is sufficiently broad to accommodate many

of the complex matters associated with the problem; however, it is

specific enough to emphasize the need to conserve beaches and

minimize the loss of coastal property through erosion. The mission

is further clarified with mission guidelines, objectives, goals and

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a proposed schedule. These details are recommended as a starting

point for the development of an EMP.

Erosion monitoring methods are a direct reflection of the tradeof f s

between social and economic values. Various methods are available;

however, costs very widely. In Hawaii initial information can be

extracted from historical maps and aerial photographs already

available. The accuracy of the results will depend on the accuracy

of maps and methods adopted for information extraction. The

methodology most suited for Hawaii requires aerial photographic

monitoring with ground measurements at places that are of high risk

or high need. High accuracy measurements cost more, but are only

needed in certain high risk areas. Initial data collection is

expected to be costly; however, ongoing data collection maintenance

will be considerably less.

All erosion control management activities have strong social,

economic and legal components. Land ownership, recreational

requirements, beach access and proximity to public facilities must

be considered when evaluating impacts from a proposed development.

It is important to realize that the success of an erosion

management plan is highly dependant on the degree of public

participation while evolving the plan. Issues connected with

erosion, e.g, rights of private land owners and potential legal

involvement, discourage regulatory agencies. These tradeoffs

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between individual rights and public benefit are unavoidable;

however, a method to evaluate potential economic losses and gains

to all parties involved, as well as other related mitigation, is

expected to be a major tool for resolving these unavoidable

conflicts.

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T B L E 0 F C 0 N T E N T S

DESCRIPTION PAGE

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . .

I. INTRODUCTION . . . . . . . . . . . . . . . . . .
A. BACKGROUND . . . . . . . . . . . . . . . . . .
B. OBJECTIVE . . . . . . . . . . . . . . . . . . 2

II. EROSION MANAGEMENT PROGRAM MISSION . . . . . . . 4
A. THE EXISTING MANAGEMENT PROGRAM . . . . . . . 6
B. ANALYSIS . . . . . . . . . o . . . . . . . . . 13
B.1. INCONSISTENT MANAGEMENT STRATEGIES . . . 14
B.2. LACK OF UNIFORM POLICY GUIDELINES . . . . 16
B.3. COMPLEXITY OF REGULATORY PROCESS . o . . 20
B.4. LACK OF COMPREHENSIVE PLANNING . . . . . 22
B.5. RECOMMENDATIONS . . . . . . . . . . . . . 24
C. MISSION BACKGROUND . . . . . . . . . . . . . . 25
D. MISSION STATEMENT . . . . . . . . . . . . . . . 32
E. MISSION GUIDELINES . . . . . . . . . . . . . . 33
F. MISSION OBJECTIVES/GOALS . . . . . . . . . . . 34
G. EROSION MANAGEMENT PLAN EXECUTION . . . . o . . 35
H. EROSION MANAGEMENT PLAN SCHEDULE . . . . . . . 36

III. EROSION MANAGEMENT PROGRAM PLANNING
A. EROSION MONITORING METHODS . . . . . . . . . . 38
A.l. BACKGROUND . . . . . . . . . o. . . . . 40
A.2. MONITORING METHODS . . . . . * ' ' ' * ' 48
A.2.a. RECOMMENDATION/BEST METHOD . . . . 58
A.3.'IMPLEMENTATION SCHEME . . . . . . o . . . 63
B. GUIDELINES AND CRITERIA FOR RESPONDING
TO EROSION HAZARDS . . . . . . . . . . . . . . 64
Bol. ENGINEERING CONSIDERATIONS . . . . . . . . 66
B.2. SOCIO/ECONOMIC CONSIDERATIONS . . . . . . 68
B.2.a. INFORMATION NEEDED . . . . . . . . 74
B.3. RESPONSE TO EROSION HAZARDS . . . . . . . 80

IV. FUTURE MANAGEMENT CONCEPTS . . . . . . . . . . . 88

V. CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . o 90

VI. REFERENCES . . . . . . . . . . . . . . . . . . o . 94

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LIST OF TABLES

DESCRIPTION PAGE

TABLE II-1 PRACTICAL STATE REGULATORY CONCERNS. . . 7

TABLE 11-2 PRACTICAL COUNTY REGULATORY CONCERNS . . . . 8

TABLE 11-3 SUMMARY OF STATE/TERRITORY EROSION
MANAGEMENT PROGRAMS . . . . . . . . . . . . 31

TABLE III-1 METHODS OF.COMPARISON MONITORING . . . . . . 62

TABLE 111-2 EXAMPLE QUESTIONS TO DETERMINE DATA FOR
RESPONDING TO EROSION AND FLOODING . . . . . 80

TABLE 111-3 EXAMPLE QUESTIONS TO FORMULATE A SOLUTION TO
EROSION PROBLEMS . . . . . . . . . . . . . . 82

TABLE 111-4 EROSION ISSUES . . . . . . . . . . . . . . . 84

LIST OF FIGURES

DESCRIPTION PAGE

FIGURE I . . . . . . . . . . . . . . . . . . . . . . . . 37

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I. INTRODUCTION

A. BACKGROUND

In January 1990 the State of Hawaii Coastal Zone Management Program

(HCZMP) issued a request for proposals to perform studies related

to the development of erosion management recommendations.

Thereafter, Oceanit Laboratories, Inc. (OLI) was selected for

execution of the study; in May 1990 an agreement was signed and we

formally began work.

The Hawaii Coastal Zone Management Program (HCZMP) is based on the

Hawaii Coastal Zone Management (CZM) law Chapter 205 A, Hawaii

Revised Statutes. Objectives and policies of the law address

recreational, historic, scenic and open space resources, coastal

ecosystems, economic uses, coastal hazards and managing coastal

development. other state statutes that authorize regulations,

plans and review processes for activities that affect Hawaii's land

and ocean environment have either been incorporated in the HCZMP as

supporting policies and mandates or, in the case of Federal

Agencies, are reviewed for consistency by the State CZM agency.

one of the objectives of the CZM program is to reduce hazard to

life and property from tsunami, storm waves, stream flooding,

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erosion and subsidence. Policies set-down under this objective

include the following:

� Develop and communicate adequate information on
storm wave, tsunami, flood, erosion and subsidence
hazard.
� Control development in areas subject to storm wave,
tsunami, flood, erosion and subsidence hazard.
o Ensure that developments comply with requirements of
the federal flood insurance program.
� Prevent coastal flooding from inland projects.

Information on hazard intensities, locations and land use

constitute an important input (for purposes implementing these

policies). Exposure to oceanographic phenomena such as waves,

currents, storms, tsunamis and sea level elevations as well as

bathymetric relief of the nearshore sea bed, and the geologic

composition of the land strip adjacent to the waterline, contribute

to the potential erosion hazard faced by the coastal land. The net

effect from these forces can be erosion of coastal land and

flooding of low lying areas along the coast. Long-term trends in

land loss is an extremely important parameter that is needed for

effective policy implementation and to control development in the

hazard areas.

B. OBJECTIVE

The purpose of this repozt is to recommend a uniform method for

monitoring long-term erosion trends and to develop erosion

management recommendations for the State of Hawaii that will

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support the establishment of an erosion management program.

Specific tasks to be addressed herein include the following:

1) Revise the mission and evaluate and prioritize the goals
and objectives of the erosion management program.
.2) Analyze methods of monitoring and predicting long term
erosion trends in terms of cost, accuracy and technical
requirements. The analysis will address applicability and
usefulness, within the framework of resources and
responsibilities of government agencies and compatibility
with previous methods used, existing erosion data and the
type of erosion in Hawaii.
3) Develop general criteria and guidelines for responding to
coastal erosion. Develop general guidelines that can be
applied for responding to coastal erosion under various
environmental, erosion hazard and ownership
circumstances. Analyze socio-econamic issues related to
erosion such as protection of public versus private
rights, and public access.

During the relatively short time available to complete this project

several meetings were held with the CZM office and other

departments in the City and County of Honolulu and State of Hawaii

to discuss the different problems faced by them while implementing

erosion management activities and engaging non-compliance actions

by coastal property owners.

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II. EROSION MANAGEMENT PROGRAM MISSION

The mission of Hawaii's erosion management program should reflect

federal, state and county laws governing coastal resource
management. Erosion is not an isolated and independent topic, it

is one of several f actors considered in making coastal resource

management decisions.

Since there are presently no clear and direct goals or objectives

that guide coastal erosion issues, actions on erosion related

matters have lacked resolve and direction. Now, more than ever,

there is a need to clarify and strengthen the state's goals

relative to coastal erosion.

Hawaii is an island-stat,e with an increasing population base that

continues to place urbanization pressures on its shoreline

resources. In areas where there are f ew usable beaches or where

population densities are high, shoreline resources have become

increasingly rare and valuable. Meanwhile, public dissatisfaction

and concern over shoreline encroachment issues has increased.

Erosion issues either directly or indirectly affect important

social issues such as:

� Public access to and along the shoreline.
o Public recreational use of the shoreline.
� The loss of private or public property.

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Coastal erosion has often been viewed as a natural hazard problem.

However, it is in f act both a natural and a man-made problem. For

example, the construction of a seawall or groin can permanently

alter the adjacent coastline.

Existing coastal erosion management activities are based on

regulation of development in the shoreline and nearshore area,

thereby limiting development in areas prone to natural erosion

hazards. Program planning has not kept up-to-date with current

social concerns over shoreline uses, as well as with technological

developments in the ocean sciences. Over the years a greater

understanding of coastal processes has developed, as well as the

effect of man-made structures upon the coastal environment, and

alternate techniques or designs for structures affecting the

coastal environment.

Hawaii's erosion management efforts reflect various pieces of

legislation that address coastal zone management issues. Section

205A-2 (b) [6], Hawaii Revised Statutes, states that one of the

objectives of the coastal zone manageme nt program is to "reduce

hazard to life and property from tsunami, storm waves, stream

flooding, erosion and subsidence." The Special Management Area use

permit procedure established in Section 205A, Hawaii Revised

Statutes implements the state's coastal zone management program

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through the regulatory process. Furthermore, the state's land. use

laws act independently to regulate shoreline management issues.

In addition to these laws, other federal, state and county laws

have been enacted to establish coastal management regulatory

mechanisms. However, despite the relative abundance of

tangentially applicable laws, only a handful of core agencies and

regulations materially affect the management of Hawaii's shoreline

areas.

Since other reports have provided comprehensive overviews of

potentially applicable laws, this report will not attempt to

duplicate those efforts. Instead, our focus will provide the

reader with an overview of the primary regulations that are

currently being used to implement shoreline policies that involve

coastal erosion issues, as well as provide a summary of the types

of problems that exist under the current management system.

A. THE EXISTING MANAGEMENT PROGRAM

The primary actions or approvals that affect regulation of the

shoreline area are listed in Table II-1 and Table 11-2, and are

further described in the narrative that follows.

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TABLE II-1

PRACTICAL STATE REGULATORY CONCERNS

DECISION-
APPROVAL MAKING PROCESSING/ ENABLING
AUTHORITY RECOMMENDATIONS LEGISLATION

Shoreline Chair, Land Survey Sections
certification Board of Administrator, 205A-42 and
Land Department of 205A-49,
& Natural Accounting & Hawaii Rev.
Resources General Stat.
Services

Land Board of Land Management Chapter
Disposition Land Division, 171, Hawaii
& Natural Department of Rev.
Resources Land & Natural Stat.
Resources

conservation Board of Office of Chapter
District Use Land & Conservation & 183-41
Application Natural Environmental Hawaii Rev.
Permit Resources Affairs, Dept. Stat.
of Land &
Natural
Resources

District Land Use Office of State Chapter 205
Boundary Commission Planning Hawaii Rev.
Amendment Stat.

Five Year Land Use Office of State Section
Boundary Commission Planning 205-18
Review Hawaii Rev.
jStat.

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TABLE 11-2

PRACTICAL COUNTY REGULATORY CONCERNS

APPROVAL DECISION PROCESSING ENABLING
MAKING RECOMMENDATION LEGISLATION
AUTHORITY

Special Planning Planning Chapter 205A
Management Commission Department Hawaii Rev.
Area Use (City (Dept. of Land Stat.
Permit council Utilization
for for Honolulu)
Honolulu)
Shoreline Planning Planning Chapter 205A
Setback Dept. Department Hawaii Rev.
Variance (Dept. of (Dept. of Land Stat.
Land Util. Utilization
for for Honolulu)
Honolulu)

SHORELINE CERTIFICATION

The shoreline certification procedure serves to standardize the

certification of the shoreline statewide, and allows this certified

shoreline to be utilized in implementing laws that affect the

shoreline. The need for a shoreline certification may arise under

several circumstances. For example, a certified shoreline may be

required for the following:

o To obtain a boundary interpretation from the Land Use
Commission to determine whether portions of a parcel are
located in the conservation district.
o To determine what portions of a parcel are'
located within the shoreline setback area.
o To prepare a metes and bounds description of a
shoreline parcel for conveyance purposes, or for
purposes of applying for rezoning or a Special
Management Area use permit.
o To obtain building permits to construct on an ocean
front property.

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LAND DISPOSITIONS

Land disposition issues may arise when shoreline str uctures intrude

upon state-owned lands. In particular, the disposition of an

easement may occur where encroachments currently exist, or are

proposed to be placed upon abutting state-owned lands.

Administrative rules governing shoreline certifications were

adopted in 1988 and have been effective as of December 1, 1988.

The certification rules state that a shoreline may not be certified

in cases where the owner's property or improvement encroaches upon

state land (Section 13-222-19, Shoreline Certifications). The

encroachment problem must be resolved with the department before

the certification can occur. Certification may be suspended for

example, in the situation where an existing seawall was built upon

state-owned lands without any type of governmental authorization.

The Division of Land Management is responsible for processing and

making recommendations to the Board of Land and Natural Resources

on land disposition items. This division has therefore taken the

lead in attempting to resolve disputes of this nature that

potentially affect state-owned lands. Faced with the difficult

problem of resolving these types of issues, the division has

drafted and is utilizing objectives, criteria and guidelines for

resolving disputes relative to shoreline encroachments on

state-owned lands.

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CONSERVATION DISTRICT USE PERMIT APPLICATIONS

Unlike the shoreline certification and land disposition processes,

the conservation District Use Application ("CDUAII) permit process

is directly tied to Hawaii Is land use laws. A CDUA must be

obtained to build a structure upon lands that are located within

the conservation district. Chapter 2, Title 13 sets f orth the

administrative rules of the Department of Land and Natural

Resources for governing uses of conservation district lands.

The CDUA often comes into play in the shoreline area since

generally, lands makai of the certified shoreline are placed in the

conservation district. In addition, many coastal parcels were

originally placed in the conservation district at the adoption of

the state land use law or during the last boundary review process F

to place tighter land use regulations on the coastal areas.

DISTRICT BOUNDARY AMENDMENTS

The State Land Use Commission is responsible for reclassifying land

to one of the four state land use districts - conservation,

agriculture, rural or urban. This boundary amendment process

pertains to coastal erosion issues since the land use

classification of the property will ultimately influence the

regulatory requirements that the property will be subject to.

once the property is reclassified to the urban district, the CDUA

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process is no longer applicable, and if no state-owned land is

involved, the state will have no further significant regulatory

jurisdiction over the development of the property.

Section 205-2 of Hawaii Rev. Stat., and Section 15-15-20 of the

Hawaii Land Use Commission Rules, sets forth the standards that the

commission must follow in determining district boundaries. Some

of the standards that pertain to lands in the conservation district

relate to coastal erosion issues. These include - providing beach

reserves, preventing floods and sail erosion, and preserving areas

of value for recreational purposes.

FIVE YEAR BOUNDARY REVIEW

Section 205-18 of Hawaii Rev. Stat. requires the office of State

Planning to undertake periodic reviews of the classification and

districting of all lands in the State. The first review process

must take place within five years of December 31, 1985, and will

take place every fifth year thereafter. As part of its review

effort, the office may initiate state land use boundary amendments

which it deems appropriate.

The last boundary review process took place in 1969. During that

review, land use boundaries throughout the state were reviewed.

Shoreline conservation was one of the issues that was considered in

reviewing the designation of conservation district lands. The

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consultants that analyzed these boundaries adhered to the concept

of the shoreline as a zone rather than a line, and in many portions

of the state a conservation district zone was adopted along the

coastal area (Eckbo, Dean, Austin & Williams, State of Hawaii Land

Use Districts and Regulations Review, 1969). The Office of State

Planning is currently conducting a boundary review process.

SPECIAL MANAGEMENT AREA USE PERMIT

Regulation of the Special Management Area (11SMA11) was delegated to

the counties through Chapter 205A of Hawaii Rev. Stat. Each county

was required to establish rules and regulations to govern the SMA

use permit procedure.

The SMA permit procedure is applied independently of the zoning.

The permit is required if a property is located within a designated

SMA area, and if a proposed action qualifies as a "development",

pursuant to the statutory definition of that term. The SMA is

defined as encompassing the land extending inland from the

shoreline on maps filed with the county, or as amended by the

county.

The SMA permit procedure does not apply in all instances of coastal

development that affect shoreline erosion. The law does exempt

certain activities, such as the construction of single-family

residences from the SMA permit requirement. In the City and County

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of Honolulu, most proposals f or shore protection structures are

exempt from the SMA use permit procedure in Honolulu county, as the

county defines the single-family residence exemption as including

seawalls to be built on parcels containing a single-family

residence.

SHORELINE SETBACK VARIANCE

The Shoreline Setback law established a state-wide setback of

forty feet from the shoreline, with a twenty foot setback from the

shoreline allowed for smaller lots which met specific criteria.

The statute essentially prohibited construction within the setback

area, but established a variance procedure that was delegated to

the counties to administer.

The statute provides for the granting of variances in cases of

hardship or public interest, the construction of shore protection

structures for the protection of property and the replacement of

nonconforming structures.

B. ANALYSIS

The current regulatory scheme addresses the management of shoreline

resources and coastal erosion problems in a piecemeal fashion.

This has given rise to numerous problems, which are identified and

discussed in this section.

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B.1. INCONSISTENT MANAGEMENT STRATEGIES

The establishment of shoreline setbacks, buffer areas or "no-build

zones" are important tools in dealing with coastal erosion, and in

preserving beaches and lateral shoreline access. Although these

are fundamental planning concepts for the coastal areas, there is

a lack of consistency and overall strategy in the utilization of

shoreline setbacks or zones.

For example, the 1969 state land use district boundary review

process sought to establish conservation districts along the

coastal areas to provide for added protection of the state's

shoreline areas. The conservation district boundaries were

established based on four major criteria:

1) Where a road or access way existed at the edge of an
agricultural use within reasonable proximity to the
shoreline, it was used as the boundary between the
Agriculture and conservation districts.
2) Where a vegetation line such as a windbreak or rows
of trees more clearly mark the edge of the
agricultural practice, this line was used.
3) Where the shoreline is bounded by steep cliffs or a
pali, the top of the ridge was used.
4) Where no readily identifiable physical boundary
such as any of the above could be determined, a
line three hundred feet inland of the line of wave
action was used.

Since the last boundary review process was completed, much

shoreline land has been taken out of the conservation district.

However, the concept of urbanizing land but retaining zones of

conservation land along the shoreline area has still been retained

on occasion. These conservation zones have not been applied in a

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consistent manner, and when they have been utilized they have not

established unif orm zones. Areas contained within the conservation
s .
trips have not necessarily followed the criteria outlined above.

Rather, development proposals have been reviewed on an ad hoc, case

by case basis.

The counties, in particular the City and County of Honolulu, has

been grappling with the width of the shoreline setbacks that were

originally established by Chapter 205A, Hawaii Rev. Stat. The

forty f oot setback has been viewed as being 'inadequate in many

instances for effectively controlling coastal erosion problems and

addressing beach preservation issues.

The Department of Land Utilization of the City and County of

Honolulu recently commissioned a study to develop strategies that

would improve the management of the shoreline setback area [12).

This study recommended the establishment of varying setbacks that

were calculated based upon a probabilistic model that utilized

historical beach transect data. This model provided preliminary

setback recommendations that ranged from forty feet to over one*

hundred feet inland from the shoreline.

The department utilized this study to introduce an ordinance to

establish setbacks greater than forty feet on specified beaches, as

recommended by the study. The ordinance was opposed by residents

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of certain af f ected properties, and to date has not been adopted by

the city council.

Both the 1969 boundary review criteria, and the recent DLU study

point to the need for a uniform method of establishing and

maintaining shoreline setback areas. This method must consider

coastal erosion issues as well as other equally important coastal

management problems. Technical criteria should be utilized in

establishing setbacks or providing for buffer zones in the

shoreline area.

B.2. LACK OF UNIFORM POLICY GUIDELINES

Agencies that have the responsibility of regulating the shoreline

area are faced with making difficult management decisions absent

clear policy direction or cmidelines. Permit procedures lack

coordinated policy directions and approval criteria.

For example, nonconforming structures such as existing seawalls

present numerous problems. Yet, there has been no consistent

policy in dealing with such structures.

As discussed earlier in this paper, the shoreline certification

process requires that encroachment disputes involving state-owned

land be resolved with the Department of Land and Natural Resources

prior to certification. Given the lack of policy direction in

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resolving shoreline disputes, the department drafted, and the Board

of Land and Natural Resources subsequently adopted guidelines to

establish some consistency in dealing with shoreline encroachment

issues.

The department's stated objective in dealing with shoreline

encroachment problems is to protect, preserve and enhance public

shoreline access and public beach areas. This objective is

supported by the following criteria: "If the encroachment serves to

protect, preserve and enhance public shoreline access and public

beach areas, it may be allowed to remain with appropriate land

disposition from this Department. If not, then the encroachment

should be removed.11 Recognizing the difficulties that are

encountered in requiring an existing structure to be removed, the

request was also made for the assistance of the Department of the

Attorney General to pursue legislation as has been adopted in other

coastal states, requiring the abutting property owner to remove

undesirable encroachments.

The department also adopted specific guidelines to govern the

disposition of state land in shoreline encroachment situations.

These guidelines allow dispositions to occur:

1) To allow repair work to be done on state-owned land for
existing seawalls built within private properties.
2) Where the seawall straddles the private property line and
the state land.
3) Where the encroachment does not prohibit public shoreline
access and does not take public beach area.

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Encroachment disputes may be resolved through the application of

these guidelines. However, if a structure fulfills these criteria

and is permitted to remain on state land, in all probability a CDUA

permit will still be required. Regardless of the fact that the

encroachment issue has been resolved with one division of the

Department of Land and Natural Resources, a second layer of

approval process still exists in the same department within a

separate division.

After-the-fact CDUA's are processed in accordance with CDUA

guidelines that are set forth in Chapter 2, Title 13. In general,

these rules are vague with respect to shoreline issues, and have no

relationship to the guidelines that are used to evaluate

encroachment issues.

In addition, the counties do not use the same guidelines as the

state. Under Honolulu's Shoreline Setback law for example,

nonconforming structures in the shoreline area do not need a

variance under many circumstances (25].

A lack of consistent criteria to review proposals for new shoreline

structures is also evident on all levels of the permit process.

From the tech nical standpoint, the design of a seawall is extremely

important and can affect the ultimate impact that the structure

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will have on the beach in front of and adjacent to the property.

However, there are no clear construction or design guidelines to

review proposals.

To obtain building permits f or a house, building plans must be

certified by an engineer and reviewed by the building department.

The department would utilize standard professional review criteria

f or evaluating the adequacy of the structure prior to issuing

permits. There is no similar method for evaluating shoreline

structures and in particular, seawalls.

The City and County of Honolulu had implemented a certification

procedure to attempt to address this problem. Rule 14 of the

county's Shoreline Setback Rules and Regulations required that all

applications for a setback variance be accompanied by a

certification report from a coastal engineer. The report was

required to indicate that: 11 ... (1) the structure is needed for

safety reasons or to protect the property from erosion or wave

damages, (2) the proposed construction is the best alternative of

several investigated, and (3) the proposed construction will not

cause any adverse effect on or significant change to, the

shoreline...

The DLU faced several problems in implementing this certification

requirement. In particular, liability concerns of coastal

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engineers were so great (liability was high with respect to fees)

that it became virtually impossible to find competent engineers to

certify a design, with respect to compliance with criteria.

Additionally, coastal engineering is a relatively new discipline.

There is no license program.

B.3. COMPLEXITY OF REGULATORY PROCESS

The current regulatory process governing the simple construction of

a seawall is such a quagmire, that many small landowners resort to

the construction of illegal seawalls. For example, a landowner

that is simply trying to build a seawall may be subjected to

obtaining a: shoreline certification, a Shoreline Setback Variance,

a SMA use permit (not applicable in Honolulu), and if the seawall

is in the conservation district, a CDUA.

Many of these permit procedures are unduly complicated, time

consuming and costly, particularly for the small landowner that is

unfamiliar with the regulatory process. The overlapping regulatory

functions between the state and the county, and even between state

agencies in the same department, can present. an overwhelming

situation to the general public.

The shoreline certification rules have added to this jurisdictional

confusion since the certification rules allow the department to

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suspend certification in cases where there are potential

encroachment issues. This suspension affects the entire permit

process since the county is then unable to establish the setback

line to determine whether a variance is required. The Office of

conservation and Environmental Affairs is unable to determine

whether a CDUA is required. The entire permit process is stalled

until the issue can be resolved with the Division of Land

Management.

Problems with the shoreline certification procedure may also affect

actions that are not being proposed in the immediate shoreline

area. For example, suspension of certification may be triggered

when there is a questionable existing seawall and improvements are

being proposed on portions of the parcel that are mauka of the

shoreline. These non-shoreline improvements may be affected since

the suspension may affect zoning, SMA permit, subdivision or

building permit approvals.

The recent ordinance that was proposed to increase the shoreline

setbacks on Oahu also contained a provision that sought to

circumvent this problem. The ordinance would have allowed the

Director of the DLU to waive the certified shoreline survey for a

development located more than fifteen feet landward of the setback.

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In 1989 Section 205A-45, Hawaii Rev. Stat. was amended to allow the

counties to expand the setback area to include the area between

mean sea level and the shoreline. This area of the beach which

extends seaward of the shoreline falls under the jurisdiction of

the Department of Land and Natural Resources. Although to date,

none of the counties have expanded their setback areas to include

this portion of the beach, this statutory amendment raises the

potential for further overlapping jurisdictions within the

regulatory process.

B.4. LACK OF COMPREHENSIVE PLANNING

A lack of comprehensive data on coastal areas has stifled the

development of a comprehensive plan for coastal erosion and coastal

resource management, and has added confusion to the regulatory

process.

It would have been impossible to establish meaningful development

policies and criteria for Hawaii's land use laws without obtaining

an accurate inventory of the land uses in the state. Establishing

a regulatory system to control development on the land, absent an

adequate inventory of land use information would have been foolish.

Yet, this is almost the situation that exists with regard to

coastal erosion and in the larger picture, with regard to coastal

resources management. There is no comprehensive inventory of the

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information regarding the type of issues that af f ect coastal uses -

public use and public access, coastal views, and historical

shoreline movement.

The lack of a comprehensive inventory of shoreline measurements

hinder planning and regulatory efforts. The shoreline location is

analogous to the Land Use Commission's boundary maps. Without the

boundary maps, the state cannot determine jurisdiction between the

county and the state. For example, if the property is in the

conservation district it falls under state jurisdiction; if the

boundary places it within the urban district it falls under county

jurisdiction.

There are many instances of illegal structures in the shoreline

area. Enforcement powers have been inadequate to address these

illegalities and are hampered by the lack of comprehens ive and

coordinated plans with regard to shoreline uses.

Landowners may challenge enforcement efforts through legal

mechanisms. These claims are all the more difficult to prosecute,

absent an overall justification for the action. Without a

comprehensive plan and supportive justification, enforcement

efforts will be disjoint.

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B.5. RECOMMENDATIONS

Based on the analysis of the existing management program, the

following actions are recommended:

1) Prioritize and coordinate federal, state and county
erosion management funding to develop a comprehensive data
base on coastal areas statewide. Necessary components of
the database are discussed in Section III of this
report.
2) Develop a comprehensive coastal erosion plan for the
state. Since coastal erosion issues affect other
pertinent shoreline issues, the coastal erosion plan would
be one component of a shoreline plan. This plan should
consider the items that are discussed in this report.
3) consolidate jurisdiction over the shoreline area to place
the bulk of the regulatory powers in one state agency.
The most logical way to develop this authority may be to
establish a separate division or "Office of Beaches"
within an existing agency that already handles these
matters, such as the Department of Land and Natural
Resources. The Office of Beaches would be responsible
for:
a) Update the coastal database discussed in item 1 on
a periodic basis.
b) Regulate proposed shoreline uses in accordance with
the comprehensive coastal erosion plan.
c) Conduct enforcement matters relative to illegal
uses or structures.
d) Implement beach replenishment actions or shore
protection measures, where necessary.

These recommendations cannot be implemented unless the state

decides to make the preservation of its beaches a priority. The

recommended course of action will require a commitment of money and

manpower. It will require hiring persons who are technically

competent with regard to coastal erosion and other shoreline

problems.

The most difficult recommendation to implement will be the creation

of a new authority. This action will obviously be controversial as

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it will require restructuring the current distribution of

Jurisdiction that is spread between the various county and state

agencies. Yet, without this consolidation, it will be extremely

difficult to effectively address the various beach conservation

problems that exist.

C. MISSION BACKGROUND

Erosion management policy decisions are the responsibility of the

Coastal Zone Management (CZM) program, which is administered by the

Hawaii office of State Planning (OSP). At present, the State of

Hawaii does not have a coherent erosion management program.

Erosion effects all of the Hawaiian Islands and becomes a serious

problem when it occurs around populated areas, such as. parts of

Maui, Kauai, Hawaii and Oahu. Sandy beaches are a resource that

supports various sectors or the State; this resource is becoming

scarce. Clearly, Hawaii would benefit from a comprehensive erosion

management program.

Many other states have CZM programs that address erosion similarly

to Hawaii (approximately 29 states have CZM programs [23]). Some

states have gone further and have developed specific legislation or

other mechanisms to deal with coastal erosion. For example,

Virginia has the Shore Erosion Control Act and subsequently set up

the Shoreline Erosion Advisory service (SEAS) to assist property

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owners in preventing erosion (21].

Nineteen states use direct regulatory authority to mitigate damage

from coastal hazards. Most states have established a threshold

erosion standard of 1 foot per year to define a high hazard area

[24]. Each state that administers an erosion management program is

unique, and reflects a trade-off between social and economic

values.

MICHIGAN

Michigan implements its management strategy for high-risk erosion

through the following [24]:

� Identification of high-risk erosion areas. Only those
receding at a long-term average of 1 foot or more per year
are considered high risk.
� Designation of high-risk erosion areas. This includes much
community participation. After reviewing community input
and other relevant information a high-risk designation is
made.
� Implementation. Michigan emphasizes a non-structural
approach by requiring setbacks.
- alert owner or buyer of shoreline property to the
potential of erosion hazard
- setback is designed to protect permanent structures for
a period of 30 years
- Building requirements. High risk designation requires
that the structure be setback a distance that would
protect it from erosion damage for 30 years.
- special exceptions are made if a parcel was established
prior to high-risk erosion designation and lacks
adequate depth to provide the minimum required setback.
The parcel is then referred to as a "substandard lot."
A special exception may be allowed on a substandard lot
if the structure can be moved before it is damaged by
rosion. other special exceptions are also available.

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NORTH CAROLINA
Over the last 50 years over half of North Carolina's coast has
experienced average erosion of 2 feet per year or greater, with 20
percent exceeding 6 feet per year. The erosion management program
has the following capabilities [24]:

o Planning
o Regulatory
o Land acquisition
o Policy development

This resulted in the development of a coordinated shore-front
development program that has the following responsibilities:

o Regulates new development
o Restricts shore erosion-control practices
o Plans for redevelopment and relocation of damaged and
threatened structures
o Purchases land for beach access
o Develops public education programs

The main three goals of the program include:

1) Minimize loss of life and property resulting from storms
and long-term erosion.
2) Prevent encroachment of permanent structures on public
beaches.
3) Reduce the public costs of inappropriately sited
development.

North Carolina adopted a statewide minimum ocean setback for all
new development in 1979. As a result, the minimum setback now
requires all new development to be located behind the farthest
landward of these four points:

1) Erosion rate setback, 30 times the annual erosion rate,
measured from the vegetation line, for small structures
and 60 times the erosion rate for structures with more
than four units or more than 5, 000 square feet total f lodr
area.
2) The landward tow of the frontal dune.
3) The crest of the primary dune.
4) A minimum of 60 feet, 120 feet for larger structures,
measured from the vegetation line.

Limited use that does not require permanent structures is allowed.

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FLORIDA
In 1968 Florida initiated a comprehensive program for beach
management in the Division of Beaches and Shores, Department of
Natural Resources. Duties of this division include [241:

� Field measurements
� Research and analysis
o Permitting and regulation
� Beach nourishment

To monitor beaches, the State of Florida installed a system of
3,400 concrete monuments at nominal spacings of 1,000 feet along
648 miles of sandy beach. Shoreline change is determined from
repeated profile surveys from these monuments. Additionally, a
separate program was initiated to establish a comprehensive data
base of shoreline positions using historic information.

A main component of the Florida regulatory program is the Coastal
Construction Control Line (CCCL) that establishes the state's
3urisdiction in coastal construction permits. The line identifies
the limits of severe fluctuations caused by a 100-year storm event.
This 100-year storm event is based on extensive data collection,
including field surveys, aerial photographs, numerical modeling of
storm surge and beach erosion. A Department of natural Resources
permit is required for any excavation or alteration seaward of this
line. State law includes a 30-year erosion provision requiring
single family dwellings to be set back 30 times the annual erosion
rate.

In 1986 the Florida Department of Natural Resources proposed to the
legislature a 10-year $472 million beach nourishment program for
Florida's critically eroded beaches, which included $362 million
for restoration and $110 million for renourishment. This amounts
to an average of $2.6 million per mile (ranging from $1.9 million
to $3.9 million per mile) to restore or renourish 140 miles of
beach plus $24 million annually for maintenance on an indefinite
basis.

CALIFORNI
California's coastal erosion as well as its management are complex.
The major programs include: the California Coastal Commission;
California State Coastal Conservency; Department of Boating and
Waterways of the Resource Agency; State Land Commission; Bureau of
Land Management; Department of Parks and Recreation; State Water
Resources Control Board, etc.[24].

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The latest revision of the California Coastal Commission requires
coastal localities to prepare their own plans for development
'thin their jurisdiction via a Local Coastal Program. Priorities
for coastal usage include the following:
wi

o Public access
o Public recreation
o Marine environments
o Land resources, including sensitive habitats and
agricultural lands
o Development, with attention to concentration of new
development, scenic resources, and development in hazard
areas
o Industrial development

The California Coastal Commission is the long-term planner for the
California coast. This requires in-depth research in the
following:

o Consequences of the greenhouse effect and rising sealevels
for the coast.
o Long-term prospects for and implications of offshore energy
resource development.
6 Toxic and hazardous materials handling and spill cleanup
in the coastal region.
o Long-term land use possibilities and dangers for flood and
geographic hazard areas.
o Power plant development and siting.
o Shore erosion, especially in developed areas.
o scientific studies of existing coastal resources and the
impact of planned development.

Because of adverse impacts associated with large coastal protective
devices, the commission has favored the use of beach nourishment to
reduce shoreline recession rates. In the case where structures are
allowed, strict conditions and mitigative actions are part of the
permit.

Each state's ability to address erosion is a direct reflection of
economic pressure, social values and political will. For example,
California suffers from many complex problems such as toxic and
hazardous materials, etc. However, Florida created a division
within its Department of Natural Resources, called the Division of
Beach and Shores, that is specifically responsible for erosion
matters.

SRI LANKA
In 1986 the country of Sri Lanka developed a Master Plan for Coast
Erosion Management that identified erosion as the most critical

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problem in their Coastal Zone Management program. objectives of
the plan include in the following [16]:

� Manage the siting of development activities in the coastal zone
- Define setbacks
- Designate no-build zones
� Halt coral mining in the coastal zone
Identify means of rebuilding reefs in critical erosion areas
� minimize impact of sand mining (on erosion)
- Conduct research to identify alternative sources of sand
- Conduct research to define sustainable yield limits
� Ensure that erosion control techniques are cost effective and
socially and environmentally acceptable
Ensure that coastal works are built according to the Master
Plan for Coast Erosion Management
Construction in areas not designated as priorities shall be
permitted only if performance standards are met
- Emergency erosion control measures shall be constructed
according to Coast Conservation Department guidelines
- Research will be conducted on coastal processes related to
erosion

OMAN
In 1986 the Council for the Conservation of Environment and Water
Resources was established in the country of Oman. A Coastal Zone
Management Plan was developed, including:

o Establishment of general planning policies
o Establishment of protected areas
o Identification of specific issues, actions, and responsibility
for implementing actions

Erosion management was included with other CZM concerns.

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TABLE 11-3
SUMMARY OF STATE AND TERRITORY EROSION MANAGEMENT PROGRAMS

STATE RECESS- RECESS- RECESS- EROS ION REF. YRS. LOCAL ONE FIXED FLOAT
TERRITORY ION ION ION SETBACK FEATU OF ADMIN FOOT SET -ING
RATES RATES RATES EST.- RE SET PER BACK SET
FROM FRO14 FROM BACK YR. BACK
AERIAL CHARTS GROUND STD.
PHO TOS SURVEY

Alabama Y Y N Y MHW NA N Y N

-Alaska Y Y N NA NA NA NA NA NA

American N N N N NA NA NA NA NA NA
Samoa

California Y Y Y N NA NA Y NA NA NA

Connecticut Y Y N NA NA NA NA NA NA

-Delaware Y Y Y4 TD NA Y N Y N
Florida Y Y Y5 NA 30 Y N Y N

Georgia Y Y N NA NA NA NA NA NA

-Hawaii N N N Y 6 N Y N Y N
Indiana- Y N y N NA NA WA Y NA NA
Illinois Y Y Y_ N NA NA NA NA NA

-Louisiana Y Y N N NA MA NA NA NA NA

Maine N N Y N7 NA NA NA NA NA NA

Maryland Y Y _N NA NA NA NA NA N@_
Massachusetts Y Y N N NA NA NA NA NA NA

Michigan Y N N Y BC2 30 Y__ Y N Y

Minnesota Y N N N NA NA NA Y HA NA

Mississippi N N N N NA NA NA WA NA NA_

New Hampshire 1 N N N N NA NA NA NA NA NA

-New Jersey Y Y Y Y MHW 50

New York Y Y N Y BC 30-40 Y Y Y N

North Y N Y DC 30-60 Y N N Y
Carolina

North N N N N NA NA NA NA NA NA
Mariana's

Ohio Y Y N Ni BC 30 NA Y I Y N

Oregon N NA NA HA NA NL_
Pennsylvania Y N Y BC 50+ Y Y N Y

Puerto RICO N N I N N NA NAI _NA NA
Rhode island N N I Y Y OC 30 N N7 Y N_
Sou th Y Y 40 Bt. Y N
_CaroLina

Texas Y Y Y N NA NA NA NA NA NA

Virgin N N N N NA NA NA NA NA NA
Istands

Virginia Y Y _N MHW_[ NA Y
Washington N NA WA NA TNA NA NA
Wisconsin Y Y N N3 NA I IIA NAI I N Y
Note: 1=setbacks may be established within 2 years; 2=1oluff crest or edge of active erosion; 3=some counties
have setbacks; 4=has 100 foot setback regulation over new subdivisions and parcels where sufficient room exists
Landward of setback; 5=not oil conties have coastal construction control tines established; 6=starm debris line
or vegetation Line; 7=2 feet per year standard. y,yes; n, no; NA, not applicable; BC, bluff crest: MHW, mean
high water; TD, toe of dune; DC, dune crest, toe of frontal dune or vegetation Line; 51, base tine. A blank
Teens no information was available.
most states have setbacks from water tine but not based on an erosion hazard.
"Managing Coastal Erosio (221

Oceanit Laboratories, Inc.
J@A

D. MISSION STATEMENT

The mission of the successful erosion management plan should

support an overall shoreline management plan and consider issues

that pertain to coastal areas, including the following:

0 estimate current and future needs of the
community
o protect valuable open space from unnecessary
encroachment and destruction
o establish principles and standards designed to
achieve an optimum scenario
o identify public and private actions necessary to
achieve goals
o protect public and private investments from
erosion or destruction

Hawaii is unique because its land use laws heavily interact with

coastal zone management regulations to such a degree, that they

appear to be inseparable. As such, a unique approach will have to

be formulated for the state, tailor-made to effectively fit into

the existing regulatory scheme.

The mission of an erosion management program (EMP) should be broad

to address the very complex issues associated with erosion;

however, it should be specific so that direction and guidance is

provided. Mission guidelines, objectives and goals must provide

support so that the mission is met. Objectives and goals should

have distinguishable and measurable products, whereby progress,

success and/or failure is measured. Goals and objectives can later

be included in a coastal resource plan that will coordinate and

regulate coastal zone utilization. The development, interpretation

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and execution of the EMP must take into account social as well as

economic considerations, both with respect to execution and

administration. The EMP will also provide reasonable guidance for

future decisions with respect to resources and manpower.

The following mission statements were considered for the EMP:

1) "Protect, preserve and where possible enhance coastal
resources from erosion effects, for the benefit of the
general public."
2) "Conserve beaches and minimize erosion."

Although we clearly believe that the outcome should benef it the

public, we chose mission statement 2 because it focuses on erosion,

yet it allows for a broad interpretation.

E. MISSION GUIDELINES

Mission guidelines that further describe the mission statement for

an EMP include the following:

o Areas with a high storm hazard risk must have adequate
planning to accommodate erosion.
o Retain as much coastal beach as possible.
o Retain shoreline in its natural state.
o Permit erosion control methods that will have the least
environmental impact (e.g., nourishment, seawall, etc.)
o Adopt a thirty (30) year planning horizon for erosion
cycles.
o Disagreements and other disputes should be resolved via
mitigation and dispute resolution methods.
o Special variances and conditions should be granted where
five (5) or more adjacent landowners share common problems
and solutions.
o Decisions should be made with the following order of
consideration; beach conservation, public access, public
recreation and marine environment.
o Information collection and management should be an ongoing
process.

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F. MISSION OBJECTIVES/GOALS

Mission objectives identify the activity, group or condition that

must be addressed. A variety of activities that cause erosion need

to be controlled, addressed and in many cases stopped, including

the following:

o Improper seawalls
o Improper groins
o Hurricanes and tsunamis
o High surf
o Sand mining
o Excess recreational use
o Fresh water and/or pollution on reef
o Excessive armoring coastlines
o Environmentally unsustainable development

Various options are available to control erosion, including the

restriction or controlled use of many of the previous activities,

as well as the proper use of structures, nourishment, etc..

Additionally, it may not be reasonable to stop erosion (it may not

make economic sense). This should be part of the planned response

to erosion in certain situations..

Specific objectives of the EMP can be summarized as the following:

o Prevent activities that cause erosion
o Control existing erosion

Five-year goals recommended for the EMP include the following:

o Information collection (e.g., erosion, boundaries, etc.).
o Public education program.
o Improve efficiency of regulatory process (e.g., office of
State Beaches).
o Develop EMP policies (e.g., setback scheme, monitoring
method, compensation).

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Long-term goals recommended for the EMP include the following:

o Information collection.
o Research (e.g., sand sources).
o Enforcement system.
o Information management.

G. EROSION MANAGEMENT PLAN EXECUTION

Execution of the erosion management plan must consider the

coordinated interaction between information, planning and

administrative needs.

Information and technology is key for the successful execution of

the EMP. Information collection has two phases: (1) a short term

data collection and (2) long-term data maintenance phase. There

are always tradeoffs between the amount of information dnd cost.

These tradeof fs can be guided from the rhetorical question: "How

much information is needed to make a good decision?" A good

decision is one that adequately addresses the immediate problem and

is always a relative judgement-call.- It does not cover all

possible cases. Technology has the same kind of trade-offs between

cost and effectiveness. An off-the-shelf design is always less

expensive; however, it might not provide the level of service that

a custom design would provide.

Planning considerations must address issues such as land-use,

infrastructure, setbacks, improvement districts, densities and the

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corresponding rules and regulations that would govern these

activities.

Administrative concerns are important for the successful execution

of the plan. Fiscal planning needs to be part of the very first

steps taken to construct an EMP. Initially costs will be high

because of major data collection efforts. Later, only maintenance

and operation costs will exist. Administrative concerns will be a

direct reflection of fiscal limitations and controls the number of

individuals employed to maintain data systems, support the

processing of related permit applications, and addresses the

various legal and institutional issues related with the execution

of the program.

H. EROSION MANAGEMENT PLAN SCHEDULE

The goals of the EMP include the timely execution of tasks that

will support the mission guidelines and objectives. Goals that

should be considered in the development of the EMP are given in

Figure II-1.

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III. EROSION MANAGEMENT PROGRAM PLANNING

A. EROSION MONITORING METHODS

Beaches are the natural boundary between land and sea, and are also

the natural defense land has to resist erosive forces from waves

and currents. Beaches are either calcarious or sedimentary.

Calcarious beaches are typically found in tropical and subtropical

climates. Sedimentary beaches are found in more temperate

climates.

Geologically, beaches are one point in the cycle of formation and

destruction of sedimentary rocks and land masses. Sediments eroded

from mountain areas far inland are brought to the coast by rivers.

once at the beach, sediments are ground finer and finer by waves

while being carried along the shore by littoral currents. When the

sediments are too fine to settle in the nearshore area, they drift

offshore and settle in the deep sea. Sediments deposited in this

manner build up over long periods of time into thick layers and

metamorphose into sedimentary rocks. Tectonic movements in the

earth's crust push these sediments above the water surface to form

mountain ranges and start the cycle again. Therefore, beaches are

one point in the sedimentary cycle that marks geological time.

Calcarious beaches are supplied from biological activities that

occur in the nearshore area. Among the various processes!

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photosynthesis reduces the acidity of seawater whereby coral polyps

absorb dissolved calcium chloride and convert it to calcium

carbonate. Millions of coral polyps living in groups form large

coral reefs. The fragile portions of these reefs are broken up by

wave action and are brought to the beach as a source of sediment.

Gradually the particles are ground to f ine sizes and drift to

deeper waters. When these settle in deeper waters the slightly

higher acidity dissolves the particles of calcarious origin. The

dissolved material eventually reaches the shallow waters due to

circulation and are converted back to calcium carbonate by the

corals. Other sources of calcarious material include grazing reef

fish that snap and nibble coral and coralline algae.

Beach sediments are sometimes carried into coastal lagoons by f lood

tides and temporarily trapped as shoals or- sand bars. Other

sediments are blown landward and trapped as coastal sand dunes.

During heavy storms when beaches experiences large waves, part of

the sand trapped in the dunes is utilized to save land behind the

dunes from erosion. Due to the interaction of sediment supply,

meteorological and oceanographic forces, beaches undergo

continuous change all the time.

Some of these changes occur over short intervals of time (up to a

year) and are termed seasonal or cyclic. However, longer term

imbalances between supply of sediment and loss of sediment result

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in continuous erosion or accretion. This can take place over

several decades or even longer until a new balance is created by

natural or artificial means. In the case of small islands far from

continents, the sources of beach material are limited to the

sediments brought by runoff from mountain areas and calcarious

sediments from coral reefs and other marine sources. In these

cases, imbalances can result in serious erosion or sedimentation

problems. Erosion in these cases can continue until hard strata is

exposed.

Urbanization and settlement of coastal lands has added a new

dimension to the instability problem. Initially, beaches were

believed to be extremely stable and would take any amount of abuse.

However, the construction of harbor breakwaters and other

navigational structures caused modifications to the existing

coastal processes that resulted in coastal erosion and

sedimentation in undesirable areas. Engineering solutions that

followed resulted in hardening parts of the coast with seawalls, or

the disruption of longshore sand transport from groins that caused

erosion in downdrift areas. It took time to realize that many of

the activities in the coastal zone upset the existing and delicate

beach equilibrium.

A.1 BACKGROUND

The concept of coastal zone management was developed as a means to

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resolve the complex problems arising from conflicting uses of

limited coastal resources and to conserve coastal resources for the

future. As a first step in coastal management, construction

setbacks were established to control development activities in the

coastal zone.

MONITORING COASTLINES

Determination of setback distances and planning for coastal

developments depends on the potential -hazards faced by the coastal

land of interest. Hazards include erosion and flooding due to

tsunamis and storm waves. In the absence of hard data, the

long-term erosion hazard can only be estimated by evaluating

coastal vegetation or by speaking to residents who have lived close

to the beach f or a long period. Comparing historical aerial

photographs with recent photographs provides qualitative

conclusions based on coastal behavior.

Shoreline changes that were of interest only to coastal

geomorphologists now attract the interest of coastal zone planners

and coastal engineers. Shoreline change information is also needed

for estimating sediment movement, predicting effects of shoreline

structures, and establishing setbacks f or control of development

activities. The types of information availablef advantages and

disadvantages of methods used, based on cost, accuracy, technical

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requirements and institutional resources available, will be

discussed in the following sections.

HISTORICAL SHORELINE MAPS

National Ocean Survey (NOS) topographic sheets are among the oldest

coastline maps available. These are also the most accurate maps

available for comparison purposes. They were prepared usually by

field surveys, later versions were compiled from aerial photographs

using stereo-plotters for rectification and plotting. NOS sheets

can be changed and updated using aerial photographs, which are

periodically available. NOS 'IT" sheets are available with a scale

of 1:10,000; stable points located on the maps are accurate to

1/75 inch of actual position. Therefore, the smallest field

distance measurable in a map is about 7 feet to 16 feet for stable

points [3]. Accuracy may be less for less unstable points such as

the shoreline.

Maps prepared by the United States Geological Surveys (USGS) cover

a 7.5 minute square and are plotted to a scale of 1:24,000. These

maps show more land details but were prepared to comply just within

the guidelines of national map accuracy standards. USGS maps are

accurate to 1/50 of an inch, which amounts to errors of up to 40

feet when determining the position of a stable location on land.

Any measurement from these sheets can be in error up to 40 feet.

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Local surveys made for land use and development activities close to

the coast may be available in developed coastal areas. These maps

usually are made to large scales and provide for higher accuracy

measurements. However, they may contain only short stretches of

the coastline. New field measurements are necessary to calculate

land loss from these maps. The resulting land loss calculated

this way will be very accurate and can probably be used to check

accuracy of other methods. In cases where shoreline levels are

available, volumetric sand losses can be calculated using

consecutive beach profiles.

AERIAL PHOTOGRAPHS

Aerial photography is an attractive alternative to time consuming

field surveys for monitoring coastline change. Many states already

use this method for shoreline monitoring. Aerial photographs pick-

up all available ground details, whereas field surveys present only

selected details. Therefore, comparing photographs offer great

flexibility. Common details will be available even if photographs

were made by different companies for different purposes.

Preparation cost is fixed; large areas can be photographed at a

relatively low unit cost. When aerial surveys are performed with

properly'surveyed ground marks, accurate maps can be constructed.

Most of topographic sheets are prepared with stereo-plotters and

stereoscopic photo pairs that are corrected for errors. However,

this involves expensive instruments and expert services.

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Aerial photographs used for shoreline monitoring can also give

inaccurate results. The waterline position depends on many

parameters. Water levels are affected by tides, winds, and waves.

Mean waterlines move horizontally on a sloping beach due to water

level variations. Additionally, seasonal beach variations also

causes the waterline to move. The waterline responds to cyclic

accretion or erosion by moving offshore or landward. A

coordination of these parameters with aerial photographs make the

process very expensive. Errors result when photographs taken

during different phases of the cycle changes are compared and

long-term erosion results are extrapolated. Furthermore, abnormal

conditions, i.e., storms, can cause large temporary changes in the

shoreline. Aerial photographs taken immediately after such an

event should not be used for monitoring long-term trends. In areas

where long-term erosion trends are small in comparison to seasonal

or cyclic changes, waterlines are not a good parameter for

comparison.

Coastal changes measured from aerial photographs reflect only the

change in land area. However, rates of erosion, as well as impacts

from protective structures, depend on the volume sand transport

due to littoral processes. This lack of three dimensional

information can cause substantial errors in predicting shoreline

changes, particularly if the land behind the shoreline shows

appreciable relief.

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Distortions cause differences between aerial photographs, which

arise from the methods used and limitations of the instruments.

The scale of an aerial photograph depends on the height of the

camera. Atmospheric disturbances make it impossible for a

airplane to always fly at the same height relative to the ground or

to fly on a perfect straight line. Photographs taken successively

during the same flight may have different scales due to variations

in the flight altitude. Edges of the photographs may show

discontinuities from the vertical and horizontal movements of the

airplane. The scale of each photograph may need correcting for

removal of distortion.

when camera axis is not exactly vertical, the center point of the

photograph does not coincide with the point vertically below the

camera. This causes a distortion in the photograph, referred to as

a tilt error. In general camera tilt is approximately one degree

but under difficult conditions it can be as large as three degrees.

In comparison studies, this error can be corrected by measuring

distances between selected control points on maps and photographs.

Lens distortions introduce errors that increase as the radial

distance from the photocenter increases. However, modern mapping

cameras have high quality lenses that minimize lens distortion.

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Ground relief is another factor that introduces errors into

measurements made from aerial photographs. High relief introduces

a scale variation in the photograph from point-to-point as well as

a distortion in the main direction of the land slope. As a result,

special care must be taken when points on photographs are selected
for comparison with corresponding points on a map. The objects

selected should be at the same level for accurate results.

However, in most coastal areas ground relief is very low and the

error due to this is small.

FEATURE TO BE MONITORED

For purposes of monitoring long-term trends in shoreline behavior,

it is essential to select a feature that can easily be identified

on aerial photographs or maps. The type of feature should also

depend on the local topography and cyclic or seasonal behavior of

the beach. Several different features have been used in earlier

monitoring projects. These are the vegetation line [12], the high

waterline (11] and the beach toe.

The vegetation line is the most seaward boundary referenced for

regular land-use. Beyond this point the berm and the beach extend

to the waterline. In most cases the berm is a temporary feature

that can accommodate temporary vegetation, which may be less than

a season old. In selecting a vegetation line the plants should be

older than one year. The vegetation line shows up fairly well in

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aerial photographs, but is not generally marked as a detail in

ordinary land maps. In general, one of the disadvantages is that,

vegetation takes time to stabilize on accreting areas. Since

identifying the line on photographs is subjective, field checks may

be necessary in ambiguous cases.

In some projects the high waterline has been used as the monitoring

feature [11]. On a sandy beach the high waterline appears as the

boundary between two different shades of gray. The line is easily

discernible in aerial photographs. Many researchers argue that

this is a good feature to monitor over long time periods. However,

the high waterline varies with the tides, waves, and winds. The

high tide line itself shows a considerable variation betvieen spring

and neap tides. Waves produce a water level elevation at the beach

called wave set-up. This can be as high as ten percent of the wave

height and hence can be considerable in areas subjected to high

swells such as the north shore of Oahu. On-shore winds also

pile-up water at the coast from wind stress at the water surface.

This contribution is generally small compared to other phenomena.

on a sloping beach the waterline moves a considerable distance

horizontally when water levels change. For example, on a beach

with a slope of one in ten (1:10) the high waterline will move ten

f eet due to a rise in water level of one f oot. Because of this

beach slope amplification and the difficulty establishing actual

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water levels above datum at the survey time (aerial or otherwise)

this method is not suitable when the rate of shoreline change are

low or moderate. The method cannot be used at all in areas devoid

of sandy beaches, as is usually the case on some eroding

coastlines. Because of these reasons, the high waterline is not a

suitable monitoring features for Hawaii shorelines.

Beach toe has also been suggested as a monitoring feature. It is

the point where the reef flat intersects the beach slope.

In general, this line is in the surf zone; during high surf

conditions it is difficult to identify because of suspended sand

and breaking waves. The position of the beach toe depends on the

amount of sand available at the beach; therefore, it can be used to

show large cyclic or seasonal variations. However, this can induce

relatively large errors in predictions of long-term trends of

shoreline behavior.

A.2. MONITORING METHODS

Even though several methods are available for beach monitoring, not

all methods are suitable. Selection must be made after considering

all relevant factors. Some of the important factors to be

considered are:

o Availability of previous data.
o Resources available for field and office for
implementation.
o Accuracy needed.
o Type of results expected.

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o Nature of the coastal area.
o Land use.

Any method will require repetitive surveys at regular intervals,
depending on the rate of erosion. Surveys, whether aerial or

field, should be planned for the same time of year to minimize

errors due to seasonal changes. Determining the most suitable

boundary to monitor, e.g., high waterline, vegetation line, etc.,

is also an important factor in long-term monitoring.

BEACH PROFILE MEASUREMENTS

Beach profiles are transects perpendicular to the shoreline that

show ground level details. Usually they are evenly spaced, level

measurements conducted regularly along the beach profiles. An

initial survey to find the position and direction of the lines, and

to establish level datum must be carried out. Repetitive surveys

can then be performed with relative ease.

Data obtained is very accurate and data analysis gives the increase

or decrease of area between the profile and the selected datum.

Volumes of beach material lost can be calculated using numerical

integration between successive beach profiles, assuming a linear

change in the shore profile between sections. However, this is not

strictly correct because some of the actual profiles will deviate

from those calculated. This introduces an error in the volume

calculations.

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Movement of the selected boundary will be known accurately only at

the prof ile locations. Linear interpolations will be used to

calculate changes in between profile locations; this too can

introduce error. However, profiles are generally selected with due

consideration of coastal behavior, errors can be kept small.

Another disadvantage is the necessity of skilled surveyors to

perform field work resulting in increased cost. However, simple

computer programs can be written to calculate losses once data is

available.

POINT MEASUREMENTS

Point measurements are made from known points to a selected shore

boundary at regular intervals of time. The points should be

selected so that linear approximations are realistic between

points.

Two methods are used in point measurements. The first method is

similar to the profile method; however, only a horizontal distance

is measured from a known point to the boundary. These f ixed points

have to be documented for repeated use. In areas where public

utilities such as highways run close to the beach, monuments can be

established easily on or by the side of the road. No land levels

are measured; therefore, the monitoring technique is simple and

does not need highly skilled personnel. The data obtained is one

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dimensional and the method suffers from all other disadvantages of

the surveys.

The second method, referred to as transect analysis, makes use of

historical aerial photographs where available. In this method

rectified photographs are obtained and scales of the photographs

are determined by identifying stable points such as road

intersections or building corners on the ground and in the

photograph and then correlating distances. Ground relief errors

are minimized by selecting stable points at the level of coastal

land. Suitable transects are decided by using conspicuous marks

close to the beach that are identifiable on the photographs. Next,

the boundary line to be monitored is identified in the photograph

with as much accuracy as possible. Distance is measured from the

fixed points to this boundary. Land loss information is extracted

by comparing this distance in successive sets of photographs.

Calculation can be performed using mechanical or electronic

digitizing methods.

This method has all the shortcomings of field methods discussed

earlier, and contains additional errors due to photographic

distortion and measurement. The photographic errors can be

minimized if the area of measurement falls near the epicenter of

the photograph and by using rectified photographs. However,

measurement errors depend on the scale of photographs used and can

Oceanit Laboratories, Inc.

be as much as 15 feet on a 1:10,000 scale. Additional distortions

can result in a potential error of up to 30 feet. The usefulness

of the method f or small beach changes is questionable. Another

disadvantage is that transect locations depend on identifiable

marks, the coast between these points may not be linear.

Costs incurred are low because the field work only consists of

making the proper aerial surveys. However, results obtained may be

below the expected accuracy. Transect analysis has been made in

selected areas of Oahu, using rectified aerial photographs from

1949 to 1988. Both mechanical and electronic methods were used in

performing measurements.

ORTHOGONAL GRID MAPPING SYSTEM

In this method the aerial photographs are compared with topographic

sheets. A base map at 1:5,000 scale is obtained; the ocean side

edge of the paper is used as a base line [11]. Rectified aerial

photographs are then enlarged to the same scale as the map by

projecting them directly on to the map with the shoreline parallel

to base line. If the photographs are not rectified then a

correction is applied by comparing object size and image size on

the photograph. Then a rectilinear grid of 100 meters by 100

meters is projected on the map using the long side of the map as

one axis. Next, the shoreline is digitized at points where the

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grid lines cut the shoreline approximately perpendicularly. The

digitization is made relative to the base line established earlier.

Orthogonal grid mapping systems produce best results on long

straight shorelines where the grids can be oriented perpendicular

to the shoreline at the photo projection stage. This in effect

amounts to a point measurement system.

Matching the enlarged projection of the photograph on to the map is

subject to errors, which can arise from the quality the of

photograph and human factors. This error is estimated to be as

large as 10 meters. Assuming an accuracy of 1\100 inches for

measurements from the photograph, this can cause a potential error

of 1.25 meters at each point. This amounts to a potential error of

2.5 meters on 1:5,000 scale. Errors due to the quality of the

photograph add to the above mentioned errors. The maximum

potential error is about 12.5 meters in addition to map errors and

photo errors.

The cost of this type of monitoring is relatively low because no

expensive equipment or highly skilled personnel are needed.

However, the accuracy is very low and is not suited for areas with

low to moderate land loss rates. This type of monitoring has not

yet been performed in Hawaii. However, basic data are available

from existing topographic sheets and aerial photographs.

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The shoreline shape may not be suitable for this type of monitoring

due to sharp land features and a relatively rugged coastline with

small pocket beaches, which may cut the grid lines perpendicularly

at only a limited area in each photograph.

SATELLITE IMAGERY

Satellite imagery is typically used for land use planning and other

activities where the land parcels are large. Presently, the

resolution of data is limited by the pixel size, which is

approximately 80 X 80 meters for Landsat Imagery. This resolution

is too low for monitoring shoreline changes that may amount to a

few meters per year even in heavily eroding areas. However, this

may be used over long time periods; future sensors may have higher

resolution. Computer methods are available that use original data

before it is converted to photographs. At present resolution is

too low for shoreline monitoring.

A major portion of the expense for this method will go to analysis

of data, since data is taken continuously at regular intervals by

satellites already in orbit. Higher resolution information will be

possible in future; this method has lots of potential.

ZOOM TRANSFER SCOPE

A Zoom Transfer Scope is used for revising maps from aerial

photographs. It provides a continuous differential change in

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magnification from 1 to 14 times between each eyepiece of a

binocular viewing system. Therefore, the photograph scale can be

considerably different from the map under comparison. Anamorphic

lenses incorporated into the viewing optics enable one to change

the scale in one direction, thereby permitting corrections f or tilt

and relief displacement as well as other geometric anomalies

between the photo image and the map image. This method of

shoreline monitoring is tedious and time consuming. Equipment is

relatively expensive and trained personnel are necessary;

transferring data to maps and calculating changes in the shoreline

are separate subsequent activities. This method is useful for

special projects; equipment cannot be used for other purposes.

STEREO PLOTTING METHODS

Presently most map revisions are performed with stereoscopic pairs

of aerial photographs and stereo-plotters. These machines correct

for distortion due to scale, tilt, etc., and plot results that are

relatively accurate. However, these machines are expensive and

skilled personnel are needed to provide quality results. Resource

requirements may not be justifiable for the purposes of shoreline

monitoring.

COMPUTER ASSISTED DIGITIZING METHODS

Recently, anew, semi-automated shoreline mapping technique (METRIC

MAPPING) (7] has been developed that uses computer techniques

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together with aerial photographic analysis, which are made by

aerial mapping cameras to ensure high image quality. Base maps

used in this case are topographic sheets made by National Ocean

Survey (NOS 'IT") and are available for many areas dating back to

several decades. Stable control points are selected on NOS 'IT"

sheets and are digitized to convert map coordinates into the state

plane coordinate system. Aerial photographs are then selected as

stereo pairs using a magnifying stereo viewer, the shoreline is

drawn on the aerial photograph as a thin line. Control points such

as road intersections or building corners that appear on the map as

well as the photograph are identified. The map coordinates of

these points are converted to the state coordinate system using the

primary point coordinate relationship established earlier. A

secondary set of corresponding points on the map and photograph are

used to correct scale and other distortions in the photographs.

Discontinuities at adjacent photograph boundaries are then smoothed

using a computer. Finally, maps of the new shoreline are plotted.

Comparisons may be made using final corrected coordinates of the

shoreline before plotting; thereby, avoiding direct measurements

off maps and associated errors. Shoreline change accuracy obtained

depends on map accuracy, as well as shoreline selection and control

point accuracy.

A major part of the work is done by a computer; the method is

relatively inexpensive. Equipment needed is generally available,

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and the need for skilled personnel is low. Results produced are

relatively free from distortion. However, map accuracies and other

errors can result in errors up to 26 feet, if 1:10,000 maps are

used and a 1/64 inch digitizing accuracy is available.

Additionally, errors of up to 13 feet are possible when 1:5,000

scale aerial photographs are digitized to the same accuracy as the

maps. Accuracy of the NOS sheet is about 7 to 16 feet, which

causes uncertainty in the results.

OTHER LOCATIONS

In many other states shoreline monitoring is carried out using

combinations of aerial photographs and, field surveys (10].

Digitizing aerial photographs is performed in Delaware,

Massachusetts and New Jersey. Aerial photography is performed in

California, where the coast is rugged and seasonal variations are

much larger than long-term trends. Aerial photographs are also

used in Michigan, Ohio, Pennsylvania, Puerto Rico and Wisconsin.

Indiana, Maine, New York, Rhode Island, North Carolina, South

Carolina, and Texas use aerial photographic studies supplemented

with topographic or other field surveys. Georgia makes use of

historical maps.

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Example data collection programs f rom several states include the

following (24]:

o Pennsylvania and Indiana update recession data with ground
surveys every two years.
o North Carolina updates with aerial photographs every 5
years.
o Michigan and texas-update every 10 years.
o Florida, each county updates every 10-12 years.

A.2.a. RECOMMENDATION/BEST METHOD

Several factors should be considered, when selecting a method for

erosion monitoring. The main issue is the amount of information

necessary to make appropriate management decisions. Any method

that utilizes available historic data will be helpful in making

immediate management decisions. Therefore, data can be in the form

of maps or aerial photographs. Results can be used to address

immediate management needs. Information needed for future and

long-term planning and management may require specific data

collection and processing methods.

Important criteria to be considered, particularly f or long-term

monitoring programs , is how the information obtained from the

monitoring program will be used for coastal management and

development projects. All methods discussed above except beach

profile measurements and stereo-mapping techniques will result in

only rates of land area change due to the changes in the shoreline.

This information may be adequate for management issues such as

setback determinations and related public use of beaches. However,

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results will not indicate volume losses of beach mat erial, which is

more closely related to predictions of future coastal behavior.

The insensitivity of these methods to hazards related to land

levels such as flooding and subsidence is another serious

disadvantage of the other methods. Volume changes of beach

material and the susceptibility of coastal land to inundation due

to severe storms or flooding are important from social as well as

coastal engineering points of view. Data on long-term volume

losses of beach materials are extremely useful in designing coastal

stabilization, sand nourishment requirements and for evaluating

impacts of coastal projects on adjacent coastal and offshore areas.

Large-scale shoreline maps and historical aerial photographs used

for determining erosion rates always lead to the questions

regarding confidence in results. As discussed earlier, most map

and photograph digitizing methods involve errors. uncertainty in

maps and photographs casts a shadow on the accuracy of results.

This is particularly true in highly developed areas where the rates

of erosion are low but the consequences of erosion are economically

significant. Land loss near valuable public infrastructure and

facilities, e.g., main roads, is a good example. In such cases

information obtained from remote operations, such as aerial

photography, may not be accurate enough. Point measurements from

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monuments established close to the beach will give more useful

information at a higher cost.

Aerial methods are cost effective for preparing surveys of long

beach stretches. However, compiling accurate maps for monitoring

purposes involves stereo-plotting equipment and highly skilled

technical personnel. The absence of clearly distinguishable ground

features in early aerial photographs, particularly in less

developed areas, is a serious drawback in their use for comparison

studies. Accuracy can be improved without significantly increasing

cost by clearly establishing distinguishable marks on the ground at

predetermined locations, and including a few of these marks in each

photograph. Large white circular patches can be established as

marks when located on easily identifiable coastal roads; thereafter

their coordinates can be calculated with respect to the state

coordinate system during field observations. Establishing and

identifying these features in aerial photographs, maps and on the

ground is a necessary step for correcting distortion in

photographs. Ideally these marks should be at the same level as

the vegetation line. This may not be critical in coastal areas of

low land relief.

Because Hawaii consists of a series of islands, erosion problems

are critical even over a relatively short length of coastline. In

critical areas where management decisions can lead to economic or

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legal issues, accurate data on beach recession is necessary. In

other areas where erosion and related socio/economic issues are not

critical, accuracy from results obtained using digitization

techniques and aerial photographs may be suitable. -

The extent and rates of erosion experienced must be weighed against

the cost of monitoring methods. In areas where decisions must be

made immediately, digitizing methods supplemented with profile

measurements are recommended. In areas that are critical,

simultaneous photographic and field profiling methods are

recommended. Information will be used to select the best method

for subsequent monitoring surveys. In areas where coastal

development activities are relatively low, monitoring methods that

use digitizing techniques are recommended.

Monitoring surveys must be made at regular time intervals with

repetitions once in three to five years. As mentioned earlier, the

best monitoring feature is the vegetation line. The f inished

photograph, scale should not be smaller than 1:20000. With a larger

scale, identifying the vegetation line and other features will be

easier; however, photographic distortion at overlapping areas may

be high. The cost at larger scales will be correspondingly higher.

In general photographs at a scale of 1:10000 are suitable for

monitoring purposes. Aerial surveys should be carried out during

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seasons with low wave activity, preferably in summer. Field

measurements should be performed simultaneously so results can be

compared.

TABLE III-1

COMPARISON OF SHORELINE MONITORING METHODS

METHOD COST TIME ACCURACY ASSESSMENT OF
SUITABILITY
for Hawaii

1. Profile Medium Medium 0.51 Good for
Measurements Horizontal Highly
0.051 Developed
Vertical Areas

2. Point Medium Medium 0-0-51 Good for
Measurements Horizontal Medium
No Vertical Developed
Data Areas

3. orthogonal Low Low 30-451 Poor
Grid Mapping Horizontal
No Vertical
Data

4. Satellite Low Low 80-1201 Poor
Imagery Horizontal
No Vertical
Data

5. Zoom Medium Medium < 201 Fair
Transfer Scope Horizontal
No Vertical
Data

6. Sterio High High 0-.51 Fair
Plotting Horizontal
7. Computer Medium Medium 7-261 Fair
ssisted Horizontal
Digitizing at 1:10,000
Methods I I I

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A.3. IMPLEMENTATION SCHEME

The following procedure is recommended for implementation of the

monitoring program:

1) Collect all available data including aerial photographs,
maps of coastal areas, local surveys maps, etc.
2) Evaluate suitability of the data for different
types of analysis.
3) Use aerial photographs and computer aided digitizing
methods for calculating the past recession rates using
vegetation line as the monitoring feature.
4) Identify areas undergoing critical erosion by using the
extent of economic loss as the criteria. These areas must
be identified in coordination with State and County
agencies, which will eventually engage the problem.
5) Establish marks identifiable on the ground from aerial
photographs, as-near-as possible to the shoreline
level. These marks will be used as secondary control
points. Mark these points on existing maps, or calculate
their central coordinates using field measurements.
Circular white marks on main road intersections or other
black background are easily identifiable on photographs.
These marks may have to be renewed prior to each
flight.
6) In order to establish the accuracy of shoreline monitoring
by digitization methods, simultaneous aerial and field
surveys must be performed. comparison of field survey
results with those of digitized aerial photographs will
show the accuracy obtainable as well as the relative costs
of the two methods. These results can be used to decide
on the best method for future monitoring. A time lag of
up to a month between the aerial and field surveys may be
acceptable if the two cannot be carried out
simultaneously.

Results from data analysis should be presented in f inal f orm,

including raw data, to the public and all agencies involved with

shoreline control activities. The State's GIS system is suitable

for storage of this data, which should be made available f or

planners, engineers, and other professionals involved in coastal

development and management activities.

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B. GUIDELINES A ND'CRITERIA FOR RESPONDING TO EROSION HAZARDS

Coastal erosion is a natural land formation and modification

process that is nature's way of seeking an equilibrium at the

land/sea interface. Sometimes erosion is undesirable due to the

risk of loosing coastal protective structures or socio/economically

important recreational and commercial facilities. Previously,

engineering solutions were implemented without'evaluating impacts

on the environment. This resulted in degrading the coastal

environment and, in some instances, caused problems to adjacent

areas. Since then, an awareness has developed whereby engineering

techniques combined with an overall management approach is

desirable for hazard management and conservation of coastal

resources.

Two basic options are available for responding to coastal hazards.

one is to apply properly designed engineering solutions that are

directed only at the erosion problem. The other is to develop a

comprehensive management program to conserve coastal resources and

control coastal hazards. It is sometimes necessary to utilize a

combination of these approaches to optimize solutions.

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Engineering solutions include:

� Construct properly designed shore protection
structures like seawalls, revetments, groins and
detached breakwaters.
� Nourish eroding beaches with sand from some
other source at regular intervals in order to
restore losses.
� Combine sand replenishment with structures designed
for retaining the sand for an extended period.

Management solutions include:

� Relocate endangered structures (roads etc).
o Establish setback for new development.
� Relocate people away from high risk areas.
� Inform the public regarding the degree of risk in
hazardous areas.

Beach sand sources can also be improved by creating conditions

conducive to coral growth. Submerged artificial reefs could act as

nuclei for developing this type of beach material source.

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B.1. ENGINEERING CONSIDERATIONS

Three types of engineering structures are frequently used in

controlling coastal erosion. Each structure affects the coast and

coastal processes in different ways. Seawalls and revetments are

constructed approximately parallel to the coast along the edge of

an eroding scarp. They prevent erosion by retaining the loose

material behind the structure, which is designed to withstand wave

forces as well as ground water forces. This type of structure will

have only a limited effect on coastal processes because they do not

cross the waterline under ordinary conditions. However, they cause

hardening of the shoreline and increase wave reflection, which may

have a detrimental effect on accretion processes. Groins, on the

other hand, are used in erosion control when strong littoral

currents are the main cause of erosion. Groins are constructed

perpendicular to the coast as a barrier to the littoral currents;

they trap littoral material moving along the beach. They also push

the longshore currents seaward reducing their erosive potential.

Therefore, groins change littoral processes in a limited area and

interrupt longshore transport of sand. This causes erosion to

downdrift beaches.

Detached breakwaters are constructed parallel to the coast at some

distance seaward from the shoreline. They absorb a portion of the

incident wave energy and deform nearshore wave patterns

drastically. Changes in nearshore wave patterns modify existing

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littoral processes; with proper design they can be used to control

erosion. However, local coastal process modifications will ease

erosion problems in one area while aggravating problems in adjacent

areas. In all of these cases structures either harden the coast or

create local modifications to the sand movement that mitigates

erosion.

Land erosion is basically an imbalance between sources and losses

of sand (sinks) . This concept has been ignored in all three

solutions mentioned above. Structures only alter the pattern of

beach loss.

Structures like seawalls and groins create problems of beach access

as well as recreational use of the beach. The scenic value and

continuity of the shore will be adversely effected by visual

barriers caused from groins. Depletion of beach resources in

adjacent areas may lead to difficult legal problems where assessing

the amount of loss due to the construction is almost impossible.

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Nourishment of eroding beaches with appropriate material that will

counteract an imbalance between sources and losses is an accepted

solution to coastal erosion. This has the advantage of creating or

maintaining recreational areas. Environmental impacts could be

minimized if the rate of replenishment could be matched to the rate

of beach material net loss. However, this is not possible because

of implementation problems. At best, nourishment schemes are

typically carried out at regular intervals where the amount of

material supplied at each execution is suf ficient to last several

years. This temporary excess of material can end up in undesired

locations and sometimes can smother coral reefs or cause

sedimentation in nearby waterways or lagoons. Extensive studies

have to be made when selecting the proper type of material and the

acceptable amount that can be supplied at any given time. It may

be advantageous under some circumstances to combine sand

nourishment schemes with structures designed to retain the sand for

a longer period. Additionally, encouraging natural growth of coral

by creating environments conducive for growth of suitable coral

species can result in an increase in ava ilable natural sources.

B.2. SOCIO/ECONOMIC CONSIDERATIONS

Coastal erosion and beach preservation measures must also consider

the various social and economic issues that arise. To address

these issues, an inventory of the following items should be

included in the comprehensive database:

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� Existence, location and current levels of usage of public
access to the shoreline
� Existence, location and current levels of usage of public
access along the shoreline
o Existence, location and current levels of usage of ancient
Hawaiian trail systems along or to the shoreline area
� Public recreational uses of the shoreline and levels of
usage

These issues are not confined to coastal erosion per se, and must

be addressed in a comprehensive shoreline management plan. The

comprehensive plan should consider the following:

o Anticipated future levels of usage with regard to public
access and public recreational use.
o Adequacy of current access and recreational availability
with respect to meeting anticipated future needs.
o Preservation of verifiable ancient Hawaiian trail systems
and kahaniki rights.
o optimum public utilization scenario to address anticipated
levels of usage.
o Necessity of implementing beach nourishment or shore
protection measures to achieve optimum scenario.

Legal issues often arise with respect to government's ability to

regulate uses of private shorefront property. The primary issue

typically centers on whether the regulation constitutes an

unconstitutional taking or results in an inverse condemnation

action. In general, such statues or regulations have been upheld

where courts have been able to find that the statute or regulation

substantially advances a legitimate state interest, and does not

deny the landowner of an economically viable use of property.

The development of a comprehensive shoreline plan should bolster

the legitimacy of the regulatory action if the plan is formulated

to contain clear policy objectives and supporting justifications.

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In addition, to address these legal issues, the guidelines, rules

and regulations for implementing the plan should, at a minimum, be

formulated to provide the following:

� Give special exception to landowners in situations where
there will be damage to existing residences or like
structures due to coastal erosion.
� Consider the impact of loss of private property from
coastal erosion processes with respect to lot size and
configuration, and ability to utilize lot for permissible
purposes.
� Provide an administrative appeal procedure.

Even though coastal erosion af f ects all aspects of the coastal

zone, erosion management is only a part of coastal zone management.

A management plan for the coastal zone should address conservation

of all resources and should have provision to control all

activities that ef f ect this resource. Hazards to lif e and property

arising from natural causes such as tsunamis, storm flooding or

erosion can only be minimized by controlling development and use

activities.

The public should be informed of potential hazards that' exist in

coastal areas from natural events such as tsunamis and storm

flooding, as well as the probable frequency of such events. The

intensity and the frequency of hazards will depend on factors like

exposure of the coast, offshore bathymetry, backshore elevations

and relief as well as the degree of development. Setback distances

should be established by evaluating potential hazard intensities

and frequencies. It may even be necessary to relocate residential

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areas f rom high risk to low risk areas. Engineering structures may

be the only acceptable solution in certain areas where existing

public infrastructure is in close proximity to the beach.

Relocation may be acceptable when public structures are threatened

by erosion.

The socio/economic issues arising from erosion are somewhat similar

to those that are important in considering development activities

within the SMA. These considerations include the following:

� Loss of public beach access.
� Loss of recreational facilities and wild life areas.
o Hazards to beach users.
� Loss of public facilities.
� Damage to the coastal environment.
o Damage to coastal ecosystems.
� Loss of scenic resources and viewsheds.

Consequences f rom the f irst f our will show an immediate social

impact because the public will be directly effected. Loss of

public facilities such as parking areas, changing rooms etc. does

not involve rights of private individuals. It enables the use of

relatively straightforward mitigative measures where no legal or

other confrontation arises.

However, when recreational beaches are backed by valuable private

land, the land owners will attempt to protect their properties from

erosion by constructing protective structures such as seawalls.

This type of s tructure will effect public access to the beach and

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may even result in loss of recreational beach area in the vicinity

of the structure.

The adequacy and suitability of a coastal structure are two

separate considerations. A seawall may be structurally adequate to

protect the land behind it from erosion and if properly designed

will not damage the beach in front of it. However, erosion is not

a process that effects isolated points on the beach. In general,

a considerable length of the coast undergoes erosion at a given

time. The erosion problem can be contained effectively only when

a solution for the entire beach stretch is formulated. This

provides a suitable solution for erosion problems. Hardening a

small portion of an eroding beach may increase the rate of erosion

at adjacent coastal areas and cause additional problems. The

suitability of a protective structure for this situation must be

evaluated independently.

Failure of an inadequately constructed structure may damage the

property it was meant to protect, irreparably damage the beach; may

even create hazardous conditions for beach users. Additionally,

the scenic and recreational value of the beach will be reduced from

scattered rocks and other debris.

Structures and erosion may cause the loss of recreational water

uses such as surfing and other wave dependant sports. Changes in

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wave behavior f rom bathymetric alterations caused by erosion, or as

a hydraulic response from the protecting structure, can result in

an environment not suitable for wave sports.

Damage to coastal ecosystems, loss of scenic resources and

viewsheds, as well as damage to the coastal environment will af f ect

the economic importance of a coastal area. This is particularly

true in the State of Hawaii where the tourist industry is oriented

to coastal and undersea recreational activities. These factors

show that coastal erosion and construction of non-conforming

protective structures will lead to adverse socio/economic impacts.

However, when valuable property bordering the beach is eroding the

land owner will do his best to protect it. Imposing conditions on

these protective efforts may lead to legal problems.

"Takings" issues involve a conflict between public interest in

stopping the degradation of natural resources versus an owner's

asserted right to use his property as he wishes. Claims regarding

specific limitations or constraints imposed on private uses of

property that are so restrictive they constitute the equivalent of

constitutionally prohibited "takings" of private property for a

public purpose without compensation will present enforcement

problems.

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When narrow strips of private land bordering the coast are backed

by important public infrastructure such as roadways, the erosion

hazard faced by the private land should be considered as a

potential future threat to the public property. In such cases the

private land can be considered a buffer and adequate protection of

land should be encouraged in the face of future social expenditure.

This can be achieved by establishing a group of qualified

personnel, e.g., in a state agency, who can provide guidance, data

requirements and expertise during construction.

B.2.a. INFORMATION NEEDED

Decision making for any public resource is always difficult;

however, coastal erosion related resource issues are further

complicated by land ownership, existing land use, proximity of

public facilities to the coast, and other socio/economic factors.

A brief analysis of the most critical information needed for

decision making is given in the following section.

The types of information needed for decision making can be divided

into two categories: environmental and socio/economic. The

environmental information including, exposure of site to tsunami

and storm flooding hazards, meteorological and oceanographic data,

morphologic and geologic data, topographic,data, value of marine

habitat, and importance of nearshore ecosystems. Socio/economic

information needed includes land and water use in the coastal zone,

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-land ownership, value of land and public infrastructure immediately
hinterland, recreational value of beach and nearshore water, public

access to beaches, scenic value of coast and type of development
pressure on the area such as,- residential, commercial or

recreational.

Impact from storm surge, tsunamis and high swells on coastal areas

will vary depending on the exposure of the coast to such phenomena,

as well as nearshore seabed bathymetry, beach characteristics and

backshore relief. Tsunami flooding hazard has already been studied

and information on the intensity is available for many areas.

Available data must be incorporated into maps; residents of high

risk areas need to be informed of the hazard risk. High density
residential development in-areas susceptible to flooding increases
potential damage from flooding because the water flow will be

restricted by buildings and other structures. Higher water flow

speeds, arising particularly during the recession of flood water,

can result in extensive damage due to scour. Construction should

be controlled to avoid these situations.

Material eroded from the beach during a heavy storm is temporarily

deposited offshore. This deposition reduces the destructive force

of the waves and decreases the rate of erosion. Sand is then

transported back to the beach after the storm passes. If the

nearshore area shows an abrupt increase in depth or the presence of

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deep channels leading offshore, the sand removed by storm waves
will be permanently lost. Damage from the storm in this area will

be more severe and permanent. Therefore, coasts fronted by deep
Ik channels or steep bathymetry must be identified and treated as high
risk areas.
11
oceanographic conditions that cause erosion hazards are high water

levels and large waves. Currents also play an important role, but
]k are generally weak except close to lagoon entrances and river
outlets. Water level data are well documented from tide

measurements and wave data for Hawaii are available from

measurements and ship observations. Data can be found in tabular

form giving wave heights, periods and wave directions as

percentages. This data needs to be analyzed to obtain wave climate

information for areas of different exposure. Wave heights and

directions are important parameters in evaluating risk because they

C
ause erosion from longshore transport. Erosion rates depend on

the geologic formation of land and the coastal geomorphology of the

area. Areas with extensive dunes can survive severe storms by

loosing part of the sand and building up again after the storm is

over. If dune protection is absent and the backshore is low lying,

the area will be at high risk from storm waves breaching through.

When the coast is composed of hard geologic strata, erosion is slow

and in general the backshore is steep. The risk of erosion or

flooding in this situation is low.

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-some nearshore environments provide uhique marine habitats and

delicate ecological systems. These areas are sensitive to any

change in nutrients, circulation, influx of sediments and
pollutants as well as physical 'disturbances from recreational
activity. These. areas should not be disturbed; development

activities in adjacent areas that may cause erosion in these unique

habitats should be closely controlled.

Accurate demarcation of the certified shoreline is very important

for controlling of development activities, This line a cts as the

boundary between the conservation district and the Special

Management Areas (SMA). Engineering structures designed to prevent

erosiofi are constructed at this boundary. This line is loosely

defined as the vegetation line and leads to different

interpretations by officials and land owners, Applications for

Shoreline Setback Variances (SSV) cannot be processed efficiently

when the location of the certified shoreline is in doubt.

Attempting to determine the line after the application is forwarded

leads to confusions and unnecessary delay. This line ideally

should be defined from monuments on land and updated periodically,

as in the case of other district boundaries.

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Socio/economic information that needs to be considered will depend
on the land, beach, and water uses in the co astal zone. Land and

water use in the area adjacent to the SMA zone is important for
decision making. Land use can.-be residential, agricultural,
commercial, recreational etc., and may include public

infrastructure and facilities. Water uses can be of recreational,

industrial or of aquacultural importance. Land ownership may be
public or private. In the case of public lands, making a decision'
on erosion management may be relatively straightforward. But in

cases of privately owned or privately leased lands, the value of

land and hardship to the owner makes matters much more complicated.

When public facilities such as main highways are separated from

the coast by a narrow strip of privately owned land, any structure

constructed for the purpose of protecting the privately owned land

from erosion may have an ef f ect on the long-term saf ety of the

road. In such cases permitting land owners to construct individual

seawalls to protect their property at their convenience may not be

in the best interest of the public. If private land is not

protected and erosion continues, the social cost of relocating the

road at a later date may be very high. In such cases serious

consideration should be given to assisting the land owners in

designing an overall protective scheme. The design effort could be

considered as an investment that would reduce large expenditures

later.

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some of the information on land-use and oceanographic data

discussed above may already be available, and needs only to be

compiled in a suitable way for use in erosion management. Data

collection programs should be designed where additional information

is needed. The ty pes of data necessary for responding to hazards

at any location will depend on dif f erences in the environment. The

degree of exposure to severe oceanographic and meteorologic
conditions 'should be the primary consideration. Intensity of

erosion and the subsequent damage should be related to the level of

development and the geologic, bathymetric, and morphologic

conditions of th e coast. Hazards due to flooding will be dependant

on development density, character of backshore, and the topography

of the area. Similarly, for economic and recreational

considerations, the location will be a major criteria. A set of

questions should be developed for determining data necessary for

responding to hazards of erosion and flooding, including the

following those found in Table 111-2:

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TABLE 111-2

EXAMPLE QUESTIONS TO DETERMINE NECESSARY DATA FOR RESPONDING TO
EROSION AND FLOODING

1) What is the level of inundation expected for a 100
year tsunami?
2) What is the water level and wave climate expected
for the 100 year storm?
3) What is the highest water level expected within the
next 100 years?
4) What is the heaviest runoff expected?
5) What is the worst wave /swell climate expected in
the next 100 years?
6) What is the geological formation of the coast?
(ease of eroding)
7) What is the character of the backshore?
(dunes/rising/low lying etc.) .
8) What is the major purpose of land utilization?
9) What is the major water use if any within the SMA?
10) What is the pattern of land ownership?
11) Is the beach accessible conveniently to the public?
12) Is the area used by the public for recreation?
13) Are there any public facilities close to the
coastline?
14) Are there any commercial uses of the coast?
(harbors/marinas etc.)
15) Is the area heavily built-up with residential units?

B.3. RESPONSE TO EROSION HAZARD

In general, waves approach the coastline at an angle, which results

in a current parallel to the beach. This current is weak but since

sediments are in suspension in the breaker zone it is capable of

moving large amounts along the beach. This is called the littoral

drift and is responsible for distributing the sand available from

sources to all parts of the beach. When the source capacity is

lower than the littoral drift, beaches undergo erosion. This type

of erosion can continue for decades or even longer until a new

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equilibrium is reached. In most areas the wave climate shows a

cyclic pattern over a period of one year. Because of this, the

onshore/offshore movement of sand and the littoral drift also show

a cyclic behavior. As a result, the beach may also show cyclic

erosion and accretion with large variation due to storms.

Engineering solutions to erosion problems are satisfactory for the

average sea conditions where they are designed. They may not

function as expected when the situation deviates from ideal design

conditions. Any type of hard structure will impose changes in the

coastal processes. Revetments or seawalls will change the

reflection of waves. The beach face will be modified, which will

further modify waves and so on. Groins and detached breakwaters

will impose more drastic changes on waves as well as on sediment

movement. Because of these reasons, hard structures must be the

last option be considered for erosion management. However, there

may be cases where such drastic measures can be justifiable.

Nourishment of beaches is a softer solution and can be applied in

most cases. Management solutions combined with engineering

solutions give the optimum results in most cases.

In responding to any erosion problem, answers to the questions

found in Table 111-3 should be sought for better understanding the

situation and to formulate a solution.

Oceanit Laboratories, Inc.

TABLE 111-3

EXAMPLE QUESTIONS TO FORMULATE A SOLUTION TO EROSION PROBLEMS

1) Is the erosion chronic or seasonal?
2) What is the approximate rate of erosion?
3) Is there an immediate danger to public/private
structures from erosion?
4) Will erosion hazard be compounded by inland
flooding?
5) Is sufficient material available on the beach for use as
a buffer in case of a storm?
6) Is the nearshore seabed dominated by sediment
sinks such as deep gullies or deep channels leading
offshore?
7) What is the extent of facilities available for
evacuating people from endangered areas during a
severe event?
8) What are the social, economical and political
repercussions of relocation?
9) Can important existing infrastructure be shifted
from high risk areas?
10) What are the repercussions of an increased set
back?
11) Will extension of the SMA boundary up to a minimum
contour help in regulation of development?
12) What types of engineering and management solutions are
acceptable f rom the point of view of land, beach and water
use activities?
13) What alternate sites are available for relocation?
14) In cases where public infrastructure is separated from
an eroding coast by a strip of private land, is it
feasible to purchase the private land?
15) What types of natural sand sources exist in the
area for replenishment of eroding areas?
16) Can the-overall eroding process effecting the
coastal beach be identified before preparing an
overall erosion management scheme?
17) To what degree will structures harm public access
to the beach, and other coastal resources the area?
18) Is establishment of artificial reefs or promoting
coral growth by other means acceptable to the area?

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Answers to some of the questions in Table III- will be simple and

straightforward, others will be complicated and interdependent.

However, the final outcome will give an indication of the best

approach possible. Some questions will have more significance in

certain areas than others. The issues identified above can be

broadly categorized in to two areas:

1) Issues of land ownership, land and water use and the threat
of erosion.

2) Issues of Socio/economic and environmental nature.

Sub-issues related to these categories are presented in Table III-

4. In This framework, different values must be placed on each sub-

issue.

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TABLE 111-4

EROSION ISSUES

I. LAND OWNERSHIP, LAND AND WATER USE

1. Extent of Erosion
a. Length of coastline effected at the eroding site.
b. Land use in the whole stretch.(e.g. Parks,
infrastructur, other public facilities, Residential,
commercial)
2. Land Ownership and Land Value
a. Totally owned by public.
b. Totally owned by one private owner.
c. Part owned by public and the rest by one private owner.
d. Owned by several private owners.
e. Extent of parcels and width of parcel landward.
f. Land use on the mauka side of the parcels.
g. Land value.

3. Beach and Water Use
a. Recreational sports (e.g. surfing, wind surfing,
swimming, diving, fishing)
b. Marinas
c. Commercial (Harbors, fishing harbors)
d. Industrial (effluent discharge, cooling water intake
and discharge)
e. Aquaculture (fish pands,shrimp farms)

II. SOCIO/ECONOMIC AND ENVIRONMENTAL
a. Potential economic losses (land, infrastructure,
structures)
b. Loss of beach access to the public ( shore protection
structures, deep escarpments at berm, narrow beach)
c. Loss of recreational area (beach,surfing areas,swimming
areas due to deepening, live reefs effected by
deposition)
d. Loss of scenic value
e. Changes in the environment (wave patterns, currents,
sediment movement and resulting effect on ecosystem)

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In order to develop guidelines for decision making, an attempt is

made to quantify losses to private and public parties from impacts

arising from erosion. Generally, it is very difficult to set down

fixed procedures for making erosion management decisions because

issues are usually complicated by the land value, land ownership

and socio/economic impacts. It should be realized that in a

dynamic zone such as the coastline, a degree of flexibility is

needed on the part of both the private individuals and regulatory

personnel. Methods to quantify positive and negative impacts are

discussed below. This procedure should be considered a.starting

point and should be modified later.

CASE EXAMPLE 1: EROSION OF PARKS AND RECREATIONAL AREAS

The loss can be divided into two parts:

1) Economic loss due to lost land.

o This is relatively straightforward and can be quantified
by multiplying the expected yearly land area loss by the
average value per square foot. Any structures that may
be partly or completely lost due to erosion may also be
included. The replacement cost should be used as the
economic loss.

2) Reduction of the recreational capacity of the park land
lost by erosion.

o Value will vary from place to place depending on the
indirect economic importance of the facility from the
point of view of the tourist and recreation industry.

o In general, people tend to use the strip of land closest
to the beach for recreational purposes. This can be

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valued by using the average number of person-hours of
recreations provided by the facility over a period of
one year. In this exercise a value of 50 to 100 feet
will be reasonable. By assuming a value for a
person-hour of recreation provided by the park, and
spreading the total over the most used strip, a
recreational value per square foot can be estimated.
Loss of recreational area from reconstruction of
destroyed facilities should also be calculated on the
same basis and added to the total loss.

The two components discussed will give a total loss from erosion.

Construction cost for protection of the coast in this example can

be weighed against the total loss calculated over the design

life-time of the structure. Any negative impact like erosion in

front of the wall can also be quantified from the loss of

recreational capacity. Values for picnicking, surfing, swimming,

and beach activities can be estimated; values will become more

accurate as more data is accumulated.

CASE EXAMPLE II: EROSION OF PRIVATE LAND

The same approach can be used in cases where protection of

expensive coastal land threatens the recreational areas availabl e

to the public. In this case the following issues should be

considered:

1) Loss to private land owner.
2) Loss of recreational beach area due to structures.
3) Possible loss of water recreational areas due to
structures.
4) Possible land and recreational area loss to adjacent
areas.
5) Partial compensation of public cost by private owners by
nourishing beach in front of structure over a period that
will be determined by the regulatory authority.

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In the case of a long stretch with multiple owners, construction of

independent structures for protection of individual parcels should

be discouraged because this type of structures is difficult to

include in a future scheme designed to protect the whole stretch.

The affected residents should be encouraged to participate in a

total scheme designed to protect the whole stretch from erosion.

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IV. FUTURE MANAGEMENT CONCEPTS

Future concepts in erosion management are provided only for the

purpose of encouraging new and innovative thinking. Ideas put

forth may not be possible under existing legal, social and

technical conditions. Additionally, new ideas sometimes bring new

problems. However, at the risk of being misunderstood, we provide

the following concepts.

In the future we expect coastal erosion problems to be dominated by

two types of issues: social and environmental. Social issues will

result from increased competition for limited resources. We are

seeing our first view of this in 1990 with Hanauma Bay. As a

result of the bay's overuse, the City of Honolulu is restricting

activities. Environmental issues include sealevel rise and other

effects of global warming. Global warming and the resulting

sealevel rise is expected to hav e a major impact on coastal beaches

in the far future. If we do not look too far into the future and

address erosion only, the following suggestions would either

provide financial resources or new planning schemes to deal with

erosion problems.

Ongoing beach nouri shment
A state funded beach nourishment program that operated all year on
all islands would dramatically reduce the cost per unit length to
re-nourish beaches. It would address major environmental and
public concerns associated with structural solutions, e.g.,
destruction of habitat, beach access, etc. It could operate with
blanket permit authority, perhaps through the "Office of Beaches."

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Special tax for beach residences/beach users
Modification to the existing property tax system could be
implemented, e.g, a tax could be levied on coastal real estate.
Perhaps, a percent of existing property tax could be used for beach
maintenance and repairs. Another approach would be to include a
use tax for those people (e.g., tourists) that use the beach for
recreational purposes.

Impact fee for coastal structures
The construction of any structure along the coastline could carry
am impact fee that would be assessed in proportion to the impact on
the related issues, e.g., environment, public access, recreational
value.

Cost sharing with state and county governments
The expense of beach repair and maintenance could be shared by the
coastal land owner in proportion to the real estate value, e.g.!
annual re-nourishment of beaches.

Improvement districts
Improvement districts would enable shore protection and repair
activities to be performed by a group of private land owners. If
the group were sufficiently large and addressed a continuous
stretch of coastline, a benefit would be bestowed to the public
because the impact from the collective efforts would be less than
the sum of impacts from individual land owners. Additionally, cost
would be reduced.

State parks on all beaches
The State could condemn all coastal lands and create a beach belt
that would surround the island. The state would have total control
over all coastal erosion and maintenance responsibilities. This
may be necessary if global sealevel rise becomes a major problem.

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V. CONCLUSIONS AND RECOMMENDATIONS

The current regulatory scheme addresses shoreline management in a
piecemeal fashion, including inconsistent management approaches
between the state and county governments, lack of uniform policy
guidelines, lack of overall planning and the overall complexity of
the regulatory process. of the various needs that exist with
respect to coastal erosion management, a lack of information is the
key shortcoming that is the most disabling. It prevents the clear
determination of policy as well as the consistent execution of
existing rules and regulations.

We recommend the mission statement of the Erosion Management
Program (EMP) to be 11 ... conserve beaches and minimize erosion."
The first and foremost mission goal that needs to be addressed is
the collection of information. other related concerns, including
planning/regulation and fiscal/administration will become more
focused as information is gathered. Without adequate information,
all other related management concerns and regulatory schemes become
considerably weakened.

The various types of information collected and evaluated in this
project were considered from the point of view of coastal hazards
and erosion management in Hawaii. Based on this information we
draw the following conclusions and recommendations.
1) INFORMATION CONCLUSIONS:

� In general, coastal land is used as a recreational
resource in Hawaii. It has a clear economic value because
of the tourist industry. Development pressure within this
area is high; therefore, a real danger exists for
damaging the environment irreversibly. Management
decisions require, at a minimum information on
land loss rates. This type of data can only be obtained
by long-term monitoring.
� For purposes of calculating past land loss rates,
historical maps are needed for baseline information. The
most appropriate maps that can be used for this purpose
are the National ocean Survey Topographic (NOS11T11) maps.
� In spite of the disadvantages of aerial photographs for
calculating shoreline changes, it is clearly the most
inexpensive approach for monitoring long coastlines.
� In areas where land loss rates are comparatively
low, but important economically, monitoring with aerial
photography has to be supplemented with field surveys
at least in a few selected places.
� Computer assisted comparison methods are most
appropriate for monitoring coastal changes in undeveloped
areas. Results may not be accurate enough for
making management decisions in highly built-up areas.

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2) PLANNING CONCLUSIONS:

� In past studies, different boundaries have been used for
monitoring coastline changes. For Hawaii, the most
appropriate boundary is the vegetation line.
� There is a shortage of data on the coastal zone for
decision making.
� At present, there is a lack of overall comprehensive
shoreline management planning and guidelines for
decision making.
o Regulatory process for obtaining permits for
activities in the coastal zone are too complicated.
This prompts the public to ignore rules.

3) RESOURCE MANAGEMENT CONCLUSIONS:

o Neither the state nor the counties have sufficient
man power or resources to effectively manage coastal
erosion problems. This is reflected in the number of
illegal, and inadequately designed protective
structures constructed by land owners.

o Problems regarding shoreline encroachments and
illegal structures already exist in Oahu.
shoreline certification rules complicate
the resolution of disputes on encroachment and illegal
structures.

o, The certified shoreline, which is the boundary
between the conservation district and SMA, is
defined as the vegetation line and is subjective and
depends on to individual judgment.

The study brought out many shortcomings in the present status of

managing erosion in Hawaii. The following recommendations are made

as a first step to ease the situation and to enable decision making

on issues in this area more streamlined.

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INFORMATIONAL RECOMMENDATIONS:

o Establish a data base for the State of Hawaii, including
oceanographic, topographic, land and water use
data for the coastal zone. Compile data already
available with Federal, State, County, or private
organizations.

o Use aerial surveys and a computer aided digitizing method
for monitoring the total coastline of Hawaii. This study
should be supplemented by shoreline surveys at selected
high risk locations for comparison purposes. These
monitoring activities should be repeated every five years.

o Prioritize and coordinate federal, state and county
erosion management funding to develop a comprehensive data
base on coastal areas statewide.
,2) PLANNING RECOMMENDATIONS:
o Define the certified shoreline by state coordinates
and tie it to already existing survey monuments so
that this line can be set out uniquely. The line
needs to be revised continuously as erosion occurs.

o Simplify permit process and inform coastal land
users regarding the permit requirements and the
procedures to follow for proposed activities in
this area.

o Draw up a master plan for erosion management for
the whole state. The plan should address the
nature of the erosion problem, causes for erosion,
problem assessment for different areas and
recommendations for the immediate, medium-term and
long-term mitigative activities.

o Develop a comprehensive coastal erosion plan for the
state. Since coastal erosion issues affect other
pertinent shoreline issues, the coastal erosion plan would
be one component of a shoreline plan.

o Consolidate jurisdiction over the shoreline area to place
the bulk of the regulatory powers in one state agency.
The most logical way to develop this authority may be to
establish a separate division or "Office of Beaches"
within an existing agency that already handles these
matters, such as the Department of Land and Natural

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VI. REFERENCES

(1] Simon Baker, Aerial Photography For Planning And Development
In Eastern North Carolina: A Handbook Directory, A
University of North Carolina Sea Grant Program Publication.
UNC-SG-76-03 (April 1976).

[2) An Analysis of South Coast Regional Commission First Year.
Coastal Zone Development in Los Angeles County.

[3] Managing Coastal Erosion, "The National Flood Insurance
Program", Committee on Coastal Erosion Management Water
Science and Technology Board Marine Board, Commission on
Engineering and Technical Systems, National Research
Council (November 1989).

(4] David A. Rice, "Taking" By Regulation And The North Carolina
Coastal Area Management Act, University of North Carolina,
Seagrant Publications UNC-SG 75-26 (July 1976).

[5] Donald B. Stafford, Jay Langfelder, Air Photo Survey of
Coastal Erosion, Photogrammetric Engineering (1971).

[6] Hawaii coastal Zone Management Program - Federal Consistency
Procedures Guide, Department of Planning and Economic
Development, state of Hawaii (April 1985).

[7] J. Beach Clow and Stephen P. Leatherman, Metric Mapping: An
Automated Technicrue of Shoreline Mapping, Proceedings of ASP-
ACSM Convention, Washington, DC. (1984).

(8] National Oceanic and Atmospheric Administration, State of
Hawaii Coastal Zone Management Program and Final
Environmental ImDact Statement (August 1978).

(91 Ocean Natural Hazards Issues Study Group, Information
Memorandum, Issue No. 3 (March/April 1988).

(10] Response Summary to the ASFPM Coastal Committee Shoreline
Erosion Setback Questionnaire. Department of Environment
Protection, Trenton, New Jersey (October 1989).

[11] Robert Dolan, Bruce P. Hayden, Paul May and Suzette May,
The Reliability of Shoreline Change-Measurements from Aerial
Photographs, Shore and Beach, pgs. 22-28 (October 1980).

[12] Sea Engineering Inc., Oahu Shoreline Study (1988).

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[13] Stephen P. Leatherman, Shoreline Mapping: A Comparison of
Techniques, Shore and Beach, pgs. 28-33 (July 1983).

[14] Stephan P. Leatherman and John J. McDonough 111, America's
Eroding Beaches - NOS Data May Hold The Key, The Military
Engineer, No. 520, pgs. 143-144 (March/April 1988).

(15] Master Plan. Coast Erosion Management, The Plan vol. 1.
Coast Conservation Department Danida - Danish Hydraulic
Institute (June 1986).

[16] F. Gerritsen, V. Dayananda, "Changes in Littoral Processes
due to Construction of Nearshore Structures", Ocean Space
Utilization 185, Springer-Verlaz, Vol. 2:197-204 (1985).
[17] S. Shikada, M. Mino, K. Haji, T. Moriuchi, A '. Arakawa, H.
Nishijima, E. Nagasaki, "A Direction and Policy for Coastal
Zone Management in Japan", Ocean Space Utilization 185,
Springer-Verlaz, Vol. 2:45-50 (1985).

[18] P. Faber, J. Liebster, "California's Fourteen Years of
Coastal Zone Management", Coastal Zone 187, American Society
of Civil Engineers, Vol. 3:2954-2967 (1987).

[19] D. Ortman,"Washington's CZMP - The First Shall Be Last",
Coastal Zone 187, American Society of Civil Engineers,
Vol. 3:2968-2982 (1987).

(20] C. Blair, E. Rosenburg, "Virginia's CZM Program", Coastal
Zone 187, American Society of Civil Engineers,
Vol. 3:2983-2998 (1987).

(21) Dr. R. Salm, J. Dobbin, "A Coastal Zone Management Strategy
for the Sultanate of Oman", Coastal Zone 187, American
society of Civil Engineers, Vol. 1:97-106 (1987).

[22] Managing Coastal Erosion, "State Programs and Experiences",
committee on Coastal Erosion Management Water Science and
Technology Board Marine Board, Commission on Engineering and
Technical Systems, National Research Council (November 1989).

(23] Edward K. Noda and Associates, Inc. and DHM, Inc., "Hawaii
Shoreline Erosion Management Study: Overview and Case Study
Sites (Makaha, Oahu; Kaulua-Lanikai, Oahu; Kukuiula-Poipu,
Kauai)" (June 1989).,

(24] Hawaii Revised Statutes, Section 205A-44 (b), (1986 as
amended).

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NOAA COASTAL SERVICES CTR LIBRARY

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