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Coastal Hazards Policy
Introduction
During the late 1970s and early 1980s Oregon established policies
aimed at reducing risks to new and existing development from chronic
coastal natural hazards. Under these policies new development is
regulated at the local level through comprehensive plans and zoning
ordinances. One goal, for example, prohibits development on beaches,
active foredunes, or other foredunes that are conditionally stable
and that are subject to ocean undercutting or wave overtopping, and on
interdune areas (deflation plains) that are subject to ocean flooding.
Hazard alleviation for existing development is regulated
principally at the state level, where two agencies share
responsibilities: the Oregon Parks and Recreation Department (OPRD)
and the Oregon Division of State Lands (ODSL).
Recently, several reports have evaluated the effectiveness of state
policies in light of increased pressure for development as well as
advances in scientific understanding. These reports concluded that
existing policies and procedures, which focus on site-specific
decision making, need to be improved. One action recommended a move
towards area-wide hazards management (individual littoral cells or subcells).
This is appealing for a variety of reasons:
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Hazard assessment is more consistent in quality when it is
carried out on an area-wide scale.
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Hazard alleviation is more effective and less expensive when it
is addressed at the same scale on which factors affecting
shoreline stability are operative.
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The potential for adverse impacts and cumulative effects are
minimized because there is an increased likelihood that these
will be considered in the decision-making process.
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Decision making is more timely and predictable because
interagency and intergovernmental coordination is enhanced.
Littoral cell management planning has the potential to improve the
public and private sector's ability to locate new development away
from hazardous areas and to minimize threats to existing development.
The document "Littoral Cell Management Planning along the Oregon
Coast" was prepared with these ideas in mind. The framework for
littoral cell management planning outlined in this document, and
summarized below, is designed to serve as a guide to city and county
planners, state and federal regulators and resource managers, coastal
scientists, property owners, business leaders, community activists,
and others who might be interested in developing and implementing such
a plan. The framework is intended to be flexible enough to
accommodate the broad range of community needs and capabilities found
along the Oregon coast.
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Littoral Cell Management Planning
A littoral cell management plan is
a comprehensive, integrated, area-wide hazards management
strategy unique to different physical and social settings
found along the Oregon coast. It is focused on the reduction
of risk to new and existing oceanfront development from
chronic coastal natural hazards. A littoral cell management
plan should include littoral cell inventories, a chronic
hazards management strategy, and implementation mechanisms.
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- The littoral cell inventory is a collection of
information describing physical, biological, and cultural
characteristics within a given littoral cell or subcell. This
inventory information, which can be in map, database, and text
formats, forms the basis for decision-making.
- The chronic hazards management strategy is a description
of preferred management measures and the policies and procedures
needed to implement them. Two parts of an overall chronic
hazards management strategy can be identified:
- The hazard avoidance strategy, which focuses on policies
and procedures pertaining to the siting and design of new
development; and
- The beach and shore protection strategy, which focuses on
policies and procedures pertaining to hazard alleviation
for existing development.
Together, these two strategies form the substance of a littoral
cell management plan.
- Implementing mechanisms include local ordinances,
coordination agreements, memoranda of understanding, or other
similar types of documents that adopt policies and procedures
prescribed in the management strategy. These materials,
together with monitoring and maintenance programs, are needed to
ensure the success of a littoral cell management plan.
Littoral cell management plans are developed through a three-step
planning process carried out in two phases. The three basic
steps—inventory, analysis, and implementation—are repeated
during both the hazard avoidance strategy and beach and shore
protection strategy phases of the planning process. However, each
step in the planning process involves different activities and results
in different products.
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Hazard Avoidance
 The objective
of the first phase of the planning process is to develop and
implement a hazard avoidance strategy. This involves
identifying chronic coastal natural hazards within a littoral cell or subcell, assessing
potential risks from these hazards, formulating policies to
avoid unacceptable risks, and prescribing measures that can be
taken to implement these policies.
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Inventory
The first step in the planning process is to
collect information describing physical and human factors affecting
chronic shoreline stability within a given littoral cell or subcell.
This information makes up the physical inventory. Information on a
broad range of environmental, socioeconomic, and jurisdictional
factors also needs to be collected. This information makes up the
biological and cultural inventories.
Analysis - Stage 1: Risk Assessment
Once inventory
information has been collected, it needs to be analyzed to assess the
potential risks attributable to the individual and cumulative effects
of chronic hazards present within any given littoral cell or subcell.
Risk assessment is a fundamental component of the littoral cell
management planning process. It provides information needed to make
decisions at other steps in the planning process.
Analysis - Stage 2: Policy Development
The next step in the
planning process is to examine the results of the risk assessment in
conjunction with biological and cultural inventory information in
order to formulate hazard avoidance policies appropriate to different
segments of littoral cell shoreline and establish procedures to
implement these policies. There are a variety of hazard avoidance
options that can be considered during this policy development stage of
the littoral cell management planning process. One of these options
is construction setbacks for various types and levels of new
oceanfront development.
Implementation
It is at this point in the planning process
that the materials which constitute the littoral cell management plan
are adopted. This may be done either formally or informally at local,
state, and federal levels of government. A process of plan monitoring
and maintenance also needs to be implemented. There are a number of
different types of administrative actions or agreements that can be
used to ensure that the policies and procedures which constitute a
hazard avoidance strategy are applied consistently across
intergovernmental and interagency boundaries. It is envisioned that:
- Local governments will formally adopt relevant
portions of the littoral cell management plan into their comprehensive
plans and zoning ordinances. These include maps and databases, as
well as avoidance policies and procedures. Also, they will enter into
coordination agreements with other jurisdictions, port districts, or
other special districts as needed.
- State and federal agencies will implement relevant portions
of the littoral cell management plan, first by being subject to
consistency with local comprehensive plans, and second through policy
letters or memoranda of understanding.
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Beach and Shore Protection
The objective of the second phase of the planning process is to
develop and implement a beach and shore protection
strategy. This involves identifying potentially applicable
beach and shore protection techniques, assessing the positive
and negative impacts of these techniques, formulating policies
regarding preferred alternatives, and prescribing measures that
can be taken to implement these policies.
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Inventory
Much of the inventory information collected during
the first phase of the littoral cell
management planning process can be used to develop beach and shore
protection strategies. However, additional inventory information may
need to be collected. In particular, littoral cell sediment budgets
may be required to more accurately assess hazard alleviation needs and
to better understand the positive and negative impacts of potentially
applicable beach and shore protection options. As interests other
than hazard alleviation are likely to play a more prominent role in
this phase of the planning process, additional biological and cultural
inventory information may need to be collected.
Analysis - Stage 1: Alternatives and Impacts Assessment
At this stage in the planning process inventory information needs to
be analyzed to identify potential beach and shore protection
techniques. All positive and negative impacts associated with
these techniques need to be specified. This will lead to the
identification of preferred alternatives. Because hazard alleviation
needs vary both within and between littoral cells, it is likely that a
combination of beach and shore protection techniques will need to be
employed. Community perspectives will undoubtedly influence the
decision as to what combination of options is appropriate in any given
littoral cell or subcell. Beach and shore protection
techniques can be compared through a cost-benefit analysis. However,
in most instances an elaborate cost-benefit analysis will not be
necessary. Simply structuring the alternatives and impacts
assessment in a cost-benefit context can be sufficient to reveal
preferred alternatives. There are certainly other methodologies that
can be used to identify preferred beach and shore protection
techniques for a given littoral cell or subcell.
Analysis - Stage 2: Policy Development
As was the case with
the hazard avoidance strategy, the results of the alternatives and
impacts assessment need to be examined in order to formulate beach and
shore protection policies appropriate to different segments of
littoral cell shoreline and establish procedures to implement these
policies.
Implementation
Materials which constitute the littoral cell
management plan—in this instance the beach and shore protection
strategies—need to be adopted either formally or informally at
local, state, and federal levels of government. It is envisioned
that:
-
Local governments will formally adopt relevant portions of the
littoral cell management plan into their comprehensive plans and
zoning ordinances. This includes maps and databases, as well as
avoidance policies and procedures. Also, they will enter into
coordination agreements with other jurisdictions, port districts,
or other special districts as needed.
-
State and federal agencies will implement relevant portions of
the littoral cell management plan, first by being subject to
consistency with local comprehensive plans, and second through
policy letters or preferably through memoranda of understanding.
Following adoption, attention will shift to the implementation of
monitoring and maintenance elements of the plan. Specialized
monitoring and maintenance programs may need to be applied to specific
techniques such as beach nourishment or riprap revetments.
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References
FEMA. 1996. "Interagency Hazard Mitigation Team Report."
Flooding, Landslides, and Stream Erosion in the State of
Oregon. FEMA DR-1099-OR. Pages 7-11.
FEMA. 1996. "Oregon Flooding Assistance Information as of
October 7, 1996." FEMA DR-1099-OR. FEMA Region 10, Bothell WA.
Shoreland Solutions. 1994. "Appraisal of Chronic Hazard Alleviation
Techniques: With Special Reference to the Oregon Coast." Shoreland
Solutions report to Oregon Department of Land Conservation and
Development.
Marion County Emergency Management. 1996. "Windstorms." Marion County,
Oregon. November 20.
Komar, Paul D. 1992. "Ocean Processes and Hazards Along the Oregon
Coast." Oregon Geology. Oregon Department of Geology and
Mineral Industries. Volume 54, Number 1.
Madin, I. "Seismic Hazards on the Oregon Coast." In Coastal
Natural Hazards: Science, Engineering, and Public Policy, edited
by J.W. Good and S.S. Ridlington. Oregon Sea Grant. Pages 3-27.
Satake, K., K. Shimazaki, Y. Tsuji, and K. Ueda. 1996. "Time and Size of
a Giant Earthquake in Cascadia Inferred from Japanese Tsunami Record
of January 1700." Nature. Volume 379. Pages 246-249.
Priest, George. "Explanation of Mapping Methods and Use of the
Tsunami Hazard Maps of the Oregon Coast." Oregon Department of
Geology and Mineral Industries. Open File Report O-95-67. Page 1.
Tsunami Hazard Mitigation Federal/State Working
Group. 1996. "Tsunami Hazard Mitigation Plan." Report to the Senate
Appropriations Committee. 22 pages.
Hill, Richard. 1996. "Quakes: Mapping the Hazards." The
Oregonian. November 11. Page A-26.
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This page contains detailed information about the Oregon
Department of Land Conservation and Development's (DLCD)
coastal natural hazards policies. It focuses on recent
efforts to move toward area-wide (as opposed to site-specific)
decision making.