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Land use planning for earthquake hazard mitigation

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Title:
Land use planning for earthquake hazard mitigation a handbook for planners
Series Title:
Special publication (University of Colorado, Boulder. Natural Hazards Research and Applications Information Center) ;
Physical Description:
1 online resource (vii, 121 p.) : ;
Language:
English
Creator:
Bolton, Patricia A
University of Colorado, Boulder -- Natural Hazards Research and Applications Information Center
Publisher:
Natural Hazards Research and Applications Information Center
Place of Publication:
Boulder, Colo.
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Subjects

Subjects / Keywords:
Land use -- Planning -- United States   ( lcsh )
Earthquake hazard analysis -- United States   ( lcsh )
Hazard mitigation -- United States   ( lcsh )
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government publication (autonomous or semiautonomous component)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Includes bibliographical references (p. 119-121).
Funding:
Prepared with the support of the National Science Foundation Design Research Program, Civil and Environmental Engineering Division
Statement of Responsibility:
Patricia A. Bolton ... et al..
General Note:
Description based on print version record.

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University of South Florida Library
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University of South Florida
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 002021649
oclc - 428808324
usfldc doi - F57-00081
usfldc handle - f57.81
System ID:
SFS0001162:00001


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Prepared with the Support of the National Science Foundation Design Research Program Civil and Environmental Engineering Division Washington, DC 20550 NSF Grant Number CEE-8118450 Any opinions, findings conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation. by the University of Colorado Institute of Behavioral Science

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PREFACE The risk of a major earthquake is faced by numerous jurisdictions allover the United States, from seismically active California to areas with great potential for a damaging earthquake, such as Charleston, South Carolina, central Utah, Puget Sound, and parts of Missouri and Tennessee. In fact, some 70 million Americans live in areas of significant earthquake risk, and 115 million people are exposed to less significant, but not negligible risk (National Academy of Sciences, 1975, p. 20). The threats to human activities posed by earthquakes are many: deaths and injuries, property loss and damage, economic problems, and the breakdown of essential urban functions. There has been much research into mitigation practices and policies, and engineering techniques to minimize an earthquake's potential destructiveness to the built environment. Mitigation activities have included developing seismically resistant structural designs, implementing codes and ordinances that require such designs, using planning and development authority to redirect development to safer locations, and improving emergency preparedness. This handbook--written by planners and hazards management specialists--has as its premise that land use planning techniques are useful and potentially less than some other mitigation measures, particularly structural that decrease earthquake loss potential. In order to demonstrate the usefulness of such techniques in a more manner, a comprehensive decision-making framework is presented. It outlines the steps local officials in an earthquake-pro"ne area can take to determine the eff.ectiveness of land use planning techniques to reduce losses in their community from an earthquake. iii

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ACKNOWLEDGEMENTS This handbook would not have been possible without support.from the National Science Foundation. Beyond funding, Frederick Krimgold, program manager at the National Science Foundation, provided us with valuable advice and support in the initial stages of the project, a role that was picked up in the project's latter stages by William A. Anderson. We would like to express our special appreciation to them both. During the course of the project, the principal investigators were assisted at various stages by Jim Hattori and Tom Laetz, and by the support staffs of the Department of Architecture and Urban Planning and the Center for Planning and Design qt the University of Washington, and of Battelle Human Affairs Research Centers. We are very grateful to the many persons who helped out with the research, administrative, and report production tasks. Special thanks is given to Charleen Sager for her cheerful and skillful production of the many revisions and complex tables necessary in the development of this handbook. We would also like to express our appreciation to the many planners, city and county officials, and other local experts--too numerous to mention by name--who provided information and review during the field testing of our framework for this handbook in the communities of Bellingham, Washington; Provo, Utah; and Santa Rosa, California. The process of formulating the concepts of implementation feasibility, cost, and effectiveness was greatly assisted by the professional advice of our Advisory Committee. For serving in the roles of critic and advisor we would like to thank the following: Nancy Fox, Planning Consultant, Seattle City Council; Richard Elmore, Department of Public Affairs, University of iv

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Washington; Neil Hawkins, Chairman, Department of Civil Engineering, University of Washington; Rick LaValla, Washington Department of Emergency Services; George Mader, Planning Consultant, William Spangle and Associates, Portola Valley, California; the late Mehmet Sherif, Department of Civil Engineering, University of Washington; and Richard Zerbe, School of Public Affairs, University of Washington. This handbook benefited from the careful and thoughtful review of the draft manuscript by several of our respected colleagues knowledgeablein planning and earthquake mitigation. For their extensive, timely, and useful comments, we would like to express our appreciation to: Nancy Fox, Steven French, Paula Gori, Martin Jaffee, William Kockelman, and George Mader. Final editing of the handbook was done by Sarah Nathe of the Natural Hazards and Applications Information Center, the University of Colorado. Special thanks are due to NHRAIC for publishing this handbook. v

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THE AUTHORS Patricia Bolton is a Research Scientist at Battelle Seattle Research Center. Dr. Bolton Received her Ph.D. in Sociology at the University of Colorado, Boulder, where she participated in the Natural Hazards Research Assessment led by Gilbert F. White. She had a major involvement in a study of the 1972 Managua earthquake that identified central issues in the recovery and reconstruction planning process, and recently completed a study comparing the use of disaster relief programs by various ethnic groups, including those affected by the 1983 Coalinga earthquake. She also has participated in a variety of studies on mitigation techniques for development projects and natural hazards. Susan Heikkala, now a Planner with the Port of Seattle, undertook this project while a Research Associate in the College_ of Architecture and Urban Planning at the University of Washington in Seattle. Ms. Heikkala has a master's degree in Urban Planning from the University of Washington, and has had extensive experience as a land use planner in Alaska. As a Research Associate at the University of Washington, she concentrated her efforts on several projects relating to earthquake hazard mitigation and land use planning, including serving in 1981 as conference administrator for an international colloquium frn urban-scale vulnerability and earthquake hazard mitigation in Italy, the United States, and Yugoslavia. Marjorie Greene, currently a Planner with the Bay Area Regional Earthquake Preparedness Project in California, began work on this project while a Research Scientist at Battelle Seattle Research Center. Ms. Greene has a master's degree in Urban Planning from the University of Washington. While at Battelle she focused on the planning aspects of natural hazards and disasters, including studies on individual evacuation decision making and emergency management, citizen perception of the hazard during the Mount St. Helens volcanic eruption, and earthquake hazard information dissemination in Charleston, South Carolina. Peter May is an Associate Professor in the Graduate School of Public Affairs and Political Science Department at the University of Washington. Dr. May received his Ph.D. in Public Policy from the University of California, Berkeley. His recent work has addressed the political and organizational influences on disaster policy and program implementation. Myer R. Wolfe, the Project Director, is now Dean Emeritus of the College of Architecture and Urban Planning at the Uni.versity of Washington. Professor Wolfe taught for almost 30 years ill Amet-iean and fore-igrl universities in the area of planning, and has done extensive planning and urban design consulting in both national and international settings. vi

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TABLE OF CONTENTS THE STARTING POINT Why Use this Approach? Organization of the Handbook Earthquake Effects SECTION I: RISK ASSESSMENT AND PLANNING TECHNIQUES Part A: Information Sources and Risk Assessment Part B: Selecting Appropriate Planning Techniques SECTION II: EFFECTIVENESS ASSESSMENT Part C: Implementation Feasibility ......... page 1 13 35 51 Part D: Considering Development Context and Community Objectives. 85 Part E: Determining the Costs of Techniques .. .. 95 Part F: Assessing the Effectiveness of Each Technique .... 111 BIBLIOGRAPHY . . . 119 vii

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THE STARTING POINT Contents Why Use This Approach? . . Organization of the Handbook Earthquake Effects . . . Figures page . 1 3 6 1 Development of a Land Use Planning Strategy for Earthquake Loss Reduction .......... 5

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THE STARTING POINT This handbook provides a framework for. assessing the effectiveness of various land use planning techniques for reducing a community's earthquake loss potential, and for determining the relative appropriateness of the techniques to the social and political reality of the community. A community can be interested in this framework for several reasons: The framework builds on a decision-making process that community officials often tacitly use now. By making these decision points more explicit, however, the framework can help to provide a stronger rationale for the decisions made, particularly in terms of implementation feasibtlity and costs. The framework discusses the potential usefulness of land use planning techniques in relation to community characteristics. Little work to date on planning and earthquake hazard mitigation has offered any kind of system for evaluation of usefulness in a particular setting. Since the framework recognizes that many land use management approaches are already used in communities--frequently to serve multiple purposes--it will be helpful to communities with limited resources. Why Use This Approach? The handbook begins with the twin assumptions that a community using it both recognizes its seismic risk and is prepared to consider and use loss reduction strategies. The handbook identifies several essential steps a loca.l government will need to take in order to plan and implement loss reduction techniques. The handbook will enable a community to compare one or more land use planning techniques in terms of their applicability to the community, costs involved, and overall effectiveness in reducing potential losses. Different communities have different reasons for considering a land use planning strategy for earthquake loss reduction. One community may have a 1

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citizens' group or city council member who is particularly concerned about seismic risk and prompts the local government to initiate action. Another community may have been damaged by an earthquake and want to minimize future losses. This handbook is designed for use at the point that community officials have come to be concerned about earthquake risk and are prepared to consider some planning action to reduce loss potential. There is no one "best" planning technique for earthquake hazard reduction. Community characteristics and community concerns make planning technique effectiveness particular to individual communities. This handbook also recognizes that not all communities approach the problem from the same starting point. For example, initiatives to consider land use planning will be taken in response to various "questions" such as the following: As long we are developing/changing this ordinance, what can be done to make it also apply to reducing losses from future earthquakes here? We don't want to do any more hazard-related data collection, but is there any land use planning technique that we can use with the information we already have? What can we do that will get [Group X] to stop doing [Practice Y], and thereby reduce what can be lost in an earthquake? How can we reduce the loss potential of development in areas identified as having an earthquake hazard? Couldn't we decide more easily if we had some idea of how [land use planning techniques X, Y, and Z] compare to each other in terms of cost and efficacy? the specific starting point, the process of considering land use planning techniques involves an assessment of information needs. However, locating or collecting the necessary information for the implementation of a particular planning technique is not to assure that it will be put into use. Determining the feasibility of a technique is a critical part of the process. This handbook is organized to address both these aspects of selecting 2

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one or more land use planning techniques for use in earthquake hazard reduction for a particular community. Land use planning techniques are most appropriate for communities that are growing and still have undeveloped land. Land use planning policies, subdivision and grading ordinances, land acquisition programs, and taxation policies work best in cases where there is adequate information with which to identify particularly hazardous locations. Another common approach to earthquake loss mitigation is to institute building codes and practices, or standards for new and existing construction. This can be done in a general way, being applied to all existing and new development, regardless of its location. Yet strategy is to combine a structural approach with a 10cationa1 approach, in which ce:tain standards, codes, or design requirements are applied only to specific sites known to be particularly This handbook reflects to some extent the combination of these two latter strategies. approaches include the use of disaster preparedness plans for coping efficiently and effectively with an event should it occur, and loss reduction strategies that structurally modify the land to reduce losses from hazards like liquefaction and slope instability. Both of these can and should be used in conjunction with land use planning for loss reduction. Organization of the Handbook The handbook is divided iDto two SECTION1; RISK ASSESSMENT AND PLANNING TECHNIQUES, discusses ways to obtain information and assess seismic risk, and to determine the appropriateness of various planning techniques. SECTION II: EFFECTIVENESS ASSESSMENT, describes the process for determining a planning technique's feasibility in the community, the costs that must be considered for various planning techniques, and the ways to evaluate the 3

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potential effectiveness of a particular planning technique (see Figure 1 for a schematic overview). The two analytical steps presented in Section I are as follows: Part A: Information Sources and Risk Assessment. Determining what the earthquake-related hazardsare in the area, how they affect the built environment, and what information currently exists on the hazards is a necessary step in selecting appropriate land use planning techniques. Part A contains discussions of data sources on local earthquake hazards, the nature of risks to the built environment, and approaches for conducting a community risk assessment. Part B: Selecting Appropriate Planning Techniques. This step draws on information about the community's risk as addressed in Part A, and on knowledge of various planning techniques, including those currently used in the county and city. In Part B, the planning techniques that appear to have the greatest possibility of mitigating the earthquake hazard in the community are determined. The four analytical steps addressed in Section II are as follows: Part C: Implementation Feasibility. This step involves asking a set of questions that will help to determine the likelihood of adoption, compliance, and enforcement for each planning technique under consideration. Part D: Considering Development Context and Community Objectives. The existing development pattern and the types of development pressures in the area narrow the choices among planning techniques. This step examines how the implementation of one planning technique will affect the ability to achieve other community objectives and/or how various land management programs interact. Part E: Determining Costs of Techniques. In this step, an examination is made of the types of costs associated with developing and implementing a program, and who bears them. Once these are determined, the community can consider them in conjunction with the advantages of selected planning techniques. Part F: Assessing Effectiveness of Each Technique. Effectiveness is defined as a combination of how much of the community-at-risk the technique will affect, how much the technique will reduce the loss potential, the likelihood of implementation, and the associated costs for each technique. In this step, these three elements are viewed s imu ltaneous 1 y. The order of the steps presented in the handbook is not necessarily the one which will be the best to follow. The process of determining a strategy for loss reduction may cause one to move from one step to another in an order 4

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\. THE STARTING POINT What land use planning technique(s) are feasible in this community to affect the seismic loss potential? Sse Introduction What information is available about local seismic hazards? IDENTIFY INFORMATION ON LOCAL HAZARDS What parts of the community are most at risk? AND RISK See Part A Which land use plan.ning techniques are applicable to the SELECT PLANNING type of hazard? OPTIONS Can they be used with the information available? See Part B U ASSESS What is the potential for achieving local adoption, IMPLEMENTATION compliance, and enforcement of a selected technique? FEASIBILITY See Part C What features of the community development context might ASSESS THE affect the applicability of various planning techniques? COMMUNITY CONTEXT How might the planning techniques interact with other community objectives, programs or concerns? See Part D What are the key cost considerations for each of the ASSESS THE selected planning techniques? COST At which implementation stage are they borne; and, by whom? See Part E How effective willa technique be, in terms of the ASSESS OVERALL area and land uses covered and the degree of EFFECTIVENESS implementation success? See Part F FIGURE 1 DEVELOPMENT OF A LAND USE PLANNING STRATEGY FOR EARTHQUAKE LOSS REDUCTION

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different from that presented above. It is also likely that various steps will be returned to as, for example, more information is acquired on the hazard or on the community1s likely acceptance of a particular approach. Each part of the handbook, corresponding to a major analytical step, opens with an introductory discussion that explains the nature and the purpose of that step. This is followed by a practical description of how to the analysis. A case study example illustrates how this step was carried out in a real community. This organization is application-oriented. After an introductory reading, a user can focus on the analytical activity described in each section, returning to the descriptive information and examples only as necessary for further reference. For the reader unfamiliar with the range of hazards associated with earthquakes, a brief introduction is provided below. Many sources exist that provide a more complete technical explanation of these phenomenon, or local experts can be called upon to discuss the hazards in greater detail and in reference to the physical context of a particular community. Earthquake Effects The damage caused by an earthquake is a result of an interaction between the ph.ysical event and the built environment. Thus, to estimate potentiallosses, one must both understand an area1s seismic risk and have information on the area1s population, land use, and structures. The National Research Counci I states that three conditions determine the scope of an earthquake disastert 1) the magnitude of the earthquake (a small earthquake may not involve sufficiently severe ground shaking to produce extensive damage); 2) the source of the earthquake (distance from the epicenter lessens ground shaking, and thus may be related to the level of damage in a certain location); and 3) the degree 6

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of earthquake preparedness in a community (good preparation and mitigation plans can help reduce the extent of the damage and disruption) (Committee on Earthquake Engineering Research, 1982, p. 4). Since the magnitude and source of a specific earthquake can not be altered, the only way to reduce future losses is to adopt measures in communities at risk to counteract the effects of the physical event (see Part A for more detail). Different planning approaches may be appropriate for specific types of earthquake effects. These earthquake hazards will be referred to in several of the parts of the handbook, so brief descriptions of the types of problems associated with them are given here. Included in the descriptions are indications of the effects of these hazards on the environment. Ground Shaking Gr9und shaking is vibratory ground motion caused by.an earthquake. The Mercalli intensity of the ground shaking, which is a subjective measure of severity based on observed damage and other effects, will vary from location to location. Factors affecting changes in intensity include the Richter magnitude of the earthquake (or the amount of energy released), the composition of surficial geologic deposits, and the distance from the epicenter of the earthquake. Ground shaking becomes a risk to the built environment when the seismic waves moving through the earth's crust destroy or seriously damage buildings, roads, and other public facilities. The waves may also cause equally damaging secondary hazards, including landslides, soil liquefaction, and other types of ground failure. Ground shaking typically causes most of the damage associated with earthquakes. Local geologic conditions can change the characteristics of earthquake ground shaking. For instance, the intensity of shaking be amplified by thick deposits of unconsolidated soil materials (Borcherdt et al., 1975, p. A52). Damage from ground shaking also depends on the kinds of structures being Studies of the hazard indicate the need to modify and/or strengthen local building codes and other construction standards. They can also guide decision making regarding the location of areas for community expansion, large-scale development projects, or other specified critical development proposals. Surface Faulting Faults are "planes or surfaces in earth materials along which failure has occurred and materials on oPPosite sides have moved relative to 7

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one another in response to the accumulation of stress II (Nichols and Buchanan-Banks, 1974, p. 2). There are several different types of faults, and their classification is based on geometry and direction of relative slip. Faults may be located far below the earth's surface, such as those in the Puget Sound area in Washington State, where the fault depth may be as much as 70 kilometers. An earthquake on a deep fault usually causes only ground shaking at the surface. On the other hand, faults located at or near the earth's surface, such as the San Andreas, may cause ground displacement as well as ground shaking. Displacement can take place suddenly during a severe earthquake or it can occur gradually over time. The latter is called "tectonic creep,'1 and can be accompanied by the slow distortion of surface features. For communities located on or near surface faults, gradual or violent fault displacement can cause damage to structures and/or their foundations, transportation corridors, utility systems, and other critical facilities. Little can be done to enable existing buildings and other community facilities to withstand fault displacement. Where surface faults do exist, knowledge of the location and nature of a fault can be used to help future development avoid these areas. Soil Liquefaction Soil liquefaction is lithe transformation of a granular material from a solid state into a liquid state" (Youd et al., 1975, p. A-68). This is caused by earthquake-induced ground shaking. In a liquefied state, soils completely lose their strength and are unable to support any weight or stress. Liquefaction problems are generally confined to areas having certain geologic and hydrologic characteristics, particularly water-saturated, clay-free sediments that are relatively unconsolidated. Liquefaction becomes a hazard to the built environment when the ground fails to support overlying structures, or when the material flows laterally or downslope--it's then called earth flow-damaging buildings and other facilities. Liquefaction presents a particularly difficult problem in terms of engineering a solution. Landslides Landslides can be seen as a secondary hazard in association with earthquakes, since earthquake ground motion may shake loose an unstable hillside. Earthquake-induced landslides can cause serious damage to buildings and other urban facilities through the loss of foundation material and/or burial. Landslides may also block emergency road and strand neighborhoods or entire communities. Even a mild earthquake can produce forces extreme enough to set a 'slide in motion. Unlike surface faulting or ground shaking--which occur independent of human activities--urban development can exacerbate or help control landslide hazards. Some of the more common human activities that affect the potential for landslides include earth fills for construction; construction of buildings, roads, or other structures; 8

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and use of septic systems, lawn watering, or other landscaping (Erley and Kockelman, 1981, pp. 5-6). Some of the following actions may help reduce the hazard: add surface or subsurface drainage, terrace the slope, stabilize the soil by grouting, remove or avoid adding external loads (additional development), protect the base of the slope from erosion, or support the slop with piling or retaining walls (Jaffe et al., 1981, p. 19). Flooding Earthquake-related flooding occurs in the form of tsunamis along coastlines, bays and estuaries; large-scale seiches in lakes and canals; and raging torrents after the failure of dams and levees due to ground shaking (Bolt et al., 1977, pp. 46-47). Tsunamis, generated by earthquakes under the ocean, can cause enormous devastation in coastal areas. A tsunami is a series of large gravity waves in the sea, and is sometimes referred .to as a IIseismic sea wavell or inaccurately as a IItidal wave" (Ayre et al., 1975, p. 93). It is generally accepted that an earthquake must have a magnitude of 7 Richter or greater to be accompanied by a tsunami of significant magnitude; however, earthquakes of lesser magnitude can produce tsunamis that may be damaging in a confined area (Ayre et al., 1975, pp. 93-94). Seiches are generated by a sudden fall of rock or soil (such as landslides caused by an earthquake) into a reservoir or lake. Seiches are undulations of water surface that travel back and forth across an enclosed body of water at regular periods determined by the depth and size of the water body (Bolt et al., 1977, p. 135). In certain circumstances, seiches may be produced by earthquake ground motion. The waves can be destructive to facilities along a shoreline, or may damage sewage and water storage basins slightly inland. Dam and levee failure can also result from ground shaking, and can be particularly problematic if there is a large population-at-risk .downstream. The development of an adequate warning system is necessary. 9

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SECTION I RISK ASSESSMENT AND TECHNIQUES

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PART A: INFORMATION SOURCES AND RISK ASSESSMENT Contents IDENTIFY INFORMATION ON LOCAL IfAZARDS AND RISK page Sources of Data on Local Earthquake Hazards 13 Experts and Information Maps Estimating Earthquake Effects on the Built Environment 16 Assessing Loss Potential in the Community ......... 18 Land Capability Analysis Probabilistic Risk Assessment Hazardous Building Inventory Tables A-I Information Types and How They Can be Used to Understand Local Seismic Risk. . 26 >Applications .. . .. . 25 A-2 Classifying Data on Hazards by Level of Detail Available.. .... 31 >Applications ... 30 11

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PART A: INFORMATION SOURCES AND RISK ASSESSMENT This section discusses severa.l techniques for determining community vulnerability to earthquakes, and directs the user to experts and sources that can provide detailed information on both the seismic risk and the elements in the built environment that are vulnerable to earthquake damage. Sources of Data on Local Earthquake Hazards To determine the specific earthquake-related hazards facing a community, there are various data-gathering and mapping techniques that are used by geologists, seismologists, and engineers. It is not our expectation that ,planners themselves use these techniques, but they can learn to recognize that certain areas may be prone to seismic problems and therefore require detailed and expert analysis. Information and Exper.ts As a first step, it is often possible to find clues about hazards in basic land use planning information. Table A-l lists information sources available in most communities, and describes what those sources might indicate about the seismic hazard. The examination of basic sources may show that there is some seismic risk; however, planners should not substitute their interpretations for those of qualified geologists, seismologists, or geotechnical engineers. If, there are indications of seismic risk, technical expertise and/or some additional investigation is necessary. It is also possible that, during the review of available information, a ,planner may discov_er that more specific studies have been completed. 13

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A review of regional-scale data should highlight potential local seismic problems. With reasonably complete information, a planner can tell whether a particular local area is stable, if it warrants somewhat closer analysis or even detailed site analysis before development is considered, or if it is so unstable as to put any development in jeopardy. The amount of available knowledge and the level of data resolution will also give an indication of the types of land use techniques that can mitigate that hazard. Table A-2 identifies for planners the types of data that seismologists and geotechnical engineers would need to develop an understanding of the seismic risk. The types of data are outlined in terms of the degree of detail needed, from the more general regional, through a community-wide level, to the sitespecific. Usually, detailed site analyses are undertaken only if more general data indicate that a particular problem exists. Not all geologic or seismic studies need to be conducted at a detailed or costly level; more general reconnaissance analyses using secondary data can also provide an adequate assessment of the severity of the seismic risk. In most states, the state geolQgist, the U.S. Geological Survey, and the Federal Emergency Management Agency are the agencies most likely to collect and disseminate information on earthquake hazards. A preliminary check on the information these agencies have is recommended. Another good place for information is a nearby college or university. The geology, geophysics, seismology, and engineering departments can play several roles: An individual professor can brief a local official on the kinds of data that are available for the community/region in question, and can suggest the beginning steps for a hazard assessment; Individual professors can serve as consultants to a local government, either operating in an advisory capacity or, with the use of graduate students, actually conducting hazard assessments; and 14

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Groups of professors can form advisory panels to review work performed by geotechnical consulting firms, and can assist local officials in understanding technical reports and data. Well-respected geotechnical firms, individual consulting geologists, and seismologists can also provide technical experts to perform studies. Additionally, it may be possible for a local jurisdiction to request that a state or federal agency gather some of the needed data. Other possible sources of experts include associations of consulting engineers and the Earthquake Engineering Research Institute. One particularly complete tool for .presenting information on a community's earthquake risk is a microzonation map. Seismic microzonation is a procedure of dividing a region into zones that indicate exposure to earthquake hazards such as ground shaking, surface fault rupture, liquefaction, and tsunamis. The intent of microzonation mapping is to estimate the location, recurrence interval, and relative severity of future seismic events so that potential losses can be estimated, mitigated, or avoided (Cluff, 1978). Microzonation mapping can provide the informational basis for applying land use planning techniques to earthquake loss reduction through zoning, subdivision ordinances, special use and critical facility permits, lifeline (roads and utilities) planning, property acquisition programs, and other measures (Scawthorn, 1982, p. 730; Mader, 1982, p. 673; Gaus and Sherif, 1972, p. 4). The information can also be used to develop building code performance standards for seismic load factors; these can then be applied to new construction as well as hazardous building abatement programs (Mushkatel, 1982, p. 1575). Microzonation requires information on both the physical risk and the expected structural responses to seismic forces. The actual content of 15

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microzonation maps may vary, depending upon availability of the data base, the nature of the local hazard, and the intended use of the microzonation map. For example, the following is a description of three microzonation products: [A]s a first step in microzonation, we might take empirically observed geo10gtc data, attenuation data, and data on depth to water table and combine these with a model of radiation of energy from a fault plane to create a microzonation map of expected seismic intensity in a specified area for a fault of specified size situated in a specific place [see Evernden et a1., 1981, for examples]. This map can then be combined with tables correlating intensity and percentage of damage to specific types of buildings, and with data on the distribution of building types, to yield a microzonation map of expected percentage of damage; this map could be combined with an empirically developed table correlating the average percentage of damage to residential structures with expected percentage of homeless to yield a microzonation map presenting the percentage of homeless (Evernden, 1982, pp. 1171-1172). These three maps are similar in that they are derived from empirical data sources and identify small geographic" areas exhibiting a similar response to earthquake phenomena. Because of their precision, however, microzonation maps require detailed technical information to prepare; therefore, they may be prohibitively expensive for local governments to use (Olson and Nilson, 1982, p. 1553). Estimating Earthquake Effects on the Built Environment The identification of what is likely to be damaged or destroyed in a particular community is important for the development of appropriate mitigation, preparedness, and response actions. These actions include the adoption of building codes and land use regulations that can actually reduce potential losses, as well as preparedness plans that increase the ability of local officials to respond appropriately to a damaging event. Information can 16

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also be assembled in advance to guide recovery and reconstruction efforts after a damaging earthquake. In assessing loss potential in a community, there are certain basic categories of information about the built environment that are important. These are briefly summarized here: Land use Inventory. The mapped inventory should include location patterns, use types, number of stories, building materials, and type. Population Data. In addition to basic demographic data, useful information includes mapped population distribution for critical time intervals or peak times, population projections, and economic development trends. Hazardous or Seismically Vulnerable Building Inventory. It is important to map date of construction, type of construction, structural configuration in plan and elevation, and nature and importance of occupancy. These data can be used to develop a map of potentially vulnerable buildings in the community (Arnold and Eisner, 1984). High Occupancy or Involuntary Occupancy Structures. Structures which have high levels of occupancy or involuntary occupancy include large apartment buildings, offices, major employment or shopping centers, theaters, auditoriums, stadiums, prisons, mental institutions, hospitals, schools, and convalescent and nursing homes. When located in areas of seismic risk, they represent a situation of high hazardousness. To define the loss potential, it is important to know not only the location of the structures, but their capacity populations, frequency of use, and time and duration of use. Lifelines. Lifelines include the transportation network, communications, water, sewer, gas, and electricity systems. Maps of individual systems should include critical components or linkages, such as airports, docks, phone exchange centers, water or gas storage facilities, power generating plants or stations, treatment facilities, shut-off valves, auxiliary suppliers, emergency power generators, bridges, and interchanges. If available, information on system age, condition, and type of structural material would also be valuable. Hazardous Facilities. Facilities whose failure or destruction in an earthquake would cause severe secondary damage should be located and mapped. The area affected by failure should also be mapped if possible. Facilities such as nuclear power plants, dams, and storage facilities for toxic materials are of particular concern. 17

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Essential Services and Supplies. Facilities housing essential emergency services and supplies should be sited or built to ensure continued functioning should a disaster occur. Maintaining up-to date maps of these facilities will aid both mitigation and response planning. These facilities include emergency communications centers, hospitals, clinics, medical supplies, critical equipment and fuel, and fire and police stations. Assessing Loss Potential in the Community There are several ways to combine information on seismic risk and on the built environment. Several examples of these techniques will be briefly summarized here: land capability analysis, probabilistic risk assessment, and hazardous building inventory. Land Capability Analysis Land capability analysis measures the ability of land to support different types of development (Laird et al., 1979, p. 2). This technique permits various comparisons: 1) alternative land uses can be judged in terms of their impacts on "natural" physical and biological systems; 2) the costs of hazard mitigation can be placed against the costs of earthquake damage should no mitigation take place; and 3) development options can be thought of in terms of tradeoffs with other community objectives. There are several ways to develop land capability analyses. One method recognizes that certain lands are more prone than others to erosion, flooding, fire, water pollution, vegetation and wildlife disturbances, landsliding, faulting, and environmental disruptions that may be exacerbated by development. Potential conflicts between natural processes and development pressures can be determined using a composite map which rates the conflicts on a scale of natural system disruptions. A grid system can be used to enter this information into a computer (Patri et al., 1970, pp. 49, 63). 18

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Lan.d uses can al so be compared by converti ng all projected impact costs (i.e., resource use, special studies required, mitigation measures) to some dollar value. This approach was used in the San Francisco Bay Area and is perhaps most appropriate for comparing relative costs of developing in seismic hazard areas. A quantitative approach to land capability can be quite complex and require a high level of sophistication, if all costs are to be identified and computed. In general, this approach would involve five major steps, as discussed in Laird et al. (1979, p. 3): 1) Collect earth science information and prepare basic maps. Basic geological information can be taken from maps prepared by U.S.G.S., S.C.S., or the state geologist. If more detail is needed, special staff or a consultant can be retained. All information should be mapped at the same scale. 2) Develop an interpretive map for each hazard problem from the appropriate basic information maps. For example, fault traces can often be identified from a geologic base map, whereas landslide potential requires the use of a map of photo-interpreted landslides, a geologic map, and a percent slope map. Interpretive maps are typically prepared by staff or a consultant. 3) Calculate the "social costs," or the dollar sum of all costs attributable to a problem (regardless of who pays) for each type of development and each geological. condition (several may be evident on a given parcel). Costs can be grouped into three categories: i Engineering, design and mitigation costs--prior to and immediately after construction Probable damage or disaster costs incurred in the future (e.g., replaci.ng buildings, infrastructure, loss of income, relocation) Opportunity costs--potential revenues and benefits that would have accrued from an alternative use of the land, which are now foregone. Costs that accrue at different t-i mes are normal i zed by calculating the present value of these costs using an interest discount rate. Costs which may occur at an unknown time are calculated by finding their average or expected value. Expected value is the sum of the probability of each outcome times the return if that outcome is realized. 4) Determine the measure of land capability for each use by totalling all the expected costs for all the conditions for each land use. 19

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5) Display the sums of these costs on a capability map for each land use. This can be accomplished by hand calculation and mapping, or by computer application. Quantitative land capability analysis relies heavily on interpreting maps and computing expected costs. The mapping component employed in all land capability analyses can be prepared manually or through the use of a computer. Both methods have their advantages and disadvantages. For example, the manual approach will be less expensive to do and will not require special expertise, but the resultant maps are less precise and less adaptable to other scenarios. The computer approach will allow for more flexibility in changing or combining maps, but it is costly to set up and frequently necessitates hiring' a consultant or providing extra staff training. In either case, however, land capability maps will be only as accurate as the base input information. Important distinctions between approaches are as follows: The advantages of the manual approach include a.low set-up cost, no hardware requirement, inexpensive information storage, and little special expertise to use the technique (although consultants may be required to develop the information). However, there are several drawbacks. Composite maps are generally less precise, difficult to reproduce quickly or to overlay more than two to three maps, time-consuming to alter, and prone to interpretation problems which grow with complexity. Because they are hand-drawn, it also is difficult to run multiple scenarios. The advantages of the computer mapping approach are ease of map and overlay reproduction, rapid map alteration, flexibility and adaptability for other planning purposes, and ease of changing variables or run scenarios. Drawbacks include high set-up cost, need to have access to or purchase/lease computer hardware, added cost to operate and maintain system, and likely need for consultants and staff training. Software and hardware for a small office can run from $10,000 to $40,000. Probabilistic Risk Assessment A risk assessment is a more comprehensive way to present information on both the earthquake risk and the built environment in a community. The following few paragraphs describe an assessment done in San Luis Obispo County, 20

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California. This case is mentioned because of its applicability to other medium-sized communities. The first step in a risk assessment is to identify the types of hazards present and their potential severity. At a minimum, this entails knowledge of: 1) area seismicity, including the recurrence intervals (statistical probabilities for future earthquakes based upon the frequency of earthquakes in the past) for earthquakes of varying magnitudes; 2) surficial geologic mapping; 3) predicted attenuation curves for ground shaking; and 4) estimates of ground acceleration. The more sophisticated or precise the base data can be, the more refined will be the risk assessment. In the San Luis Obispo study, the cost of surficial geologic mapping (i.e., collecting primary geologic information) was between $10,000 and $20;000; assembling secondary information took 50 person hours to cover an area of 144 square miles (French, 1983). Various methods can be used to map the hazards. A probabilistic approach estimates the recurrence potential for an earthquake of a predicted magnitude. (Note: the selection of the recurrence interval is a key decision and implies that the community has arrived at a definition of acceptable risk.) The expected ground motion from such an earthquake is then mOdeled, based on knowledge of area attenuation characteristics. This analysis requires expertise that is generally beyond the capability of small planning staffs. The product is a hazard map that can be done manually, aggregating the hazard if.tO :;t:veral categor"ies (e.g., high, medium, low), or by using a computer model. In San Luis Obispo County, a computer model was used to identify hazardous areas, based on a 10% probability of a 30-year recurrence. Modeling seismicity involved 200 person-hours; 120 hours were needed to put existing landslide and liquefaction maps into machine readable format. Input and 21

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operating the model required an additional 110 person-hours, for a total of 410 person-hours for the complete seismic risk analysis (French, 1983). The second step is to inventory land use and key features of the built environment. The number of structures and complexity of detail logged in will have a direct bearing on the refinement, accuracy, and cost of the inventory. Greater detail results in a higher degree of accuracy, but depends on the available resources to do the inventory--staff or funds. For the San Luis Obispo study, only the total number and value of structures were assessed for a limited range of construction types: wood frame, steel frame, masonry and brick, and mobile homes. The study did not distinguish between uses, number of floors, or structural densities. This information required two weeks of field work. By comparison, in San Francisco, Algermissen et al. (1978) used a much more extensive list of building types, but they also did not building uses and assumed a uniform structural density throughout the study area. The third analytical step in a risk assessment is to estimate the amount or proportion of expected damage to different buildings in different location. This step involves: 1) identifying the spatial distribution of building types by construction class; 2) developing for each construction type a relationship of the expected loss at different earthquake intensities; and 3) identifying the expected intensity at different sites. The expected loss for certain construction types at different locations in an earthquake of a specified intensity is then calculated using the above three determinations. This information can be expressed in terms of estimated dollar loss, percent loss, loss ratio, or an other relative measure. In the San Luis Obispo study, digitizing the land use information (for a relatively small population) and operating the model required 70 person-hours. Computer costs were approximately $50 per run, and at least four runs were 22

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required (French, 1983). If a computer model is developed, several future land use scenarios can be generated and then evaluated for comparative risk. Hazardous Building Inventory There are several ways to conduct a hazardous building inventory, including the method used by Los Angeles to determine that there are over 8,000 unreinforced masonry structures that were built there before seismic codes existed. These buildings were identified through a computerized listing and from building department field checking. Another method, which will be described briefly in the paragraphs, was used to determine "seismically suspicious" buildings in Oakland (Arnold and Eisner, 1984). The Oakland inventory assumed that not all pre-code unY'einforced masonry buildings are equally hazardous, and that many post-code buildings may also be hazardous (including large reinforced concrete buildings with non-ductile frames built before 1971, tilt-up concrete structures, and structures of mixed construction and poor architectural configuration). All inventories start with field .work to identify buildings with certain visible symptoms of potentially poor seismic performance. This field work results ina list of "seismically suspicious" buildings that are then further checked through conventional sources such as building department records, Sanborn maps, reports, and revisits. The term-"seismically suspicious" refers to buildings that are not necessarily hazardous, but present visible evidence might be. The criteria used in evaluating buildings are listed below. Date of construction Type of structural system 23

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Architectural/structural configuration (size and shape), and structural irregularities that can lead to torsion and stress concentration: soft stories discontinuous shear walls complex plans (re-entrant corners) weak column/strong beam conditions variations in elevational strength and stiffness extreme setbacks in elevation extreme plan or section proportions variations in column strength and stiffness Types of materials, e.g., unreinforced masonry, non-ductile reinforced concrete, tilt-up concrete, mixed materials Importance of occupancy high-density functionally critical (e.g., elderly, handicapped) Sanborn maps, building department files, historical surveys, and assessor's records are used as supplemental data sOUrces to the field survey. The result of.a building inventory is frequently a map of seismically suspicious buildings. 24

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HOW TO USE TABLE A-I 1) This table will guide the search for commonly available data sources on local hazards. The list of available sources will help you determine whether or not additional data are needed. 2) The left column of the table divides available planning information sources into three categories: natural systems, earthquakes and associated hazards, and the built environment. 3) The middle column describes how several pieces of information can be interpreted for a "more complete picture of seismic risk and potential losses. Planners will need the expertise of a seismologist or ge"ologist when reviewing the base data, particularly if there are any questions regarding the hazards. 4) The right column lists possible sources for much of this information, which typically has not been gathered into one location. Planners may be surprised at the amount of data that are available, but not commonly used by decision makers. APPLICATIONS Planners can use the table to learn what general geologic information is available, and then review those data for indications of seismic risk in their locale. Planners that are generally aware of the local hazards can identify the information sources that are likely to give them data on specific hazards and resultant community loss potential. If those data have not been collected for their jurisdiction, the community must determine whether it is worthwhile to gather additional data. For example, in conducting the case study in Santa Rosa, we used the table to ascertain that the city's data base covers seismic activity, flooding, noise, hillside areas, sewer capacity, and traffic impact. Readily available information on earthquakes and related hazards includes several maps prepared by the State of California (a special studies map, a geologic map, geology for planning). Reports on the earthquake of 1969 also exist. The availability of these data, particularly on surface faulting arid landsliding, indicates that certain planning approaches requiring geographic delineation of hazard areas could be considered: open space zoning, purchase of development rights, existing use taxation, and lifeline location. However, because the information on the ground shaking and liquefaction hazards is less geographically precise, these hazards are not amenable to management using the same planning approaches. 25

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Type of Information TABLE A-l PLANNING INFORMATION TYPES AND HOW THEY CAN BE USED TO UNDERSTAND LOCAL SEISMIC RISK What It Can Tell You Probable Sources NATURAL SYSTEMS Topographic maps- Indicate areas with steep U".S. Geological Survey trace the 1 and slopes; can be used to State geology offices contour at regular calculate slope Most commercial map interval s Interpretation of physi-outlets ography may provide clues on faulting or landsliding Relevant to developing dam inundation or flood plain maps Geologic maps Fault location; may show U.S. Geological Survey (bedrock or direction of movement State geology offices surficial geology)- Relevant to ground shaking Geology department of divide an area into attenuation estimates local university homogeneous cells Relevant to assessing based on the age susceptibility to slope and type of geologic failure and material; strati-graphic relation-ships are sometimes shown Soil surveys- Relevant to landslide Local or regional divide an area into potential office of the Soil homogeneous cells Relevant to liquefaction Conservation Survey based on soil type potential; indicates (U.S. Department and slope soil engineering of Agri cul ture) properties Relevant to ground shaking attenuation estimates Slope maps- Relevant to landslide divide an area into potential homogeneous cells based on the slope percentage 26

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TABLE A-l (cont'd) Type of Information What It Can Tell You Probable Sources Aerial photos Indicate faulting NASA (stereographic) through landform Hi gh-a 1 ti tude analysis or landsat Low altitude Indicate 1 andsl ide Commercial aerial deposits photographers Maps of subsurface Relevant to i denti fyi ng State geology offices water location-areas with liquefaction indicate the depth, potential location, and Relevant to predicting distribution of landslides (information on subsurface water changes in water levels, sources coupled with climate data, can help predict ground failure probability) Maps of vegetati on Relevant to identifying Regional office of types-areas subject to landU.S. Forest Service divide an area into slides (vegetation plays homogeneous cells a role in stabilizing characterized by hillsides) common native Analysis of vegetation vegetation types patterns may provide evidence of past faulting activity Map showing Relevant to predicting National Weather precipitation future landslide potential Service contours in unstable areas 27

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TABLE A-l (cont'd) Type of Informati on What It Can Tell You Probable Sources EARTHQUAKES AND ASSOCIATED HAZARDS Map of tsunami Flood Insurance run-up areas Administration (FEMA) Map of flood Flood Insurance inundation Admi ni stra ti on State flood control agency Map of acti ve Identifies probable For all the remaining faults hazardous areas information: Map of historic Relevant to all hazard U.S. Geological Survey earthquakes, mappi.ng State geologist showing area Local university and intensity Map showing predicted ground response due to ground shaking Map of areas prone to liquefaction Map of areas susceptible to 1 andsl ides Map of past land Identifies probable slide deposits-hazardous areas, which a map, may fail again in an usually compiled earthquake from air photo interpretation and field examination 28

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TABLE A-l (cont'd) Type of Infonnation What It can Tell You Probable Sources BUILT ENVIRONMENT I Land use map I Relevant to estimate of I Local planning or potential earthquake community development damage department I Structural type map-I Relevant to estimate of I Primary data indicatesthe type of probable earthquake collection construction, age, damage (pennits a more and number of accurate estimate than stories; use may be a land use map) included I Map of transportation I Relevant to estimating I Local transportation facilities--probable damage to or engi neeri ng identifies roads, transportation systems department bridges, overpasses, (lifelines) from an tunnels, and traffic earthquake capacities if possible I Map of sewer, water, I Relevant to estimating I Appropriate city other utilities probable damage to critical department, or utility systems (lifelines) I Various utility from an earthquake companies I Population map-I Relevant to estimating shows the exposure to risk and injury distribution of in the event of an earthpopulation density; quake it may be useful to map both a daytime and nighttime distribution I Maps of hazardous I Relevant to identifying I City/county fire installations--areas of high risk department or indicate the emergency services location of storage office areas .. I Map of dam I Identifies flood potential I Should be part of inundatiQn in the event of earthquakefederal or state zone induced dam failure flood plain requirements 29

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HOW TO USE TABLE A-2 1) Use this matrix to assess the resolution provided by existing data. Alternatively, once the level of information detail necessary for a particular purpose is known, this matrix can indicate the types of data that will meet that need. 2) Data on earthquake and associated hazards are developed at different scales, which, for the sake of simplification, fall in three main categories: regional, approximately 1:64,000-1:250,000 or greater; city, or 1:12,500-1:24,000; or site-specific. The level of data resolution reflects how precisely the hazard can be pinpointed. For example, even at a scale of 1:24,000, a line that is 0.01 inch thick covers 20 feet of actual area. At smaller scales, there is even less preclslon. The severity of the hazard will influence how important it is to be precise. In turn, the level of data resolution will affect the types of approaches that will be effective in hazard mitigation. This will be discussed in much more detail in Part B. APPLICATIONS Table A-2 can be used in two situations. A) The planners have gathered all available information and they want to assess the level of detail prior to identifying planning approach options. For example, one of the city maps may be a 1:250,000 geological map showing faults. Referring to Table A-2, in the surface faulting row, it can be seen that a map that scale falls under the classification of regionwide mapping. Planners can see that knowledge of faults is accurate only to the regional scale. B) If the city already knows what type of planning technique it wants to apply, Table A-2 will indicate the data that are needed to achieve the level of detail required for each planning technique. For example, the community may want to place a special hazard zone designation on areas with a landslide potential, and therefore it will need data that provide a geographic delineation of hazard areas. The matrix shows that a landslide inventory using time series photos and some .fieldwork, or a slope stability map meet the requirements. 30

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Level of Detail Type of Hazard 1) SURFACE FAUL TING 2) GROUND 1) SHAKING 1) LIQUEFACTION 1) LANDSLIDING 2) 3) 4) TABLE A-2 CLASSIFYING DATA ON HAZARDS BY LEVEL OF DETAIL AVAILABLE Ci ty /Countywi de Regional Mapping Geographic Delineation of Hazardous Areas Regional map showing 1) Location of faults Known and inferred using historic data, fault location physiographic analysis, and Recurrence interval instrumentation and magnitude 2) Faul t activi ty estimates cl assi fication 3) Fault zone width identification Generalized regional 1) Quantitative ground shak.ing regional intensity intensity map or peaK acceleration map Generalized lique1) Detailed liquefaction faction potential potential map using map based on soils grain size distribu-and hydrologic data tion data and estimates of peak. surface acceleration Regional map of 1) Landslide inventory past landslides using time series air using air photos, or photos and field Evaluation of soils investigations, or data surficial 2) Slope stabil ity map geologic maps Reconnaissance slope stabil i ty Terrain analysis 31 Site-Specific Study 1) Location of faults and fault traces using instrumentation 2) Fault zone width identification using field investigation 3) Estimates of recurrence interval and magnitude using instrument data 1) Ground motion modeling usi ng detail ed geographic and seismic information 1) Site maps based on field investigations and/or laboratory tests of soil samples 1) Detailed landslide hazard inventory, or 2) Quantitative slope stabil i ty map

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PART B: SELECTING APPROPRIATE PLANNING TECHNIQUES Contents SILICf PLAMIIG OPTIONS page Eleven Planning Approaches ..... 35 Selecting Your Approach ........ 37 Innovative Possibilities ......... 38 B-1 B-2 Tables Planning Techniques Appropriate to Earthquake Hazard Mitigation Data Detail Needed to Use Each Planning Technique . . . . . 40 >Application .... 45 46 33

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PART B: SELECTING APPROPRIATE PLANNING TECHNIQUES Eleven Planning Approaches Planning techniques provide a way to modify urban or regional development--its location or building standards/characteristics--in order to reduce the earthquake damage potential. Because land use issues are traditionally the province of local governments, this project focuses on 6nly those actions that local governments can initiate and carryon with little or no legislative action or financial support. This part of the handbook identifies 11 techniques that are commonly used in guiding community development, or that have been developed specifically to deal with seismic and related hazards. The approaches are listed below: Zoning ordinances Subdivision ordinances Sensitive area ordinances Building codes Hazardous building abatement ordinances Special use or critical facility permits Environmental impact statements Infrastructure (lifeline) development standards Real estate requirements Property acquisition Tax credits When evaluating the appropriateness the techniques for mitigating haiards, it is useful to examine the distinguishing characteristics of each. Four pertinent characteristics to consider are: 1) the means used for influencing development change, 2) the required local government action for adoption, 3) the amount of information required to use the technique, and 4) the aspect/s of the development process affected by each planning approach. 35

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A majority of the techniques are regulatory, the most common local government strategy for shaping community development in a fair and equitable manner. Regulatory approaches directly influence land use and development activities by specifying use, structure location and type, construction standards, and building materials. Regulatory mechanisms are generally adopted legislatively and become the laws governing land use. Because of the legal standing and potential liability local governments assume when regulating land use, more precise development restrictions increase the need for a substantial data base. Of the eleven techniques mentioned, the following have regulatory aspects: zoning ordinances, subdivision ordinances, sensitive area ordinances, building codes, hazardous building abatement ordinances, special use permits, and environmental impact statements. Most of these planning approaches are part of a local government's standard repertoire. However, just as zoning bonuses can be developed to provide public amenities such as street-level recalling or open space, it is possible to modify any planning approach to address earthquake hazards. More detailed descriptions of the techniques, and possible modifications to them, are provided in Table B-1. Several other techniques work by offering incentives to owners and developers to modify development activity in hazardous areas. These approaches rely on presenting an incentive--in the form of increased information or tax benefits--to enccurage risk-uvoiding behavior. Tax credit programs and real estate disclosure laws are the two primary examples. The creation of the incentive program usually requires government action, for the local council will have to adopt a tax credit program or, in the case of real estate disclosure, it must require real estate agents to make hazardous conditions 36

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known to a prospective purchaser. Typically, these techniques are used to affect development location and intensity. Lastly, there are several techniques that preclude subsequent private Two such techniques are property acquisition and lifeline development standards. Local government purchase of hazardous areas effectively eliminates inappropriate private uses. Standards for lifeline location can steer growth to "safer" areas where water, sewer, roads, and power are already provided. Alternatively, new lifelines can be designed and built in such a manner that they can withstand damage from a severe earthquake. Table 8-1 provides greater detail about all 11 of the approaches. Selecting Your Approach It is advisable to screen the techniques first.to narrow down the possible choices to those that seem potentially appropriate. Those techniques can then be subjected to more in-depth analyses. Four criteria can help you with the screening: 1) What planning techniques are already adopted by the community? The types of planning approaches in use, and how well they work, give an indication of what other options are likely to be applied successfully to new situations. For example, if a community already has a zoning ordinance, a modification of that ordinance may be relatively simple. If special studies are already required in flood the same mandate could be extended to areas prone to seismic hazards. However, the list of currently used approaches should not limit what is given further consideration; in some cases, a fresh approach can succeed where more tried and true ones have not .. 2 What is the general nature of the development to be managed? By clarifying the problem the planning techniques are meant to solve, it is possible to identify the more potentially useful approaches. To take an extreme example, if continued new development in known hazard-prone areas is the concern, zoning provisions would be more appropriate than, say, a building code to regulate structural design. 3) What information is available on the hazard? Some techniques require a substantial amount of base information--particularly when it is necessary to specify the boundaries of an area-at-risk. Table B-2 gives a general indication of the minimum amount of information 37

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needed in order to apply each of the techniques presented in the handbook. A community can use the table to determine which approaches are appropriate given the information already available. On the other hand, the community could also decide it wants to utilize a particular approach, and then use the table to ascertain what information must be acquired in order to do so. A decision would then have to be made to expend the resources to collect/develop the needed information. 4) Political considerations. Subjective considerations will also affect the selection of planning techniques. For instance, the city council's current attitude towards regulatory proposals or program costs, or the availability of knowledgeable staff to operate a program will influence the choices that are made. Users of this handbook must rely on their own knowledge of the community to guide them. Taken together, these criteria can guide the user in specifying techniques appropriate for further investigation. Innovative Possibilities The list of planning techniques presented in the handbook is not an exhaustive one. The list does represent the most commonly used techniques, but users are strongly encouraged to use it as only a starting point. Techniques may be combined in new ways, or entirely new approaches may be tried. For example, Provo City has established a Site Plan Review Committee to provide an interdisciplinary review of most major development projects. Provo could consider a modification of the existing review process to incorporate an assessment of the earthquake hazard. This could be done with an additional requirement that the developer provide a report on how earthquake hazards may affect the project, indicate how the design will mitigate losses, and provide engineering geology expertise to the committee. This option not only builds on existing approaches, but also adds that aspect of an environmental impact statement which requires applicants to address/discuss potential adverse project impacts. 38

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HOW TO USE TABLE B-1 1) The left-hand column of the table lists 11 planning techniques that could be employed for earthquake hazard mitigation. Two of these techniques have been developed specifically to address the issue of earthquake hazard mitigation: a hazardous building abatement ordinance and real estate disclosure. The remaining techniques are more general, but can be modified by special provisions. 2) The left-hand column of the table identifies some of the options for modification. It is important to note that these represent just some possibilities, and communities should not limit themselves to these. Creativity in designing new tools or combining others is encouraged. 3) A brief description of each planning technique is provided in the center column. 4) The right-hand column briefly describes how the techniques can reduce the loss potential from earthquakes, or other hazards, for existing or future development. This information, coupled with an understanding of the nature of the hazard to be mitigated, is useful in narrowing the list of planning techniques for further consideration HOW TO USE TABLE B-2 1) Table B-2 gives the user an indication of the level of detail on the existing hazard that is generally required in order to apply anyone of the planning techniques. 2) The shaded boxes indicate the specificity of information needed. If a box is not shaded, that level of detail is generally considered insufficient for application of the technique. For example, a with a ground shaking and landsliding hazard that is interested in developing an overlay zone for its zoning ordinance would require, at a minimum, data on the community's geographical area or, even better, on specific development sites. An overlay zone approach can not r'ealistically considered with only regional"data. 3) If the community has data for the landslide hazard but not ground shaking, it might still be possible to develop the ordinance to cover landslides and not ground shaking. It is not necessary for one technique to address all hazards, but it may be more desirable from the community's point of view. 39

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PLANNING TECHNIQUE 1) ZONING Options for tailoring: a) Special Seismic Study Zone b) Hazard Zone With Performance Standards TABLE B-1 PLANNING TECHNIQUES APPROPRIATE TO EARTHQUAKE HAZARD MITIGATION DESCRIPTION Most cities and counties commonly use zoning to regulate the type and location of land uses, structure, siting, structure height and bulk, parcel size, land use intensity, and other development performance standards. Zoning ordinances can be tailored specifically to restrict development near earthquake hazard areas. A separate zone is created and applied to active faults, other well-defined hazards, or a combina tion of hazards. The ordinance speciffes allowable uses and any special development standards (e.g., building setbacks from a fault trace, open space requirements). It would also be possible to write the ordinance requiring a special site evaluation as a means of determining the development standards. California's Alquist Priolo Special Studies Zone Act is an example of this type of zone. There, no structure for human occupancy is permitted to be placed across the trace of an active fault, and all development within the zone must be accompanied by a geologic report. Another option is to develop a series of graduated risk zones (e.g., high, medium, low) and attach appropriate development standards to each. Rather than create a separate zone as above, a map overlay of areas would define ment or performance standards in addition to those contained in the overlay. Supplemental standards might include setback regulations, clearing or grading restrictions, or additional construction standards. 40 LOSS REDUCTION FUNCTION Restricts or prohibits new development (by location and/or type of use) in identified areas. Affects the built environment with respect to: volume allocation location density

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PLANNING TECHNIQUE c) Open Space/ Conservation Zone 2) SUBDIVISION STANDARDS Options for tailoring: a) Perfonnance Standards for Sensitive Lands b) Planned Unit Development TABLE B-1 (cont'd) DESCRIPTION Some hazardous areas can be included in a community's open space system, thus providing a dual benefit of meeting a community's open space needs, as well as precluding development that would pose a threat to life and property. For example, a potential landslide area might also be a wildlife or park area that should, according to community goals, be zoned as open space. Most cities have anordinance which sets procedures and requi.rements for all land subdivisions. The ordinance may specify development standards for the size and shape of lots and blocks, or street dimensions. Often these ordinances contain availability requirements and/or construction standards for streets, curbs, gutters, seWers, water mains, and sidewalks. For certain identified lands, such as those with slopes in excess of 20% or areas with a high water table, the ordinance could allow the city to require special site studies and impose special development standards on a case-by-case basis. (Examples of types of special studies in a steep hillside area include a landslide/slope stability investigation report; a soil engineering investigation report; and a composite geologic and soil engineering report detailing sufficient mitigation measures to reduce potential for i nstabil i ty. ) Planned unit developments (PUDs) can/may be estab lished as a geographically defined zone, or they may be allowed to "float" and locate in any of a number of zones. Because PUDs generally require careful review on a case-by-case basis, hazardous conditions can be addressed in the development plan review. The plan submission requirements can be expanded to include a discussion of any potential hazards and appropriate actions to mitigate them. 41 LOSS REDUCTION FUNCTION Restricts new development location in certain areas. Sets standards for site layout and services (roads, utilities, open space)

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PLANNING TECHNIQUE c) Development Standards 3) SENSITIVE AREA ORDINANCE 4) BUILDING CODES TABLE (cont'd) DESCRIPTION Where hazards are thought to be well understood, a community may choose to add specific development standards to their subdivision ordinance, which would be applicable to all subdivisions (e.g., all structures larger than a certain size may need engineered foundations). For hillside areas, for example, all developments could be required to have adequate drainage facilities to intercept and carry identified or expected surface and subsurface seepage flows to the nearest storm drain or sewer lateral for all hillside development; to have sanitary sewer installations instead of septic tank systems; to have egress and ingress from two independent road systems; to obtain right-of-way easements to preclude development directly adjacent to public improvements in unstable or potentially unstable areas. A sensitive area ordinance requires that any project falling within the boundaries of an identified area must submit a special study showing how fragile or hazardous conditions will be addressed in development, so that any potential degradation or hazards are minimized. This ordinance has some similarities with a hazard overl ay zone. Building codes protect public welfare by regulating and controlling the design, construction, quality of materials, use and occupancy,location, and maintenance of all buildings and structures within a jurisdiction (UBC, Chapter 1, Section 102). Since 1961, special seismic standards have been included in the Uniform Building Code. Similar standards are contained in the Building Official Conference of America (BOCA) and the Southern Building Code Congress (SBCC). 42 LOSS REDUCTION FUNCTION Establishes structural standards for different types of new construction.

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PLANNING TECHNIQUE Options for tailoring: a) Adopt Code Standards b) Supplemental Seismic Standards c) Sub-area Supplemental Seismic Standards 5) HAZARDOUS BUILDING ABATEMENT ORDINANCE 6) SPECIAL USE AND CRITICAL FACILITY PERMITS TABLE B-1 (cont'd) DESCRIPTION Local governments may choose to adopt the basic building code and its seismic standards. Generally these standards are tailored to different seismic regions across the U.S. Local governments can develop or adopt more stringent anti-seismic structural standards to address the hazards in their particular community. For communities concerned about particular hazards in selected areas, it is possible to adopt structural standards designed for these small areas. Such an approach is used relatively infrequently. This type of ordinance is used to require property owners to bring designated substandard and hazardous buildings (or portions of them) into closer conformance with the current building code or possibly be faced with condemnation and demolition. For examp1e, buildings with parapets may be required to anchor the parapet or remove it, or unreinforced masonry buildings may be required to provide anchoring of floors to walls. The property owner is liable for the development costs. A special permit review procedure can be developed for certain uses and critical facilities which the developer require!; to prepare more detailed studies, demonstrating that the project will meet applicable safety standards. This would apply to uses which, because of the nature of their use or function (e.g., emergency facility, dangerous operations, dependent population facility or high occupancy building) require a reasonably high margin of safety. 43 LOSS REDUCTION FUNCTION Establishes standards for retrofitting specified existing buildings or building types. May relocation or demolition. May restrict the .1ocation of identified facilities or set design and structural standards for development.

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PLANNING TECHNIQUE 7) ENVIRON MENTAL IMPACT STATEMENTS (OR REPORTS) 8) TAX CREDITS TABLE B-1 (cont'd) DESCRIPTION For those states requiring an impact report prior to permit issuance, this review can be used to ensure that seismic concerns are addressed and mitigation options considered. Where state regulatory code allows, special conditions could be attached to the permit, based on the findings in the impact statement. For example, the state may have an impact reporting requirement that could be used or adapted for this purpose. This program reduces the property owner's tax liability as long as the land is left undeveloped or developed at a very low density. Tax credit programs may take a variety of forms including current use value, deferred use, or a restrictive agreement. LOSS REDUCTION FUNCTION Provides incentive for owner to limit development in seismically vulnerable areas. --------------------.----------------------------9) REAL ESTATE DISCLOSURE 10) PROPERTY ACQUISITION OR PURCHASE OF DEVELOP MENT RIGHTS 11) INFRASTRUCTURE (LIFELINE) LOCATION AND DESIGN STANDARDS Within identified areas, realtors are required to provide prospective purchasers of real property information on the existence of a natural hazard. Information on the hazard is intended to work as an incentive to take risk avoidance action, such as not locating in the hazardous area, purchasing earthquake insurance, or building to higher structural standards. These actions put the management of identified hazardous areas into the hands of local government. Once purchased, the lands can be managed to protect public safety and, in some cases, meet other :ommunity objectives such as providing open space or low intensity recreation areas. Policies and plans to locate lifelines away from known hazardous areas reduce the community's exposure to losses by steering private development from these areas. Better lifeline design standards can aJso reduce community loss exposure by insuring that lifelines are more able to withstand damage in an earthquake. 44 Informs purchaser of existing hazard affecting all real estate trans actions. Restricts or limits development location through property purchase. Directs new development location away from hazardous areas. Ensures new lifelines are con structed to meet standards of seismic safety.

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TABLE B-2 DATA DETAIL NEEDED TO USE EACH PLANNING TECHNIQUE SURFACE GROUND FAUL TING SHAKING LIQUEFACTION LANDSLIDING Hazard ...-..... ...-...i g e e e 1 e e Ie e Analysis ::s 0 ::s 0 ::s f;: ::s i ..... CI.l ..... CI.lI ..... CI.l CI.l +'" en en +'" en +'" and 0 ..... CI.l 0 CI.l 0 V; 0 u II') ex: u 11'), ex: u u Pl anni ng Mapping $.. $.. $.. $.. $..1 $.. $.. $.. $.. $.. 0 0 0 0 0, 0 0 0 0 0 Techniques II.&.. I.&.. I.&.. I.&.. I.&.. I.&..t I.&.. I.&.. I.&.. I.&.. I.&.. Special sei smic I studv zones I I I 1) ZONING Hazard overlays with, I I I I I I I I ORDINANCE performance s tandardsl Open space/recreation' I I I II I I I I zones Design standards I I I I I I Planned unit I I I I I I I 2) SUBDIVISION develooment ORDINANCE Location (specified) I I I I standards Location I I I I 3) SPECIAL USE sDecifications AND CRITICAL Development I I I I FACILITY standards Performance I I I I I I I standards Adopt UBC I I I 4) BUILDING Modify UBC I I CODE Modify UBC I bv sub-area 5) HAZARDOUS Performance I I I I I I I I BUILDING standards ABATEMENT Development I I I I ORDINANCE standards 6) LIFELINE Locational I I I I SEISMIC REQU IREMENTS Structural I I I I I I I 7) REAL ESTATE I I I I I I I DISCLOSURE 8) TAX CREDIT I I I I Fee simple purchase I I I I 9) PROPERTY ACQUISITION Development rights I I I I 10) SENSITIVE AREA I I I I I I I ORDINANCE 11) ENVIRONMENTAL I I I I I I I I I I I I IMPACT STATEMENT 45

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APPLICATION Bellingham, Washington, is a moderate-sized, growing community located in the northern reach of Puget Sound. It is the largest city in Whatcom County and is, therefore, a major regional service center. It is situated in an area of multiple natural hazards. In applying this framework there, we answered the following questions to select planning techniques for further analysis: 1) What planning tools are already used? Current planning approaches in Bellingham include the zoning ordinance, subdivision ordinance, building permits, special permits for shoreline and flood plain developments, the environmental impact statement process, and a development standard for unsuitable areas (steep or unstable soils). 2) What is the general nature of the development to be managed? In Bellingham, the haiards in most of the developed parts of the city is ground shaking or subsidence. The city is also growing at a moderate rate and expanding into adjacent areas of the county. Areas of high attractiveness in the urban fringe include some with steep slopes or landslide hazards. 3) What information is available on the hazard? Mapped information does exist on geologic hazards in the city and county, although not at sufficient detail to allow application of planning techniques to existing development in the city. 4) Political considerations? We identified support among some staff for a sensitive area ordinance. Other staff said that the city council would be very reluctant to consider adoption of a new regulation aimed at earthquake hazard mitigation unless they could compare damages expected without such a regulation. All the information available led us to conclude that for purposes of further analysis we should consider: a) techniques that only required modifications to existing ones (perhaps reducing some costs associated with implementation); b) techniques directed at future development; and c) 46

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techniques that could rely, to at least a certain extent, on existing mapped information. Thus, we selected for further analysis: 1) modification of the zoning ordinance to more specifically address the seismic risk, 2) modification of the subdivision ordinance to more specifically address the seismic risk, and 3) development of a sensitive area ordinance. 47

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SECTION II EFFECTIVENESS ASSESSMENT

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PART C: IMPLEMENTATION FEASIBILITY Contents Adoption, Compliance, and Enforcement ASSESS IMPLEMENTATION FEASIBILITY page 51 Ways to Determine Implementation Feasibility 0 0 0 0 0 0 53 C-1 C-2 C-3 C-4 C-5 C-6 C-7 C-8 C-9 C-10 C-ll C-12 Tables Zoning ........... Subdivision Ordinance 0 0 0 0 Sensitive Area Ordinance 0 0 0 Building Code Seismic Requirements 0 0 0 Hazardous Building Abatement Ordinance 0 Critical Facility and Special Use Permit Environmental Impact Statement 0 Tax Credits 0 0 0 0 0 0 0 Real Estate Disclosure 0 0 0 0 Property Acquisition 0 0 0 0 0 Lifeline Location/Design 0 0 0 0 >Application 0 0 0 0 0 0 0 Considerations in Determining Implementation Feasibility 0 0 00 0 0 0 0 0 0 0 0 0 0 0 49 55 57 59 61 62 64 66 68 70 72 74 76 79

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PART C: IMPLEMENTATION FEASIBILITY It. is important to remember that the availability of the best information possible does not necessarily ensure that a planning technique will be effective in reducing loss potential in the community. Even the most apparently appropriate planning measure, based on the most sophisticated information, will not reduce earthquake damage if it is not implemented.. If the political and/or economic trade-offs are viewed by the community as unacceptable, the measure will not work. To determine a technique's chance of being implemented, it is helpful to answer the following question: what kinds of hazard mitigation measures have the best likelihood of being adopted and enforced by the city, and complied with by the populace? Adoption, Compliance, and Enforcement Adoption, although fraught with its own difficulties, is a one-time process. Compliance and enforcement are ongoing challenges that demand vigilant personnel and available financial resources. A planning technique is sometimes unpopular in a community for such economic reasons; in another community, the technique may be unpopular for political, social, or similar complex reasons. For instance, since manj of the planning techniques have a regulatory dimension, they involve governmental actions to change development pr building activities in hazardous areas. The "targets" of the regulation are the individuals, builders, or developers whose activities are supposed to change. In principle, the target .groups behave as the regulation specifies, thereby reducing present or future loss potential. In practice, however, some target groups do not abide by regulations because to do so runs contrary to 51

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their own vested interests. Needless to say, regulations that are not followed will not have the desired affect of mitigating the earthquake hazard. It is necessary to gather information on how likely it is that a planning approach will be adopted, complied with, and enforced. Adoption The adoption of a planning approach can be interfered with by an administrative inability to delineate the hazardous area, or to specify performance criteria for building projects in the hazardous area. For example, information necessary to mapping hazardous areas may not be available and the community may not want to spend the money needed to get it. On the other hand, there may be sufficient information, but there might not be expert staff in key agencies to review all the projects and separate the safe from the unsafe .. To ensure adoption, all such local exigencies must be recognized aDd dealt with. Compliance There is no point in securing adoption of a land use planning measure without also providing for compliance to its specifications. Levels of compliance will be influenced by various considerations--social, political, economic, psychological--all of them incentives (or disincentives). For instance, some groups will think that it costs too much to comply, others will see comp1iance as ethically correct, and still others will will think that community acceptance of a certain regulation is politically and socially If noncompliance is unlikely to be detected, or if the penalty for noncompliance is not viewed as greater than the benefits derived from engaging in the prohibited activity, the degree of compliance is likely to be low. Therefore, provision must always be made for monitoring activities in the hazardous areas, and for enforcing the regulations. 52

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Enforcement In general terms, the effectiveness of enforcement depends on 1) how easily noncompliance can be detected, 2) the number of cases to be regulated, 3) the economic and political importance of the cases being regulated, 4) the number of enforcers, 5) the enforcers' incentives to do their jobs, and 6) the ease with which exemptions and variances are granted (the greater the ease, the more difficult the enforcement). Ways to Determine Implementation Feasibility The points must be addressed with respect to each planning technique in order to judge its implementation feasibility: Requirements for enabling officials to adopt the technique must be met. The technique must be made acceptable to various interests. The likelihood of the interests' compliance must be estimated. Enforcement difficulties must be anticipated. The technique must be made as compatible as possible.with other community objectives. Tables C-1 through C-11 present the ABCs of determining implementation feasibility for each of the 11 planning techniques. Table C-12 summarizes important considerations for all techniques. 53

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HOW TO USE TABLES C-1 THROUGH C-11 A separate table is provided for each planning technique. 1) The left column indicates the types of questions that need to be answered about the feasibility of getting it adopted, having a high level of compliance with it, and being able to enforce the way in which it is applied. Other considerations affecting implementation feasibility also are addressed where applicable. 2) The right column indicates types of information that will be gathered on implementation feasibility when it suffests that less than full implementation can be expected for one or more reasons, the planning technique should be considered with caution. 3) However, it be noted that a negative assessment of the implementation feasibility of a particular technique, rather than simply being considered as grounds for rejecting the tool, can be used as a guide for what elements in the implementaiton process will take extra attention. HOW TO USE TABLE C-12 Table C-12 summarizes for each technique other important considerations for implementation potential 1) Each of the techniques is listed down the left-hand column. 2) In the columns to the right, description is given of additional important analytical elements to consider. As the individual column heads indicate, the implementation of any technique involves: the target group (whose behavior is to be affected); who is likely to be in control of the implementation process; what additions or modifications need be made to establish the technique; what will be enforce or monitored; and what is the most likely barrier to full implementation. 54

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TABLE.C-l IMPLEMENTATION FEASIBILITY: ZONING FEASIBILITY CONSIDERATION A. Can it be adopted? 1. Can hazardous areas be delineated? 2. Are there undeveloped areas where zoning would apply? 3. Can performance standards be developed? B. How likely is compliance? 1. Is there much existing development in the hazardous areas? 2. How much change would be required in existing zoning designations? 3. What is the size and value of parcels in affected areas? 4. Is there a legal incentive for developers to comply? 5. Is there an economic incentive for developers to comply? 55 HOW IT AFFECTS IMPLEMENTATION Mapping can be time-consuming and expensive, depending on level of existing information and level of detail required. Zoning would be most effective in lesser developed areas. Additional study would likely be necessary to establish standards. Possible further staff expertise required to review plans to ensure standards are met. Where there is already nonconforming use, variances are more likely. Large changes create greater pres sure for granting variances and may entail hi gher "opportuni ty costs. II Large, high value parcels are in a better position to negotiate variances. If failure to comply might make developers liable, compliance more likely. Direct economic i'ncentive may make compliance more likely.

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TABLE C-l (cont I d) FEASIBILITY CONSIDERATION C. How difficult is enforcement? 1. Will the city have the ability to assess conformance with zoning categories or development standards? 2. Is it possible to detect nonconformance with specific project requirements? 3. Is there much willingness to grant variances? 4. What is the economic value of future developments in the hazardous areas to the jurisdiction in terms of tax revenues, employment? 5. Is there likely to be fo110w through on implementation by the local jurisdiction? D. Other considerations 1. Primarily, who will be affected by the zoning ordinance? 2. Political support. 56 HOW IT AFFECTS IMPLEMENTATION Inability to detect nonconformance diminishes enforcement success and thereby undermines effectiveness. Inability to detect nonconformance undermines effectiveness. Variances from standards undermines their utility. Jurisdiction may be more willing to permit variances in order to not lose high value developments. Less than total implementation undermines effectiveness. Most likely to affect developers. Target groups can influence political acceptability of tool. Ease with which tool can be adopted and enforced may depend on political endorsement and support.

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TABLE C-2 IMPLEMENTATION FEASIBILITY: SUBDIVISION ORDINANCE FEASIBILITY CONSIDERATION HOW IT AFFECTS IMPLEMENTATION A. Can it be adopted? 1. Can hazardous areas be delineated? 2. Can seismic safety design and performance standards be developed? 3. Are future subdivisions anticipated? B. How likely is compliance? 1. Are there legal and economic incentives for the subdivision developer to comply? 2. Are there alternative sub division sites available in nonhazardous areas? C. How d1ff1cu1t is enforcement? 1. Will requirements be developed for individual subdivisions? 2. What is the economic value of future subdivisions to the local jurisdiction in terms of tax revenues, employment? 57 Mapping can be time-consuming and expensive, depending on level of existing information and level of detail required. Establishes whether or not such requirements can be used. This tool would only apply to future subdivisions. Requirements viewed only as economic disincentives may prompt developer to go elsewhere, ignore requirements or dispute requirements. If other sites are available, developer is likely to use them. Negotiating requirements for each subdivision requires staff skilled in such negotiations and knowledge of subdivision problems. Jurisdiction may be more willing to weaken requirements in order to not lose high value developments.

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TABLE C-2 (cont'd) FEASIBILITY CONSIDERATION 3. How difficult is it to detect nonconformance with the requirements for each subdivision? D. Other major considerations 1. Primarily who will be affected by such a modification to the subdivision ordinance? 2. Political support. 58 HOW IT AFFECTS IMPLEMENTATION Enforcement effectiveness related in part to ease of detecting nonconformance. Most likely to affect developers. Target groups can influence political acceptability of tool. Ease with which tool can be adopted or enforced may depend on political endorsement and support.

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TABLE C-3 IMPLEMENTATION FEASIBILITY: SENSITIVE AREA ORDINANCE FEASIBILITY CONSIDERATION A. Can it be adopted? 1. Can sensitive areas be delineated? 2. Is it possible to specify the types of reports to be required for different developments? 3. Is it passi b1 e to develop "performance standards"? 4. Are there undeveloped areas where this ordinance would apply? B. How likely is compliance? 1. Is there much existing development in the potential sensitive areas? 2. Is there an economic incentive for developers to comply? 3. Are there alternative development sites available? 59 HOW IT AFFECTS IMPLEMENTATION Mapping can be time-consuming and expensive. Necessary to formalize requirement to apply ordinance consistently. Such standards would be necessary to establish development conditions Ordinance most applicable to undeveloped areas. Where development already exists in areas to be designated as sensitive, variances are more likely. If such an incentive exists, compliance more likely. If other sites exist a developer could choose to go there; however, this ordinance most likely to lead to design or modification, not total restriction.

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TABLE C-3 (contJd) FEASIBILITY CONSIDERATION C. How difficult is enforcement? 1. Is it possible to assess the adequacy of special site reports and prepare development standards or mitigation requirements on a case-by-case basis? 2. What is the economic value of future developments in these areas to the jurisdiction in terms of tax revenues, employment, etc.? 3. What is the willingness to reduce development standards for particular projects? 4. Is it possi bl e to detect nonconformance with specific project requirements? 5. Is there 1 i kely to be foll owthrough on implementation by the local jurisdiction? D. Other considerations 1. Primarily who will be affected by a sensitive area ordinance? 2. Political support. 3. Compatibility with other goals and programs? 60 HOW IT AFFECTS IMPLEMENTATION Inability to assess report adequacy diminishes enforcement success and thereby undermines effectiveness. May affect willingness of jurisdiction to condition development proposals. Much willingness may weaken ordinance; however, some flexibility necessary for adoption. Inability to detect nonconformance undermines effectiveness. Less than total implementation undermines effectiveness. Most likely to affect developers. Target groups can influence political acceptability of tool. Ease with which can be adopted and enforced may depend on political endorsement support. The more compatible the better.

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TABLE C-4 IMPLEMENTATION FEASIBILITY: BUILDING CODE SEISMIC REQUIREMENTS FEASIBILITY CONSIDERATION A. Can it be adopted? 1. Can seismic safety standards be developed, or amended? B. How likely is compliance? 1. What are the economic or legal incentives of builders to comply? 2. What is the availability of building sites in nonseismically hazardous areas? 3. What are the size and value of buildings affected? c. How difficult is enforcement? 1. How difficult is it to assess conformance with building requirements? 2. What is the willingness to grant exemptions? 3. What is the economic value to the jurjsdiction of buildings subject to seismic standards? D. Other considerations? 1. Political support. 61 HOW IT AFFECTS IMPLEMENTATION Such standards would be necessary to establish code requirements. If" there are few incentives, requirements may be ignored. Adequate knowledge of nonhazardous areas makes it more likely that building activity will relocate rather than build to more stringent standards. Large, high-value parcels may be in a better position to negotiate exemptions. Inability to detect nonconformance diminishes enforcement success and thereby undermines effectiveness. Exemptions from standards undermines their utility. Jurisdictions may be more willing to grant exemptions or otherwise weaken the requirements in order not to lose high-valup development. Suggests ease with which policy tool can be adopted, plus willingness to grant exemptions/impose sanctions.

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TABLE C-5 IMPLEMENTATION FEASIBILITY: HAZARDOUS BUILDING ABATEMENT ORDINANCE FEASIBILITY CONSIDERATION A. Can 1t be adopted? 1. Can the hazardous buildings be identified? 2. Is it possible to prepare retrofitting standards? B. How likely is compliance? 1. What is the economic or other incentive for property owners to comply? 2. What are the size and value of buildings affected? 3. Is there a mix of private/ public building ownership in affected areas? C. How difficult is enforcement? .. di ffi cul t wi 11 it be to assess property owner conformance with retrofitting requirements? 62 HOW IT AFFECTS IMPLEMENTATION Potentially hazardous buildings must be precisely identified, although fairly general criteria can be used to isolate buildings requiring an inventory. Inability to define standards would make ordinance preparation di ffi cul t. Potential liability would make compliance more likely. The higher the building value the more likely the owner can afford the retrofitting cost. Retrofitting of public buildings demonstrates the city's commitment to the program. If most of the buildings are private, city has less leverage and greater difficulty in showing benefits of program. Enforcement effectivenss related in part to ease of detecting non conformance.

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TABLE C-5 (cont1d) FEASIBILITY CONSIDERATION 2. What is the willingness to reduce retrofitting requirements for specific buildings? 3. What is the economic value to the city of buildings and/or uses subject to retrofitting requirements? D. Other considerations? 1. Political support. 63 HOW IT AFFECTS IMPLEMENTATION Willingness to reduce requirements could weaken the program; however, flexibility might also be necessary to gain political support. Jurisdiction may be more willing to negotiate requirements for high value buildings. Ease with which a tool can be adopted and enforced may depend on political endorsement and support.

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TABLE C-6 IMPLEMENTATION FEASIBILITY: CRITICAL FACILITY AND SPECIAL USE PERMIT FEASIBILITY CONSIDERATION A. Can it be adopted? 1. Can hazardous areas generally be defined? 2. Can uses and facilities be identified that would be subject to permit? 3. What future facilities are anticipated? B. How likely is compliance? 1. What is the economic incentive of the facilities to comply? 2. What is the availability of alternative facility sites in nonhazardous areas? C. How difficult is enforcement? 1. Does local capability exist to specify requirements for individual facilities? 2. What is the economic value of future facilities to local jurisdiction. 64 HOW IT AFFECTS IMPLEMENTATION Establishes the geographic area for which the requirements would apply. Establishes whether or not such requirements can be used. This tool only applies to future development of facilities. If compliance is costly, facility may not be built or may be put elsewhere. If a public facility, may involve rate increases/approval. If other sites are available, facility may use them. May lead to development shifting to another jurisdiction. Negotiating requirements for each facility requires staff skilled in such negotiations. Jurisdiction may be more willing to weaken requirements for high value facilities.

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TABLE C-6 (cont'd) FEASIBILITY CONSIDERATION 3. What type of ownership will potential facilities have? 4. How difficult will it be to detect nonconformance with requirements for each facility. D. Other considerations 1. Political Support. 65 HOW IT AFFECTS IMPLEMENTATION Mix of public/private complicates negotiating. May not have authority for some types of facilities. Enforcement effectiveness related in part to ease of detecting nonconformance. Ease with which the tool can be adopted, and willingness to negotiate specific requirements are related to the 1 evelof political support.

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Table C-7 IMPLEMENTATION FEASIBILITY: ENVIRONMENTAL IMPACT STATEMENT FEASIBILITY CONSIDERATION HOW IT AFFECTS IMPLEMENTATION A. Can it be adopted? 1. Are large-scale developments expected in hazardous areas? 2. Can hazardous areas be delineated? B. How likely is compliance? 1. What is the economic incentive of the property developer to undertake special seismic studies? 2. What is the availability of alternative development sites? C. How difficu]t is enforcement? 1. Is there expertise to determine necessity for evaluating the earthquake risk? 2. What is the economic value of future developments to the local jurisdiction? 3. What is the number of future developments likely to be by affected a special seismic review? 66 This establishes the need for this tool. This is necessary for requiring on-site geologic investigations. Mapping can be expensive and time consuming. If compliance is costly, developers will go elsewhere or provide only minimal coverage. If other sites are available, the developer is likely to use them. If not, development may be shifted to other areas. More than minimal information will not be provided, unless it is clear that it is required. For more profitable developments the jurisdiction may be less willing to require and/or act on earthquake hazard information. As the number of developments increases, more administrative staff/expertise may be required.

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TABLE C-7 (cont1d) FEASIBILITY CONSIDERATION 4. What is the seriousness which EIS review agencies attach to seismic hazards? D. Other considerations 1. What is the compatibility of the EIS seismic safety provision with other provisions? 2. What is the expertise of the review agency? 67 I HOW IT AFFECTS IMPLEMENTATION If agencies not concerned about the hazard, the EIS information will have little impact on agency actions/design requirements. Greater compatibility makes adoption more feasible and likelihood of acting on information higher. Information will be taken more and legal challenges to decisions based on earthquake information will be fewer if agency staff has earthquake expertise.

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TABLE C-8 IMPLEMENTATION FEASIBILITY: TAX CREDITS FEASIBILITY CONSIDERATION A. Can be adopted? 1. Can hazardous areas be delineated? 2. What is the existing use of properties in these areas? 3. What is the ownership of property in the affected areas? 4. Is such a program legal? B. How likely is compliance? 1. What is the economic incentive for property owners to opt for current use taxation? 2. What is the economic value of property in future unregulated uses to local jurisdiction? 3. What is the turnover of property in affected areas by likely participants? 68 HOW IT AFFECTS IMPLEMENTATION Establishes geographic area in which credits would be available so number and types of potentially affected properties can be determined. Existing nonconformance with eligible uses affects suitability of program to area (because program geared at avoiding future nonconforming uses). Complex public/private mix of ownership increases adoption and implementation difficulties. In some states, for example, some forms of tax credit (e.g., current use taxation) are against the state constitution. If opportunity cost of use restriction is great, participation will be low. Jurisdiction may be less willing to restrict use (to open space or other less hazardous uses) of high value property. Higher turnover creates less incentive to take credit, adds to the administrative burden of running the program.

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TABLE C-8 (cont'd) FEASIBILITY CONSIDERATION C. How difficult is enforcement? 1 How difficult will it be to detect nonconformance with use restrictions among those taking tax credit? 2. What is the willingness to impose penalties for nonconformance? D. Other considerations 1. Political support. ..,. 69 HOW IT AFFECTS IMPLEMENTATION Constant checking may be requi.red to determine compliance. If not imposed, compliance with use restrictions is less likely. Affects the ease with which program can be adopted

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TABLE C-9 IMPLEMENTATION FEASIBILITY: REAL ESTATE DISCLOSURE FEASIBILITY CONSIDERATION A. Can it be adopted? 1. Can hazardous areas be delineated? 2. Are property sales in seismic areas anticipated? B. How likely is compliance? 1. What is the willingness of real estate agent$ to disclose hazardous area information? C. How difficult is enforcement? 1. What is the ability to detect failure to disclose? 2. What are the sanctions for failure to disclose? 3. What is the volume of real estate transactions and does it vary? 70 HOW IT AFFECTS IMPLEMENTATION The more difficult and expensive the mapping effort is, the more difficult adoption of such a tool will be. Real estate turnover is the point at which the policy has its impact. This also indicates the amount of potential impact. This willingness is the key to implementation of this tool, affected by turnover of agents, sales patterns, sanctions, enforcement and mapping quality and availability. Compliance is less likely if conformance is difficult to detect. Compliance is less likely if the sanctions are weak; yet if they are too strong, the tool may not be enforced. As the volume of goes up, more enforcement/administrative apparatus may be required.

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TABLE C-9 (cont'd) FEASIBILITY CONSIDERATION D. Other considerations 1. How likely are buyers to consider the earthquake hazard to be serious? 2. What is the endorsement and support of real estate/ regulatory authorities? 71 HOW IT AFFECTS IMPLEMENTATION If potential buyers are not con cerned about the hazard, disclosure will have little impact on purchase or mitigation behaviors. Since real estate agents are the critical implementation link, endorsement is important.

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TABLE C-IO IMPLEMENTATION FEASIBILITY: PROPERTY ACQUISITION FEASIBILITY CONSIDERATION HOW IT AFFECTS IMPLEMENTATION A. Can it be adopted? 1. Can hazardous areas be delineated? 2. Can the jurisdiction establish a financing mechanism for such a program? 3. What is the ownership of property in affected areas? B. How likely is compliance? 1. What is the economic incentive of the property owner to sell the property? 2. What is the economic value of property in its existing use to the local jurisdiction? C. How d1fficult is enforcement? 1. Is there likely to be fo110wthrough on implementation by the local jurisdiction? 72 This establishes the appropriateness of this tool and would indicate the number and type of potentially affected properties. Without funding the jurisdiction cannot acquire properties, and the extent of funding (as well as cost of property) determines number that can be acquired. A complex public/private mix of ownership makes it more difficult to adopt and implement. If cost and other concessions are not suitable, acquisition cannot be made. Jurisdiction may be less willing to downgrade use of high value property. If the jurisdiction acquires a property fee simple, there should be no enforcement issue. If only the development rights are purchased, the jurisdiction would want legal recourse in the event a property is developed at a different density or for a use than all owed.

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TABLE C-IO (cont'd) FEASIBILITY CONSIDERATION D. Other considerations 1. Public concern for the earthquake risk. 2. Endorsement and support of elected officials. 73 HOW IT AFFECTS IMPLEMENTATION This will affect willingness of the voters to support referenda approving public financing of the acquisition program. Affects ease with which tool can be adopted.

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TABLE C-ll IMPLEMENTATION FEASIBILITY: LIFELINE LOCATION/DESIGN FEASIBILITY CONSIDERATION HOW IT AFFECTS IMPLEMENTATION A. Can it be adopted? 1. Can hazardous areas be delineated? 2. Can design/development standards be prepared for infrastructure development? 3. Will existing or future lifelines be affected by these standards? 4. Can negotiated agreements be made between the local government and the lifeline owners (service providers)? B. How lfkely is compliance? 1. What is the need for these lifelines to support growth demands? 2. Are alternative locations in nonhazardous areas available? 3. Is there any economic incentive to comply? 74 Establishes geographic area where tool would apply. Delineates (potential) location of lifelines .Inability to define reasonable standards would make adoption impossible. Locational standards only apply to future lifelines. As number of affected lifelines increases more negotiations required. Open communication required to negotiate a memorandum of under standing or other agreements. Multiple public/private ownership complicates negotiation. High need for new lifelines increases difficulty of redirecting service extensions. Lack of alternative sites may lead to development being shifted to other cities if cannot be redirected in local area. May be possible to service provider that better design of facilities will reduce future losses due to earthquakes (and other natural disasters). Increases willingness to comply.

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TABLE C-ll (cont'd) FEASIBILITY CONSIDERATION C. How difficult is enforcement? 1. Can design and/or locational plans be developed for each lifeline? 2. Can the jurisdiction maintain negotiated agreements with the service provider? 3. What is the economic value of future lifelines to the city? D. Other considerati ons 1. Political support. 75 HOW IT AFFECTS IMPLEMENTATION Requires a staff with knowledge of technical problems and the capabilities to negotiate requirements. Jurisdiction needs tools to ensure that service provider follows through with memorandum of under standing. The value of the lifelines to jurisdiction may affect willingness to do without relocation. Affects the ease with which tool can be adopted as well as the to negotiate relocation speci flCS.

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APPLICATION Following is an example from the field test done in Bellingham, Washington. The potential for adopting a sensitive area ordinance, obtaining compliance with it, and enforcing it are examined (see table C-3). The sensitive area ordinance is considered in the specific context of Bellingham. A. Can a sensitive area ordinance be adopted? 1) Can these areas be delineated? 2) Is it possible to specify the types of reports to be required for different developments? 3) Is it possible to develop "performance standardsfl? 4) Are there undeveloped areas where this ordinance would apply? Yes. Possible sensitive areas, including seismic hazards, are already mapped. Professional judgement is needed to determine which areas should be labeled sensitive. Yes. In essence, this is already generally defined in the existing ordinance and through current practice. The requirement needs formalization. lt would be difficult, and perhaps detailed standards are not necessary. Assuming a qualified professional reviewed the site-specific studies, conditions can be tailored on a case-by-case basis. Yes. The city is expanding into fringe areas of the county and continues to be infill development within the city. However, a better calculation of the amount of land potentially affected is needed. B. How likely are developers to comply with such an ordinance? 1) How much existing development is there in the potential sensitive areas? 76 A moderate Areas over the old coal mines are extensively developed and it may be difficult to place very strict on projects. In addition, there is some residential development along shoreline bluffs.

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2) What is the economic incentive to comply'? 3) Are there alternative development sites available? c. How difficult is enforcement likely to be? 1) Is it possible to assess the adequacy of special site reports and to prepare development standards or mitigation requirements on a case-by-case basis? 2) What is the economic value to the jurisdiction of future developments in these areas in terms of tax revenues or employment? 3) What .is the willingness to reduce development standards for particular projects? 4) Is it possible to detect non conformance with specific project requirements? 77 There will be a strong incentive to comply since the local government will not issue the appropriate permit unless there is compliance. However, if the study and potential mitigation costs appear too high, there may be a tendency to avoid development. Generally, study costs are scaled to development size. Yes. A developer could choose to go elsewhere, but that is less likely since this ordinance leads to modifications, not total restrictions. Only to a limited degree, given present staffi ng. in the city and county. Implementing a sensitive area ordinance would require either hiring .an engineering geologist or having one on retainer. This would be an added cost. Thi s wi 11 vary,. and may have an effect on how willing the city or county is to approve development proposals. However, most of the affected development will be for residential uses. Development may be conditioned, but probably not prohibited. This is difficult to predict, but it is likely there will be some. The county and city will want to avoid placing an undue burden on developers, especially if that would make an economically valu able project unfeasible. Yes, there are multiple checks. Most of the requirements will be reflected in the project design, which must be approved prior to the issuance of a building permit. There are also three site inspections prior to occupancy.

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5) Is there likely to be follow through on implementation? Yes, although there may be a breakdown when it comes to imposing sanctions since this takes place through the county prosecutor. D. Are there other considerations that affect implementation feasibility? 1) Primarily who will be affected by the ordinance? 2) Is there likely to be political support for this ordinance? 3) How compatible is the sensitive area ordinance with other goals or programs? 78 Private developers, generally those engaged in residential projects or a few industri"al and commercial/retail endeavors. That is unclear. Any regulation tends to generate oPPosition in the area, and the county staff indicated that the time might not be right. However, this ordinance is similar to existing standards and formalizing it will provide development predictability. Very. As mentioned earlier, it is similar to the concept of "unsuitable lands" which is now used by both the city and county. Such an ordinance could also be jointly administered since the city and county already have such an arrangement with certain codes. "

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-.....J \.0 PLANNING TARGET TECHNIQUE GROUP 1) ZONING Developers individual buFders larpe-scale dew. 1 opme n ts 2) SUBDIVISION Develorers ORDINANCE 3) SENSITIVE AREA ORDINANCE developments Developers individual buil1ers larg!-scale TABLE C-12 CONSIDERATIONS IN DETERMINING IMPLEMENTATION FEASIBILITY CONTROL OF IMPLEMENTATION Local entity has direct control through its zoning authority) Local entity has di rect control; negotiates standards for each subdivision Local entity has direct control administra tion of ordinance) PROGRAM DEVELOPMENT AND ADOPTION Revisions or possible new ordinance zoning maps performance standards Development of subdivision ordinance Development of ordinance and standards ADMINISTRATION AND ENFORCEMENT Conformance with zoning standards Conformance with negotiated requirements Conformance with ordinance standards IMPLEMENTATION BARRIERS Undermined by granting of variances; may not be able to detect nonconformance for some standards May not be able or willing to negotiate strong seismic provisions because of economic interests Undermined by granting of variances; may not be able to detect nonconformance for some standards 4) BUILDING Owners/managers Local entity has Can adopt UBC Conformance with Undermined by weak enforceCODE of future direct control seismic standards sei smi c safety ment/exemptions; may be SEISMIC buildings in through building and/or develop standards as part difficult to detect nonREQUIREMENTS seismically department own standards of construction conformance for some vulnerable areas and permit process standards 5) HAZARDOUS Owners/managers Local entity has Can adopt previously Must identify nonUndermined by weak enforceBUILDING of existing direct control developed standards conforming buildings; ment/exemptions; may be ABATEMENT buil di ngs in through building and/or develop own enforce conformance difficult to detect nonORDINANCE seismically department standards as part of building conformance for some vulnerable areas inspection process standards

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(Xl a PLANNING TECHNIQUE 6) CRITICAL FACILITY AND SPECIAL USE PERMITS 7) ElS REQUIREMENTS 8) TAX CREDIT for land uses which are compatible with se i smi c hazards 9) REAL ESTATE DISCLOSURE of sei sm1c vulnerability TARGET GROUP Operators/owners of sei smically vulnerable special facilities (e.g., schools, nuclear facilities) Developers of large-scale developments Owners of property in sei smi ca lly vulnerable areas Purchasers of property in seismically vulnerable areas CONTROL OF IMPLEMENTATION Local entity control depends on authority to regulate facility; negotiates specific requirements for each facility Local entity has indirect control (through administration of EIS, required by state) Local jurisdiction provides incentives (assuming has tax 1 evy authority); participation is voluntary Local entity control is indirect; requires cooperation of real estate agents and target group response to information TABLE C-12 (cont'd) PROGRAM DEVELOPMENT AND ADOPTION Design of requirements for each class of facility State develops EIS requirements Ordinance specifying eligibility for tax credits Local entity must delineate seismic zones, Rrepare maps, establish disclosure requirements ADMINISTRATION AND ENFORCEMENT Conformance with negotiated requirements Conformance with requirements Must i denti fy eligible properties; monitoring of land use as part of assessment practices Requires monitoring of disclosure practices (presumably by real estate board) IMPLEMENTATION BARRIERS May not be able or willing to negotiate strong seismic provisions because of cost to facility and need for the facility Undermined by weak enforce ment/exemptions Property owners may not find the tax credit amount sufficient to induce land use changes Undermined if agents/boards not willing to disclose and monitor disclosure; disclosure itself means little unless purchaser concerned with hazard

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co I--' PLANNING TECHNIQUE 10) PROPERTY ACQUISITION T.ARGET GROUP Owners of property in sei smi cally for property vulnerable areas in sei smi cally vu1 nerable areas 11) LIFELINE Agencies which LOCATION AND own/operate DESIGN FOR lifelines (e.g SEISMIC water mains. SAFETY sewers. gas lines) CONTROL OF IMPLEMENTATION Local jurisdiction provides incentives; participation is voluntary Local entity control depends upon owner-ship of lifeline; must negotiate specific requirements for each lifeline TABLE C-12 (cont'd) PROGRAM DEVELOPMENT AND ADOPTION Requires identification and authorf ty to purchase property; may require special public financing/ approvals Design of acceptable locations for siting lifelines and/or performance ADMINISTRATION AND ENFORCEMENT No enforcement required other than normal policing of acquired property Conformance with negotiated locationa1 or performance requirements IMPLEMENTATION BARRIERS Property owners may not be willing to sell at price offered; voters not authorize/financing hard to obtain Ability to control lifeline decisions may be limited; may not be willing to have strong seismic provisions because of ratepayer cost

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n. PART D: CONSIDERING DEVELOPMENT CONTEXT AND OTHER COMMUNITY OBJECTIVES Contents ASSESS THE COIIMUNITY CONTEXT page The Context of Development Pressures . . 85 Earthquake Hazard Mitigation and Other Objectives 88 Tables D-1 Interaction of Planning Techniques with Other Community Objectives 83 . . . . 91

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PART D: CONSIDERING DEVELOPMENT CONTEXT AND COMMUNITY OBJECTIVES The appropriateness of a particular land use planning technique and the likelihood that it can be implemented must be judged against the situation in the community for which it is proposed. The relationship of the existing development pattern to the hazard area is one important contextual factor. Another is the social, economic, and political environment of the community--that is, any community decision, such as implementing one of the land use planning techniques.discussed in this handbook, is a reflection of what is acceptable to various interests and compatible with other community objectives. Both the development context and the political context must be taken into account, along with the nature of the earthquake hazard, when selecting an appropriate land use planning technique for reducing losses from future earthquakes. The Context of Development Pressures There are five features of the development context that affect the selection of relevant land use planning techniques: the physical nature of the hazard, the intensity of development in hazardous areas, the community growth rate, the availability of alternative development sites outside hazardous areas, and considerations. The nature of the area's hazard affects the appropriateness of land use planning techniques. Areas with geographically definable hazards are more likely to be able to adopt more precise techniques. For instance, if the geographic area of the hazard has been precisely delimited, then it is possible 85

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to adopt techniques such as zoning or subdivision ordinances that have explicit prohibitions or performance standards for development. Geographically definable hazardous areas include those assessed as likely to be subject to faulting, landsliding, or flooding (from tsunamis or dam failure). If, however, the nature of the hazard is defined as ground shaking from earthquakes, and the hazard is diffused over the entire area of the community (developed and undeveloped), it is not feasible to adopt zoning ordinances to mitigate earthquake loss potential. In such an instance, construction standards for all new development would be easier to institute. With respect to existing development in high-hazard areas, certain portions might come to be viewed as particularly vulnerable, either because, of their location (e.g., on areas prone to liquefaction or subsidence) or because of their construction characteristics (e.g., unreinforced masonry). In such instances, regulations might require the relocation of certain types of existing development (e.g., hospitals or schools) to a less hazardous irea, or at least the reinforcement of buildings or lifelines. In areas where there is already extensive development in identified seismic risk zones, jurisdictions are likely to be wary of restricting new development for fear of litigation over equal protection. In addition, those areas with a high concentration of development and services tend to attract additional development. Economic and political pressure may be brought to bear for acce5S to those ctreas, making use testrictions difficult to apply and enforce. A related issue is whether there are available development sites in the surrounding area. In jurisdictions where few new sites remain, economic demand will make it difficult to restrict new development, even if hazardous 86

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conditions exist. While restricting development zoning may not be feasible, enforcing stricter building standards may be acceptable. Large, rapidly growing areas may be willing to consider the adoption of land management controls to reduce future earthquake hazards. Areas subject to rapid growth often are more receptive to applying controls because the problems associated with unregulated development are generally exacerbated during boom times. Again, however, the availability of developable sites is important in a community's receptivity to land use management controls. Finally, the complexity of the hazard in a particular area may require considerable technical expertise for its definition or mitigation. As was noted in the preceding section on implementation feasibility, a jurisdictlon may lack the economic resources or staff capability to provide the precisely defined boundaries of a particular hazard area. For example, considerable technical expertise may be needed to designate areas particularly prone to intensified shaking, liquefaction, or subsidence. A community must have or acquire the technical expertise to determjne the exact location of such areas before it can adopt and enforce land use planning controls. Where it is known that particularly hazardous areas are likely to be present, but large-scale and precise mapping of them has not been accomplished, it also possible to shift the burden of identifying the hazardous araas to the developer. This is done through the adoption of management techniques requiring that certain performance standards be met, rather than by specifying what type of development is or is not permitted in a specific area. In this instance, the jurisdiction still must have the necessary technical expertise to review the plans, but will be spared the cost of the hazard study. 87

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Earthquake Hazara Mitigation and Other Objectives The need to attend to the threat of an earthquake has, for may communities, little sense of urgency. Often political support is minimal for earthquake mitigation and preparedness activities and, in a list of priority activities for local officials, earthquake preparedness might rank in the lower third. On the other hand, even when a community has decided to address earthquake concerns, it may be possible to sell the idea of earthquake risk reduction only as it enhances another community objective, such as reducing potential damage from flooding or landsliding. Thus, the interaction between earthquake mitigation and other community objectives can sometimes be both positive and negative. It is important for planners to remember that such interactions exists and can be important to the ultimate implementation of any particular technique. It is also important to realize that implementation of any planning technique in a community often involves a series of trade-offs and compromises. The series of questions asked in Part C on the feasibility of implementing a selected technique aims, in part, at this point. Political acceptability is particularly important. This section serves as a further reminder that other interests and objectives exist in each community, and that they can, in some cases, enhance or compete with the goal of earthquake hazard mitigation. Table D-1, which follows, provides examples of the ways in which the specific planning techniques may enhance or conflict with other community objectives. A primary concern is how compatible the proposed of risk reduction is with existing community goals and programs. Where goals compete, it will be necessary to decide priorities in the political arena. Where the actions necessary to reduce the damage potential from earthquakes might well 88

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enhance other community objectives, the creative design of planning initiatives to capitalize on this is in order. In any policy decision, the community social, economic and political context will be a factor. While the physical development context can be defined in fairly general terms, the social, economic and political context of a community is more idiosyncratic. For example, the amount of effort needed to implement an earthquake-related land use policy in a particular community will be influenced by such things as the general predisposition locally for or against regulation, time-specific budget constraints, current rulings on legal liability, or the overall importance placed on seismic hazards as one of many community agenda items. These factors cannot be quantified and entered into a formula, but they will be influential in the ultimate decision to adopt--or not to adopt--an earthquake loss reduction program. The insight of a community's planners and administrators is necessary for identifying how these factors will affect attempts to implement any land use planning techniques. 89

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HOW TO USE TABLE 0-1 1) This table offers, for each of the 11 planning techniques identified in Part C, an example of how the technique might enhance or conflict with another community objective. The examples provided here are illustrative, and not necessarily exhaustive. Users of this handbook, familiar with their own community situations, undoubtedly will be able to identify other.possible interactions between a technique to reduce damage and other community objectives. 2) The techniques are listed in the left-hand column, and possible ways in which each technique might enhance or conflict with other objectives are listed in the next two columns. 90

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TABLE 0-1 Planning Technique ZONING ORDINANCE SUBDIVISION ORDINANCE SENSITIVE AREA ORDINANCE BUILDING CODE HAZARDOUS BUILDING ABATEMENT ORDINANCE CRITICAL FACILITY PERMIT ENVIRONMENTAL IMPACT STATEMENT TAX CREDIT REAL ESTATE DISCLOSURE PROPERTY ACQUISITION LIFELINE LOCATION/DESIGN INTERACTION OF PLANNING TECHNIQUES WITH OTHER COMMUNITY OBJECTIVES Could enhance Cou 1 d confl i ct another community with another community objective such as: objective such as: Reduction of the Economic development flood hazard Reduction of the Private developers' landslide hazard provision of low-cost housing Preservation of Minimize government open space regulations Improved public Minimize government safety regulations Improved emergency Historic preparedness preservation Improved public Minimize government safety regulations Growth management The encouragement of development projects Preservation of Economic development agricultural land Protection of Real estate agents' sensitive areas right to practice Preservation of open Maintenance of existing space development patterns Growth management Maintenance of development patterns *The examples given here are meant to be illustrative, not exhaustive. 91

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PART E: DETERMINING THE COSTS OF TECHNIQUES Contents Types of Costs Associated with Adoption, Compliance, and Enforcement for each of the Planning Tools (see Tables E-1 through E-11) E-1 Zoning Ordinance .. E-2 Subdivision Ordinance Tables E-3 Sensitive Area Ordinance >Application E-4 Building Code Seismic Requirements. E-5 Hazardous Building Abatement Ordinance E-6 Critical Facility and Special Use Permit E-7 E-8 E-9 E-lO E-ll Environmental Impact Statement Tax Credits . . Real Estate Disclosure Property Acquisition . Lifeline Location/Design 93 . . . . . . . . . page 95 96 97 98 107 99 100 101 102 103 104 105 106 ASSESS THI COST

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PART E: DETERMINING THE COSTS OF TECHNIQUES The costs associated with implementing a particular planning technique are an important consideration in an overall assessment of its risk reduction potential. Costs can be estimated for each of the three implementation stages--adoption, compliance, and enforcement. Costs can also be broken down according to how much is borne by government and by the private sector. Any way you look at it, however, there are both front-end and future costs. It is always most useful to be able to identify dollar figures, although that can be difficult. There is some value in estimating only level of cost (high-moderate-low). A final detailed evaluation of a planning technique in a particular community does, however, require dollar amounts for the costs of implementation. HOW TO USE TABLES E-l THROUGH E-ll The following 11 tables identify the categories of costs associated with the implementation of each of the techniques. 1) The left-hand column identifies types of fur compliance, and enforcement. 2) The middle column describes the costs in terms of who bears the cost and when. 3) The far right-hand column provides a brief description of how each cost can be assessed. 95

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TABLE E-1 COST CONSIDERATIONS: ZONING ORDINANCE COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to identify and map the hazardous areas? 2) Will new zoning maps be required, and what would their costs be? 3) How much will it cost to develop the ordinance (or modification) and standards? How much does it cost to comply? 1) What are the design and development costs for future developments resulting from new standards or zoning provisions? 2) Would there be changes in revenues (particularly property taxes) resulting from changes in future land use? 3) Are there potential increases in permit costs? How much does it cost to enforce? 1) What are the costs of reviewing compliance with new zoning standards? 2) What are the costs of conditioning development (e.g., requiring certain performance standards)? WHO BEARS COST/WHEN Front-end cost to be borne by city and/or county. Front-end cost to city or county. Front-end cost to city or county. Engineering and site preparation costs (front-end) to developer. Future, across time, cost to local jurisdiction. Front-end cost (in a review time) to local jurisdiction and in .permit fees to developer. Front-end and future cost to local jurisdiction. Ongoing cost to local jurisdiction. 96 HOW TO ASSESS COST (Major Considerations) Will field work be required? Additional staff expertise? Consulting expertise? New maps? Overlay? Staff time to write ordinance? Review time? Nature of site and construc tion project will determine. Will SUbstantial change in nature of development occur? Will additional review necessitate consulting with engineer or geologist? Wi 11 addi ti ona 1 exrerti be required (staff or consulting)? Will additional review capability be required?

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TABLE E-2 COST CONSIDERATIONS: SUBDIVISION ORDINANCE COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to map the hazardous areas? 2) How much will it cost to prepare basic standards? How much does it cost to comply? 1) Changes in design and development costs for future developments resulting from new standards or requirements? 2) Changes in revenues'resu1ting from changes in future uses (opportunity costs)? 3) Costs of negotiating specific requirements for each development (e.g., special staff review, extra legal fees, consultants)? How much does it cost to enforce? 1) Cost of reviewing compliance with requirements? 2) Increases in permit costs resulting from new requirements? 3) What are the costs of conditioning Other costs 1} Delay:; resulting from compliance with or disputes over new requirements? 2) Potential loss of development because of unwilling ness to comply with new requirements? WHO BEARS COST/WHEN Front-end cost to local jurisdiction (unless regional, state or federal agency can undertake the project). Front-end cost to local jurisdiction. Front-end cost to developer. Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction and/or developer. Ongoing cost to local jurisdiction. Ongoing cost to developer. Ongoing cost to local jurisdiction. nngoing cost to local jurisdiction and developer. Future cost to local jurisdiction. 97 HOW TO ASSESS COST (Major Considerations) Additional information required? Expert-consultant estimates. Comparison with similar efforts. Comparison with past and/or similar efforts. Expert judgment. Preliminary site-specific study will determine need. Significant only if expect substantial change in the nature of development. Additional staff time for review? Additional expertise (structural engineer)? Nature of development can determine. Types of site-specific studies required?' Additional expertise required on site? Additional time to comply? Degree of acceptance of changes (interviews with developers)? Assess willingness to comply through interviews with potential developers.

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TABLE E-3 COST CONSIDERATIONS: SENSITIVE AREA ORDINANCE COST CONSIDERATION How .uch does it cost to adopt? 1) How much will it cost to identify and map the hazard? 2) How much will it cost to develop the ordinance and standards? How auch does it cost to comply? 1) What are the costs of preparing site investigations? 2) What are the design and development costs associated with these new standards? 3) Are there potential increases in permit costs? 4) What. if any. will be the change in revenues as a result of the new ordinance? How Much does it cost to enforce? 1) What are the costs of review ing site studies and condi tioning development? 2) What are the increased costs of reviewing project compliance? Other costs 1) What are the effects on other regulatory programs? WHO BEARS COST/WHEN Front-end cost to be borne by local jurisdiction. unless regional, state or federal agency willing to undertake project. Front-end cost to local jurisdiction. Front-end cost to the developer. Front-end cost to developer. Front-end cost (permit fee) to developer. Frontend cost (staff review of permit) to jurisdiction. Future, across time, to local jurisdiction. Front-end and future cost to local jurisdiction. Ongoing cost to local jurisdiction. May increase/decrease ongoing costs to local jurisdiction. 98 HOW TO ASSESS COST (Major Considerations) Will field link be required? Additional staff expertise? Consulting expertise? Staff time to write ordinance? Review time? Coordination with other departments, programs? Nature of site and size and type of construction project will determine. Nature of project will determine. Will additional review necessitate additional expertise? Will there be a significant change in development pattern? Will additional expertise be required? Will additional review capability be required? Can separate regulatory programs be streamlined by this?

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TABLE E-4 COST CONSIDERATIONS: BUILDING CODE SEISMIC REQUIREMENTS COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to map hazardous area? 2) How much will it cost to prepare seismic building requirements How much does it cost to comply? 1) What are the changes in design and building costs for new construction because of sei smi c standards? How IllUch does it cost to enforce? 1) What are the costs of reviewing compliance 'with requirements? ,2) What are the increases in permit costs resulting from new requirements? Other costs 1) Will there be a potential loss of development because of inability to meet seismic requirements? 2) Will there by delays in building construction resulting from compliance with or disputes over new requirements? WHO BEARS COST/WHEN Front-end cost to local jurisdiction and/or another public agency. Front-end cost to local jurisdiction. Front-end cost to developer, building owner (could be passed on to buyer, occupants) Front-end cost to local jurisdiction. Front-end cost to developer (could be passed on to buyer, occupant) Ongoing cost to local jurisdiction. Front-end cost to local jurisdiction and developers. 99 HOW TO ASSESS COST (Major Considerations) Will field link be required? Additional expertise? Will additional, specialized expertise be required? Staff time to prepare requirements? Additional engineering work required? Additional staff time, expertise required? Nature of project will determi nee Assess likelihood that new requirements will prevent How much additional time will be required for compliance.

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TABLE E-5 COST CONSIDERATIONS: HAZARDOUS BUILDING ABATEMENT ORDINANCE COST CONSIDERATION How IlUch does 1t cost to adopt? 1) What is the cost of mapping hazardous areas? 2) What is the cost of identifying hazardous buildings? 3) What is the cost of preparing seismic building requirements? How much does 1t cost to cOllply? 1) What is the cost of design and building renovations in order to comply with standards? What are the enforcement costs? 1) What are the inventory costs? 2) What are the costs of reviewing compliance with the retrofitting standards? 3) Are there likely to be other enforcement costs? Other costs 1) What is the potential loss of redevelopment because of the inability to meet seismic requirements? Or potential increase in tax base? WHO BEARS COST/WHEN Front-end cost to local jurisdiction (if it doesn't a 1 ready exi st) Front-end cost to local jurisdiction. Front-end cost to local jurisdiction. Front-end cost to developer or building owner. Front-end cost to local jurisdiction. Ongoing cost to local jurisdiction. If compliance is not 100% there may be legal and demolition costs to the local jurisdiction. Ongoing cost to local jurisdiction. 100 HOW TO ASSESS COST (Major Considerations) Will field work be required? Will it just be screening criteria or detailed survey? Staff time necessary? Additional expertise? Staff time to prepare ordinance? Review time? What is the necessary additional engineering structural work required? Additional expertise (structural required? Additional staff (inspectors) required? Over time, high rehabilitation costs likely to translate into higher rents.

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TABLE E-6 COST CONSIDERATIONS: CRITICAL FACILITY AND SPECIAL USE PERMIT COST CONSIDERATION How much does it cost to adopt? 1) What does it cost to map the areas? 2) What are the preparation costs to establish a basic set of requirements? How much does it cost to comply? 1) What are the likely changes in design and development costs for special facilities resulting from new requirements? 2) What are the costs of negotiating specific requirements for each new facil ity? How much does it cost to enforce? 1) What are the costs of revi ewi ng compli ance wi th requirements? 2) Is there likely to be increased permit costs resulting from new requirements? Other costs 1) Possible delays in facility construction resulting from compliance with or disputes over new requirements? 2) Potential loss of development because of lack of facil i ti es? WHO BEARS COST/WHEN Front-end cost to local jurisdiction. Front-end cost to local jurisdiction. Front-end cost to facility owners/operators. Front-end cost to local jurisdic"tion and facil ity owner. Front-end cost to local jurisdiction. Front-end cost to facility operator (may be passed on to citizens/ratepayers) Potential front-end cost to facility operator and local jurisdiction Future cost to local jurisdiction. 101 HOW TO ASSESS COST (Major Considerations) How much information is required? Additional expertise? Additional expertise? Will revisions be required? Change in materials or additional equipment? Staff time required? Negotiation tools? Additional staff time? Nature of facility will determine. Additional staff time? Additional expertise required (legal, technical)? Likelihood that new requirements would prevent building of faci 1 i ty?

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TABLE E-7 COST CONSIDERATIONS: ENVIRONMENTAL IMPACT STATEMENT COST CONSIDERATION How .uch does it cost to adopt? 1) How much will it cost to map hazardous areas? 2) What will it cost to prepare guidelines for an EIS? How RUch does it cost to c0lllp1y? 1) What is the cost of preparing an EIS seismic component? 2) Will there be changes in revenues if EIS provisions lead to land use changes? 3) Costs of negotiating specific EIS requirements for applicants? How much does it cost to enforce? 1) What are the costs of reviewing compliance (may be considered a negotiation cost)? 2) What are the increases in review fees resulting from new requirements? Other considerations 1) Might there be delays i" development reslllting from compliance with or disputes over need for EIS? 2) Is there a potential loss of development because of unwillingness to comply with EIS preparation? WHO BEARS COST/WHEN Front-end cost to local jurisdiction. Front-end cost to local jurisdiction or permitting agency. Front-end cost to future developers Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction or permitting agency. Front-end cost to future developers. Ongoing cost to local jurisdiction and future developers. Ongoing cost to local jurisdiction. 102 HOW TO ASSESS COST (Major Considerations) Level of detail required? Additional expertise? Additional staff time? Additional expertise? Additional time and/or information required? Significant only if expect SUbstantial change in the nature of development. Extra legal fees'? Consultants/additional expertise Additional expertise required? Additional staff time? Nature of project will determine. Additional time to comply? Degree .of acceptance of changes? Assess willingness of potential developers to comply.

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TABLE E-8 COST CONSIDERATIONS: TAX CREDITS COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to identify and map hazardous 2) What will it cost to identify eligible properties? How much does it cost to comply? 1) Cost of tax credit to the jurisdiction? 2) Opportunity cost to the property owners? 3) Cost of administering program? How .ch does it cost to enforce? 1) Costs of reviewing compliance with land use restrictions required to be eligible for the program? Other costs 1) Potential disputes over conditions under which credit is granted. WHO BEARS COST/WHEN Front-end cost to local jurisdiction. Front-end cost to local jurisdiction. Ongoing cost to the local jurisdiction. Future cost to property owners. Ongoing" cost to local jurisdiction. Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction and owners. 103 HOW TO ASSESS COST (Major Considerations) Level of detail? Additional expertise required? Staff time to prepare inventory? Knowledge of existing property descriptions? Foregone tax revenues? Value of credit? Present discounted value of the difference between income from land if no credit is taken and value of the credit. Additional staff? Legal fees? Additional time to review?

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TABLE E-9 COST CONSIDERATIONS: REAL ESTATE DISCLOSURE COST CONSIDERATION How .. ch does it cost to adopt? 1) How much will it cost to identify hazardous areas? 2) How much does it cost to prepare disclosure requi rements? How .. ch does it cost to cOIIJ)ly? 1) Training of real estate brokers about disclosure? 2) Economic impact of disclosure resulting in purchase changes: lost commissions, decreased property value? How much does it cost to enforce? 1) What are the costs of reviewing real estate agent compliance with disclosure requirements? Other costs 1) Disputes over location of disclosure zone. 2) Potential loss of development because of seismic zoning. WHO BEARS COST/WHEN Front-end cost to local jurisdiction (or other governmental agency). Front-end cost to local jurisdiction Front-end cost to local jurisdiction and/or real estate industry. Ongoing cost to real estate industry, property owners. and local jurisdiction (lost property values). Ongoing cost to real estate industry. Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction. 104 HOW TO ASSESS COST (Major Considerations) Level of detail? Additional expertise required? Additional expertise required? Numbers to be trained, training frequency, cost of each session and materials wi 11 determi ne. Assessment of impact of disclosure upon purchases from past experience and/or expert judgment. Method and frequency of monitoring will determine. Additional expertise required? Legal fees? Assess that new requirements will discourage new development (experts and experiences of other juri sdi cti ons).

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TABLE E-l'O COST CONSIDERATIONS: PROPERTY ACQUISITION COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to identify and map hazardous areas? 2) What will it cost to identify properties for acquisition? 3) Voter approval required (e.g., for bonds)? How much does it cost to cOllp1y? 1) Cost of acquisitions to legal jurisdiction? 2) Opportunity cost to local jurisdiction? 3) What property management is required? How IllUch does it cost to enforce? SELF-ENFORCING Other costs 1) Potential disputes over acquisition process. WHO BEARS COST/WHEN Front-end cost to be borne by local jurisdiction. Front-end cost to local juri sdi cti on. Front-end cost to local jurisdiction. One-time purchase cost borne by jurisdiction. Ongoing cost to local jurisdiction. Ongoing cost to local jurisdiction. Local jurisdiction and/or property owners. 105 HOW TO ASSESS COST (Major Considerations) Will field work be required? Additional staff expertise? Consulting experience? Staff time to prepare inventory? Knowledge of existing property descriptions? What financing will be employed? Authority of local officials to issue debt? Acquisition cost of properties? Financing costs? Legal costs? Lost property tax revenues from previously private property. What use will be made of the property? Costs of maintain i ng property? Method of financing.

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TABLE E-ll COST CONSIDERATIONS: LIFELINE LOCATION/DESIGN COST CONSIDERATION How much does it cost to adopt? 1) How much will it cost to map the areas? 2) What are the preparation costs to establish development standards? How much does it cost to cOilply? 1) What are the likely changes in design and development costs for lifelines resulting from new requirements? 2) What are the costs of negotiating specific requirements for each lifeline? How IlUch does it cost to enforce? 1) What are the costs of receiving compliance with requirements? 2) Are there likely to be increased permit costs resulting from these new requirements? Other costs 1) Delays in lifeline construction resulting from compliance with or disputes over new requirements. 2) Potential loss of development because of inability to build lifeline or relocation of development away from local jurisdiction. WHO BEARS COST/WHEN Front-end cost to local jurisdiction Front-end cost to local jurisdiction Front-end cost to lifeline owners and/or operators? Front-end cost to local jurisdiction and lifeline owners/operators. Ongoing cost to local jurisdiction. Ongoing cost to lifeline owners/operators. Future cost to local jurisdiction and lifeline owners/operators. Future cost to local jurisdiction. 106 HOW TO ASSESS COST (Major Considerations) Level of detail necessary? Additional expertise? Additional expertise required? Change in materials? Additional equipment? Additional legal fees? Consultants required? Will additional expertise (special consultant) be required? Nature of the project and the local jurisdiction will determine. Additional staff time? Additional expertise? Legal fees? Assess likelihood that new requirements will prevent building new facilities experts and experiences of other jurisdictions).

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APPLICATION Below is an example from the field test done in Bellingham, Washington. This example illustrates the questions posed and the estimate made of costs for the adoption, compliance, and enforcement of a sensitive area ordinance for that community (see Table E-3). In this example, costs were identified by level rather than by actual dollar cost. How much does it cost to adopt? 1) How much will it cost to identify and map the hazard? 2) How much will it cost to develop the ordinance and standards? How much does it cost to comply? 1) What are the costs of preparing site investigations? 2) What are the design and development costs associated with these new standards? 3) Are there potential increases in permit costs? 4) What, if any, will be the change in revenues as a result of the new ordinance? 107 Low. Information exists; only a small amount of review is needed. Moderate. This consists primarily of staff time to write an ordinance draft and take it through the adoption process (this will likely take 6-9 months for a part-time planner).' Requires coordination or modification with other existing standards. Variable, depending on development scale. It can range from as low as several hundred dollars for a residence to thousands for a large scale nonresidential development. The developer bears the cost. Variable. The developer bears the cost which is decided on a case-by-case basis. Yes, but these are usually reflected in higher permit fees. Fees generally cover costs of the extra review at the local government level. Low-Moderate. No major change in development patterns is anticipated.

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APPLICATION (cont'd) How much does it cost to enforce? 1) What are the costs of reviewing site studies and conditioning development? 2) What are the increased costs for reviewing project compliance? Are there other cost considerations? 1) What are the effects on other regulatory programs? 108 Moderate. Probable means adding a staff geotechnical engineer ($30,000-$50,000/yr.). This cost could be shared by the city and county. Low. This can be incorporated into existing review processes. The program may permit streamlined management of sensitive areas in the two jurisdictions that are now covered by several, separate programs.

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PART F: ASSESSING THE EFFECTIVENESS OF EACH TECHNIQUE Contents ASSESS ovmIALL EFFECTIVENESS page The Concept of Effectiveness . . 111 Elements of Effectiveness. 111 Comparing Technique Effectiveness Tables and Figures F-1 Evaluation of Loss Reduction Potential and Costs >Application 2 Calculating Maximum Loss Reduction Capabilities for Planning Techniques 109 113 115 116 117

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PART F: ASSESSING THE EFFECTIVENESS OF EACH TECHNIQUE The Concept of Effectiveness Considering the effectiveness of a particular technique in reducing a community's risk from an earthquake is an important part of the selection process. Although it is desirable to estimate effectiveness in terms of dollars saved through averted property damage or the number of lives saved, it is rather difficult. Officials in the community must know: 1) probable location and intensity of a design earthquake and the distribution of effects; 2) expected damages. based on a structural/demographic analysis; and 3) the possible damages and deaths both with and without the proposed new policy. However, this information does not exist for most communities at risk to earthquakes and, even in the few communities where there is such information, experts frequently disagree over the estimates. Additionally, if a local jurisdiction develops costly damage scenarios, they may be controversial enough to preclude any policy decision being based on them. This handbook takes a somewhat different approach to assessing effectiveness. If a community does have access to damage scenarios, they should be used to refine the broad-brush procedure suggested here. Elements of Effectiveness To establish the relative effectiveness of a planning technique in a particular community, each technique must be examined in terms of its coverage, potential impact, and implementation success. Coverage refers to how much of the total area (the structures therein) at risk will be affected, or "covered," by the application of the planning technique. Potential impact describes the 111

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relative amount of loss reduction that can be expected if the technique is fully implemented. For example, a zoning ordinance which prohibits development reduces the loss potential completely, or 100%, whereas improved structural will reduce some damage, but not all of it. This measure does not allow for the fact that implementation may not be complete. Implementation success describes the likelihood that an ordinance will be fully complied with and enforced. This measure is somewhat subjective, based on the knowledge of the characteristics of each community and the expected level of enforcement, sanctions, incentives and support. This element can also be considered a "discount factor" to be applied to potential impact. Coverage Coverage is the estimate of the area of the community affected by the planning technique, expressed as a percentage of the total hazard area (see Figure 2). It can be estimated using the following steps: 1) To determine A, identify all areas .within the jurisdiction that are exposed to earthquake hazards. 2) Identify as B the area within A that will be affected by the planning technique. 3) Calculate B as a percentage of A, assuming 100% policy implementation (or it can be expressed as an estimate: high medium-low). Potential Impact This measure is a constant measure of loss reduction potential for each planning technique. In other words, open space zoning, if fully implemented, will have a high maximum impact because development is limited, but the impact of a sensitive area ordinance will be less because development is still allowed as long as certain conditions are met. The maximum ability of a planning technique to reduce losses can be seen as the product of the three elements of effectiveness: Coverage x Impact Potential x Implementation Success = Maximum Risk Reduction Potential Once estimated, the loss reduction ratings for several techniques can be compared to determine which of several options may have the greater potential ability to reduce losses. These estimates for each of the .techniques in Figure 2 were developed in consultation with planners and public policy administrators. It is possible to change the estimates in other communities' calculations of loss reduction potential, but it is important to keep all these measures constant for each of the different 112

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techniques. (See also the accompanying example of using only general categories of high-medium-low rather than percentages.) Implementation Success This subjective measure is based on knowledge of characteristics in the local jurisdiction. It can be considered a "discount factor," applied to the potential impact, adjusting that measure to .reflect the real possibilities of successful implementation. Calculating implementation success is site-specific and is likely to be issue-specific as well. Comparing Technique Effectiveness Some users of this handbook will be able to assign percentage figures to the estimate of coverage, potential impact, and implementation success. Other users will not have sufficiently detailed data to assign numbers, and will instead use the deSignations low, moderate, and high. Both approaches can be useful. It is less and takes less specific data to estimate the loss reduction elements in non-quantitative terms, and can still facilitate a comparison among techniques (see the attached example). Once effectiveness of a particular planning technique has been estimated, it should be possible for a local decision maker to set this against the costs of technique implementation (see Part E) and determine whether the technique is appropriate for use in the community. 113

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HOW TO USE TABLE F-1 1) This table is somewhat different from the other tables in the handbook because it presents a structure for summing up information presented in the earlier parts of this handbook. A community official, evaluating one or more planning techniques, identifies coverage, potential impact, implementation success, and costs as follows: Coverage is estimated using the technique described above in in Part F. Potential impact is determined from Figure 2 in Part F. Implementation success is a summary of information developed in Part C. Cost estimates are taken from information developed in Part E. 2) This table is a summary tool, it can provide justification for the selection (or rejection) of a planning technique for community consideration. This table explicitly identifies the criteria used in such selection decisions. EXAMPLE/APPLICATION The table following F-1 is an example taken from'the Bellingham, Washington, field test of the decision-making framework. It illustrates how Table F-1 can be filled out by a community considering several planning techniques. A local official more familiar with the specific situation in Bellingham, and able to spend sufficient time to gather specific cost figures, could fill out this table using percentages and dollar estimates. For our purposes in testing the framework we used the measures low-moderate-high. The table does not provide a summary score or identify the technique most appropriate for Bellingham. The table is to be an aid, recognizing that decisions regarding the appropriateness of a planning technique have complexities that are not amenable to being boxed in on paper. Local officials in the jurisdiction are the most appropriate final interpreters of the information provided in the table. 114

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TABLE EVALUATION OF LOSS REDUCTION POTENTIAL AND COSTS PLANNING TECHNIQUE A B C Coverage: The amount existing development: existing development: existing development: of buildings located in all sensitive areas which will be affected future development: future development: future development: i by the ordinance (assuming I I it is fully implemented). I I Impact \ A rating of how much change in risk exposure would result from the full of planning techniques. Implementation success: The likelihood of adoption, compliance, and enforcement of the planning techniques. Cost: to government future front-end future front-end future to private sector l 115

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COVERAGE--the amount of buildings located in all sensitive areas whi ch wi 11 be affected by the ordinance it is fully implemented). IMPACT--a rating of how much change in risk exposure would result from the full impl ementation of planning techniques. IMPLEMENTATION SUCCESS--the likel ihood of adoption, compli ance, and enforcement of the plan ning techniques. .Qll--to adopt, comply, and enforce To Government: To Private Sector: APPLICATION Modification to Zoning Ordinance (hazard overlay map with performance standards) A Existing Development: NA Future Development:. Low--only small and welldocumented hazard areas are likely to be included in the ordinance. High--a well-enforced zoning ordinance can significantly restrict or condition development. Low--adoption likely to be a stumbling block because of map preparation and standards. Front-End Future High--info Hi gh--coul d gathering, require hiring map prepaof additional ration. expertise, updating of information. Low. Moderate-could require site and engi neeri ng changes. 116 PLANNING TECHNIQUE Modification to Subdivision Ordinance (site-specific geologic reports in areas of particular seismic hazard sens i ti vi ty) B Development: NA Future Development: Moderate--technique would apply on a site-specific basis. Likely that developers would would steer away from hazardous area development anyway. Low-moderate--a subdivision regulation does not affect the type of use or structural characteristics. Instead, it can only regulate the location of development on the site and somesite preparation and foundation characteristics. High--city & county have subdivision ordinance in place. Might require addi tional expertise to enforce. Similar requirements to existing procedures. Front-End Future High--some Moderate to new infor-high--might need mation readditional qui red to experti se to determine review/interpret areas of studies. Large particular number of permits seismic to be reviewed. sensitivity. High for Moderate-residential could require developers-design changes. must provide information. Development of a Sensitive Area Ordinance with Performance Standards C Existing Development: NA Future Development: extensive--an SAO will only "missY those areas too smal to be picked up by other mapping High--effectively used performance standards would emphasize end result and control land use. Moderate--burden of developing criteria for sensitive areas on city/ county. Indication that political mood not right. Front-End Future Moderate. Moderate-could require hiring additional None. Moderate-requires site studies & may necessitate development modifi cati ons.

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Coverage -Community BOll'ldar( [JJI] Hazard area -.Athln c omm unity b 0 un dary .Aleacovered by Ii[{1:I plannino tool A = Hazard Area B = Hazard area where planning tool will be in effect AlB = % of total community hazard area covered by the planning tool Impact times Potential (The ability of the planning technique to reduce loss potential if fully implemented) FOR FUTURE DEVELOPMENT Zoning ordinance Subdivision ordinance Sensitive area ordinance Envi ronmenta1 impact statement Building code Special use and critical facility Lifeline location/ standards Tax credit Property acquisition FOR EXISTING DEVELOPMENT: Hazardous building Implementation times Feasibil ity An assessment made for each planning technique, given the specific community context (Can it be adopted? How likely is compliance? How difficult is enforcement?) abatement Real estate disclosure I _________ --L ______ ___ .. FIGURE 2 CALCULATING MAXIMUM LOSS REDUCTION CAPABILITIES FOR PLANNING TECHNIQUES 117 equal s: MAXIMUM LOSS i REDUCTION POTENTIA FOR A SPECIFIC PLANNING TECHNIQUE

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REFERENCES Algermissen, S.T., K.V. Steinbrugge, and H.L. Lagorio 1978 Estimation of Earth uake Losses to Buildin s Exce t Sin le Dwellings. U.S.G.S. Open File Report # 78-441. Reston, VA: Geological Survey. Arnold, Christopher and Richard Eisner 1984 Planning Information for Earthquake Hazard Response and Reduction. San Mateo, CA: Building Systems Development Inc. Ayre, Robert S. et al. 1975 Earthquake and Tsunami Hazards in the United States: A Research Assessment. Program on Technology, Environment and Man Monograph #5. Boulder: University of Colorado, Institute of Behavioral Science. Blair, Martha. L. and W.E. Spangle 1979 Seismic Safety and Land-Use Planning--Selected Examples from the San Francisco Bay Region, California. Geological Survey Professional Paper #941-B. Washington, DC: U.S. Government Printing Office. Bolt, Bruce A. et al. 1977 Geological Hazards (Revised, 2nd Edition). New York: Verlag. Borcherdt, R.D. et ale 1975 "Response of Local Geologic Units to Ground Shaking.11 in R.D. Borcherdt (ed.), Studies for Seismic Zonation Francisco Bay Region. Geological Survey Professional Washington, DC: U.S. Government Printing Office. Cluff, Lloyd S. Springer-Pp. A52-A67 of the San Paper #941-A. 1978 "Geologic Considerations for Seismic Microzonation.11 Pp. 135-152 in Proceedings of the Second International Conference on Microzonation, Vol. I. San Francisco, November 26-December 1, 1978. Committee on Earthquake Engineering Research 1982 Earthquake Eneineerin g Research-1982. National Research Council. Washington, 0 : National Academy Press. Dunne, Thomas and Luna B. Leopold 1978 Water in Environmental Planning. San Francisco: W.H. Freeman. EERI Committee on Seismic Risk 1984 "Glossary of Terms for Probabilistic Seismic-Risk and Hazard Analysis." Earthquake Spectra 1 (#1), pp. 33-40. Erley, Duncan and William Kockelman 1981 Reducing Landslide Hazards: A Advisory Service Report #359. Association. 119 Guide for Planners. Planning Chicago: American Planning

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Evernden, Jack F. 1982 "Comments on Seismological Input to Microzonation Maps." pp. 1171-1189 in Proceedings of the Third International Conference on Microzonation, Vol. III. Seattle, July 28-July 1, 1982. French, Steven P. 1983 Personal communication to the authors. San Luis Obispo: California Polytechnic State University. French, Steven P. and Mark Isaacson 1984 "Applying Earthquake Risk Analysis Techniques to Land Use Planning." Journal of the American Planning Association (Autumn), pp. 509-522. Gaus, M.P., and M.A. Sherif 1972 "Zonation and Microzonation.11 Pp. 3-11 in Proceedings of the First International Conference on Microzonation. Seattle, October 30-November 3, 1972. Jaffe, Martin, JoAnn Butler, and Charles Thurow 1981 Reducing Earthquake Risks: A Planner1s Guide. Planning Advisory Service Report #364. American Planning Association. Kohler, and G.D. Clow 1981 Seismic Intensities of Earthguakes of Conterminous United States-Their Prediction and Interpretation. U.S.G.S. Professional Paper #1223. Reston, VA: U.S. Geological Survey. Laird, R.T. et al. 1979 Quantative Land-Capability Analysis: Selected Examples from the San Francisco Ba Re ion, California. Geological Survey rofessional Paper 945. Washington DC: U.S. Government Printing Office. Mader, George G. 1982 "Progress in Using Microzonation Data in Urban Planning--A Current Appraisal." Pp. 673-680 in Proceedings of the Third International Microzonation Conference, Vol. II. Seattle, June 28-July 1, 1982. Mushkatel, Alvin H. 1982 "Land-Use Policy in the United States and the Potential Use of Microzonation." Pp. 1569-1578 in Proceedings of the Third International Conference on Microzonation, Vol. III. Seattle, July 28-July 1, 1982. National Academy of Sciences 1975 Earthguake Prediction and Public Policy. Washington, DC: National Academy of Sciences. Nichols, D.R. and J.M. Buchanan-Banks 1974 Seismic Hazard and Land-Use Planning. Geological Suryey Circular #690. Reston, VA: U.S. Geological Survey. 120

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Olson, Richard Stuart and Douglas C. Nilson 1982 "Microzonation as a Policy Tool: Factors for and Against Adoption." Pp. 1545-1556 in Proceedings of the Third International Microzonation Conference, Vol. III. Seattle, June 1, 1982. Patri, T., D.C. Streatfield, and T.J. Ingmire 1970 Early Warning System: The Santa Cruz Mountains Regional Pilot Study. Berkeley: Department of Landscape Architecture, College of Environmental Design, University of California. Preuss, Jane et al. 1982 Land Management Guidelines in Tsunami Hazard Zones. Seattle: Urban Regional Research. Scawthorn, Charles 1982 liThe Locational Approach to Seismic Risk Mitigation." Pp.729-740 in Proceedings of the Third International Microzonation Conference, Vol. II. Seattle, June 28-July 1, 1982. Youd, T.L. et al. 1975 "Liquefaction Potential." Pp. A68-A74 in R.D. Borcherdt (ed.), Studies for Seismic Zonation of the San Francisco Bay Region. Geological Survey Professional Paper #941-A. Washington, DC: U.S Government, Printing Office. 121

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PUBLICATIONS OF INTEREST from the Natural Hazards Research and Applications Information Center Institute of Behavioral Science #6 Campus Box 482 University of Colorado Boulder, Colorado 80309 (303) 492-6818 Special Publications #2. Reduce Flood Losses, Volume 3. #3. to Volume 3 #4. B to Volume 3 #5. Floodplain Re ulations and the Courts 1970-1981. on Kusler. 1982. 51 pp. 5.00. #10. Evaluating the Effectiveness of Floodplain Management Techniques and Community Programs. Proceedings of a Seminar, Washington, DC, April 30-May 1, 1984. 1985. 143 pp. $8.00. #12. Flood Hazard Management in Government and the Private Sector. Proceedings of the Ninth Annual Conference of the Association of State Floodplain Managers. 1985. 358 pp. $8.00. #13. State and Community Durin the Aftermath of Mexico City's November 984 as Explosion. Kirsten Johnson. 985. 48 pp. 4.00. Working Papers #47. Disseminatin Disaster-Related Information to Public and Private Users. Claire B. Rubin. 982. 32 pp. 4.50. #50. Restoration and Recovery Following the Coalinga Earthquake of May, 1983. Steven P. French, Craig Ewing, and Mark Isaacson. 1984. 25 pp. $4.50. #54. The Environmental Hazards of Colorado Springs. Eve Gruntfest. 1985. 58pp. $4.50. $55. Disaster Pre aredness and the 1984 Earth uakes in Central Ital David Alexander. 1986. 98 pp. 4.50.

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Monographs #39. Terminal Disasters: Computer A plications in Emer Sallie Marston, ed. 986. 225 pp. 0.00. #41. Community Recovery from a Major Disaster. Claire Rubin et al. 1985. 295 pp. $10.00. #43. Unreinforced Buildings in Earthquakes: City Ordinances for Rehabilitation. Daniel Alesch and William Petak. 1986. 280 pp. $10.00. Bibliographies #11. Natural Hazards and Land Use Planning. Ann FitzSimmons. 1984. 107 pp. $5.50. AB. A Selected, Partiall Annotated Biblio ra h of Recent 1984-1985} Natural Hazards Publications. David Morton. 986. 150 pp. 7.00. Newsletter The Hazards Observer. Bi-monthly. 20 pp. No cost in USA .


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