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Preparing for the Storm:
Recommendations for Management of Risk from Coastal Hazards in Massachusetts
Chapter 1 - Introduction
Massachusetts and its 78 coastal communities are vulnerable to the damaging impacts of major storms, such as northeasters and hurricanes, along more than 1,500 miles of varied coastline. As coastal development increases, less-intense storms that occur more regularly and sea-level rise will also lead to costly storm damage. The Commonwealth has consistently sought to prevent or mitigate storm damage through planning and regulations that seek to protect lives and existing property, and guide new development away from vulnerable coastal areas.
Over the past two decades, a significant amount of progress has been made in our understanding of coastal processes, risk assessment, policy, planning, regulations, and engineering. There remains, however, a clear need for an evaluation of the factors that contribute to storm damage, a review of the policies and regulations that guide the management of coastal hazards, and a comprehensive assessment of publicly owned shore protection infrastructure in the Commonwealth. The purpose of the Coastal Hazards Commission (CHC) is to review existing coastal hazards practices and policies, identify data and information gaps, and make recommendations for administrative, regulatory, and statutory changes, when necessary.Coastal Hazards in the Commonwealth
The natural forces of wind and waves continuously shape the shorelines of Massachusetts, seeking to achieve a dynamic equilibrium between land and sea. As a result of this natural process, coastal areas cannot be studied or developed as stable environments. These dynamic environments shift and change in response to relative shoreline shape and position, the availability of sediment (sand, gravel, and cobble), periodic increases in energy (wind and waves), and continuously rising sea levels. The illusion of a stable shoreline results from nature's continuing reassessment of the balance between these factors, in which a change in the nature or amount of one triggers corresponding changes to the others until a temporary equilibrium is once again established. This tendency for shorelines to seek equilibrium is central to the problems associated with coastal development.
In the absence of development, shoreline migration—either rapid during high energy coastal storms, or gradual in response to sea-level rise—constitutes a natural phenomenon that, while dramatic, presents few long-term problems to natural systems and resources. When static systems such as coastal development are confronted with these dynamic forces, however, the migration or loss of coastal landforms is frequently accompanied by significant adverse impacts. The impacts to development associated with natural coastal processes constitute significant management challenges when they threaten the health, safety, welfare, or economics of individuals and communities.
Erosion and flooding are the primary coastal hazards that lead to the loss of lives or damage to property and infrastructure in developed coastal areas. Storms including northeasters and hurricanes, decreased sediment supplies, and sea-level rise contribute to these coastal hazards. The risk to coastal communities from these hazards continues to present major challenges to coastal developers, managers, and emergency responders at all levels of government. Policymakers are also challenged to balance development and natural resource protection in coastal areas.Northeasters
Northeasters occur frequently in New England and are a primary concern for residents and managers alike. These low pressure systems, named for the direction from which their winds originate, are typically accompanied by considerable precipitation, high winds, and waves that cause erosion, particularly along easterly facing shores. In addition, these slow-moving weather systems, with storm surges often in excess of two feet above normal high water levels, can pound the coast over several tidal cycles piling up additional water along the shoreline, resulting in major and extended flooding of coastal and inland properties. With rising sea levels, the flooding and erosion associated with less intense northeasters can now influence coastal development on a more frequent basis.
One or two northeasters per year usually strike the coast of Massachusetts between October and April causing shoreline erosion, flooding, and property damage (MEMA and DCR, 2004). The New England Blizzard of 1978 and the No-Name or Halloween Storm of 1991 are examples of moderate to severe northeasters that influenced the coast of Massachusetts. The New England Blizzard brought record-breaking snowfall and hurricane-force winds that caused beach erosion, flooding, and property damage. The Halloween Storm also resulted in erosion and considerable property damage due to heavy surf and lunar-enhanced storm surges along the coast. Damages that occurred during these and other storm events illustrate the need for improved coastal management approaches.Hurricanes
Hurricanes are another type of storm that causes damage along the coast. These storms form over warm tropical waters from June to November and are typically accompanied by higher wind velocities and precipitation amounts. Hurricanes that reach New England tend to be relatively fast moving, rarely impacting the coast over multiple tidal cycles. Although they are relatively infrequent visitors to Massachusetts (seven since 1938), when landfall is made, these concentrated, strong low-pressure systems usually pound south facing shores with high winds, precipitation, and storm surge. Fortunately, the shorelines of Massachusetts have not experienced a hurricane since Bob made landfall as a Category 2 in August of 1991. Five other hurricanes hit between Bob and the Great New England Hurricane of 1938, which was also a Category 2 when it tracked across Massachusetts (NOAA, 2005). While Massachusetts has never experienced a Category 4 or 5 hurricane and the frequency of hurricanes has been relatively low in New England over the last 50 years, warming of the Atlantic Ocean may drive more high-intensity storms up to Massachusetts in the future. As Hurricane Bob demonstrated, with greater levels and density of development along the coast, even a Category 2 storm will cause millions of dollars in damage.Decreased Sediment Supplies
Coastal landforms such as coastal banks are essential to maintaining a supply of sediment to beaches and dunes. Where engineering structures are used to stabilize shorelines, the natural process of erosion is interrupted, decreasing the amount of sediment available and causing erosion to adjacent areas. Under conditions of reduced sediment, the ability of coastal resource areas such as dunes and beaches to provide storm damage prevention and flood control benefits is continually reduced. A major challenge is to ensure that regional sediment supplies are managed effectively and in ways that allow the beneficial storm damage prevention and flood control functions of natural coastal processes to continue—both for future projects and, where possible, existing coastal development.Sea-Level Rise
Climate change and sea-level rise are persistent contributors to coastal land loss in the Northeast. Increased volumes of water in the oceans due to thermal expansion of water as it warms and the addition of fresh water from melting ice sheets and glaciers result in the rise of sea surface levels. Records of tide gauges around Boston, Woods Hole, and Nantucket indicate that our relative sea level (the combination of a rising water surface with land subsidence) has risen approximately 10 inches over the past 100 years. The Intergovernmental Panel on Climate Change (IPCC) predicts that sea-level rise and its risk to coastal resources will accelerate over the next 100 years (IPCC, 2007). Conservative projections of sea-level rise by the end of the century range from 4 to 21 inches, while projections given a higher emissions scenario range from 8 to 33 inches (Union of Concerned Scientists, 2006). With an accelerated rate of sea-level rise, low-lying coastal areas will be particularly vulnerable to increased erosion, flooding, and inundation. In addition, these impacts will extend further inland, resulting in greater loss of land and damage to development along the coast of Massachusetts. The combination of rising sea levels, more frequent and intense storms, and increased coastal development will result in greater erosion and flooding impacts over time.Approaches to Address Coastal Hazards
Managers generally employ many different measures to reduce the risks posed by coastal hazards along developed coasts. Policies and regulatory tools, such as setbacks and building codes, can be developed to prevent or limit new development in hazardous locations, relocate buildings at risk of severe damage, and prohibit reconstruction of destroyed buildings. Regulations are also implemented to limit the use of new shoreline-stabilization structures and to ensure that adverse impacts of project are minimized. These measures can result in a wide range of environmental and economic costs varying with the physical, economic, human, social, and natural character of coastal communities.
Non-structural measures such as beach nourishment (i.e., the active addition of sediment to a beach system) are also being considered as viable alternatives to protect development with the added benefit of maintaining recreational beaches. Massachusetts successfully completed a beach nourishment project on Revere Beach State Reservation in 1992 using an upland source of approximately 768,000 cubic yards of sediment, financed by the state and federal governments. Smaller nourishment projects were also completed on Dead Neck Beach in Osterville (1998) and Long Beach in Plymouth (1999) using sediment from offshore sources and private and local funds respectively. Two major beach nourishment projects using offshore sources of sediment have been proposed for Winthrop Beach and Siasconset Beach using state and private funds respectively. Nourished beaches can be quite successful in restoring the vitality of communities, energizing local economies, and minimizing property and infrastructure damages. Maintaining an artificial beach width, however, does require continued placement of sediment.Work of the Coastal Hazards Commission
To address current and future coastal hazards issues in the Commonwealth, the Romney Administration and the Legislature launched the CHC in February of 2006. Governor Mitt Romney and Environmental Affairs Secretary Stephen Pritchard asked the CHC to review existing coastal hazards practices and policies, identify data and information gaps, and prepare a report with recommendations to the Legislature. The six statements below represent the charge of the CHC.
At the initial monthly meetings of the CHC, the members were presented with background information on coastal hazards and management measures by experts in the field. The information included an overview of the Massachusetts coast, erosion, flooding, state and local hazard mitigation planning, publicly owned coastal structures, beach nourishment including fisheries and other habitat concerns, vulnerability to coastal storms such as hurricanes and northeasters, and potential impacts of sea-level rise on the coast. In May, five forums were held in Ipswich, Boston, Scituate, Hyannis, and Wareham to allow the public to express their concerns about erosion, flooding, storms, and sea-level rise to the CHC. The primary issues raised at the public forums include Flood Insurance Rate Maps (FIRMs), seawalls, beach nourishment, and permitting of various projects.
Five working groups of experts, primarily from state and local government agencies, academia, and the private sector, were also formed in May and met over the summer and fall to assist the CHC with drafting recommendations. The working groups focused on:
The CHC met in June and July to discuss the issues raised by the public at the May forums and the initial recommendations drafted by the working groups.
Draft recommendations were released to the public in August and comments were solicited through September. Fourteen comments were presented at the September meeting of the CHC. A total of 29 comments were discussed by the chairs of the working groups at the end of October and appropriate revisions were made to the draft recommendations. Also during the fall, the working groups drafted brief implementation plans for each of the recommendations that identified potential lead agencies, funding sources, next steps, and estimated timelines. The CHC approved 29 recommendations and implementation plans at their last meeting in February of 2007. Four priority recommendations were identified at this meeting. Staff of the Massachusetts Office of Coastal Zone Management (CZM) drafted the report and it was approved by the CHC in May of 2007.Report Overview
Chapter 2 of this report presents the CHC's 29 recommendations, which are organized according to the four working groups that drafted them. Each section begins with one of the four priority recommendations. The recommendations are accompanied by detailed background information on the issues and include brief implementation plans. Chapter 3 describes the pilot infrastructure inventory project on the South Shore and presents some of its preliminary findings. Appendix A includes a list of the recommendations with the four priority recommendations highlighted. Appendix B contains links to coastal hazards data and tools compiled by the Hazards Information Working Group. Finally, the Protection Working Group analyzed and documented the potential benefits and impacts of a variety of alternatives to control flooding, erosion, and other coastal hazards along the coast of Massachusetts (Appendix C). This resource is intended to guide decision makers conducting site-specific analyses of protection alternatives who may not know what potential benefits and impacts may exist.