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Preparing for the Storm:
Recommendations for Management of Risk from Coastal Hazards in Massachusetts
Chapter 3 - Infrastructure Inventory
The Infrastructure Plan Working Group of the Coastal Hazards Commission (CHC) was tasked with prioritizing coastal structure maintenance and repairs. As a result, the working group did not draft recommendations similar to those of the other four working groups.South Shore Pilot Project
Many types of structures exist along the coast of Massachusetts to protect buildings and infrastructure constructed prior to coastal management policies and regulations. Historically, coastal land was developed out of economic necessity. Commercial development primarily included piers, wharfs, and warehouses. Residential development, roads, and other infrastructure followed due to increasing population demand and the desire to work and live near the ocean. Public and private buildings along the coast are often more valuable than their inland complements and represent an extraordinary economic investment. Today, maintenance of coastal structures built prior to 1978 to protect public and private development in dynamic coastal areas challenges the Commonwealth, municipalities, and individuals.
The Infrastructure Plan Working Group focused primarily on shoreline stabilization structures and their ability to resist major coastal storms and prevent damage due to flooding and erosion. Since ownership and maintenance are major issues for these coastal structures, a pilot project to research, inventory, survey, and assess existing coastal infrastructure was conducted along the shoreline from Hingham to Plymouth (South Shore). This coastal region was chosen since it represents the variable characteristics of the other four coastal regions in Massachusetts (Figure 1). An atlas of coastal hazards on the South Shore has also been completed and is a valuable resource for this project (Applied Coastal Research and Engineering, Inc., 2006). A methodology was developed to replicate the project along the North Shore, Boston Harbor, Cape Cod and Islands, and South Coast.
The objectives of the South Shore infrastructure inventory were to:
Potential municipal and state-owned coastal structures on the South Shore, identified through state and local records research, were located, recorded, and described. Coastal structures encompassed hard or man-made structures including seawalls, revetments, bulkheads, groins, jetties, breakwaters, and dikes or levees that are designed to control coastal hazards by preventing erosion and flooding from damaging property. Soft or natural landforms including beaches, dunes, and coastal banks that are managed to provide protection and minimize potential damage to property were also considered structures for this inventory. Civil engineers performed initial condition surveys and, based on visual inspections, described and assessed the general condition of each structure. Geographically referenced digital photographs were taken of each structure to supplement the inspections. The visual inspections resulted in the rating of each structure according to its condition using a letter system (Table 1). Each structure was also assigned a priority rating based on its condition and ability to protect buildings from coastal hazards (Table 2). The capacity of the shoreline stabilization structure to protect infrastructure, such as roads and utilities, was not considered in the analysis due to time and resource constraints.South Shore Preliminary Findings
A final draft of the South Shore Pilot Project report, including GIS data files, is currently being reviewed by members of the working group with completion of work anticipated for the end of March. Some preliminary findings from this report are presented below.
Along the South Shore, 312 publicly owned coastal structures were assessed (Bourne Consulting Engineering, 2006). The structures included bulkheads, seawalls, revetments, groins, jetties, and breakwaters (Table 3). Bulkheads and seawalls were the most abundant, with a combined total of 177 (57%). The condition of the structures ranged from excellent (A) to critical (F), but the majority of the structures were either in good (B) or fair (C) condition. Overall, 152 (49%) structures are stable and 160 (51%) need moderate to immediate repair (Figure 2). The priority ratings of the structures are currently being finalized. These findings, along with the results of the projects in the remaining coastal regions, will serve as the beginning of the development of a statewide plan for maintenance and/or repair of the Commonwealth's coastal structures.Figures and Tables
Figure 1 - Five coastal regions of Massachusetts (PDF, 177 KB)
Figure 2 - Condition of Coastal structures on the South Shore (PDF, 53 KB)
Table 1 - Rating system for the condition of coastal structures
Table 2 - Rating system for the prioritization of coastal structure repair
Table 3 - Quantity and condition of coastal structures along the South Shore.