DESIGN AND PERFORMANCE OF A MIXED SEDIMENT NOURISHMENT PROJECT ALONG AN URBAN SEDIMENT-STARVED SHORELINE

Abstract

The long-term shore protection of Boston's open ocean shoreline has utilized a variety of coastal engineering strategies to prevent or at least inhibit the impacts of coastal flooding and storm wave action to urban development. The Winthrop Beach region is located to the north of the Boston Harbor entrance and historically incorporated a variety of coastal engineering structures, beginning in the late 1880s, to mitigate the impacts of coastal flooding and storm wave action. To some degree, these "hard† shore protection measures have prevented further degradation of upland infrastructure; however, loss of the littoral sediment supply due to coastal armoring of the adjacent upland and the related lowering of the beach fronting the seawall along the length of Winthrop Beach have increased the storm damage potential of the community protected by these structures. Recent, relatively minor northeast storms have caused significant damage to the seawall originally constructed in 1899, requiring temporary stabilization to prevent failure of the wall and the adjacent roadway. Winthrop Beach faces the open ocean, is approximately 2,100 meters in length, and is situated along the east side of Winthrop between two glacial headlands or relic drumlins. To address the issues of shore protection and "sediment starvation† along the Winthrop Beach shoreline, a beach nourishment project has been designed to return the shoreline to historic conditions.