Evaluation of Downdrift Shore Erosion, Mattituck Inlet, New York: Section 111 Study

Book excerpt: This report was prepared for the U.S. Army Engineer District, New York, to evaluate shore erosion in response to construction of the Federal navigation project at Mattituck Inlet, NY, under the authority of Section III of the River and Harbor Act of 1968, Public Law 90-483, approved August 1968. The original navigation project was authorized in 1896 and modified in 1935 and 1964. The report is organized into seven chapters and two appendixes. Chapter 1 gives an introduction to Section III authority and the physical setting at the study site. Chapter 2 discusses shoreline change and change rates in the vicinity of Mattituck Inlet. Shoreline change rates are calculated for the region and compared for shorelines adjacent to the inlet. Chapter 3 describes numerical simulations of waves, wave-induced and tidal currents, and sediment transport pathways at the inlet. Chapter 4 develops the sediment budget for the site and region. Chapter 5 describes estimated future conditions without a project. Chapter 6 evaluates the responsibility of the Federal government for downdrift shore erosion, and Chapter 7 presents alternatives for mitigation. Appendixes A and B document analysis results for shoreline change.