The Long Island Coastal Planning Project

Total Page:16

File Type:pdf, Size:1020Kb

The Long Island Coastal Planning Project Regional Sediment Management: The Long Island Coastal Planning Project Lynn M. Bocamazo Senior Coastal Engineer USACE-New York District 22 September 2009 US Army Corps of Engineers BUILDING STRONG® Outline Project Location General Setting Purpose Goals Tasks Performed Plan through April 2010 BUILDING STRONG® Project Location Block Island Sound Long Island Sound Montauk Point Manhattan Shinnecock Bay Moriches Bay Long Island Shinnecock Inlet Montauk Moriches ay th B t Sou Inlet Grea Ponds Atlantic Ocean Jones Fire Island Westhampton E. Rockaway Inlet Inlet Rockaway Inlet Inlet Jones Fire Island Scale Long Island Beach 0 8 16 Kilometers Rockaway BUILDING STRONG® 6RXWK6KRUHRI/RQJ,VODQG 0LOHVRI*HRORJLF3RSXODWHG'LYHUVLW\ • %DUULHU,VODQGV • +HDGODQGV • %D\V • 0DLQODQGRI/RZO\LQJ &RDVWDO3ODLQ • 8UEDQ6XEXUEDQDQG 5XUDO$UHDV • 7UHPHQGRXV3RSXODWLRQ *URZWKRQ/RQJ,VODQG VLQFHWKH+XUULFDQHRI BUILDING STRONG® Shifting Sand BUILDING STRONG® Shifting Sand BUILDING STRONG® The South Shore of Long Island Six Federal Navigation Projects (Rockaway, East Rockaway, Jones, Fire Island, Moriches and Shinnecock Inlets) Four Corps Storm Damage Reduction Projects (Coney Island, Rockaway, Westhampton Interim, West of Shinnecock Interim) Feasibility Studies: Long Beach, Fire Island Inlet to Montauk Point, Montauk Point Lighthouse Area Intracoastal Waterway within three south shore bays, also Jamaica Bay Many County and Local Channels, Marinas and Harbors Diverse Economy, Geology and Ecology BUILDING STRONG® Long Island Coastal Planning Project “Institutionalizing RSM on the South Shore of Long Island” NAN has ad hoc RSM, trying to make it into a program Reach out to State, Counties, Municipalities, NGO’s, Sea Grant, other Federal Agencies and other stakeholders Motivation? Congressionals seeing that the Corps and other Federal and local entities need to come together over borrow material, environmental and jurisdictional issues regarding sand resources From “Lessons Learned”, experience from other Districts, NAN saw the necessity of moving from ad hoc coordination to a more deliberate networking/coordination BUILDING STRONG® Congressional Direction Over the course of the 4 year project, legislation specifically asked for the following: (1) Collect and inventory sediment resources and related coastal process data from various federal and state agencies as well as academic institutions and other nonprofits, municipal governments, and individuals. Through the National Coastal Data Bank, this data will also be available at no cost for any to use. (2) Identify gaps in data and how best to use the resources of cooperating agencies and institutions to fill those gaps. (3) Develop a regional sediment budget (location, quantity, and qualities of sand sources) for the Atlantic Coast of Long Island. (4) Develop an inventory of existing sediment borrow areas off the coast of Long Island and subsequently develop a plan to monitor and manage those borrows areas in conjunction with sound water resource management practices. BUILDING STRONG® Congressional Direction Also from the legislation: Immediately following its funding, a Project Team will be formed with federal, state, and local government participation. The Project Team will meet at least bi-monthly to agree upon Regional Sediment Management (RSM) goals and plans to achieve them, assign tasks and monitor progress in developing the plan. At the beginning of the fifth year, the Project Team will adopt one or more regional plans for the management of existing inlets, channels, beaches, borrow areas, and related coastal environmental resources. BUILDING STRONG® LICPP Development Build off existing RSM program demos Leverage work being done for other Corps studies (FIMP, Jones Inlet) and other non-Corps studies Initially no large scale data collection Tap into local knowledge (Stony Brook University, NY Sea Grant, South Shore Estuary Reserve Program, Counties, Municipalities other NGO’s) Develop outyear priorities with input from stakeholders BUILDING STRONG® Ultimate Goals of the LICPP LICPP will leverage numerous ongoing activities on the South Shore of LI, as well as ongoing national initiatives to accomplish the following: Increase the efficiency of maintaining navigation channels Optimize the beneficial use of material dredged from inlets, ports, harbors, and other opportunistic sediment sources Reduce shoreline erosion and coastal storm damages Provide for environmental restoration and protection Restore and preserve beaches Improve collection and dissemination of data related to the movement of sediment Facilitate cooperation among federal and non-federal interests “Institutionalize” RSM on the South Shore of Long Island BUILDING STRONG® Tasks Performed to Date (Aug 09) Formed internal and external Project Delivery Teams (PDT), held numerous mtgs/conference calls. Held technical workshop to review and inventory sediment resources and related coastal processes b white paper under preparation Developed shoreline and inlet morphology model (CASCADE) for the Fire Island to Montauk Point area, technology transferred to the District. Developed inventory of existing sediment borrow areas. Compiled existing inlet and shoreline sediment budgets. Cooperated with USGS on offshore borrow sources monitoring plan and shoreline change analysis for inclusion in sediment budgets. Performed 7 monthly beach profiles at Pt. Lookout following beneficial use placement of inlet material (Jones Inlet). Further developed the Long Island Sediment Needs Assessment (LISNA) database. BUILDING STRONG® Cascade Model For New York NewFY09 Existing Cascade Model BUILDING STRONG ® Cascade: Montauk Point to Fire Island Inlet 250000 Atlantic Ocean ear) Fire Island Inlet 200000 Shinnecock Moriches Inlet Inlet 150000 Simulation of Shoreline 100000 Evolution 1931-1983 (detail) 50000 Data from 5200 Rosati et al. (1999) 0 Land Shinnecock Inlet meas. 1983 initial 1931 (m**3/y Transport Longshore Mean -50000 4800 calc. 1983 0 40 80 120 160 Distance West from Montauk Point (km) 4400 Calculated Net Longshore 4000 Shoreline Position (m) Position Shoreline Sediment Transport (1983-1995) Moriches Inlet 3600 3200 20 40 60 80 100 120 140 160 Distance West from Montauk Point (km) Work Done By: Sophie Munger & Nick Kraus, ERDC, Coastal & Hydraulics Lab. BUILDING STRONG® 8 ) 3 Cascade: Inlet Evolution Shinnecock Inlet 6 Moriches Inlet 4 2 4 Ebb Shoal Complex Volume (mill. m (mill. Volume Complex Shoal Ebb 0 ) 3 1920 1940 1960 1980 2000 3 Time (year) Ebb shoal complex volume 2 2000 Moriches Inlet Shinnecock Inlet 1 1600 Shinnecock Inlet Flood Shoal Volume (mill.m Moriches Inlet 1200 0 1920 1940 1960 1980 2000 Time (year) 800 Flood shoal volume Minimum Inlet Area (m**2) 400 0 1930 1940 1950 1960 1970 1980 1990 2000 Time (year) Inlet cross-sectional area BUILDING STRONG® Planned Cascade Application FY 09: Jones Inlet New FY09 Data collected at Point Lookout as part of the monitoring and channel dredging projects will be used as input and verification data for the Cascade modeling effort. • sediment source term (placement) • calibrate aeolian transport parameters BUILDING STRONG® LICPP Borrow Tasks Develop an inventory of existing sediment borrow areas off the coast of Long Island and subsequently develop a plan to monitor and manage those borrows areas in conjunction with sound water resource management practices. By no later than the beginning of the fifth year after the initiation of this plan, the Project Team will adopt one or more regional plans for the management of existing inlets, channels, beaches, borrow areas, and related coastal environmental resources. This plan can contain elements that can be implemented by both federal and non- federal interests. It will be integrated with the substance and recommendations of the reformulated Fire Island to Montauk Point Plan (FIMP). BUILDING STRONG® Inventory Results BUILDING STRONG® Inventory Results BUILDING STRONG® Progress to Date on Offshore Sediment Resource Issue From the Technical Workshop held to review and inventory sediment resources and related coastal processes: Consensus was reached on the following: the area of interest is sediment rich; that the distribution of wave energy will change due to borrow pit excavation on sand ridges; that sand is likely to move onshore, and that the distribution of the mechanisms is unknown at this point. The following data was proposed for potential collection, towards the aim of improving predictability of the onshore sand transport, recovery of the borrow sites, and wave impacts on the shoreline, as part of pre- and post borrow area monitoring program to be recommended by NYD in order of priority for an area surrounding the ridge borrow areas, and a non-ridge control area: repeated high resolution bathymetry; installation of two directional wave gages (one in the area of interest, one at the boundary); installation of current meters; CT gage (to measure water density), installation of ADV gages (to measure bottom stress); and ABS gages (to measure suspended sediment concentrations). The model to be used has not yet been determined, however, it was estimated that the modeling effort would require approximately one year to conduct. BUILDING STRONG® SEDIMENT BUDGETS Fire Island to Montauk Point, 83 miles, recently completed (Reformulation Study) Coney Island, 4 miles (GDM, 1990) Rockaway, 7 miles (Section 934, 1993) Long Beach, 9 miles (Feasibility, 1996) Inlet Sediment Budgets Shinnecock, Moriches, Fire Island, &
Recommended publications
  • L Ong Isl and Nor Th a Tl Antic Ocean
    342 ¢ U.S. Coast Pilot 2, Chapter 10 Chapter 2, Pilot Coast U.S. 73°30'W 73°W 72°30'W LONG ISLAND SOUND 41°N GREAT PECONIC BAY Hampton Bays L ONG ISLAND Westhampton SHINNECOCK INLET Patchogue Bay Shore MORICHES INLET GREAT SOUTH BAY 12352 Lindenhurst Freeport FIRE ISLAND INLET EAST ROCKAWAY INLET JONES INLET 40°30'N NORTH ATLANTIC OCEAN 12353 Chart Coverage in Coast Pilot 2—Chapter 10 19 SEP2021 12326 NOAA’s Online Interactive Chart Catalog has complete chart coverage http://www.charts.noaa.gov/InteractiveCatalog/nrnc.shtml 19 SEP 2021 U.S. Coast Pilot 2, Chapter 10 ¢ 343 South Coast of Long Island (1) This chapter describes the south coast of Long Island information on right whales and recommended measures from Shinnecock Inlet to and including East Rockaway to avoid collisions.) Inlet, several other inlets making into the beach along this (12) All vessels 65 feet or greater in length overall (LOA) part of the coast, and the canals, bays, and tributaries inside and subject to the jurisdiction of the United States are the beach. Also described are the towns of Patchogue and restricted to speeds of 10 knots or less in a Seasonal Oceanside, including Oceanside oil terminals; Bay Shore, Management Area existing around the Ports of New a large fishing center; and the many smaller communities York/New Jersey between November 1 and April 30. that support a large small-craft activity. The area is defined as the waters within a 20-nm radius (2) of 40°29'42.2"N., 73°55'57.6"W.
    [Show full text]
  • Journal of the American Shore and Beach Preservation Association Table of Contents
    Journal of the American Shore and Beach Preservation Association Table of Contents VOLUME 88 WINTER 2020 NUMBER 1 Preface Gov. John Bel Edwards............................................................ 3 Foreword Kyle R. “Chip” Kline Jr. and Lawrence B. Haase................... 4 Introduction Syed M. Khalil and Gregory M. Grandy............................... 5 A short history of funding and accomplishments post-Deepwater Horizon Jessica R. Henkel and Alyssa Dausman ................................ 11 Coordination of long-term data management in the Gulf of Mexico: Lessons learned and recommendations from two years of cross-agency collaboration Kathryn Sweet Keating, Melissa Gloekler, Nancy Kinner, Sharon Mesick, Michael Peccini, Benjamin Shorr, Lauren Showalter, and Jessica Henkel................................... 17 Gulf-wide data synthesis for restoration planning: Utility and limitations Leland C. Moss, Tim J.B. Carruthers, Harris Bienn, Adrian Mcinnis, Alyssa M. Dausman .................................. 23 Ecological benefits of the Bahia Grande Coastal Corridor and the Clear Creek Riparian Corridor acquisitions in Texas Sheri Land ............................................................................... 34 Ecosystem restoration in Louisiana — a decade after the Deepwater Horizon oil spill Syed M. Khalil, Gregory M. Grandy, and Richard C. Raynie ........................................................... 38 Event and decadal-scale modeling of barrier island restoration designs for decision support Joseph Long, P. Soupy
    [Show full text]
  • Modern Functional Design of Groin Systems
    CHAPTER 96 MODERN FUNCTIONAL DESIGN OF GROIN SYSTEMS Nicholas C. Kraus1, Hans Hanson2, and Sten H. Blomgren3 ABSTRACT: Coastal zone management policy in the United States and many other countries discourages use of groins for shore protection, even though properly designed groins can maintain beach width, increase longevity of beach fills, and prevent loss of sand into inlets, navigation channels, and submarine canyons. A lack of a systematic approach to groin functional design and a poor image from incorrect applications are probably responsible for the aversion to groins. In this study, a modern approach to groin functional design is demonstrated by applying the shoreline response model GENESIS to simulate the action of single and multiple groins. Groin bypassing and permeability, evolution of the shoreline in a groin field, and groin tapering are discussed. The balance between net and gross sand longshore transport rates emerges as an important factor controlling groin func- tioning. A criterion is introduced for judging groin success, and an example design diagram is developed based on this criterion to demonstrate the feasibility of developing a general and rational functional design procedure. Predictions are tested in reproducing shoreline change observed at the 15 groins at Westhampton, Long Island, New York. INTRODUCTION Coastal zone management policy in the United States and many other countries strongly discourages use of groins for shore protection, despite observations of good performance and their potential for maintaining beach width, increasing longevity of beach fills, and preventing loss of sand into inlets, navigation channels, and submarine canyons. No guidance on groin functional design is available other than rules of thumb, and many examples of poor performance of groins caused by mis- judgments in either design or in planning have turned this structure into a cliche representing auto- matic beach destruction.
    [Show full text]
  • Appendix H: 2007 HMP Hazard Events
    Appendix H: 2007 HMP Hazard Events This appendix includes the hazard event tables that were found in the 2007 Suffolk County HMP. These tables include events that occurred in the County through 2007. DMA 2000 Hazard Mitigation Plan Update – Suffolk County, New York H-1 April 2014 Appendix H: 2007 HMP Hazard Events Table H-1. Coastal Erosion Events FEMA Declaration Suffolk County Dates of Event Event Type Number Designated? Losses / Impacts September 22- 23, 1815 Severe Storm N/A N/A Many structures damaged including Montauk Lighthouse, major erosion October 29, 1893 Severe Storm N/A N/A During “The Great Storm of 1893”, Fire Island Cut broken through October 24, 1897 Nor’easter N/A N/A Separated Orient Village from the North Fork March 4, 1931 Nor’Easter N/A N/A Created Moriches Inlet, severe beach erosion and structural damage September 21, 1938 Hurricane N/A N/A “Long Island Express” or “Great Hurricane of ‘38” caused approximately $6.2 M, multiple deaths, Shinnecock Inlet created, Moriches Inlet widened by over 4,000 feet. More then 200 homes had been perched on dunes 20-feet high, destroyed fishing industry, created 12 new inlets. The storm produced winds that reached 200 miles per hour (mph), generated 5-meter-high breakers, overwashed 1/3 to 1/2 of Long Island, and created approximately 12 new inlets. altered natural coastline erosion responses from future storms (Mandia, 1992). September 14, 1944 Hurricane N/A N/A The “Great Atlantic Hurricane” storm center crossed the eastern portion of Long Island during a falling tide.
    [Show full text]
  • Long Island's Dynamic South Shore
    Long Island’s Dynamic South Shore A Primer on the Forces and Trends Shaping Our Coast Jay Tanski Long Island’s Dynamic South Shore A Primer on the Forces and Trends Shaping Our Coast Introduction Long Island’s Atlantic coastline is a special place for many reasons. The south shore is home to a wide variety of habitats which support a vast array of plants and animals, some threatened or endan- gered. It is also the place where millions of people live, work, and play. The 120-mile coast stretching between Coney Island and Montauk is remarkably diverse in terms of its physical characteristics, use, and development. This shore contains everything from heavily developed urbanized barrier islands to New York State’s only federally-designated wilderness area. Area beaches are a prime recreational resource, attracting millions of visitors every year and serving as the foundation of a multibillion-dollar regional tourism industry. Long Island’s coast is also extremely dynamic, constantly changing in response to natural processes associated with wind, waves, and tides as well as human activities. The dynamic nature of the shoreline coupled with people’s desire to use and enjoy the shoreline presents unique chal- lenges in managing this resource. Making decisions that balance conservation of the natural environ- ment with significant demand for use of the shore requires a sound understanding of the processes shaping and impacting the coast. This primer provides a brief overview of what we know about coastal processes and erosion on Long Island’s south shore, based on the best available scientific information.
    [Show full text]
  • New Inlet Formation Caused by Hurricane Sandy
    10/26/2016 Background on Project Used Aerial Photography from Google Maps and NOAA’s Hurricane Sandy Response Imagery Viewer to compare pre- and post- Sandy landscapes. Focused on new inlets created by Hurricane Sandy’s storm surge and wave action. Used ERDAS Imagine 9.3 to indicate inlet locations by combining pre- and post-Sandy imagery. 3 Sites 1 10/26/2016 Information on Sites: Cupsogue Beach County Park Located in the Village of Westhampton Beach, NY; Owned by Town of Brookhaven. 296 acre barrier beach (Suffolk County Government, 2012) On the western end of Dune Road; Groin located on the western most point of the Park and Island (West side of Moriches Inlet) Source: http://wpcontent.answcdn.com/wikipedia/commons/thumb/c/c0/Long_Island_Landsat_Mo Info: Cupsogue Beach County Park Moriches Inlet – Created in 1931 by a Nor’easter. Split West Hampton from Fire Island (Mandia, 2012). Between 1933 and 1938 the Inlet widened and deepened, impacting lattoral sand transportation. Widening stopped in 1938 when the Long Island Express created the Shinnecock Inlet on the eastern end of the island. Construction of the groins on the east and west side of Moriches Inlet started in 1952 by the US ACOE. Source: http://www.striperonline.com/pict ures/smith_point/smith_point_4.j 2 10/26/2016 Information on Sites: Fire Island New inlet is located on Fire Island west of Smiths Point County Park Smiths Point County Park is located in Shirley, NY Source: NPS (http://www.nps.gov/fiis/planyourvisit/images/WVC- Aerial_285.jpg) Info: Fire Island Most of Fire Island is only accessible by boat and ferry.
    [Show full text]
  • Shinnecock Indian Nation Climate Vulnerability Assessment and Action Plan
    September 2019 Shinnecock Indian Nation Climate Vulnerability Assessment and Action Plan September 2019 Peconic Estuary Climate Vulnerability Assessment and Action Plan Prepared for Peconic Estuary Program Shinnecock Indian Nation Riverhead County Center 100 Church Street 300 Center Drive, Room 204N Southampton, New York 11968 Riverhead, New York 11901 Prepared by Anchor QEA, LLC 123 Tice Avenue, Suite 205 Woodcliff Lake, New Jersey 07677 The Nature Conservancy 250 Lawrence Hill Road Cold Spring Harbor, New York 11724 Fine Arts and Sciences LLC PO Box 398 East Hampton, New York 11937 Project Number: E71147-01.01 \\iris\woodcliff\Projects\SuffolkCountyPEP\Deliverables\Task 2c Final Report PEP and SIN\SIN\Shinnecock CRA 091919.docx TABLE OF CONTENTS 1 Introduction ................................................................................................................................ 5 1.1 The Shinnecock Indian Nation ....................................................................................................................... 6 1.2 Regional Environment ....................................................................................................................................... 7 1.2.1 Shinnecock Bay..................................................................................................................................... 7 1.2.2 Peconic Bay ............................................................................................................................................ 8 1.2.3 Regional Land Uses
    [Show full text]
  • Dark Blue Template for Slide Presentations
    Coastal and Marine Geology Program and the National Assessment of Coastal Change Hazards U.S. Department of the Interior U.S. Geological Survey USGS Coastal and Marine Geology Program · Regional Cooperative Studies · Coral Reef Studies · National Coastal Change Hazards USGS Coastal and Marine Geology Program Building National Capacity to Anticipate and Respond to Coastal Change Hazards Storms, Chronic Erosion and Climate Change - Geologic, Geomorphic and Oceanographic Observations - Research - Models, Forecasts, and Assessments - Delivery Mechanisms USGS Coastal and Marine Geology Program Regional Cooperative Studies - Fire Island Coastal Erosion - DelMarVa Coastal Erosion Shoreline Position at 8000 years B.P. - Gulf of Mexico Barrier Island Evolution 10 km - California Coastal Change - Florida/Caribbean Corals - Hawaii/Pacific Corals - Puget Sound Restoration Integration of Geologic and Shoreline Structure and Change Oceanographic FIGURE 4: Long Island subregion Montauk 0 10 20 KILOMETERS 0 Deployments Point Erosion Accretion Erosion Accretion 0 10 20 MILES Montauk Point 0 Montauk Point $ 20 20 40 40 Shinnecock Inlet 60 60 Shinnecock Inlet Shinnecock Inlet Westhampton Westhampton Westhampton Westhampton Beach Island 80 ) m Westhampton Island Beach Beach Island Beach 80 Westhampton Moriches Inlet k Moriches Inlet Moriches Inlet ore ( ore h 100 100 along s along Fire Island Fire Fire Island Fire Fire Island ance t 120 120 Dis Democrat Point Democrat Point Fire Island Inlet Fire Island Inlet Fire Island Inlet 140 140 Gilgo Beach Gilgo Beach
    [Show full text]
  • Numerical Prediction of Natural Sediment Bypass Partitioning at Moriches Inlet
    Numerical Prediction of Natural Sediment Bypass Partitioning at Moriches Inlet Frank S. Buonaiuto Daniel C. Conley Marine Sciences Research Center State University of New York at Stony Brook Stony Brook, NY 11794-500 Tidal inlets on open ocean coastlines represent a significant potential sink of sediment from the littoral zone. It has been argued that along the Atlantic coast of North America much of the coastal erosion results from the interruption of long-shore sediment transport at tidal inlets, yet inlets in equilibrium have been shown to bypass a major fraction of the long-shore transport to the down drift shoreline. The processes by which this bypassing occurs controls the location and rate of natural sand nourishment to the down-drift beaches (FitzGerald, 1988). A quasi 3-D numerical surf zone sediment transport model which incorporates wave- current interactions has been applied to Moriches Inlet in order to investigate rates and pathways of bypassed sediment. Model results show cross-shore variation of the location of mean long-shore currents and transport, due to tidal forcing. The simulations predict continuous sediment bypassing around the ebb-tidal shoal with additional bypassing through the inlet throat implying stable inlet processes. Patterns of erosion and deposition indicate down-drift migration of bar formations suggesting additional contributions from discontinuous bypassing processes. Introduction Moriches Inlet, located on the south shore of Fire Island, NY, is one of five inlets along the barrier island chain. The possible lack of bypassing at the inlet may contribute to the erosion of several down-drift barrier beaches. Little is known about the inlet’s present state of natural sediment bypassing, however, long-term stability of the throat cross- sectional area suggests that Moriches Inlet has attained equilibrium which would infer the inlet is presently bypassing sediment down-drift.
    [Show full text]
  • Long Island's Dynamic South Shore
    Long Island’s Dynamic South Shore A Primer on the Forces and Trends Shaping Our Coast Jay Tanski Long Island’s Dynamic South Shore A Primer on the Forces and Trends Shaping Our Coast Introduction Long Island’s Atlantic coastline is a special place for many reasons. The south shore is home to a wide variety of habitats which support a vast array of plants and animals, some threatened or endangered. It is also the place where millions of people live, work, and play. The 120-mile coast stretching between Coney Island and Montauk is remarkably diverse in terms of its physical characteristics, use, and development. This shore contains everything from heavily developed urbanized barrier islands to New York State’s only federally-designated wilderness area. Area beaches are a prime recreational resource, attracting millions of visitors every year and serving as the foundation of a multibillion-dollar regional tourism industry. Long Island’s coast is also extremely dynamic, constantly changing in response to natural processes associated with wind, waves, and tides as well as human activities. The dynamic nature of the shoreline coupled with people’s desire to use and enjoy the shoreline presents unique challenges in managing this resource. Making decisions that balance conservation of the natural environment with significant demand for use of the shore requires a sound understanding of the processes shaping and impacting the coast. This primer provides a brief overview of what we know about coastal processes and erosion on Long Island’s south shore, based on the best available scientific information. While by no means an extensive treatment of the subject, the information presented here is intended to familiarize the reader with the major shoreline trends and technical issues associated with erosion and erosion management on the south shore.
    [Show full text]
  • Shinnecock Flood Tidal Delta and Coastal Stabilization Problems West of Shinnecock Inlet
    A- 4 1 Shinnecock Flood Tidal Delta and Coastal Stabilization Problems West of Shinnecock Inlet Larry McCormick INTRODUCTION The shoreline along the south side of eastern Long Island changes regu­ larly in character along an east-west traverse. From Montauk Point to Napeague Harbor it is characterized by cliffs up to 60 feet high overlooking narrow cobble beaches. A relatively short segment of the shore between Napeague Harbor and the village of East Hampton consists of a series of low dune ridges trending roughly parallel to the present water line. From East Hampton to Southampton Village is a sandy beach bordered landward by a single narrow dune ridge that rests on the truncated margin of a gently sloping outwash plain. Westward from Southampton the beach and dune ridge are separated from the rest of Long Island by a series of shallow bays. At one time this barrier island system was continuous to Fire Island Inlet, but is now interrupted by Shinnecock and Moriches Inlets. Much of the shore zone from East Hampton westward is densely populated. The construction of numerous dwellings close to the water has caused much attention to be focused on the continual recession of the beaches in this area. This concern has resulted in periodic rather piecemeal beach nourish­ ment programs as, well as construction of grain fields to trap sand from the prevailing westerly littoral drift. Shoreline recession results from both natural processes and from works of man. An understanding of the causes should be helpful in determining where beach stabilization programs are needed, and to some degree, guide the selection of the kind of remedial action necessary.
    [Show full text]
  • Hypothetical Relocation of Fire Island Inlet, New York
    In: Proceedings Coastal Sediments ’03. 2003. CD-ROM Published by World Scientific Publishing Corp. and East Meets West Productions, Corpus Christi, Texas, USA. ISBN 981-238-422-7. HYPOTHETICAL RELOCATION OF FIRE ISLAND INLET, NEW YORK Nicholas C. Kraus1, Gary A. Zarillo2, and John F. Tavolaro3 Abstract: Hypothetical eastward relocation of Fire Island Inlet is examined as a thought exercise in regional sediment management. Subjects considered include morphologic behavior of the inlet, hydrodynamics of the present and hypothetical relocated inlet, collapse of the existing ebb-tidal shoal and formation of new ebb and flood shoals, sand bypassing, navigability, and stability of the beaches east and west of the inlet. The relocated inlet would be more hydraulically efficient than the present inlet, increasing tidal exchange (prism), promoting circulation in Great South Bay, and increasing sand storage in the inlet shoals. Collapse of the abandoned ebb shoal would feed the eroding beaches to the west, such as Gilgo Beach, for 50- 100 years. Oak Beach would no longer experience an erosional ebb current and wave action. The east jetty would impound sediment, gradually building the width of the fragile beaches of Fire Island located to the east. Several sediment-sharing projects would benefit from the inlet relocation, a goal of regional sediment management. Potentially unacceptable negative consequences that require study, such as increased storm surge susceptibility, are identified. INTRODUCTION The U.S. Army Corps of Engineers has recently launched a Regional Sediment Management Research (RSM) Program to advance knowledge and develop predictive tools for the Corps and society to effectively manage water resource projects and associated sediments.
    [Show full text]