Regional Sediment Management: The Long Island Coastal Planning Project

Transcription

1 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

2 Outline Project Location General Setting Purpose Goals Tasks Performed Plan through April 2010

3 Project Location Long Island Sound Block Island Sound Montauk Point Manhattan Long Island Great South Bay Moriches Bay Shinnecock Bay Moriches Inlet Shinnecock Inlet Ponds Montauk Rockaway Inlet E. Rockaway Inlet Long Beach Jones Inlet Jones Island Fire Island Inlet Fire Island Westhampton Atlantic Ocean Scale Rockaway Kilometers

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5 BUILDING STRONG

6 Shifting Sand

7 Shifting Sand

8 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

9 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

10 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.

11 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.

12 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

13 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

14 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 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.

15 Cascade Model For New York Existing Cascade Model New FY09

16 Cascade: Montauk Point to Fire Island Inlet Shoreline Position (m) Simulation of Shoreline Evolution (detail) Shinnecock Inlet Moriches Inlet meas initial 1931 calc Mean Longshore Transport (m**3/year) Atlantic Ocean Land Shinnecock Inlet Moriches Inlet Data from Rosati et al. (1999) Fire Island Inlet Distance West from Montauk Point (km) Calculated Net Longshore Sediment Transport ( ) Distance West from Montauk Point (km) Work Done By: Sophie Munger & Nick Kraus, ERDC, Coastal & Hydraulics Lab.

17 Ebb Shoal Complex Volume (mill. m3) Shinnecock Inlet Moriches Inlet Cascade: Inlet Evolution 4 Minimum Inlet Area (m**2) Time (year) 800 Ebb shoal complex volume Moriches Inlet Shinnecock Inlet Flood Shoal Volume (mill. m3) Time (year) Flood shoal volume Shinnecock Inlet Moriches Inlet Time (year) Inlet cross-sectional area

18 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

19 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 nonfederal interests. It will be integrated with the substance and recommendations of the reformulated Fire Island to Montauk Point Plan (FIMP).

20 Inventory Results

21 Inventory Results

22 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.

23 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, & Jones Inlets

24 Inventory of Previous Sediment Budgets South Shore of Long Island 2. INVENTORY OF PREVIOUS SEDIMENT BUDGETS 2.1 Taney (1961a,b), South Shore of Long Island 2.2 Panuzio (1968), South Shore of Long Island 2.3 Research Planning Institute (1983), Fire Island to Montauk Point 2.4 USACE-NAN (1987), Shinnecock Inlet 2.5 Nersesian and Bocamazo (1992), Shinnecock Inlet 2.6 Williams and Morgan (1993), Fire Island 2.7 USACE-NAN (1988), East Rockaway Inlet to Rockaway Inlet 2.8 USACE-NAN (1989), Jones Inlet to East Rockaway Inlet 2.9 Gravens et al. (1991), Coney Island 2.10 USACE-NAN (1992), Coney Island 2.11 USACE-NAN (1995), Jones Inlet to East Rockaway Inlet 2.12 Moffatt & Nichol Engineers (1998), Jones Inlet 2.13 Kana (1995), Fire Island to Montauk Point 2.14 Gravens et al. (1999), Fire Island to Montauk Point 2.15 Schwab et al (1999) 2.16 Batten (2003), Jones Inlet to Montauk Point 2.17 Moffatt & Nichol (2007), Fire Island to Montauk Point

25 Figure 3-1 Shoreline Reaches

26 Table 3-1: Range of longshore sediment transport rates (m³/yr) at the ends of reaches Location Max Min Mean # of Estimates East end Montauk Reach 110, ,083 6 West end Montauk Reach 281, , ,250 8 East end of Westhampton Reach 251,000 45, ,500 4 West end of Westhampton Reach 437,000 29, ,333 6 East end of Fire Island Reach 345,000 52, ,000 4 West end of Fire Island Reach 460, , ,714 7 East end of Jones Beach Reach -79, , ,500 4 West end of Jones Beach Reach 459, , ,375 4 East end of Long Beach Reach 153, , ,600 6 West end of Long Beach Reach 306,000 7, ,767 3 East end of Rockaway Reach 153, , ,000 1 West end of Rockaway Reach 139, , ,000 1 East end of Coney Island Reach -8,900-12,400-10,650 2 West end of Coney Island Reach 8,700 5,500 7,100 2 Positive values correspond to westward transport and negative values correspond to eastward transport.

27 Sediment Budget Recommendations Develop more detailed budgets for western inlets, to follow sediment pathways Develop budget for Jones Island Use new tools, where available, to develop recent bathy/topo for updated volume change estimates Work on uncertainties in a statistical manner Sediment Budgets for the Eastern Bays Barrier Shorelines to be Initiated w/fy 09 funds

28 Point Lookout/Jones Inlet Beneficial Use of Dredge Material Monitoring Dates of Point Lookout Monitoring Surveys Date Survey Equipment General Field Notes 06/25/2008 Traditional (rod/transit) 07/28/2008 Traditional (rod/transit) 08/25/2008 Traditional (rod/transit) 09/30/2008 Traditional (rod/transit) installed sand fencing 10/29/2008 Traditional (rod/transit) strong, west winds, aeolian transport toward inlet 11/26/2008 Traditional (rod/transit) aeolian transport toward inlet 01/13/2009 RTK System

29 Station 1 strong westerly winds Station 9

30 Profile Volume: from transect origin to 0 NGVD Contour Location of 0-NGVD Contour: measured from transect origin Station 9: (outside of placement area) general increase in profile volume and position of shoreline Stations 1,3,4: (inside groin compartments) initial decrease in profile volume then appear to level off in the latter few surveys. Stations 5,6,7,8: (placement area outside of groin compartments) consistent decrease in profile volume throughout survey period

31 Long Island Sediment Needs Assessment Building on the FY07 efforts, further development of the LISNA website Folding data into LICRSM Addition of FY08 dredging data

32 Original Purpose: GIS Web Tool to Connect: SEDIMENT SOURCES: Show where material has been dredged and placed historically (last 10 years initially) SEDIMENT NEEDS: Locations where sediment will be needed in the future

33 Find disposal sites Aid planning for funding, permitting Identify sediment needs Reduce the timing problem between supply & need Provide framework for discussion Identify cost-effective distances from source to placement Record data, show where sediment has gone

34 Expanded Purpose: Archive Long Island Coastal data in web-accessible format Navigation channels Sediment data Borrow area locations, core sample data Project & contract documents Photos Profiles Historic shorelines Wave, wind, current data Storm information Species data Sediment budgets

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36 Projects can be viewed by District, State, and Geographic Area. Click to display New York District Projects

37 Click to display all New York District Projects Click to see contract details

38 Click to display contracts by year

39 Click here to retrieve all contracts by location

40 Dredge/Placement Area Visuals

41 Click on the cell ID to see contract details Placement Areas in Google Earth

42 LICPP Plan through April 2010 Complete the Project Management Plan and coordinate with External PDT Convene the external PDT for bi-monthly meetings and hold bi-annual stakeholder workshops: 1 st Stakeholder workshop - 29 Sep 2009 Continue the LISNA effort Initiate development of sediment budgets for LI back-bay regions Do a gap analysis for coastal processes data Develop a working CASCADE Model for scenario planning at Jones Inlet (1/2)

43 LICPP Plan through April 2010 Analyze data collected at Pt. Lookout and summarize findings in a letter report Identify environmental windows associated with bays, inlets, and ocean and document in a GIS database Generate report discussing submerged aquatic vegetation and its association with navigation channels, beach nourishment, and impacts related to sediment transport in the bays Develop print and web-based local government and public outreach plan (2/2)

44 Summary LICPP will address RSM issues by: consolidation of existing sediment data in formats that are usable to all stakeholders, innovation of techniques to analyze and manage sediment resources, and stakeholder outreach, communication and input to RSM decisions.