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ACOE Coastal Storm Management Alternative for Jamaica Bay Communities

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ACOE plan for storm protection focusing on the communities around Jamaica Bay

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ACOE Coastal Storm Management Alternative for Jamaica Bay Communities

  1. 1. COASTAL STORM RISK MANAGEMENT ALTERNATIVE FORMULATION FOR JAMAICA BAY COMMUNITIES JAMAICA BAY TASK FORCE MEETING November 1, 2018 Peter Weppler, Chief Environmental Analysis Branch Planning Division New York District U.S. Army Corps of Engineers Jamaica Bay, facing South from Brooklyn towards the Bay, Rockaway Peninsula, and Atlantic Ocean. Source: Boating Times Long Island, Photo by Jim Mobel Jamaica Bay, New York City
  2. 2. 2 CORPS OF ENGINEERS PLAN FORMULATION PROCESS • Identify problems and opportunities • Inventory and forecast conditions • Formulate alternatives to manage the risk of flooding from coastal storms • Evaluate alternatives o Plans are screened for completeness, effectiveness, efficiency, and acceptability o Compare reduced damages of proposed alternatives against without project conditions to determine benefits o Perform an initial evaluation of environmental impacts o Compare benefits to costs for each alternative  To be economically justified a plan must have a benefit-to-cost ratio (BCR) greater than one • Compare alternatives • Select alternative
  3. 3. ADDRESSING SEA LEVEL RISE 3 • Adapting to sea level rise is NOT optional and it is a shared responsibility. • Incorporates the most recent, sound science analyses of how to adapt coastal storm risk measures to increased future sea level in their design and analyses. • This includes assessing risk and uncertainty based on an uncertain future.
  4. 4. 4 EAST ROCKAWAY INLET TO ROCKAWAY INLET AND JAMAICA BAY – ROCKAWAY BEACH
  5. 5. BACKGROUND ON ROCKAWAY REFORMULATION Draft Report Released August 2016  wide-ranging public and agency comments were received Tentatively Selected Plan in the 2016 Draft Report recommended a comprehensive $3B plan (which has since been revised) but included: Storm surge barrier across Jamaica Bay inlet Atlantic Shorefront seawall dune and beach system with groin enhancement Smaller features in the Back-Bay to manage risk for frequent flooding when the barrier would remain open The $5B “perimeter plan” of floodwalls and tributary gates around Jamaica Bay was screened out in favor of the above Public and Agency Input called for further analysis of proposed storm surge barrier across Jamaica Bay Numerous comments requested the inclusion of additional natural and nature-based features (NNBFs) in Jamaica Bay Equally, there were many comments requesting that the study be expedited to construct the Atlantic Shorefront feature earlier than proposed Draft Revise Report Released August 2018. Comment period closed October 22, 2018 5
  6. 6. RECOMMENDED PLAN ATLANTIC SHOREFRONT REACH • Reinforced vegetated dune and beachfill with structure crest of +17 ft NAVD88, dune crest of +18 ft NAVD88 for 35,000 LF from Beach 9th Street to Beach 149th Street, and include sand tapers at the ends of the project • 5 groin extensions, 1 optional groin rehabilitation • 13 new groins • Obtaining sand from borrow area located approximately 2 miles south of the Rockaway Peninsula and about 6 miles east of the Rockaway Inlet. 6
  7. 7. TENTATIVELY SELECTED PLAN (CIRCA 2016)
  8. 8. DRAFT BARRIER ALIGNMENT ALTERNATIVES EVALUATED (CIRCA 2016) Three alignments of the storm surge barrier originally considered - Hydrodynamic modeling undertaken for design of openings - Effects of scour on Gil Hodges Bridge eliminated C-1W - Impacts to existing utilities considered C-1E is the preferred alignment, C-2 is close in comparison
  9. 9. HIGH FREQUENCY FLOODING RISK REDUCTION FEATURES (HFFRRFS) • Due to the scale, complexity, and cost of the proposed storm barrier, and the need for additional study, the barrier was moved to New York/New Jersey Harbor and Tributaries Feasibility Study which came out of the North Atlantic Coast Comprehensive Study (NACCS) • High Frequency Flooding Risk Reduction Features (HFFRRFs, formerly ‘Residual Risk Features’) are designed to complement a potential future storm surge barrier • In order to be recommended, each element must be justified as stand-alone feature (without the proposed storm surge barrier) and have a positive benefit-to-cost ratio 9 New York and New Jersey Harbor and Tributaries Study Area—The study team is evaluating a suite of storm surge barriers in the region to evaluate potential for regional storm risk management measures
  10. 10. BACK BAY FLOODING 10 3yr RP (2068) Flood Extent Verified 5yr RP (2068) Flood Extent Verified 10yr RP (2068) Flood Extent Verified Flood extents calculated only within HFFRRF study area. Excludes Broad Channel and areas outside (west) of storm surge barrier alignment C-1E
  11. 11. NATURE BASED FEATURES LOCATIONS ANALYZED 3 Sites at Arverne 1 Site at Edgemere 1 Site at Norton Basin 1 Site at Bayswater 2 Sites at Mott’s Basin NNBF PROTOTYPE DEVELOPMENT  NNBFs created to accommodate a variation in coastal edge conditions.  Two main variations are distinguished:  Horizontal space available between the urban developed edge and the water line  Existing plant species composition and the need to either extend the existing coastline or cut back the existing bank line to accommodate a suitable habitat for wetland creation/enhancement  Rapidly descending bathymetry near shoreline  Limited horizontal width between front toe of new shoreline slope and flood control structure on back edge  Already existing living shoreline habitats performing CSRM function  Presence of heavy anthropogenic infrastructure along shoreline (e.g. docks, piers).  Gray feature structures set far back from shoreline…no interactive capacity.  Combinations of all these factors (most likely scenario)  Does not increase risk of wildlife hazards to planes; habitat type restrictions near JFK airport DID NOT SITE NNBFS WHERE THERE IS…
  12. 12. 12 12 OLD HOWARD BEACH CANARSIE HEAD OF BAY NORTON BASIN MOTTS BASIN INWOOD BAYSWATER PARK Flood extents calculated only within HFFRRF study area. Excludes Broad Channel and areas outside (west) of storm surge barrier alignment C-1E ROSEDALE MEADOWMERE LAWRENCE BROAD CHANNEL STRUCTURAL SCREENED, NONSTRUCTURAL PASSED MID-ROCKAWAY BACK-BAY W/ NNBFs High Frequency Flooding Risk Reduction Features - SCREENING RESULTS • 3 sites are in the Final Plan, including 5 NNBFs at the Mid-Rockaway Back-Bay site • Non-structural plan for Broad Channel screened using data and experience from Build it Back
  13. 13. RECOMMENDED PLAN JAMAICA BAY REACH 13 NNBF considered but not recommended in this location: • Existing high quality mudflat and mussel habitat already performing NNBF functions • Avoid habitat exchange Motts Basin North HFFRRF
  14. 14. RECOMMENDED PLAN JAMAICA BAY REACH 14 HFFRRF Projects Mid-Rockaway HFFRRF Arverne Area/Subreach (left) Mid-Rockaway HFFRRF Edgemere Area/Subreach • NNBFs are integral features to control erosion on the berm which will be overtopped frequently throughout the project life • NNBF+berm design is more cost effective than alternative non-erodible floodwall • BCR underestimates benefits due to “leaving benefits on the table”
  15. 15. 15 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study ALTERNATIVES OVERVIEW • Alternative 1: No Action • Alternative 2: Harbor Wide Gate and Beach Restoration • Alternative 3A/3B: Multiple Bay/Basin Gate and Floodwalls & Levee Systems • Alternative 4: Individual Waterbody Gate and Floodwalls & Levees • Alternative 5: Perimeter Only New York Harbor.
  16. 16. ALTERNATIVE 1: NO ACTION (FUTURE WITHOUT PROJECT CONDITIONS) 16
  17. 17. ALTERNATIVES 2-5 • Alternative No. is a reference to the scale of solution and general strategy • Siting and quantities are approximate for screening purposes and will be refined • Design level 1% event (mean) + RSLC + Wave Run-up (measure and location specific) • Focus on biggest cost drivers (storm surge barrier) in each alternative • Nonstructural, NNBF, and perimeter structural placeholders to be refined in future formulation 17 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study Alt. 2 Alt. 3A Alt. 3B Alt. 4 Alt. 5 In-Water Measures Land-Based Measures
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  22. 22. 23 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study Alternatives at AMM Best performing alternatives (Draft Interim Report) TSP and Draft Report Work needed to identify TSP Parametric analyses ADM and optimization Recommended Plan
  23. 23. FACTORS CONSIDERED - ALTERNATIVE SCREENING 1. Hydrodynamic Modeling Induced Flooding during Storms Tidal Influences 2. Relative Sea Level Change Based on intermediate 3. Period of Analysis 50 year period may limit full evaluation given many measures will likely have far longer period of utility 4. Operations and Maintenance Assumptions Storm event condition selected for surge gate operation has substantial effects on plan selection 5. Benefits Model 24 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study
  24. 24. 25 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study ENVIRONMENTAL CONSIDERATIONS  Changes to tidal range/regime, flow velocity, salinity concentrations, sedimentation rates, scour, and elevation  Water quality, dissolved oxygen, nutrients, and phytoplankton biomass (i.e. eutrophication), and pathogenic bacteria  Anadromous/catadromous fish migration and aquatic species  Marsh inundation  Air quality  Transportation (marine vessels, etc.)  Aesthetics and recreation  National Historic Landmarks and Historic Properties  Listed species and critical habitat  Noise and vibration  Bay bottom impacts, as well as landside impacts  Location of Superfund, National Priority List, and other contaminated sites Jamaica Bay, New York City
  25. 25. 26 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study PUBLIC INVOLVEMENT  Scoping Period through November 5th  Release of the Draft Interim Report – Winter 2019  Public/ Agency Reviews with Public Meetings  Draft Feasibility Report and Tier 1 EIS – Spring 2020  Public/ Agency Reviews with Public Meetings  Optimization of the Selected Plan  Final Feasibility Report and Tier 1 EIS – Spring 2021  Chief’s Report – Summer 2022  Public Involvement during Pre-Construction Engineering and Design Phase –Tier 2 EIS *The red boxes indicate the best opportunities for the public to provide input to the study. The scoping period extends until November 5, 2018. Comments and input submitted by this deadline will be used to develop the Draft Interim Report. Comments received after the deadline are welcome and will be used to help identify the Tentatively Selected Plan (TSP) in 2020. Once the Draft Interim Report is released, the public and agencies will have a chance to review and submit comments and public meetings will be held as part of the public review period. The comments are used to inform the agency as it moves to identifying the TSP.
  26. 26. 27 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study STUDY SCHEDULE Milestones Milestones Dates* Draft Interim Report Winter 2018/2019 Draft Feasibility Report and Tier 1 EIS Spring 2020 Final Feasibility Report and Tier 1 EIS Spring 2021 Chief’s Report (for Congress) Summer 2022 * The schedule is contingent upon available funding, non-federal partner support, and concurrence by Corps higher-authority offices.
  27. 27. 28 New York-New Jersey Harbor and Tributaries Coastal Storm Risk Management Feasibility Study HOW TO STAY INVOLVED Project Webpage http://www.nan.usace.army.mil/Missions/Civ il-Works/Projects-in-New-York/New-York- New-Jersey-Harbor-Tributaries-Focus-Area- Feasibility-Study/ Stakeholder Mailing List Email NYNJHarbor.TribStudy@usace.army.mil if you would like to join our mailing list and receive periodic updates. Scoping Comments Send any questions and/or comments to NYNJHarbor.TribStudy@usace.army. mil OR Fill out and submit a comment card at a scoping meeting Scoping Comment Period open through November 5, 2018
  28. 28. 29 JAMAICA BAY PLANNING REGION EFFORTS Elders Point East and West Marsh Islands Restoration (Mitigation for NY Harbor and CAP Beneficial Use of Dredged Material): Constructed 2007 & 2010 Black Wall and Rulers Bar Marsh Islands Restoration (NY Harbor Sand Placement): Constructed 2012 and differential cost paid for by sponsor. Existing Rockaway Project: Constructed 1977 and Repaired in 2014. Proposed Ecosystem Restoration Sites Jamaica Bay Navigation Channel: O&M Dredging in 2019 (subject to availability of funds) Plumb Beach CSRM Project (CAP Beneficial Use of Dredged Material): Constructed 2012/2013 Gerritsen Creek Restoration (CAP Section 1135): Constructed 2011 Hudson Raritan Estuary (HRE) Proposed Restoration Sites Yellow Bar Hassock Marsh Island Restoration (CAP Beneficial Use of Dredged Material): Constructed 2012 East Rockaway Inlet Navigation Channel: O&M Dredging in 2019 (subject to availability of Funds) Spring Creek South CSRM/Restoration (NYSDEC/FEMA IIS): 60% designs completed and EA public release August 2018 Spring Creek North Restoration (CAP Section 1135): Report approved Mar 2018 and D&I PPA scheduled Jul 2018
  29. 29. SPRING CREEK SOUTH FEMA HAZARD MITIGATION GRANT PROGRAM (HMGP) PROJECT Goals • Manage coastal storm risk with Natural/nature-based features; Decrease risk of fire • Align with NPS Gateway National Recreation Area (GNRA) Management Plan • Coordinate with complementary Jamaica Bay projects • Recommended Plan  Berm - 19 feet NAVD 88; 50-foot-wide path at crest  Tie-ins at Belt Parkway and Addabbo Bridge  Freshwater wetlands  Flap gates  Local access points; Improved edge aesthetic

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