Mid-Chesapeake Bay Feasibility Study
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Mid-Chesapeake Bay Feasibility Study. Screening Criteria. Tier I: Island needs to be in study area Tier II: Island needs to be or have historically been at least 200 acres; currently needs to possess the ability to be 200 acres or more

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Presentation Transcript

Screening criteria
Screening Criteria

  • Tier I: Island needs to be in study area

  • Tier II:

    • Island needs to be or have historically been at least 200 acres; currently needs to possess the ability to be 200 acres or more

    • Island must be reasonably accessible for dredged material placement

    • Island restoration cannot negatively affect the hydraulic conditions of existing river systems

    • Island cannot significantly impact current navigation of existing waterways

    • Must be an island/not shoreline


  • Tier II Continued:

    • Island must not be a highly populated center

    • Island must not involve any unexploded ordinance or hazardous, toxic and radioactive waste

    • If island is currently State or Federally managed as a wildlife area, must have support from the landowners for restoration

    • Compatibility with any other Corps-led studies being conducted on the island


  • Barren Island, Dorchester County

  • Holland Island, Dorchester County

  • Hoopers Islands, Dorchester County

  • James Island, Dorchester County

  • Little Deal Island, Somerset County

  • Ragged Island, Dorchester County

  • Smith Island, Somerset County

  • South Marsh Island, Somerset County


Formulate alternative plans
Formulate Alternative Plans

  • Screen the Island(s)

  • Collect Detailed Environmental - Engineering - Socioeconomic Data

  • Prepare Conceptual Plans

    • Determine Potential Island Configurations/Acreages

      • No configuration pre-determined

  • Analyze/Compare Plans

  • Select Recommended Plan


Corps six step planning process
Corps Six Step Planning Process

  • Specify Problems and Opportunities

  • Inventory and Forecast Conditions

  • Formulate Alternative Plans

  • Evaluate Effects of Alternative Plans

  • Compare Alternative Plans

  • Select Recommended Plan


Site Locations:

James and Barren Islands Dorchester County, MD

James

Island

Barren

Island



James island study findings coastal engineering
James Island Study FindingsCOASTAL ENGINEERING

  • Water depths in concept area(s) are 2-12 feet

  • Highest waves approach from north and south

  • East side of island sheltered from waves

  • Longest fetch from south

  • Currents relatively weak

    • Maximum velocity 1 ft/sec

  • Update bathymetric survey Fall 2002


James island study findings hydrodynamics sedimentation
James Island Study FindingsHYDRODYNAMICS & SEDIMENTATION

  • Minimal impacts on local tidal elevations

  • Current velocities impacted

    • Maximum change ±0.4 ft/sec

  • Beneficial effects on sedimentation rates and patterns

    • Less shoreline erosion of James Island and portions of Taylors Island

  • Probable reduction of suspended sediment and improved water quality


James island study findings existing environmental conditions fall 2001 2002 summer 2002 studies
James Island Study FindingsEXISTING ENVIRONMENTAL CONDITIONSFall 2001/2002 & Summer 2002 Studies

  • In situ water quality results were in expected range

  • Diverse fish community with juveniles of commercially important species

  • Essential Fish Habitat for 9 finfish species

    • Bluefish, red drum and summer flounder present

  • Low B-IBI scores

    • Average score of 1.6 in Summer 2002



James island study findings environmental conditions continued
James Island Study FindingsENVIRONMENTAL CONDITIONS (continued)

  • Variety of wildlife utilizes island remnants

    • 42 bird species present

    • 9 species of wildlife

  • No adverse impacts expected on terrestrial vegetation, including wetlands

  • Commercial crabbing within concept area will be displaced

  • Temporary viewshed and noise disturbance during construction

  • No cultural resources within concept area



James island additional studies
James Island Additional Studies

  • Crab Pot Surveys

    • April – September

  • Submerged Aquatic Vegetation (SAV) Survey & Popnetting

    • Late season grasses

  • Pound net surveys

  • Clam Surveys

    • Soft shell

    • Razor shell




Barren island study findings coastal engineering
Barren Island Study FindingsCOASTAL ENGINEERING

  • Water depths in concept area are 3-10 feet

  • Highest wind speeds from the southwest and northwest

  • Longest fetch from the south

  • Eastern side of island requires less armor because it is sheltered


Barren island study findings environmental conditions fall 2002 summer 2002 studies
Barren Island Study FindingsENVIRONMENTAL CONDITIONSFall 2002 & Summer 2002 Studies

  • In situ water quality results were in expected range

  • Area inhabited by numerous finfish species

    • Several species support commercial and recreational fisheries

  • Essential Fish Habitat for 9 finfish species

    • Bluefish, summer flounder, and red drum present in area

  • B-IBI scores were high

    • Average 3.84

  • SAV beds present along eastern shoreline and in quiescent waters east of island

  • RTE species: bald eagle, royal tern, Wilson’s plover


Barren island study findings environmental conditions continued
Barren Island Study FindingsENVIRONMENTAL CONDITIONS (continued)

  • Two NOBs located in areas adjacent to proposed dike alignment

  • Island important habitat for colonial waterbirds and wading birds

    • 61 bird species observed in Summer 2002

  • Variety of wildlife utilizes island remnants

    • 13 species

  • Reduction of commercial crabbing area

  • Negligible noise and viewshed disturbance

  • MHT- no records of historically significant sites



Barren island additional studies
Barren Island Additional Studies

  • Crab Pot Surveys

    • May – September

  • Submerged Aquatic Vegetation (SAV) Survey & Popnetting

    • Late season grasses

  • Pound net surveys

  • Clam Surveys

    • Soft shell

    • Razor shell


Plan formulation
Plan Formulation

  • Goal

    • The goal for this feasibility study is to restore and protect valuable but threatened Mid-Chesapeake Bay island ecosystems through the beneficial use of dredged material.


Plan formulation1
Plan Formulation

  • Objectives

    • Restore and enhance wetland, aquatic and terrestrial island habitat for fish, reptiles, amphibians, birds, and mammals;

    • Protect existing island ecosystems, including sheltered embayments;

    • Minimize impacts to fisheries nursery-, feeding-, and protective-habitats;

    • Increase wetlands acreage in the Chesapeake Bay watershed;

    • Decrease turbidity and shoreline erosion;


Plan formulation2
Plan Formulation

  • Objectives (continued)

    • Promote conditions that promote the establishment and protection of submerged aquatic vegetation;

    • Promote conditions that support oyster recolonization;

    • Minimize impacts to rare, threatened and endangered species and their habitats

    • Minimize establishment of invasive species; and

    • Allow for placement of 2 millioncubic yars/year of dredge material.


Plan formulation3
Plan Formulation

  • Design Criteria and Constraints

    • Must protect existing island habitat

    • Dredge placement depths will be considered in the range of 7-9 feet.

    • Footprint should be based on geomorphology (i.e. clay areas)

    • Dike heights need to be at a minimum of 10-12 feet above MLLW.


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