New York City Salt Marsh Restoration and Protection, Sandy

New York City Salt Marsh Restoration and Protection, Post-Hurricane Sandy Christopher Haight, Marit Larson, Rebecca Swadek, and Ellen K. Hartig

New York City Department of Parks & Recreation

Forestry, Horticulture, and Natural Resources Super Storm Sandy: Five Years Later Meadowlands Conference October 26, 2017

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Sandy Conference 2017

2 Title of Presentation Goes Here

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Urban Coastal Wetlands

• Coastal wetlands are a critical part of a livable NYC

o Resilient coastal natural areas

o Aesthetic, recreational and educational value

o Ecosystem services (fisheries, bird communities, water quality)

• Coastal wetlands are at risk

o Sea-level rise and storm surge

• Planning, management and restoration can help

protect our wetlands for the future

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Project Goals

• Assess current condition of

natural marshes

• Evaluate vulnerability to sea-

level rise (SLR)

• Identify opportunities for

protection, conservation &

restoration

Prioritize restoration & protection opportunities

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Ecological Assessment at 25 salt marshes across NYC

Long

Island

Sound

Staten

Island

Jamaica Bay

Desktop Analysis

o Historic Loss Analysis

o Sea Level Affecting

Marshes Model (SLAMM)

Rapid Ecological

Assessments

o Mid-Atlantic Tidal Rapid

Assessment Method

(MidTRAM)

o NAC Salt Marsh

Assessment (NACSMA)

Conditions and

vulnerability indices

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Marsh Loss Analysis

6

• 1,011 acres were

assessed

• 160 acres, or 18

percent of salt marsh

was lost in the

waterward direction

(shoreline, ditch,

creek) between 1974-

2012

• Alley Creek lost 12

acres or 23%

Alley Creek, Queens

Long Island Sound

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Site Scores: Condition and Vulnerability

-2 -1.5 -1 -0.5 0 0.5 1 1.5

Marsh Area

Percent Developed

Native Species Richness

Total Vegetated Cover

Low Marsh Soil Strength

Salt Marsh Breeding Bird Count

Bare Peat Coverage

Trend in Pool Size

Ditch Density

Total Score

Z-Score

Saw Mill Creek Outer: Condition

-1.5 -1 -0.5 0 0.5 1 1.5

Marsh Area

Potential Marsh Loss to SLR

Potential Marsh Gain from Migration

Trend in Waterward Marsh Loss

Edge Density

Percent High Marsh

Total Score

Z-Score

Saw Mill Creek Outer: Vulnerability

-2 -1.5 -1 -0.5 0 0.5 1 1.5

Marsh Area

Percent Developed

Native Species Richness

Total Vegetated Cover

Low Marsh Soil Strength

Salt Marsh Breeding Bird Count

Bare Peat Coverage

Trend in Pool Size

Ditch Density

Total Score

Z-Score

Lemon Creek Outer: Condition

-1.5 -1 -0.5 0 0.5 1 1.5

Marsh Area

Potential Marsh Loss to SLR

Potential Marsh Gain from Migration

Trend in Waterward Marsh Loss

Edge Density

Percent High Marsh

Total Score

Z-Score

Lemon Creek Outer: Vulnerability

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Alley Creek Inner

Alley Creek Outer

Hutchinson Inner

Hutchinson Outer

Pelham Bay Cove

Pugsley Creek Marsh

Turtle Cove

Udall's Cove Marsh

Westchester Creek

Four Sparrow

Fresh Creek Marsh Idlewild Marsh Inner

Idlewild Marsh Outer

Spring Creek Arlington Marsh

Fresh Kills Marsh

Lemon Creek Inner

Lemon Creek Outer

Neck Creek Inner

Neck Creek Outer

Richmond Creek

Saw Mill Creek Inner Saw Mill Creek Outer

W. T. Davis Inner

W. T. Davis Outer

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

-1.5 -1 -0.5 0 0.5 1 1.5 2

Long Island Sound

Jamaica Bay

Staten Island

Lower Condition / Lower Vulnerability Lower Condition / Higher Vulnerability

Higher Condition / Lower Vulnerability Higher Condition / Higher Vulnerability

Priority site for

protection

Priority site for restoration

Co

nd

itio

n

Vulnerability

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Actions

Long Term

Viability &

Function

of NYC

Saltmarsh

in Study

Area

Acquisition/

Transfer

Restore flooded

hard surfaces

Increase Marsh

Surface Elevation Erosion and

Decreased Size

Restore Eroded

Marsh Edge

Opportunities for Restoration and Protection

Threats Targets

Obstacles to

Marsh Migration

Reduced Capacity

for Vertical

Growth

Large Scale Marine

Debris Removal

Marine Debris

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Acquisition/

Transfer

Restore flooded

hard surfaces

All Sites (25)

Owner Current

Marsh (ac) Future

Marsh (ac)

NYC Parks 864 +204

Private 21 +29

Other Govt.

37 +24

0

50

100

150

200

250

300

Private Public

Siz

e (

acre

s)

Property Type Additional Future WetlandCurrent WetlandNon Wetland Area in Parcel

Future flooded hard surfaces

Parking Lots* = 29 ac

Roads** = 7 ac

Other Hard Surfaces = 6 ac

Total = 42 ac

* Mostly Orchard Beach parking lot in Pelham Bay Park

**Includes Brookville Blvd. in Queens and Travis Ave in

Staten Island

Future flooding in Pelham Bay Park, Bronx

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8.9

4.8

2.1 0.7 0.7

0

2

4

6

8

10

IdlewildMarshOuter

LemonCreekOuter

SpringCreek

IdlewildMarshInner

TurtleCoveP

riority

Are

a (

acre

s)

Increase Marsh

Surface Elevation

Field Data

• % low marsh

• % bare ground

• Breeding birds

Desktop data:

• Future marsh loss (SLAMM)

• Accessible for sediment

placement

Photo: Patty Doer, TNC-NJ Idlewild, Queens

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8.4

5.7 5.6

2.7 1.5 1.5 1.2 1.2

0

2

4

6

8

10

Pri

ority

Are

a (

acre

s)

Restore Eroded

Marsh Edge

Desktop data:

• High area, width, and % marsh loss

(1974-2012)

• Future marsh loss (SLAMM)

• Accessible for sediment placement

Alley Creek Loss

Analysis 1974- 2012

Alley Creek, Queens Super S

torm Sandy C

onference 2017

13

Large Scale Marine

Debris Removal

Before

After

Example Site: Four Sparrow Marsh, Brooklyn

Before

After

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• Pilot new approaches to wetland

protection and restoration:

Shoreline protection and

waterward restoration

Elevation / sand

enhancement

• Continue debris removal

• Protect future marsh migration

areas (reduce impervious area in

parks, use existing regulations,

acquisition, easements)

• Expand assessment approach to

include non-Parks properties

Recommendations

Marsh loss at Idlewild, Queens

Clean-up in Four Sparrow, Brooklyn

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•http://naturalareasnyc.org/in-print

Towards a Salt Marsh Management Report for NYC

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http://naturalareasnyc.org/in-print



16

Goal: Restore salt marsh area lost to

interior marsh pond expansion

Approach:

• Coir logs placement to form new edge

• Sand placement behind coir into

expanded pool

• Volunteer planting

Interior Marsh Restoration in Alley Pond Park, Queens

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17

Goal: Increase salt marsh surface

elevation to improve salt marsh

sparrow habitat and resilience to SLR

Approach:

• Thin layer sediment application (10-

20cm in depth) onto existing low

marsh and depressions

• Monitor salt marsh sparrows

Thin Layer Sediment Application in Idlewild Park, Queens

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18

Goal: Restore eroded marsh and

establish a reinforced shoreline edge

Approach:

• Sand placement and planting in

eroded area

• Establish a front facing armored toe

or breakwater structure on restored

marsh edge (e.g. oyster castles, reef

balls, coir log)

Reinforced Shoreline Project in Alley Pond Park, Queens

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Acknowledgements

NYC Parks - Natural Resources Group

Marit Larson

Rebecca Swadek

Ellen K. Hartig

Novem Auyeung

Jennifer Greenfeld

Natural Areas Conservancy

Helen M. Forgione

Sarah Charlop-Powers

Bram Gunther

The Nature Conservancy

Nicole Maher

Stephen Lloyd

Lauren Alleman

Funding from U.S. EPA Region 2,

Wetlands Protection Program

Development Grant

Kathleen Drake

Contact: [email protected]

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Documents

New York City Salt Marsh Restoration and Protection, Sandy