Coastal Landscapes and How they Must Adapt to Climate Change

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Coastal Landscapes: Considerations for Healthier Ecosystems while Adapting to Change Enterprise Community Partners Rotterdam-NYC Roundtable on Urban Coastal Landscapes Sept. 20, 2016

Transcript of Coastal Landscapes and How they Must Adapt to Climate Change

Page 1: Coastal Landscapes and How they Must Adapt to Climate Change

Coastal Landscapes:

Considerations for Healthier Ecosystems

while Adapting to Change

Enterprise Community Partners Rotterdam-NYC Roundtable on Urban Coastal Landscapes

Sept. 20, 2016

Page 2: Coastal Landscapes and How they Must Adapt to Climate Change

MORE RESILIENT, SUSTAINABLE COASTAL LANDSCAPES

can be located and designed to respect both human life and the life in

our adjacent ocean and estuarine ecosystems

Marcha Johnson, ASLA, PhD Landscape Archictect

and Ecological Restorationist, NYC Parks

Page 3: Coastal Landscapes and How they Must Adapt to Climate Change

Floodable coastal communities around the world are growing; most of the structures in these communities are not able to easily tolerate changing coastal conditions and water level.

Many coastal landscape and engineering projects continue to disregard the connection between what we do on the shore and the impact on life in the ocean.

LIVES AT STAKE

Barrier beach homes being raised and moved inland

Page 4: Coastal Landscapes and How they Must Adapt to Climate Change

Hudson R. Park, NYC GoogleEarth.com

Irregular natural habitats contain a lot of variety and include changeable, ephemeral patches. New methods, materials and arrangements are being explored to enhance biodiversity on in-water structures, to offset some of their habitat displacement impacts:

.

SURFACES AND STRUCTURES

In-water infrastructure is typically uniform in texture and straight; biodiversity

much lower than natural habitats. Even new, otherwise well-designed

structures often meet the water with biologically sterile materials.

Photo: Biodiversitysnapshots.net.au.

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Athens, NY Greenwall

Photo by the designers: Anchor-QEA, Seattle

Photo by the manufacturer: LI Precast,

GRADUAL RELEASE FROM HARD STRUCTURES - a few examples

Bulkheads which intercepted bluff

material feeding an eroding pocket

beach were removed at Seahurst

Park, in a Seattle suburb. After loss

of 4 vertical feet on the beach, it is

now rebuilding, restoring itself. Marsh grass boxes in Newtown Creek, Sarah Durand, Carter Craft

Page 6: Coastal Landscapes and How they Must Adapt to Climate Change

RESPONSES TO TURBULENCE AND FLOODING:

• Zonation in response to gradients of light, wave exposure, etc.

• Moveable substrate

• Fractal arrangements, clustering,

• Conical, streamlined forms,

• Flexible, regenerating structures

• Complex surface textures

• Taking advantage of temporary pools

Page 7: Coastal Landscapes and How they Must Adapt to Climate Change

ANCIENT TECHNIQES Some earlier North American coastal cultures adapted to rapid oscillations in sea level 4000 years ago: • Raised surfaces of earth and shells.• Seasonal settlements (summers at the beach, inland in winter) • Flexibile, light, portable or temporary structures easily transported to higher ground• Stacked elements adjustable in place• Built to be easily replaceable with inexpensive, local materials • Integrated with range of water level

Raised shell rings built 5- 20’ high, built 4000 years

ago in what is now coastal salt marsh,

Georgia and S. Carolina The Kincaid Site in Massac Co., Illinois, showing platform mounds above floodstage. Illustration by artist Herb Roe

Page 8: Coastal Landscapes and How they Must Adapt to Climate Change

THE NEW NORMAL OF INLAND MIGRATION:

Storms accelerate the inland shoreline movement during eras of sea level rise.

Photos: NYC Mayor’s office PLANYC

Beach 94th St: Dune developedBefore storm “Sandy” Oct. 2012 After storm. Sand moved from

beach inland onto lawns and streets

After storm “Sandy.” Sand added to dune face; more of jetty is exposed

Beach 56th St. Remnant dune. Before storm “Sandy” 2012

Page 9: Coastal Landscapes and How they Must Adapt to Climate Change

Project

Area

HARLEM R. AND RANDALL’S IS. LIVING SHORE

Queens

Manhattan

Bronx

NewJersey

ProjectArea

Harlem R. Park

Randall’s Is.Living Shore

Funded with Dept. of State Coastal Resources grants for research + capital project -- demonstrating innovative, sustainable waterfront design

Page 10: Coastal Landscapes and How they Must Adapt to Climate Change

• Reuse site resources

•Convert seawall to softer edge

•Increase diversity of substrate, slope

•Conserve existing plants, animals, habitats

•Improve near-shore water quality via biofiltration

•Raise public awareness of coastal dynamics

•Make tidal and sea level change more visible in a playful way

•Plant native species in community/guilds

•Demonstrate ways to accommodate floods, sea level rise, coastal dynamics as a normal park experience

“Designing the Edge” principles

Page 11: Coastal Landscapes and How they Must Adapt to Climate Change

Much of the material behind NYC seawalls contains contaminated soil and rubble exceeding state Restricted Residential limits.

Below the modern surface rubble is a mix of gravel, broken stone and soil - a stable, porous mix for good drainage behind the seawall.

A possible source of the pollutants esp. PAHs is “clinker” or “boiler slag” from incomplete combustion inindustrial coal burning furnaces.

TYPICAL WATERFRONT LANDFILL

Page 12: Coastal Landscapes and How they Must Adapt to Climate Change

DESIGNING THE EDGE at HARLEM RIVER PARK - Replacing some natural floodplain functions.

Harlem R. Park 2011, 2013, 2015

Harlem R. at MacCombs Dam,ca. 1865 Currier & Ives print

•Flood storage capacity•Ecological connections•Wave absorption instead of reflection.•Resistance to rust, scour, salt corrosion•Self-repairing

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HARLEM RIVER PARK, completed 2009

SOFTENING ARMORED SHORES : FLOODPLAIN TERRACES

POROUS SEAWALLSHELLFISH-ATTRACTING MATERIALS

SET-BACKS TO SLOW LAMINAR FLOW, Photo: Ricardo Hinkle, NYCParks

MIX OF EDGE CONDITIONS photo: Fred Landa, NY DOS 2008

Page 14: Coastal Landscapes and How they Must Adapt to Climate Change

CONSTRUCTING URBAN TIDE POOLS:

Gabions with shells, topped with tide pools and coastal upland planting

Harlem River Park, NYC Parks-Ricardo Hinkle, Marcha Johnson, Dewberry Engineers, Harlem R.

Park Task Force

Page 15: Coastal Landscapes and How they Must Adapt to Climate Change

Intentional flooding-Harlem River Park tidepool and porous seawall

A NY HARBOR ESTUARY PROGRAM OBJECTIVE:

INCREASE POROSITY IN FLOODZONES

Unintentional flooding-

Randalls’ Is. seawall

overtopped during very high water

RECONSIDERING FLOODING AS A “HAZARD”

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Progressive water levels:

Elevations 5’ and 7’ above existing Mean High Water

MAKING SEA LEVEL RISE PART OF THE PARK

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2015 Design for an Adaptable Edge- Randalls Is.

Remnant of old seawall

and toe stones

Berm constructed to “feed” the beach and

stabilize itself by adjusting slope

Vegetation can migrate in relation to water level

and open soil.

Surface of new beach face

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PLANT COMMUNITIES THAT MIGRATE INLAND AS WATER RISES

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ACCESSIBLE PICNIC TABLES

FLOOD PLAIN TERRACES

BEACH

PEDESTRIAN ACCESS TO BEACH

BRIDGE STORMWATER INFILTRATION

BANK RUN GRAVEL PATH

PLAQUE

REMNANTS OFSTONE SEAWALL

BERM

GRAVELPARKING (13 SPACES)

HEADWALLS TIDE POOLS

BOULDER EDGE

PEDESTRIAN ACCESS TO WATER EDGE

PICNIC GROVE

Proposed 2015 Changes:Remove upper part of crumbling seawall, reuse stone on site

Improve water edge access, mark water elevations

Public parking area

Cusp beach, berm, terraced slope, tidepools, headland features

Environmental education/citizen science features

Connect planted zones based on coastal ecological communities

DEC-Solid Waste Concerns:Reusing soil contaminated with Lead, Mercury, PAHs

Stockpiling soil for other Randalls Island projects

New beach would be dynamic

Beach surface could have contaminants similar to

present surface but more mobile

Randall’s Island Living Shoreline Recreation Area, Dec. 10. 2015

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PHYTOREMEDIATION: Considering a more sustainable alternative to exporting contaminated soil to landfills in other states, exposing communities and the environment to possible leaks.

Benefits:

• Cheaper, cleaner, safer than exporting soil to landfills

• Habitat value

• More efficient use of resources

Concerns:

• Not applicable to every site

• Results not as predictable; natural systems are variable

• Takes longer

Randalls Island Living Shoreline Recreation Area,

From Roux Associates, 2015 “Living Cap” installation

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Graphics from: Phyto, by Kate Kennan, Niall Kirkwood, 2015 p. 36-37.

3 Phyto Methods:

Rhizodegradation: PAH molecules are broken down into benign compounds by soil bacteria in root zone.

Phytodegradation: Contaminants are degraded into benign compounds by plants.

Phytoextraction: Plant concentrates metals in its leaves or other tissues.

Randall’s Island Living Shoreline Recreation Area, Dec. 10. 2015

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Seawall Condition B

Existing Condition On-site Soil Treatment

• Upper seawall is very unstable / dangerous• Top of stable portion is above mean high water

• Use unstable stones used to make terraces• Dormant cuttings layered between stones extract

metals

Randalls Island Living Shoreline Recreation Area, Dec. 10. 2015

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Switchgrass, Panicum virgatumBlack Willow, Salix nigraBlack Locust, Robinia pseudoacacia, Red Mulberry, Morus rubra

Randall’s Island Living Shoreline Recreation Area, Dec. 10. 2015

Build current designTemporary seeding

Plants that extract Mercury Plants that degrade PAHsRed Maple, Acer rubrumWillow, Salix spp.

Plants that extract Lead Sunflower, Helianthus annuusRed maple, Acer rubrumHoneylocust, Gleditsia triacanthos

Sources: Kennan and Kirkwood, Phyto, 2015; Southwesternurbanhydrology, 2015,

EPA https://clu-in.org/download/studentpapers/henry.pdf, 2001

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Reduced scope - minimal grading - allowed project to go forward.Trade-off: fewer public benefits.

Randall’s Island Living Shoreline Recreation Area, Dec. 10. 2015

Build current design

Intertidal pockets

Leave as is

Meadow grasses and Trees Build picnic area per 2015 design

Woody phytoremediation thickets

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ACCESSIBLE PICNIC TABLES

PLANTED BIOENGINEERED TERRACES

PLAQUE

REMNANTS OFSTONE SEAWALL

GRAVEL

TIDE POOLS

MEADOW PICNIC GROVE

Randall’s Island Living Shore Recreation Area 2016 Site Plan

INTERTIDAL WETLAND THICKETS OF COASTAL SHRUBS

SAPLINGTREES

WOOD CHIP MAINTENANCE PATH

Page 26: Coastal Landscapes and How they Must Adapt to Climate Change

CONSTRAINTS, OPPORTUNITIES AND “BEST PRACTICES” FOR CONTAMINATED SOIL MANAGEMENT

• Common urban soil contaminants add to cumulative public health burden

• Most of our waterfront contains fill, typically not clean materials, variable across a site

• The era of cheap, easy of disposal in leaky, local, open pits and piles is over

• Using 20th C. rules and methods for 21st C. problems is costly, expands environmental impacts, potentially exposes many more citizens to harm

• Managing contaminated soil on-site is complex: more sustainable, may in some cases be safer, cheaper and environmentally sound, but take longer and requires new skill sets and regulatory approaches

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Marcha Johnson, ASLA, PhD Landscape

Archictect

and Ecological Restorationist, NYC Parks

(718) 760-6646

[email protected]

This presentation was supported by NYC Parks, the NYS

Dept. of State with funds provided under Title 11 of the

Environmental Protection Fund,

Page 28: Coastal Landscapes and How they Must Adapt to Climate Change

Photo credits: http://www.conservewildlifenj.org/species/spotlight/pinnipeds/ Harbor seal

http://www.fws.gov/northeast/pipingplover/overview.html

www.nydailynews.comhttp://assets.nydailynews.com/polopoly_fs/1.1574111.1389357933!/img/httpImage/image.JPG_gen/derivatives/gallery_1200/toddmaisel-1847729.JPGConey Is. July

http://news.maryland.gov/dnr/2012/11/30/funding-available-to-help-coastal-communities-prepare-for-natural-disasters/ Crisfield,MD Houses under water, Sandy

http://news.nationalgeographic.com/news/special-features/2014/07/140725-outer-banks-north-carolina-sea-level-rise-climate/ House being moved off a beach in Outer Banks, NC

www.Busseltonjetty.com.au purple barnacles www.alamy.com blue mussels on rocks at Gorran Haven, Cornwallwww.telegraph.co.uk Limpets nature’s tough guy revealed

Fig Island photos, S. Carolina Dept. Archives and History, 2007 http://www.sapelonerr.org/education-training/the-history-of-sapelo/

https://www.bamertseed.com/switchgrass/

https://en.wikipedia.org/wiki/Platform_mound#/media/File:Chromesun_kincaid_site_01.jpghttp://www.arkive.org/horseshoe-crab/limulus-polyphemus/image-G8860.html

Monterrey, California tide pool Photo: www. Coastalcare.org