Lessons Learned with Energy Attenuating Hybrid Living Shorelines

Douglas JaniecNatural Resources Program Manager & Senior Restoration EcologistSovereign Consulting Inc.

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Resilience Example – Natural vs. Urbanized Barrier Islands

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Pre H. Sandy Post H. Sandy

11/03/2012

11/03/201209/20/2010

12/30/2010 09/06/2013

10/05/2014

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What Does an Attenuating Hybrid Living Shoreline Do?

Establishes a multi-step wave energy attenuation system that mimics natural processes.

It addresses the cause (energy) of the shoreline instability before it can interact destructively with the shoreline.

It offers the greatest diversity and quantity of functional ecological uplift throughout the entire shoreline profile.

• Supports LS Projects in Moderate to High Energy Systems

• Sediment Conservation

• Cost Saving for Dune and Nourishment Projects

• Infrastructure Protection

• Resilience (50+ years)

• Reef Habitat

• Oyster Habitat

• Beach Stabilization for Horseshoe Crab

• Migratory Birds Habitat

• EFH Uplift

• Sea grass/SAV Restoration

• Improved Ecosystem Services

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Designing an Attenuating Hybrid Living Shorelines Requires:

•An understanding of (all LSs):

• how waves interact with a coastline

• how waves interact with structures

• how waves interact with other waves

• coastal/shoreline ecology

AND………

•An understanding of (attenuating hybrids):

• how nature deals with wave energy

• how wave energy attenuation process actually works

• coastal/shoreline ecology

Apollo Bay, AU

Wave Diffraction

Constructive Wave

Destructive Wave Condition

Energy Redirectioningand Focusing

What wave energy attenuation is not doing.

Higher Shoreline ErosionLower Shoreline Erosion

Energy can have its form changed, can be moved, and can be stored, but not destroyed.

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So what does wave energy attenuation do…..In simplest terms, a wave energy attenuation design:

1) Take focused energy (waves) and breaks it up into many smaller units2) Creates a destructive wave environment so that wave energies become out of phase.3) The net result is vastly reduced wave energy impacts and typically the creation of accretion zones.

Out of PhaseIn Phase

Step 3(severe storm) Attenuation

Step 1(higher energy) Attenuation

Step 2(lower energy) Attenuation

MLW

MHW

Hybrid Structure (n.t.s.)

Passive accretion and/or optional nourishment (may be beach, intertidal bars, and/or some SAV)

Created or existing supratidal feature

Existing Beach

Existing Bottom

MLW

MHW

Step 1 is or mostly gone

Existing supratidal feature gets hammered

Existing Beach

Existing Bottom

Most or all of Step 2 is absent

MLW

MHW

Feature (i.e. sand bar, reef, wide shallows, channel, structure)

Arrows Represent Wave Energy

Natural Accretion Zone (may be long beach, low marsh, intertidal bars, and/or mudflats)

Dune, high marsh edge, forest, or other supratidal

feature

Existing Beach

(mixed dune/beach/marsh/flat system)

Bottom w/o Irregular Feature

Hybrid Energy Attenuation System (concept cross sections)

DELSI Tactic DELSI Tactic Hybrid Oyster Castles Shell Bags

DELSI Hybrid– Mispillion Lighthouse, DE (Cedar Creek-Mispillion River Confluence, Kent/Sussex County Line, DE)

A pretty neat project,with a complicated energy

paradigm

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Cupped Wave Spreader – Loop Canal, Bethany Beach, DE

Thank you, Delaware Center for the Inland Bays for sharing

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Cupped Wave Spreader – Loop Canal, Bethany Beach, DE

Thank you, Delaware Center for the Inland Bays for sharing

Cupped Wave Spreader – Loop Canal, Bethany Beach, DE

Thank you, Delaware Center for the Inland Bays for sharing

SchematicWave refractionsWave diffraction

Tidal Vegetated Mud Sill – Marshyhope Creek Federalsburg, MD (Eastern Shore)

Tributary to the Nanticoke R., tidal, maintained navigable channel

Chronic Wake Action + Highly Erodible Soils 1’-3.5’ vertical bank near high tide lineBUT… Creek edges had gentle, consistent slopes,

conducive for living shoreline design

Tidal Mud Sill – Marshyhope Creek, Federalsburg, MD (Eastern Shore)

Lower Tide

Higher TidePrevious Point of Shoreline Energy Contact

New Point of Shoreline Energy Contact

Calm Zone

Photographs provided by Duffield Associates, Inc.

Passive Accretion – Cape Charles, VA

Cape Charles, VA • WAD Deployment occurred

just before SS Sandy hit.• Year 1 monitoring results.

• Above: Note similar tide elevations by the amount the WADs are exposed

• Right/Above: Note the passive accretion in one year

Thank you LSS, Inc., Dade City, FL & Mid Atlantic Environmental LLC, Virginia Beach, VA for share monitoring photography

Energy Attenuation Technology at Work

Video provided by Living Shoreline Solutions, Inc.

Wayfarers® (low to moderate energy)

Oyster Castles® (low to moderate energy)

WADs™(moderate to high energy)

No One Treatment Works Everywhere

• Know your products

• Stay focused on project goals

Douglas Janiec

Natural Resource Program Manager

& Senior Restoration Ecologist

Sovereign Consulting Inc.

973-433-6480

djaniec@sovcon.com

Thank You

If this looks like a Cape May Point sunset, your are right!!!