Sustainable Approaches to Coastal Design and Adaption to Sea Level Rise

Shannon E. Cunniff, Director, Coastal ResilienceWCEL Workshop2 February 2017

Helping People, Economies and the Environment Thrive

Building on the Louisiana Experience

• Economic Growth• Coastal

Community Protection

• Coastal Restoration

2

Coastal Defenses

• Integrate natural and manmade defenses• Multiple Lines of Defense Strategy

3

Shellfish & coral reefs = low breakwaters.

Vegetated dunes better withstand waves & provide attractive habitat

Maritime forests reduce wave & wind energy, capture debris; wetlands can attenuate waves.

Drainage, elevation, retention systems, relocation

1: USACE, 2015

1

Important QuestionsPart I

• What are nature-based solutions?– a.k.a. Natural Infrastructure, Green Shores, Living Shorelines, Eco-

Based Disaster Risk Reduction, et al.

• Where and how do they work?

Part II

• Why would a community choose natural-based solutions?

Part III

• Lessons on creating comprehensive solutions for your community’s needs

Shore Re-nourishment

Credit: Ecoshape

Credit: Woods Hole Group

• Manage sediment as a resource

• Take advantage of littoral processes

• Keep vegetation & washed up algae

Credit: Dr. Brett Milligan

Dune Restoration

Reduce coastal erosion

Reduce nuisance

floods

Reduce force &

height of waves

Stop or reduce storm surge

beach builders & wave chew toys

Wetlands Restoration

Credit : Delaware NERC

Credit: Norfolk, VA

Slow inland water

transfer

Reduce force &

height of waves (<2’

– 5’ )

Can reduce

impact of stormsurge

Improve water quality

Credit: CRCL

Re-establishing lost connections & processes

8

Oyster Reefs

Reduce coastal erosion

Reduce force & Height of short

waves (<2’)

Improve water quality

Speed bumps

Greener Gray Solutions • Breakwaters

– Concrete & forms • Tidepool, Fish, Oyster

Habitats

Photo credit: Econcrete

• Seawalls– 3 design features: Light,

shallow habitat w gravel, wall texture

• Salmonid migration, habitat for marine inverts

Credit: City of Seattle

“Hybrid” Solutions

• Living Shorelines: sills & wetlands

– East Coast Bays • VA, MD, DE, NC, SC,

AL, etc.

– Riparian areas• NY, NJ

Integrated Solutions

Part I

• What are nature-based solutions?– a.k.a. Natural Infrastructure, Green Shores, Living Shorelines, Eco-

Based Disaster Risk Reduction, etc.

• Where and how do they work?

Part II

• Why would a community choose nature-based solutions?

Part III

• Lessons on creating comprehensive solutions for your community’s needs

Important Questions

Lower Cost

14

• Oyster reef breakwaters ~ $1M/mile Standard rock breakwaters cost1: $1.5-3M/mile

• Wetlands w/ sills: $50 - 500/ft Bulkheads/riprap2: ~$500 - 1,200/ft

Community hybrid soft shore − 3 scenarios: ranged between 30 – 70% less

costly than traditional hard approach seawall3

1: Dow et al., 2013; 2. CBF, 2007; 3: Lamont et al., 2014

Multiple Benefits

Sustainable

• Keep pace with sea level rise– Dunes & oyster reefs can grow

• More effective with age– Surface and root densities– Overall width and height

16

Important QuestionsPart I

• What are Nature-Based Solutions?– a.k.a. Natural Infrastructure, Green Shores, Living Shorelines, Eco-

Based Disaster Risk Reduction, etc.

• Where and how do they work?

Part II

• Why would a community choose nature-based solutions?

Part III

• Lessons on creating comprehensive solutions for your community’s needs

Comprehensive Planning

18

Reactive• Scramble to spend

• Power competition

• Impulse to return to what was familiar

Deliberative• Time to think through

community goals and build consensus pre-disaster

• Maximize opportunities next recovery affords

• Greater potential for innovative funding

• Pilots to prove concepts

19

Adaptive Governance• Unite coastal protection & restoration under a single

agency with co-equal goals– Articulate clearly the priorities necessary to achieve

comprehensive coastal protection– Develop, implement, and enforce a comprehensive coastal

protection and restoration master plan.

Credit: LA CPRA

Yields a Comprehensive Plan for the Mississippi Delta

Generating Big Ideas – The Art of Inspiring

• Changing Course – EDF – Design teams from around the

world created innovative visions for how to achieve a more sustainable Lower Mississippi River Delta

• Structures of Coastal Resilience

– Rockefeller Foundation, after Super Storm Sandy

– Universities: Design; Architecture; Science

• Sediment diversions higher in the delta

• New navigation inlet

• Need to address migration of people

• Amphibious suburb

• Fingers of High Ground 

Generating Vision & Buy In

• Room for the River

– Netherlands’ Rhine, Meuse & Scheldt Rivers Delta

Nijmegen

• Rebuild by Design

– Designs underway using similar principle of public collaboration

Generating Vision & Buy In

• Participatory Design

• Deliberative Democracy

• Crowd Co-Design

• “Dutch Dialogues”

Common elements:• Multiple disciplines

• Bring experts & citizens together

• Two-way education• Time investment• Infusion of capital

24

PLANNING TEAM

252017 Coastal Master Plan

SUPPORTED BY:

TECHNICAL TEAMCOLLABORATIVE TEAM OF OVER 70 EXPERTS

262017 Coastal Master Plan

272017 Coastal Master Plan

FRAMEWORK DEVELOPMENT TEAM