COASTAL IMPOUNDMENT DECISION MAKING ADAPTATION IN ACTION

Rob Hossler and Karen Bennett – Delaware Div. Fish & WildlifeAustin Kane - National Wildlife Federation

LIONS, TIGERS and On The GROUND CLIMATE CHANGE ADAPTATION…

OH MY!

Delaware’s Efforts to get over the Fear and Make Decisions to Implement/Adapt to Climate Change for its Coastal Impoundments

Coastal Impoundments History

Rice production Mosquito controlSalt hay farming

Waterfowl habitat

Today…Multiple Functions for Wildlife: Breeding habitat for shorebirds,

rails, bitterns, waterfowl Feeding habitat for migrating

shorebirds, waterfowl, post-breeding wading birds

Roosting habitat for shorebirds, waterfowl

Fish nursery habitat Muskrat habitat

Waterfowl hunting Birding, wildlife viewing, photography Furbearer trapping Flood-hazard reduction Mosquito control

Today…Multiple Socioeconomic Functions:

Coastal Impoundments in DE: • State maintains 14 coastal

impoundments comprising 2,400 acres on several state wildlife areas along the central to southern Delaware Bay coast, and a few along the Atlantic Coast.

• USFWS maintains 1,100 acres at Bombay Hook NWR and 4,200 acres at Prime Hook NWR, both along Delaware Bay coast.

Urgency to Do Adaptation Thrust Upon Us

Prime Hook NWR – after Hurricane Sandy 2012.

Breaches 2010

ImpoundmentWetland Habitat

at risk

Prime Hook NWR – after 2009 Mother’s Day storm.

Breaches 2012

Impoundment wetlands converting to open water.

STATE IMPOUNDMENTS ARE NOT IMMUNE!

Breach of State Impoundment Dikes after Hurricane Irene (2011)

Step 1: Initiation of a State Impoundment Management Plan/Philosophy

• Collective wisdom of administrator, program and land managers, and staff scientists to support continued management and preservation of state impoundments.

• Goal is to Avoided Administrative Neglect, i.e., “I will be retired before it’s an issue” and make adaptation an immediate priority among other current funding needs.

• Begin the development of a systematic approach for evaluating the current status of impoundments, identifying objectives and developing an adaptive strategy to enhance resilience in face of climate change.

• Maximize Breeding Marsh Birds

• Maximize Roosting Red Knots and Spring Migrating Shorebirds

• Maximize Breeding Shorebirds (e.g., Black-necked Stilt)

• Maximize Migrating and Wintering Waterfowl

• Maximize Fall Migrating Shorebirds

• Maximize Breeding Waterfowl

• Maximize Juvenile Fish Populations

• Maintain Furbearer populations at a desired level (e.g., Muskrat)

• Minimize Mosquito Production• Maximize Recreational Use• Minimize Cost

Multiple OBJECTIVES:

Now what??? It’s complicated….• We can’t manage for everything, everywhere…

not physically possible given biological needs of target wildlife.

• We’ll never have all the data we think we need.• Cost constraints and uncertainty are a reality.• Tradeoffs among competing objectives must be

made.• We want to find the best combination of

management actions to achieve multiple affordable objectives in the face of climate change uncertainty.

• Developed a prototype decision model for 4 impoundments looking 30 years out (estimated impoundment life span).

• Small team of experts identified key management objectives and predicted outcomes (e.g., duck-use days, roosting red knots, mosquito and fish counts) of different actions under different SLR scenarios (5 and 10 mm/year).

• SDM is an explicit, organized way to deal with multiple, competing objectives and uncertainty.

Step 2: Approach - Structured Decision Making

• Flexible• Transparent• Adaptive

• Incorporates cost constraints• Provides a suite of actions that

maximizes benefit

GOAL: If we are spending the time and money on these impoundments we need to maximize their functions in an explicit, organized way that deals with multiple, competing management objectives and cost constraints under the uncertainty of SLR.

Coordinated water-level management (% of full pool) across a suite of impoundments to provide for:Vegetation growth (waterfowl)Exposed mudflat (shorebirds)Pools and channels (fish and mosquitos)

Dec Jan Feb

Mar Apr

May June Jul

yAu

gSe

pt Oct Nov0

20

40

60

80

100

120Annual Drawdown Actions

MOSQREKNWFEs.FishDE Saline

% o

f Ful

l Poo

l

Roosting Red Knots

Water Mgmt

Stopover Population

Predator Control

Weather

Vegetation Control

Predators

Water Level Amt. Roost Habitat

Habitat Configuration

Tide Distance to Foraging Habitat

Climate Change

Rectangles = management decision nodes; ovals = stochastic process nodes; rounded rectangles = intermediate calculations; and hexagons = outcomes (e.g., objectives).

Influences – Consequences Diagram

These objectives were than weighted for Relative Importance. Example - Red Knots = 0.31 Waterfowl = 0.38 Fish = 0.17 Mosquito = 0.14

Utility Functions for Objectives

0.00.10.20.30.40.50.60.70.80.91.0

0 10000 20000 30000

Valu

e

Waterfowl Abundance Score

0.00.10.20.30.40.50.60.70.80.91.0

0 500 1000

Valu

eRed Knot Abundance Score

00.10.20.30.40.50.60.70.80.9

1

0 1 2 3 4 5

Valu

e

Fish Score

(a) Waterfowl (b) Red Knot (c) Fish

LONG-TERM ACTIONS UNDER SLR UNCERTAINTY: Water management regime? Repair levees and water-control structures? Raise elevation with thin-layer application of

dredge material? Create salt marsh buffers? Build new impoundments in uplands? Abandon and restore to tidal salt marsh habitat?

Consequences – Predictions and Uncertainty

Impoundment Action Plan Sea Level ΔBase Cost

(k)Add. Cost

(k) REKN 10yr REKN 20yr REKN 30yr

Primehook - Unit 3 Action 1 ("WF") Accelerated Rate 22.5 na 75 50 0

Primehook - Unit 3 Action 1 ("WF") Current Rate 22.5 na 100 75 50

Primehook - Unit 3 Action 2 ("REKN") Accelerated Rate 15 na 225 150 0

Primehook - Unit 3 Action 2 ("REKN") Current Rate 15 na 300 225 150

Primehook - Unit 3 Action 3 ("DE Saline") Accelerated Rate 10 na 50 0 0

Primehook - Unit 3 Action 3 ("DE Saline") Current Rate 10 na 50 50 15

Primehook - Unit 3 Act.4: Raise levee, replace WCS +WF Accelerated Rate 22.5 1200 100 75 50

Primehook - Unit 3 Act.4: Raise levee, replace WCS +WF Current Rate 22.5 1200 100 100 100

Primehook - Unit 3 Act.5: Raise levee, replace WCS +REKN Accelerated Rate 15 1200 300 235 150

Primehook - Unit 3 Act.5: Raise levee, replace WCS +REKN Current Rate 15 1200 300 300 300

Primehook - Unit 3 Act.6: Raise levee, replace WCS +DNREC Accelerated Rate 10 1200 50 40 25

Primehook - Unit 3 Act.6: Raise levee, replace WCS +DNREC Current Rate 10 1200 50 50 50

UncertaintyUncertainty

How Do We Decide?

• Each action has an expected benefit.• Benefit is determined by:

– Species response– Uncertainty– Species weighting

• Each action has a cost.

Using Excel “Solver” Add-in:Mgt. Unit Management Action WEV Waterfowl WEV Knots WEV Fish Portfolio Management Benefit Cost ($K)Unit III PH A1: Waterfowl water regime 0.3619 0.1234 0.1255 1 0.6108 $23Unit III PH A2: Red Knot water regime 0.2744 0.1623 0.1255 0 0.5622 $15Unit III PH A3 DE Saline water regime 0.1269 0.0269 0.1255 0 0.2793 $10Unit III PH A4: Raise levee, replace wcs, & (A1) 0.6494 0.0748 0.1255 0 0.8497 $1,200Unit III PH A5: Raise levee, replace wcs, & (A2) 0.2996 0.2251 0.1255 0 0.6501 $1,200Unit III PH A6: Raise levee, replace wcs, & (A3) 0.2177 0.0376 0.1255 0 0.3807 $1,200Raymond A1: Waterfowl water regime 0.0369 0.0000 0.0000 0 0.0369 $2Raymond A2: Red Knot water regime 0.0191 0.0402 0.0000 0 0.0593 $2Raymond A3: DE Saline water regime 0.0126 0.0000 0.0000 0 0.0126 $1Raymond A4: Raise wcs @ 20 yrs, & (A1) 0.0382 0.0000 0.0000 0 0.0382 $200Raymond A5: Raise wcs @ 20 yrs, & (A2) 0.0191 0.0402 0.0000 1 0.0593 $200

LoganS A1: Waterfowl water regime 0.0217 0.2688 0.0983 0 0.3887 $10LoganS A2: Red Knot water regime 0.0209 0.4159 0.0988 1 0.5355 $10LoganS A3: DE Saline water regime 0.0152 0.0021 0.2234 0 0.2406 $13LoganS A4: Construct new 150 ac imp, pumping, & (A1) 0.0756 0.2812 0.0072 0 0.3640 $700LoganS A5: Construct new 150 ac imp, pumping, & (A2) 0.0442 0.3239 0.0072 0 0.3752 $700LoganS A6: Construct new 150 ac imp, pumping, & (A3) 0.0415 0.0000 0.0072 0 0.0487 $700

LittleCrk A1:Waterfowl water regime 0.0163 0.2776 0.0588 0 0.3527 $5LittleCrk A2: Red Knot water regime 0.0119 0.4226 0.0588 1 0.4933 $5LittleCrk A3: DE Saline water regime 0.0082 0.0000 0.4382 0 0.4465 $7LittleCrk A4: Replace wcs, dike work, sediment control, & (A1) 0.0191 0.3739 0.0308 0 0.4239 $800LittleCrk A5: Replace wcs, dike work, sediment control, & (A2) 0.0137 0.5610 0.0308 0 0.6055 $800LittleCrk A6: Replace wcs, dike work, sediment control, & (A3) 0.0087 0.0000 0.4396 0 0.4484 $800

1.6989 $238

1.6989Waterfowl 0.4138

Red Knot 1.0021Fish 0.2831

Cost Constraint $250

Step 3: Pilot Habitat Projects • Select “no regret” restoration projects anticipated

to have success to restore wetland habitat and enhance impoundment resiliency to climate change.

• These project fall in three categories: Better Management Practices Resiliency in the Form of Structure Integrity (improvements

or buffers). Strategic Retreat.

Better Management Practices • Better Data Collection: Vegetation

Transects, Integrated Waterbird Management and Monitoring (“IWMM”), Hydrology and Hydraulic studies.

• Are we achieving what we want – qualitatively and quantitatively?

• Provides baseline for monitoring of pilot projects, SLR scenarios and evaluating management practices.

Buffer ConstructionRestore old levee

Create tidal marsh within 106-acre containment cell, eventually with tidal exchange via channel creation.

Reinforce existing dikes

Strategic Retreat• Wildlife Conservation Society-

funded project working with The National Wildlife Federation.

• Inland retreat of a 389-acre impoundment where we have lost some of our management capabilities to maximize functions and values.

• Creates an 86-acre impoundment complex from an existing pond and two agricultural fields augmented with freshwater to maximizes functions and values and replace larger impoundment.

• National Fish and Wildlife Foundation• Wildlife Conservation Society• State Wildlife Grants and Wildlife and Sport Fish

Restoration• National Wildlife Federation – Climate Smart Guidance

Project• Delaware Impoundment Management and SDM Team

Thank you!!!