using habitat equivalency analysis to estimate ecosystem ... · •strong preference for in-kind...
TRANSCRIPT
Using Habitat Equivalency Analysis to
Estimate Ecosystem Services:
A Natural Resource Damage Case Study
Timothy Barber, PhD
ENVIRON International Corp. | 13801 W. Center St. | Burton, OH 44021
What is a natural resource damage claim?
• A natural resource damage claim is a legal
process
• It seeks to collect monetary damages to make
the public whole for lost or diminished natural
resource services releasing from an
unauthorized release of hazardous substance(s)
• Public made whole through restoration or
replacement of the injured natural resource or
through acquisition of an equivalent resource
What are Natural Resources and Ecosystem
Services?
Non-living
• Surface water
• Groundwater
• Sediment
• Soil
• Air
Living
• Aquatic wildlife
• Terrestrial wildlife
• Vegetation
Ecosystem Services
• Provisioning
• Food
• Raw materials
• Regulating
• Water supply
• Nutrient cycling
• Erosion control
• Moderation of extreme events
• Habitat
• Nursery
• Biodiversity
• Cultural
• Aesthetics
• Recreation/tourism
• Spiritual
The Natural Resource Damage Assessment
Process
• Assess baseline conditions but for the
unauthorized release of oil or hazardous
substance
• Determine whether an injury to natural
resources has occurred
• Quantify the spatial and temporal magnitude
and extent injury (lost services)
• Injury estimates are used to scale restoration
actions to ensure the public is made whole
• Preferred restoration project(s) based on
comparison to selection criteria
• The purpose of an NRD assessment is to make the
public whole
• Identification and quantification of ecosystem
services are critical for quantifying injury and
scaling restoration
– Identification of ecosystem services that should be provided
(baseline)
– The relative importance of each service or service category
– Estimation of ecosystem services that are lost or diminished
– Estimation of ecosystem services that will be restored
• Restoration-based valuation focuses solely on
compensating for the habitat, resources, and
services that were injured
NRD and ecosystem services: Injury
quantification and restoration scaling
The fundamental challenge of an NRD claim is:
how do you make the public whole?
Time (years)
0 5 10 15 20 25
Se
rvic
e F
low
(%
)
0
20
40
60
80
100
DEBIT
Time (years)
0 5 10 15 20 25
Se
rvic
e F
low
(%
)
0
20
40
60
80
100
CREDIT
• Use Habitat Equivalency Analysis (HEA) to estimate
value provided by project
• Service-to-service valuation method
• Uses habitat-specific units
• Services flow from the injured or restored habitats
– Injury (debit) calculation
– Restoration (credit) calculation
Debit ≤ Credit
The Habitat Equivalency Analysis (HEA) model
Debit Calculation
• Present year
• Injury start date
• Injured area
• Relative service losses
• Recovery curve
– Time to full recovery
– Shape of recovery curve
• Discount rate
(compound interest)
Credit Calculation
• Restoration start date
• Time to provide benefits
• Area impacted by
restoration activities
• Improvements of services
above baseline
• Duration of benefits
(project lifespan)
• Discount rate
A case study: Background information
• Site in northeastern Ohio
• Adjacent to a river
contaminated by PCBs and
other chemicals of interest
• Federal and state natural
resource Trustees
• Injury claim presented in
terms of discounted
service∙acre∙years (DSAYs)
• Settlement based on
restoration scaled to the
level of injury (lost services)
Lake
Erie
First step: Develop a conceptual restoration
design
• Removal of invasive species
• Construction of a hydraulic
connector and wetland buffer
• Stream bank re-grading
• Stone toe protection
• Re-vegetation of native species
• Five year maintenance and
monitoring
• Evaluation of ecosystem services is necessary to
ensure restoration will offset injury
• Identify each habitat types and the services they
provide, for example:
– Improve quality of stormwater entering the river
– Provide nursery habitat for fish and wildlife
– Improve aesthetics and enhance opportunities for recreation
• Compare pre- and post-restoration services to
estimate a service improvement
– Functional assessment
– Expert opinion, literature review, precedents from settled cases
– Stakeholder survey using a Likert-type scale
– Probabilistic evaluation to bound reasonable best- and worst-case
scenarios
Second step: Inventory and valuation of
ecosystem services
Time (years)
0 5 10 15 20 25 30 35 40 45 50
Se
rvic
e A
cre
Ye
ars
0
1
2
3
4
Third step: Restoration credit analysis
• Project area = 10 acres
• Baseline service level = 40%
• Project service level = 80%
• Relative benefits = 40%
• Maturation curve
– Linear
– 5 years full service flow
• Discount rate = 3%
• Project lifespan = 50 years
Service∙Acre∙Years = 196
Discounted∙Service∙Acre∙Years (DSAYs) = 92
Habitat Translator (unitless)
0.0 0.2 0.4 0.6 0.8 1.0
Connected Upland Forest
Riparian Streambank
Emergent Wetland
• Different habitats provide different services
• Strong preference for in-kind restoration, but
translators can be used to convert between habitats
• Based on a surrogate measure of service
– Productivity, biomass
– Some functional assessment metric
– Expert opinion, literature review, precedents
Restoration of multiple habitat types
may require use of habitat translators
1.0
0.67
0.80
Cost factors for restoration alternatives
analysis
• Design and permitting
• Land acquisition
• Implementation
– Mob/demob
– Site prep (invasives control)
– Excavation/material
handling/disposal
– Plantings/soil amendments
– Temporary control measures
– Abiotic habitat structures
• Maintenance and
monitoring
• Reporting
– Monthly status
– Construction completion
– Annual monitoring
– Final completion
• Agency oversight
Liability may be resolved using monetary or
restoration-based approach. Typically a
premium is added to a cash-out.
Factors considered in the selection of
preferred restoration alternatives
• Technical feasibility and likelihood of success
• Benefits relative to cost (compare $/DSAYs)
• Relationship to injured natural resources and
lost ecosystem services
– Preference for in-kind restoration
• Geographic location
– Preference for in-place restoration
• Consistency with Trustees’ restoration goals
• Compliance with laws and regulations
• Public health and safety
• Public acceptance
Public involvement is required: Restoration alternatives,
including preferred alternative, undergo public review.