Largescale Acquisitions &
Associated Ecosystem Services
in Floodplain ManagementKAMM
May 2018
Julia Rinaldi, MEMJarred White, EITJohn Bucher, AICP
Agenda
I. Research Objectives
II. Methodology
III. Results
IV.Recommendations
V. Contact Information
Background
Largescale Acquisitions Acquiring multiple structures
on contiguous land with resulting area returned to green
open space with limited allowable use.
Precedents:
Rainbow Bend, WA Hoffman Grove, NJ
Research Objective 1
Gain greater understanding of cost-effectiveness and
viability of individual versus largescale acquisition
projects.
Individual Acquisitions
(“Checkerboarding”)
Largescale Acquisition
Research Objective 2
Gain greater understanding of implications of using
national versus regionally-specific ecosystem service
benefit (ESBs) in a benefit-cost analysis (BCA).
National ESB Values Regional ESB Values
Scenarios
1 2
3 4
• Individual acquisitions
• National ESB values
• Individual acquisitions
• Regional ESB values
• Largescale acquisition
• National ESB values
• Largescale acquisition
• Regional ESB values
Methodology: Project Area Selection
…where to start?
• Results from February 2017 run
of the Mitigation Benefits
Estimator (MBE) Tool
• Used MBE to target viable study
areas (groups of high acquisition
Mitigation Benefit Ratios (MBRs))
• 8 selected hypothetical project
areas (182 structures)
Methodology: Project Area Selection
Methodology: Inputs
For BCA
• Building Replacement Value*
• Depth Damage Function
• First Floor Elevation*
• Parcel Lot Area*
• Flooding Depth*
• Riverine Discharges
• …and many others
Constants
Ecosystem TypeFEMA National Value
(per acre per year)
New Jersey Value
(per acre per year)
Greenspace
(Contiguous)$8,624.92 $3,265.16
Greenspace
(Checkerboard)$993.50 $451.55
Riparian $41,053.50 $4,466.65
Forest $575.13 $1,948.79
Wetlands $6,239.26 $15,273.51
Estuary $1,867.63 $8,093.59
Restoration Action Estimated Cost**
Structure Demolition $5.36 per square foot
Regrading $4.00 per cubic yard
Revegetation
(Contiguous Greenspace)$2,750 per acre
Revegetation
(Checkboard Greenspace)$500 per acre
Revegetation
(All Other)$5,500 per acre
Roadway and Utility Demolition $25,000 per acre
Annual Maintenance Cost
(Contiguous and Checkerboard
Greenspace)
$200 per acre per year
Annual Maintenance Cost
(All Other)$50 per acre per year
* Sourced from MBE* Specific to New Jersey
Methodology: Analysis
For all scenarios of all study areas, the FEMA BCA Toolkit was
used to calculate:
Initial Project BCR
Final Project BCR
(Structure Damages Avoided + Content Damages Avoided)
(Aquisition Cost + Demolition Cost)
(Structure Damages Avoided + Content Damages Avoided + Ecosystem Services Benefits)
(Aquisition Cost + Demolition Cost + Resoration Costs)
Results – Passaic Linwood Study Area
Restoration TypeArea
(Acres)% of Total
Urban Greenspace 1.19 78.9%
Riparian Buffer 0.32 21.1%
Total 1.51 100%
Activity Cost/UnitArea
Cost
Revegetation
(Greenspace)$2,750/acre 1.19 $3,281
Revegetation (Riparian) $5,500/acre 0.32 $1,752
R&U Demolition $25,000/acre 1.51 $37,790
Total - - $42,823
Scenario Initial BCR Final BCR
FEMA Checkerboard 1.100 1.208
NJ Checkerboard 1.100 1.204
FEMA Largescale 0.918 1.023
NJ Largescale 0.918 0.930
Cumulative
BCR from
Toolkit w/o
ESBs or
restoration
Cumulative
BCR inclusive
of ESBs and
restoration
Results – Passaic Linwood Study Area
Restoration TypeArea
(Acres)% of Total
Urban Greenspace 1.19 78.9%
Riparian Buffer 0.32 21.1%
Total 1.51 100%
Activity Cost/UnitArea
Cost
Revegetation
(Greenspace)$2,750/acre 1.19 $3,281
Revegetation (Riparian) $5,500/acre 0.32 $1,752
R&U Demolition $25,000/acre 1.51 $37,790
Total - - $42,823
Scenario Initial BCR Final BCR
FEMA Checkerboard 1.100 1.208
NJ Checkerboard 1.100 1.204
FEMA Largescale 0.918 1.023
NJ Largescale 0.918 0.930
Cumulative
BCR from
Toolkit w/o
ESBs or
restoration
Cumulative
BCR inclusive
of ESBs and
restoration
Results – Passaic Linwood Study Area
Restoration TypeArea
(Acres)% of Total
Urban Greenspace 1.19 78.9%
Riparian Buffer 0.32 21.1%
Total 1.51 100%
Activity Cost/UnitArea
Cost
Revegetation
(Greenspace)$2,750/acre 1.19 $3,281
Revegetation (Riparian) $5,500/acre 0.32 $1,752
R&U Demolition $25,000/acre 1.51 $37,790
Total - - $42,823
Scenario Initial BCR Final BCR
FEMA Checkerboard 1.100 1.208
NJ Checkerboard 1.100 1.204
FEMA Largescale 0.918 1.023
NJ Largescale 0.918 0.930
Cumulative
BCR from
Toolkit w/o
ESBs or
restoration
Cumulative
BCR inclusive
of ESBs and
restoration
• BCR increases with addition of
ESBs and restoration benefits.
• Differences b/w FEMA BCR and NJ
BCRs
Results – Checkerboard vs. Largescale
Project Area ESB Values SourceFinal Project BCR(Checkerboard)
Final Project BCR (Largescale)
Atlantic MottsFEMA 4.097 3.202
New Jersey 4.056 3.550
Bergen LamkerFEMA 1.165 0.476
New Jersey 1.161 0.569
Gloucest PoplarFEMA 7.565 7.340
New Jersey 7.554 7.334
Gloucester WillowFEMA 5.539 4.958
New Jersey 5.518 4.768
Passaic LinwoodFEMA 1.208 1.023
New Jersey 1.204 0.930
Salem CrosslandFEMA 1.391 1.273
New Jersey 1.362 1.730
Salem PineFEMA 1.943 1.518
New Jersey 2.051 1.256
Warren RiverFEMA 4.158 3.963
New Jersey 4.141 2.795
Results – National vs. Regional ESBs
Project Area Project ApproachFinal FEMA Eco
Values BCR
Final NJ Eco
Values BCR
Checkerboard 4.097 4.056
Largescale 3.202 3.550
Checkerboard 1.165 1.161
Largescale 0.476 0.569
Checkerboard 7.565 7.554
Largescale 7.340 7.334
Checkerboard 5.539 5.518
Largescale 4.958 4.768
Checkerboard 1.208 1.204
Largescale 1.023 0.930
Checkerboard 1.391 1.362
Largescale 1.273 1.730
Checkerboard 1.943 2.051
Largescale 1.518 1.256
Checkerboard 4.158 4.141
Largescale 3.963 2.795
Salem Crossland
Salem Pine
Warren River
Atlantic Motts
Bergen Lamkar
Gloucest Poplar
Gloucester Willow
Passaic Linwood
Bergen Lamker
Final Project BCR(FEMA ESBs)
Final Project BCR(NJ ESBs)
Conclusions & Recommendations
1. Largescale restoration projects offer higher overall benefits, which can sometimes
translate into viable largescale acquisition projects.
Recommendation: The determination of whether to pursue largescale versus
checkerboard acquisition projects should be done on a case-by-case basis with
detailed assessment.
2. Values assigned to ESBs have meaningful impacts on BCRs and overall benefits.
Recommendation: Locally or regionally appropriate ESBs should be used
whenever possible for most accurate BCA results.
3. Having common ecosystem classification systems would benefit flood mitigation by
providing a “common language” between funding and agencies using BCAs.
Recommendation: A common classification system between agencies to
easier facilitate coordination of mitigation projects.
Contact Information
Julia Rinaldi
John Bucher
Jarred White
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