Click to edit title style
Samuel B. Merrill, PhD
Jeffrey Western
Ron Frazier
September 16, 2015
• Click to edit Master text styles
– Second level
Benefit-Cost Analysis
• Third level
– Fourth level
» Fifth level
A Framework for
Transportation Organizations
Northeast Extremes in 1-Day Precipitation
1910-2015
http://www.ncdc.noaa.gov/extremes/cei/graph/ne/4/01-12
http://publicradio1.wpengine.netdna-cdn.com/updraft/files/2014/03/320-NOAA-2014Spring_flood_risk.jpg
Flooding on the Red River in Minnesota
http://www.floodsafety.noaa.gov/state-images/mn-97-3.jpg
Surge from Hurricane Sandy crashes over a sea wall in Kennebunk, Maine on October 29, 2012
How to prioritize vulnerable assets?
• Ranking tools
– VAST
– Many state-level tools tailored to each individual setting
– e.g. Maine’s Decision Support Tool
• (Judy Gates, Session 26)
But ranking doesn’t get us there
• Still have important questions:
– Now what?
– Which design is best in this most important location?
– How much money does it make sense to spend here?
SLR Scenario Predictions
for Portland, ME
http://en.wikipedia.org/wiki/Darts
What is standard these days?
• NOAA Sea Level Rise viewer, Surgingseas.org
– Powerful visualizations and risk metrics
– Limit for BCA: not tied to local dollar values or actions
What is standard these days?
• NOAA Sea Level Rise viewer, Surgingseas.org
– Powerful visualizations and risk metrics
– Limit for BCA: not tied to local dollar values or actions
• ADCIRC and most other hydrologic modeling
– Detailed understanding of where water will go
Detailed water models are available, but …
http://www.antiochne.edu/wp-content/uploads/2013/11/T3Dd.pdf
Detailed water models are available, but …
http://www.antiochne.edu/wp-content/uploads/2013/11/T3Dd.pdf
Detailed water models are available, but …
http://www.antiochne.edu/wp-content/uploads/2013/11/T3Dd.pdf
What is standard these days?
• NOAA Sea Level Rise viewer, Surgingseas.org
– Powerful visualizations and risk metrics
– Limit for BCA: not tied to local dollar values or actions
• ADCIRC and most other hydrologic modeling
– Detailed understanding of where water will go
– Limit for BCA: not tied to local dollar values or actions
• FEMA’s HAZUS-MH
– Detailed analysis of damage from single events
– Limit for BCA: not cumulative; no gradual SLR;
risk reduction comparisons are not possible
• FEMA’s BCA toolkit
– Detailed analysis of real estate damage from single events
– Limit for BCA: Same as for HAZUS-MH; BCA, while strong,
is per-building only. Not well-suited for transportation.
What is standard these days?
• NOAA Sea Level Rise viewer, Surgingseas.org
– Powerful visualizations and risk metrics
– Limit for BCA: not tied to local dollar values or actions
• ADCIRC and most other hydrologic modeling
– Detailed understanding of where water will go
– Limit for BCA: not tied to local dollar values or actions
• FEMA’s HAZUS-MH
– Detailed analysis of damage from single events
– Limit for BCA: not cumulative; no gradual SLR;
risk reduction comparisons are not possible
• FEMA’s BCA toolkit
– Detailed analysis of real estate damage from single events
– Limit for BCA: Same as for HAZUS-MH; BCA, while strong
for single buildings, is not well-suited for transportation.
The Framework
Engineering Project Timeline
Benefit-Cost
Benefit-Cost
Analysis
Analysis
$
$
$
Planning
Build
Design
Preliminary Design Start
Conceptual Design BCA
The Framework
Engineering Project Timeline
Conceptual
Design BCA
D1
D2
D3
BCRs
Cumulative
Avoided
Damages
5:1
Construction
and
Cumulative
Repair Costs
1:1
0.2:1
25x savings
So what do we design for?
http://www.ncdc.noaa.gov/extremes/cei/graph/ne/4/01-12
19
So what do we design for?
A key measure of the value of any adaptation
design investment is cumulative avoided damage
2015
2100
20
Muskie School of Public Service
University of Southern Maine
Portland, Maine
Some Project Sites
Completed or Underway
Selsey, United Kingdom
Santos, Brazil
Fort Lauderdale, Florida
Key Largo, Florida
Islamorada, Florida
Kingston, New York
Piermont, New York
Catskill, New York
Groton/Mystic, Connecticut
Hampton, New Hampshire
Seabrook, New Hampshire
Hampton Falls, New Hampshire
East Machias, Maine
Falmouth, Maine
Portland, Maine
Bowdoinham, Maine
Old Orchard Beach, Maine
Scarborough, Maine
Bath, Maine
Duxbury, Massachusetts
Marshfield, Massachusetts
Scituate, Massachusetts
Duluth, Minnesota
Rochester, Minnesota
Bridge Sensitivity to
Elevated Water Levels
View of a bridge over the Sandy River on ME-41 in Farmington, an example of
the types of structures that have been evaluated with COAST software.
Maine 2014 FWHA Pilot
• Key elements:
– For each asset, the software analyzed benefitcost relationships of three alternatives:
• Replace “in-kind”
• Replace with structure built to 3.3’ of SLR
• Replace with structure built to 6.6’ of SLR
– In general:
• Costs:
– Initial replacement or construction costs.
– Maintenance and repair over time, after each surge
event.
• Benefits:
– Avoided damages provided by each structure in the
face of a range of SLR and surge scenarios –
cumulatively over time.
Depth Damage Functions
Designed for Each Candidate Structure
Elev. Damage Cost
12-16’ Extreme
= $E/event
11-12’ Severe
= $D/event
8-11’
Moderate = $C/event
7-8’
Minor
= $B/event
0-7’
Slight
= $A/event
Waterway
Base
Elevation
Scarborough
Low Sea Level Rise (3.3')
Initial
Construction
Costs
Total
Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE COST
BY 2100
Replace in Kind
$3,600,000
$349,128
$3,949,128
Replace with 3.3' SLR design
$4,300,000
$181,330
$4,481,330
Replace with 6' SLR design
$6,000,000
$3,323
$6,003,323
High Sea Level Rise (6')
Initial
Construction
Costs
Total Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE
COST
BY 2100
Replace in Kind
$3,600,000
$823,325
$4,423,325
Replace with 3.3' SLR design
$4,300,000
$642,948
$4,942,948
Replace with 6' SLR design
$6,000,000
$69,547
$6,069,547
Replace in Kind was the most cost effective choice for both Low and High sea level rise scenarios.
Bath
Low Sea Level Rise (3.3')
Initial
Construction
Costs
Total
Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE COST
BY 2100
Replace in Kind
$400,000
$697,476
$1,097,476
Replace with 3.3' SLR design
$594,000
$697,476
$1,291,476
Replace with 6' SLR design
$1,000,000
$281,242
$1,281,242
High Sea Level Rise (6')
Initial
Construction
Costs
Total Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE
COST
BY 2100
Replace in Kind
$400,000
$1,867,580
$2,267,580
Replace with 3.3' SLR design
$594,000
$1,867,580
$2,461,580
Replace with 6' SLR design
$1,000,000
$916,598
$1,916,598
Replace in Kind was the most cost effective choice for a Low sea level rise scenario, but
Replace with 6’ SLR design was the most cost effective choice for a High sea level rise scenario.
Bowdoinham
Low Sea Level Rise (3.3')
Initial
Construction
Costs
Total
Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE COST
BY 2100
Replace in Kind
$250,000
$1,656,830
$1,906,830
Replace with 3.3' SLR design
$394,000
$1,162,080
$1,556,080
Replace with 6' SLR design
$491,000
$205,159
$696,159
High Sea Level Rise (6')
Initial
Construction
Costs
Total Damage/Repair
Costs
by 2100
TOTAL LIFE CYCLE
COST
BY 2100
Replace in Kind
$250,000
$2,163,283
$2,413,283
Replace with 3.3' SLR design
$394,000
$1,900,813
$2,294,813
Replace with 6' SLR design
$491,000
$908,565
$1,399,565
Replace with 6’ SLR design was the most cost effective choice for both Low
and High sea level rise scenarios.
Minnesota DOT Example:
Spring Valley Creek, Rochester
Projected Hydrologic Conditions
24-Hr
Storm
Return
Period
2-yr
storm
5-yr
storm
10-yr
storm
25-yr
storm
50-yr
storm
100-yr
storm
500-yr
storm
Low Scenario
Discharges (cfs)
Medium Scenario
Discharges (cfs)
High Scenario
Discharges (cfs)
Existing
Discharge
(cfs)
2040
2070
2100
2040
2070
2100
2040
2070
2100
850
880
880
880
960
1,020
1,080
1,000
1,120
1,270
1,380
1,430 1,430
1,430
1,520
1,590
1,660
1,690
1,990
2,320
1,880
1,930 1,930
1,940
2,030
2,120
2,210
2,440
3,010
3,630
2,670
2,720 2,740
2,750
2,860
2,970
3,090
3,540
4,430
5,400
3,340
3,420 3,440
3,460
3,590
3,720
3,870
4,420
5,520
6,770
4,100
4,200 4,230
4,240
4,390
4,560
4,740
5,350
6,650
8,150
6,160
6,320 6,380
6,410
6,620
6,900
7,200
7,710
9,350 11,370
Option #1
• Incremental improvement at
the site.
• Add 2 6’x10’ culverts.
• Widen stream channel.
• Maintain existing Culverts and
roadway profile.
• Addresses inadequate
conveyance.
Option #1
64’
10’
6’
• Improvements allow for 25-year storm to pass
through facility (50-yr storm still overtops).
Option #2
64’
3.6’ Rise
31.5’ Span
• Complete replacement and major site improvement
• New dual 32-foot span bridge
• Raise the roadway profile by 3.6-feet
Option #2
• Provides 3-feet of clearance over the 50-year storm
event for the moderate climate conditions in 2070.
• Span sized to meet current FEMA criteria
• Addresses 2 of 3 hydraulic impairments
– Undersized conveyance area
– Low lying roadway profile
Large Culvert #5722 Carrying US 63 over Spring Valley Creek
64’
3.6’ Rise
Option #3
31.5’ Span
Bridge Carrying US 16 over Spring Valley Creek
4.7’ Rise
70’
• Holistic on-site and off-site improvements
• Replaces 47’ bridge with a 70’
• Addresses all hydraulic impairments
Sample MN Results
And how to optimize across scenarios?
Framework Summary
• In terms of fiscal efficiency, there is no one right
answer to the question “what design standard
should we use?” Site-specific analysis is
required.
“…The construction costs of seawall and road elevation are different for different
the economic analysis should be
conducted based on the actual construction plan
in proposed locations.”
states or situations, so
Framework Summary
• In terms of fiscal efficiency, there is no one right
answer to the question “what design standard
should we use?” Site-specific analysis is
required.
• Non-local, non structural elements can be
incorporated into these BCAs, to reflect broad
categories of agency costs.
Framework Summary
• In terms of fiscal efficiency, there is no one right
answer to the question “what design standard
should we use?” Site-specific analysis is
required.
• Non-local, non structural elements can be
incorporated into these BCAs, to reflect broad
categories of agency costs.
• BCA for transportation structures should occur at
the conceptual design stage, prior to launch of
typical preliminary design efforts.
Final Points
• Asset-specific benefit-cost work
– Does not need to cost new money
– Does not need to be politically charged
Thank You!
IMPLEMENTATION
Sam Merrill: 207-615-7523
[email protected]
PLANNING
Jeff Western: 608-831-1092
[email protected]
Ron Frazier: 302-322-9600
[email protected]
Image courtesy of Renjith Krishnan at FreeDigitalPhotos.net