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Capital Area Metropolitan Planning Organization
City of Austin, Office of Sustainability Cambridge Systematics, Inc.
Extreme Weather and Climate Change
Vulnerability Assessment of Central Texas
Transportation Infrastructure Federal Highway Administration (FHWA) Pilot Project
TxDOT Transportation Planning Conference June 4, 2014
Two types:
Vulnerability Assessment Pilot
Adaptation Options and Integration
Completion Date September 2014
Evaluate transportation assets
CRITICALITY TO REGIONAL
TRANSPORTATION
VULNERABILITY TO EXTREME
WEATHER EVENTS
Use and share results
Transferable methodology
FHWA Pilot Project
2013 Vulnerability Assessment recipients:
Alaska DOT
Arizona DOT
Capital Area MPO (CAMPO)
Connecticut DOT (ConnDOT)
Iowa DOT
Maine DOT
Michigan DOT
Minnesota DOT (MNDOT)
North Central Texas Council of Governments
Tennessee DOT (TDOT)
Project Partners
CAMPO
City of Austin, Office of Sustainability
Williamson, Travis, Hays, Bastrop, Burnet and Caldwell
counties
TxDOT, Capital Metro
City Departments: Transportation Department, Public
Works, Homeland Security and Emergency
Management, Capital Planning Office
Lead Consultant: Cambridge Systematics
FHWA
Project Objectives
Assess the vulnerability of the region’s
transportation system to the impacts of extreme
weather
Incorporate results into the 2040 planning process
to increase extreme weather resiliency, now and in
the future
Nature of the results will determine how they are
incorporated into the 2040 Plan
Share results with partner jurisdictions, agencies and
the public
Project Area
PROJECT AREA
POPULATION (April 1st, 2013)
CITY OF AUSTIN: 842,750
REGIONAL: 1,870,872
REGIONAL 2035: 3,250,000
Project Scope
Regional transportation
system (6 counties)
Highways, bridges, rail,
aviation, transit
Existing and planned
facilities through 2040
Extreme weather:
Precipitation,
temperatures, wildfire,
drought
Physical Characteristics
UNIQUE FEATURES
TOPOGRAPHY & GEOLOGY
WEST - ROCKY HILL
COUNTRY
EAST – FLAT, SOFTER SOILS
SOURCE: CAMPO, FEMA
SOURCE: GEOLOGIC ATLAS OF TEXAS, TEXAS WATER
DEVELOPMENT BOARD
Soil Plasticity
Clay soils on the east side
have high soil plasticity
Causes pavement, road
bed and utility problems
when soil expands and
shrinks with varying soil
moisture
Impacts of Extreme Weather
Buckling roads - 2009
Drought: Disrupted Water - 2011
Flooding: Tropical Storm Hermine - 2010 Wildfires - 2011
High winds - 2013
Fallen tree - 2013
Aftermath of wildfire - 2011
Sinkhole - 2009
Project Approach
Task I – Select/Characterize Assets + Asset
Criticality
Task II – Identify Climate Variables to Study
Task III – Assess Vulnerability + Integrate
Vulnerability
Asset Criticality Assessment
Guiding principles—critical assets selected for
evaluation should:
Provide regionally-significant access and connections
Reflect the region’s multimodal system
Take into account the region’s extreme weather
vulnerabilities
Broadly represent similar assets
Consider geographic and social diversity
Critical Assets for Further Evaluation
Critical Assets for Further Evaluation
Recommended Asset for Evaluation County
Potential
Vulnerabilities AADT
Evacuation
Route?
US 290E at Johnny Morris Road Travis F, D, H 38,000
MetroRail Red Line at Boggy Creek Travis F, D, H N/A
SH 71E at SH 21 Bastrop F, D, W, H 27,000 (SH 71)
9,500 (SH 21)
I-35 at Onion Creek Parkway (including
Old San Antonio Road low water crossing) Travis F, H 186,000
US 290W/SH 71 – Y at Oak Hill Travis F, D, W, H 38,000 (US 290W),
29,000 (SH 71)
Loop 360/RM 2222 Travis F, D, W, H 40,000 (Loop 360)
44,000 (RM 2222)
FM 1431 at Brushy Creek/Spanish Oak
Creek Williamson F, D, H 30,000
US 281 and SH 29 Intersection Burnet F, H 11,000 (US 281)
11,000 (SH 29)
US 183 north of Lockhart Caldwell F, D, H 13,000
SH 80 (San Marcos Highway) at the Blanco
River Hays F, H 9,500
Potential vulnerabilities: F: Flooding, D: Drought, H: Extreme Heat, W: Wildfires
Extreme Weather Sensitivities in
Central Texas
Asset Type Flooding Drought Extreme Heat Cold/Ice Wildfire
Roads Major impact,
especially on rural roads (disruption,
washout)
Cracking, failures on
edge of pavement; soil destabilization if roadside
vegetation affected
Some cracking and
degradation, especially on edge
of pavement
Hazardous
roadway conditions; cracking on
longitudinal joints
Disruption; Low
short-term impact on pavements;
destruction of
guardrail and sign posts
Bridges Minimal impact,
except where heavy debris and sediment
loads
Minimal impact Minimal impact Hazardous
driving conditions, icing
Operational
disruptions
Rail Service interruptions Minimal impact Speed restrictions,
delays during extreme heat; risk
of thermal
misalignment
Damage to
switches
Major impact, if
exposed
Transit (bus) Routes disrupted, but
may have ability to detour
Damage to routes, but
may have ability to detour
A/C issues in high
heat
Risks to
passenger health at stops
Operational
disruptions
Major Impact Moderate Impact Lesser or long-term impact Minimal or no impact
Legend
Extreme Weather Sensitivity
Thresholds in Central Texas
Impact
Mode(s)
Affected Threshold
Flooding Highways, Rail,
Transit
General flood risk increases when rainfall > 2” in less than 12 hours
Rural roads: >3.44” in 24 hours
Principal arterials: > 7.64” in 24 hours
Major highways: > 10.2” in 24 hours
Pavement cracking
or other deterioration
Highways Extended temperature > 100°F (empirical)
Average 7-day maximum temperature > 108°F (design)
Drought lasting longer than 14 days
Alternating wet and dry weather patterns, cycling between a few
days or weeks
Extremely wet conditions for > 1 month
Temperatures < 50°F
Thermal
misalignment
Rail Risk increases when surface temperatures > 100° - 115°F
Extreme Weather Sensitivity
Thresholds in Central Texas (cont’d)
Impact Mode(s) Affected Threshold
Air conditioning stress
and failures
Rail, Transit Temperature > 100°F
Limited ability for
maintenance and
construction work
Highways, Rail,
Transit
Temperature > 100°F
Icy, unsafe road
conditions
Highways Surface temperature ≤ 32°F and precipitation (any)
Damage to switches Rail Temperature ≤ 32°F and precipitation (> 3/16” of ice)
Wildfire Highways, Rail,
Transit
KBDI ≥ 575
Relative humidity < 20%
Winds > 15-20 mph
La Niña conditions favoring Southern Plains Wildfire Outbreaks
Obtain Climate Data (2040)
Focus on extreme
weather sensitivity
thresholds
Weather Research and
Forecasting Model
(WRF)
Data at 30km resolution
Dr. Kerry Cook, UT-
Austin, leading climate
data team
Sample output: Observed annual mean temperature (C)
Accounting for Model Uncertainty
Scenario 1: Values as predicted by the Regional
Climate Model
Scenario 2: Take values from the regional climate
simulations, but for a location 200 (miles) to the
north.
Scenario 3: Take values from the regional climate
simulations, but for a location 200 (miles) to the
west
Scenario 1 is the most likely scenario
Temperature Changes for Mid-Century
Surface Temperature
Differences (°F)
Scenario 1: 2.9 °F
Scenario 2: 2.9 °F
Scenario 3: 2.7 °F
Austin: 30.3°N and 97.8°W
Contour interval = 0.2°F
Summer and Winter Mean Surface
Temperature Differences (°F)
JJA = June, July, August mean DJF = December, January, February mean
Winter Scenario 1: 2.2 °F Scenario 2: 2.2 °F Scenario 3: 2.2 °F
Summer Scenario 1: 3.6 °F Scenario 2: 3.4 °F Scenario 3: 2.9 °F
Contour interval is 0.5 °F
Precipitation Changes for Mid-Century
Annual Differences (%)
Scenario 1: 7.5% reduction in annual
rainfall (blue triangle = Austin)
Scenario 2: 5% increase in annual
rainfall (2 degrees of latitude north of
Austin)
Scenario 3: No change in annual
rainfall (2 degrees of longitude west
of Austin)
Seasonal Precipitation Differences (%) Summer Scenario 1: 15% reduction Scenario 2: 10% increase Scenario 3: no change
Winter Scenario 1: 5% reduction Scenario 2: 5% increase Scenario 3: no change
Model Hydrological Impacts
Leverage vFLO
(already used for CoA
FEWS)
Derive extent, depth,
and flow of 100-year
events
Dr. Baxter Vieux, U of
Oklahoma (emeritus),
leading hydrologic
modeling team
Some Factors Affecting Flooding
Rainfall amount, intensity and duration
Structure design and condition
Amount of impervious cover
Using 2040 Plan population and employment estimates
as a surrogate for future impervious cover
Next Steps
Complete climate and hydrological modeling
Evaluate selected critical assets for potential
Disruption
Deterioration
Damage
Characterize risk for critical assets and asset types
Share results with stakeholders
Incorporate results in the 2040 Plan
