Oregon Dept. of Transportation Climate Change Adaptation Strategy Report

The Oregon Department of Transportation’s (ODOT) Climate Change Adaptation Strategy Report is intended to provide a preliminary assessment of likely climate change impacts on ODOT assets and operations and adaptation strategies. ODOT is responsible for more than 19,000 lane miles of state highway, 2,700 bridges, thousands of culverts, and other critical infrastructure. All of this infrastructure is potentially vulnerable to the impacts of climate change, such as increased incidence of landslides, flooding, coastal erosion, and wildfires. Beyond the impacts to ODOT’s structural assets, climate change will impact the way ODOT does business, and potentially impact the way the agency plans and develops projects and responds to emergencies.   

The report provides detailed recommendations on the data collection needs for further assessing the state’s vulnerability, actions the state is already taking to prepare for impacts, and recommendations for additional adaptation measures. The report contains four sections examining: potential impacts of climate change in Oregon, economic impacts, impacts to ODOT, and next steps.

First, the report discusses potential climate change impacts in the state based upon findings of the 2010 Oregon Climate Assessment Report  produced by the Oregon Climate Change Research Institute and updated on a biennial basis pursuant to a statutory mandate.  The main impacts identified relate to sea-level rise, changes in air temperature, increased storm intensity, and changes in precipitation:

  • Sea-level rise – 55 centimeters by 2050 and 128 centimeters by 2100 in the Pacific Northwest region, with a link to higher storm surges, noting that a 100-year wave in the region could reach 46 feet or higher. 
  • Increased temperatures – 0.2-1 °F increase in temperature per decade resulting in changes in vegetation, wildlife migration patterns, and risk of wildfires (expected 180 to 300 percent increase in regional forest area burned by 2100).
  • Storm intensity – increase in major natural disasters and related impacts including falling trees and tree corridor management in Oregon.
  • Changes in precipitation – sharply rising (15-30 percent) winter precipitation, combined with falling (5-15 percent) summer precipitation. Related impacts include greater risk of flooding, changes in seasonal flow rates, and landslides.

The report also examines potential social impacts from climate change and population growth in the state.

Second, the report discusses the potential economic impacts of climate change for Oregon and ODOT. This section examines the costs of inaction, and the costs of adapting ODOT assets, with particular emphasis on the cost of landslide repairs, delays, and stresses on alternative routes. The report estimates making Oregon infrastructure resilient to climate change impacts could cost $82.5 billion to $825 billion. The report notes that many variables for assessing adaptation are unknown, however the report provides metrics for assessing the costs and benefits of adaptation:  annual maintenance costs, emergency repairs costs, and indirect costs due to service disruptions.

In the third part of the report, organized by climate impact, ODOT identifies the known vulnerabilities to assets and the system, discusses data needs for conducting a more thorough assessment of climate risks, and discusses current state agency action and possible adaptive strategies.

Sea-level Rise

  • Known threats: Several key roadways in the state are vulnerable to flooding, erosion and landslides including U.S. Highway 101 near Seaside, Oregon
  • Further assessment: To address these threats, the report recommends further identification and mapping of vulnerable points along U.S. Highway 101, an inventory of coastal assets assessing their condition and frequency of repair, an assessment of how sea-level rise will impact rivers and adjacent infrastructure, and identification of critical freight and lifeline routes.
  • State agency actions: The report notes a variety of state agency actions already underway to prepare for coastal impacts, including relocation of the Spencer Creek Bridge, and scour analyses of 69 coastal bridges.
  • Potential adaptation actions: Suggested actions include developing best management practices for mitigating shoreline erosion and stabilizing infrastructure, standardized detailed coastal hazard maps for priority areas of the coast, and standards for the design and engineering of bridges, roadways and culverts given climate change projections.

Rising air temperatures

  • Known threats: Impacts from temperature changes include faster degradation of pavements, leading to rutting, cracking, and potholing and attendant safety risks and repair costs. The report notes that since pavement life is only 15-20 years, current pavement on the road will likely not be impacted. Rail infrastructure is also more vulnerable to deformation under high temperatures. Changes in temperature will also lead to shifts in vegetation and wildlife migration, and increased threat of wildfires.
  • Further assessment: The report recommends assessment of how different pavement types perform under high temperatures, pavement failures under high temperatures, and the vulnerabilities on critical routes; an inventory and assessment of vegetated storm water systems, wetland mitigation sites, and wildlife migration patterns; and an inventory and assessment of critical transportation infrastructure that is vulnerable to wildfires.
  • State agency action: The state is already developing an inventory of current vegetation distribution and has efforts to eradicate invasive species.  The Oregon Department of Forestry already hosts a web-based resource on wildfires and performs fire detection and suppression activities.
  • Potential adaptation actions: For vegetation changes, the plan recommends that the state incorporate climate change induced shifts in vegetation into the state’s Vegetation Management Plan and develop permitting guidance for wetland mitigation banks. For wildfire risks, the plan recommends that the state research how heat from wildfires will impact transportation structures, develop a mitigation and stabilization plan for wildfire- and slide-prone areas, and implement more aggressive forest management practices.

Increased storm intensity

  • Known threats: Oregon is already experiencing elevated extreme weather risk, in the form of windstorms, ice storms, and extreme precipitation events. These events are known to damage infrastructure directly and increase the risk of hazard trees, landslides, flooding, and erosion.
  • Further assessment: The report recommends an assessment of the vulnerability of critical routes to storms and regional capacity to respond to extreme events, and the identification of hazard trees and possible impacts to critical routes.
  • Potential adaptation actions: Implement a strong emergency management plan and better integrate with local hazard mitigation plans. Prioritize hazard tree removal and vegetation management.

Changes in precipitation and elevated flood risk

  • Known threats: More intense precipitation will impact culverts and stormwater systems. Seasonal change in flow rates and river levels has potential to damage to roadways and bridges. Precipitation can also increase the risk of landslides, which already cost the state in excess of $100 million in some years.
  • Further assessment: Continue to identify and inventory the location and assess capacity of culverts and stormwater systems, assess the accuracy of current flood maps, assess the capacity of bridges, inventory corridors damaged by landslides, and assess landslide hazards for critical routes.
  • State agency actions: ODOT has begun building larger culverts or bridges to allow aquatic organism passage, which also has adaptive benefits. ODOT has already developed automatic systems at the towns of Seaside and Cushman to warn the public of flooding hazards and is testing a database to automatically provide notification regarding hazardous conditions at bridges throughout the state. The state is also developing RiskMaps with FEMA and is re-delineating flood hazards in select counties with high-resolution LiDAR data.
  • Potential adaptation actions: Armor critical areas and infrastructure and implement a consistent statewide standard for inventorying and assessing the condition of culverts along state highways.  Increase the number of monitoring stations and stream gauges. Continue Unstable Slopes Program, consider climate change as a factor in rating landslide areas, and develop design and engineering standards for mitigating landslides.

The report concludes by offering several concrete recommendations for next steps:

(1) Form a department-wide ODOT Climate Change Adaptation Work Group to work though issues related to vulnerability assessment, develop prioritization criteria for strategies and actions, coordinate with regulatory partners, develop a communication plan; and identify further
research needs.

(2) Conduct vulnerability and risk assessments. 

(3) Identify further research needs and data gaps on the impacts of climate change and potential adaptation strategies.

(4) Monitor how the climate changes and impacts the transportation sector over time.

(5) Coordinate and collaborate with other Oregon and neighboring state agencies.

(6) Engage in public outreach to communicate about how climate change will impact the state and what ODOT is doing to prepare for impacts.
 

This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on December 23, 2014.
 

Publication Date: April 2012

Related Organizations:

  • Oregon Department of Transportation (ODOT)

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Resource Types:

  • Adaptation plan
  • Assessment

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