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Orange County Rail Infrastructure Defense Against Climate Change Plan

SB1 Adaptation Planning Grant: Final Case Study

 

SummaryMap of the project area, showing areas of historical funding, rail lines, highways, and jurisdictional boundaries

The Orange County Rail Infrastructure Defense Against Climate Change Plan (Plan) evaluated the exposure and risk levels of the rail corridor within Orange County Transportation Authority (OCTA)-owned rail right-of-way (ROW) south of the City of Irvine in Orange County and all Orange County rail stations against the negative outcomes of climate change stressors such as precipitation effects on erosion and flooding (coastal and inland), sea level rise and storm surge, high heat, wildfire and drought. The project study map is shown to the right. The project addressed the facility-level analyses aimed at estimating lifecycle costs of inaction and adaptation options as well as prioritizing these options for the rail system.  The study identified specific climate hazard threats and offered mitigation solutions for segments of the railroad alignment and at stations as follows:

  1. Coastal alignment - erosion and flood risk and mitigations (MP 200.2 – 207.4)
  2. Inland alignment; Mission Viejo Trench and Extended Oso Creek Tributary (010)/Oso Creek - flooding and erosion/sediment control risk and mitigations (MP 189.0 – 194.6)  
  3. Stations - passenger weather exposure and green infrastructure solutions 

Facility-level assessments applied the Federal Highway Administration (FHWA) Adaptation Decision-Making Process (ADAP) as a framework to consider facility-level adaptation strategies and to develop recommended adaptation actions. The plan identified protective measures and climate change adaptation strategies which were tested against climate scenarios to evaluate the performance of the system with the implementation of adaptation options. An economic analysis which included life cycle costs assessments of the various adaptation options was performed to refine a Facility Adaptation Plan. The study can be used for future decision making and investments in transportation assets and services.  

More than two thirds of the corridor is located in or near a Disadvantaged Community or Low-Income (DAC-LI) census tract, with approximately 270 DAC-LI census tracts within two miles of the corridor.  In addition, of the 12 stations in Orange County, ten are in or near DAC-LI, providing service to these communities. Certain census tracts have up to 49 percent transit dependency.  If the rail line were impacted, it would severely hinder transportation for these communities.

The 19-month long project started in September, 2019 and closed out in Spring 2021.  The key project deliverables consist of field assessment matrices including inventory, parameters and deficiencies, and cost estimates, technical memoranda with summary and recommendations, and a final report.  The final report will assist OCTA to plan, track and implement climate change related mitigations for the railroad corridor in south Orange County. Final deliverables can be viewed on the project webpage.3 Caltrans workers standing on a rail line as waves overtop the rails.

Lead Agency and Partnerships

OCTA as the lead agency on this project collaborated with key stakeholders Caltrans, Southern California Regional Rail Authority (SCRRA), and the Los Angeles – San Diego – San Luis Obispo (LOSSAN) Rail Corridor Agency) in the development of this project. 

Caltrans as a key partner in the development of the initial scope of work and cost estimates, monitored project progress to ensure deliverables met project goals. SCRRA as the operator of the system and maintainer of the track, signals, structures, and most of the ROW provided maintenance records and safety protection for access to the railroad ROW during the facility assessment activities. The LOSSAN Corridor Agency operates the Amtrak Pacific Surfliner Intercity service that utilizes the rail corridor in this study.  

Caltrans provided important project scope feedback and guidance for grant goals and requirements. Local Cities and agencies were also engaged to obtain necessary data and provide relevant input to the project. The County of Orange, California State Parks, Cities of Dana Point and City of San Clemente, the U.S. Army Corps of Engineers, and the California Coastal Commission were other important stakeholders in reviewing and providing input on coastal reaches of the railroad corridor.

DriversFlooding and erosion along an embankment above a rail line.

In December 2010, a rainstorm in the City of San Clemente caused mud slides that destroyed a section of the OCTA-owned Los Angeles-San Diego-San Luis Obispo (LOSSAN) rail corridor.  The event disabled rail service between Orange County and San Diego, forcing rail users to use other modes of transportation in the congested Interstate 5 (I-5) corridor. 

The Caltrans Adaptation Planning Grant Program offered OCTA the opportunity to identify potential climate change related issues on the OCTA-owned Orange subdivision in Orange County and develop solutions to improve and protect the rail corridor from impacts of climate change stressors such as storm activity, rising sea levels and wave action, and high heat.

Engagement Process

The Plan included a project development team comprised of OCTA, SCRRA, Caltrans, LOSSAN, and consultants to drive the progress of the project and its deliverables. Progress on the Plan and deliverables were communicated to a Project Working Group (PWG) which met over three workshops to discuss and provided input on project issues and study findings at specific decision points of the study to completion. The members of the PWG were solicited from a stakeholder list which included representatives from federal, state and local public entities. The public outreach component of the study conducted patron surveys on station amenities through social media channels and geofencing campaigns during the study period and provided valuable feedback on station amenity priorities. An infographic summarizing the outcomes of the public engagement process is shown at the bottom of the page.

Climate Impact Area

This project responds to storm activity, rising sea levels, temperature, and other climate change stressors.

The Plan conducted a comprehensive assessment of the southern rail corridor in Orange County and identified problematic locations, with near-term to long-term mitigation measures, and costs. The Plan determines mitigation measures that are most cost effective and beneficial to the region and corridor.

Funding Source

The total project cost was $659,641, with a $461,771 from a Caltrans Adaptation Planning Grant award, and $197,870 in local matching cash and in-kind support. The local match was 13% greater than originally budgeted.

Research and Data

See the final report bibliography for project references and data sources.

Challenges

Using the Right Science

The availability of relevant data to support analyses and an appropriate framework for the development of plans and strategies was uncertain during project scoping. This was quickly resolved during the data collection phase of the project as numerous sources of reliable information became available through consultant’s research and outreach to stakeholders. The FHWA ADAP framework also provided a suitable decision-making tool for the project.    

Building Public Support

The project faced an unanticipated but significant challenge to its’ public outreach effort due to state government/local health official stay-at-home orders/movement restrictions resulting from the COVID-19 pandemic in 2020. The prolonged effects of the pandemic on transit ridership were also a concern that confronted the project team during the study period. Conventional in-person survey methods to capture public comments could not be implemented. The project team quickly adapted to this challenge by deploying patron surveys and through social media channels (Facebook and Twitter) and geofencing campaigns (location-based advertisement). These methods proved to be highly effective for collecting patron responses and capturing public input on station amenity improvements that would be most valuable to riders.

Developing Plans and Strategies

OCTA’s jurisdiction over limited railroad right of way within the County’s coastal corridor system presents challenges in the agency’s reach and ability to implement proposed plans and strategies; some of which may be in conflict with the interests of other stakeholders. Continued discussion and coordination with local, regional, and state agencies are necessary to reach climate change defense solutions that will benefit all stakeholders.

Outcomes

A final report including a summary of the findings of the study and recommendations was produced and will be used as a guiding document for planning, engineering and capital/maintenance investment decisions on the following aspects of the rail corridor and stations:

  • Slope repair, reinforcement/revetment to reduce the risk for mudslides, flooding and coastal surge during storm events;
  • Enhancement of vegetation management and sustainable vegetation strategy for periods of drought and high precipitation;
  • Improve amenities at stations for passengers to enhance shade; and
  • Long term adaptation measures such as rail relocation and cooperation with other agencies for beach nourishment efforts along the coastal segment of the railroad.

The project also conducted a benefit/cost analysis of the various adaptation options to address coastal alignment issues. The results are shown in Table 1. 

The anticipated next steps for the coastal alignment is for OCTA to review performance criteria and utilize adaptation triggers based upon the best available projections and on the amount of time it takes to implement a solution.  For the inland alignment and the stations, OCTA will evaluate and incorporate the recommendations as new projects are being developed within these locations.

Table 1. OCTA Benefit Cost Ratios (2% Discount Rate; Benefits are avoided Hazard-related Costs from Baseline; Costs are Installation costs)

Scenario
Alternative
Low End 80% Confidence Interval
Best Guess
High End 80% Confidence Interval

Low (low emissions, 17% chance)

Baseline Revetment

 -  

 -  

 -  

Low (low emissions, 17% chance)

Improved Revetment

 4.09

 4.88

 5.56

Low (low emissions, 17% chance)

Revetment w/ Seawall

 3.23

 3.85

 4.39

Low (low emissions, 17% chance)

Relocation

 0.03

 0.04

 0.05

Medium (high emissions, 17% chance)

Baseline Revetment

 -  

 -  

 -  

Medium (high emissions, 17% chance)

Improved Revetment

 2.98

 3.50

 4.27

Medium (high emissions, 17% chance)

Revetment w/ Seawall

 2.60

 3.05

 3.72

Medium (high emissions, 17% chance)

Relocation

 0.03

 0.04

 0.05

High (high emissions, 0.5% chance)

Baseline Revetment

 -  

 -  

 -  

High (high emissions, 0.5% chance)

Improved Revetment

 2.21

 2.60

 2.86

High (high emissions, 0.5% chance)

Revetment w/ Seawall

 2.29

 2.69

 2.96

High (high emissions, 0.5% chance)

Relocation

 0.06

 0.08

 0.09

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replicability

Many aspects of this project are replicable to other communities or type of properties.  This project is mainly focused on the railroad corridor and the stations.  The project methodology and data sources can be applied to similar on transportation infrastructure management and protection against climate change.

Further Information

Louis Zhao

Section Manager, Discretionary Funding Programs
Orange County Transportation Authority
(714) 560 - 5494

Jason Lee

Project Manager, Rail Programs
Orange County Transportation Authority
(714) 560 - 5833

 

 

 

 

 

 

Additional Resources and Bibliography

Final study link: https://www.octa.net/programs-projects/programs/plans-and-studies/completed-studies/rail-infrastructure-study/ 

An infographic of outreach and survey results from community engagement.

An infographic showing demographic information from the outreach survey.

 

 

 

List of Project References: