California High Speed Rail Authority - Sustainability Services
Statewide, California
PEC Water served as a subconsultant to Arup on the California High-Speed Rail Sustainability Services project, providing climate hazard risk analysis and adaptation planning across an 800-mile statewide corridor and 24 stations. Working under the CHSR Authority's sustainability program, PEC Water evaluated five climate perils — extreme heat, precipitation, flooding, sea level rise and storm surge, and wildfire — using state-of-the-art climate model datasets and projections through the end of the century, contributing to both the project's Climate Adaptation Plan and ongoing peer review of station and corridor designs for climate resilience.
Client
Prime
Subconsultant
Hazard, Vulnerability, and Risk Analysis
At the core of PEC Water's scope is a comprehensive hazard, vulnerability, and risk analysis covering all five climate perils along the CHSR corridor. For flooding hazards — both riverine and coastal — this means evaluating FEMA flood mapping, state and federal climate datasets, and hydraulic and hydrologic modeling outputs to assess where the corridor and its stations are exposed to current and future flood risk. Our team reviewed station locations and infrastructure segments against projected flood extents under multiple climate scenarios, identifying where risk is highest and where adaptation measures are warranted.
For sea level rise and storm surge, PEC Water evaluated projected inundation scenarios for the corridor's coastal segments under low, medium, and high sea level rise projections through the end of the century, drawing on the latest California Ocean Protection Council sea level rise guidance. For wildfire, we assessed the corridor's exposure to historical and projected wildfire hazard using 30-year maximum risk datasets, identifying segments that run through or adjacent to areas of elevated fire risk. The combined multi-peril assessment provides the CHSR Authority with a spatially explicit picture of where each peril poses the greatest risk to system operation and long-term performance.
Climate Adaptation Planning
Identifying risk is only the first step — translating that risk into actionable adaptation strategies is where the Climate Adaptation Plan (CAP) comes in. PEC Water has contributed to the development and update of the CHSR Climate Adaptation Plan, which synthesizes the hazard and vulnerability findings across all five perils and documents the approaches the CHSR system will use to reduce risk, increase resilience, and maintain performance as climate conditions change over the life of the project.
The CAP addresses each peril in turn, establishing the basis for adaptation recommendations across the corridor and station network — from design criteria modifications to operational protocols to monitoring and maintenance requirements. PEC Water's flood and sea level rise analysis directly informs the adaptation measures proposed for hydrologic hazards, and our wildfire exposure assessment contributes to the CAP's treatment of fire risk along the corridor. The CAP also satisfies the CHSR Authority's obligations under California ESG reporting requirements, documenting the project's climate risk framework for statutory reporting purposes.
The Project
The California High-Speed Rail Authority is responsible for planning, designing, constructing, and operating an 800-mile high-speed rail network with 24 stations across California. The system is designed to provide a fast, low-carbon alternative to driving and short-haul flying between the state's major metropolitan areas — and it is being built to standards that account for a future climate very different from the one the corridor experiences today. California statute requires the CHSR Authority to address climate change adaptation, sustainability planning, and resilience in its program delivery, and Arup's sustainability services team is the vehicle for meeting those requirements.
PEC Water serves as a subconsultant on that team, providing technical expertise in climate hazard identification, flood risk analysis, and climate adaptation planning. Our work is organized around five climate perils — extreme heat, precipitation, flooding, sea level rise and storm surge, and wildfire — and covers the full 800-mile corridor and all 24 stations. The scale of the analysis demands rigorous use of the best available climate data, careful interpretation of model uncertainty, and close coordination with design teams who are making real engineering decisions based on what the risk assessment shows.
FEMA flood risk mapping along the CHSR corridor — current 100-year flood extents inform baseline vulnerability for riverine flooding analysis
Independent Peer Review for Climate Resilience
As individual station and corridor designs advance through the CHSR design-build program, they require independent review to ensure that climate resilience has been adequately addressed. PEC Water performs independent peer reviews of hydraulic and hydrologic analyses submitted by design teams, evaluating whether the analyses correctly incorporate future climate data and whether the resulting designs are consistent with the project's climate adaptation objectives.
This peer review role requires PEC Water to act as a technical check on the design process — assessing whether design teams have applied future climate projections at the appropriate level of detail for the design phase, whether the methods used to incorporate climate data are defensible given current science, and whether the proposed designs are resilient to the range of climate futures projected for the site. Our review comments are incorporated into the e-builder design review process and help establish consistent standards for climate-informed hydraulic design across the CHSR program.
What we Delivered
PEC Water's work on the CHSR Sustainability Services project spans the full arc of climate risk management — from initial hazard identification through vulnerability analysis, adaptation planning, and independent technical review of design submittals. Our multi-peril assessment covers 800 miles of corridor and 24 stations, evaluating exposure to extreme heat, precipitation, flooding, sea level rise and storm surge, and wildfire using state-of-the-art climate model datasets and end-of-century projections. Our contributions to the Climate Adaptation Plan have helped translate that risk picture into actionable guidance for one of California's most consequential infrastructure programs.
Our peer review work ensures that as individual designs advance through the program, the climate resilience objectives established in the CAP are actually reflected in the hydraulic and hydrologic analyses underpinning those designs. And our ongoing support on vulnerability analysis updates means the CHSR Authority has a trusted technical partner to help navigate the rapidly evolving landscape of climate data and modeling as the project moves through design and into construction. The result is a high-speed rail system better positioned to serve California reliably across the full range of climate futures the state will face this century.
Engineering resilience into the backbone of California's transportation future — across 800 miles, 24 stations, and a century of climate change.
Projected 100-year flood extents under sea level rise scenarios — statewide analysis for CHSR coastal segments
Climate projections through end of century, evaluated across multiple scenarios, to ensure the corridor is designed for the future — not just the present.
30-year maximum wildfire risk assessment along the CHSR corridor — key input to multi-peril climate hazard analysis
Statewide Vulnerability Analysis Updates
Climate science and climate datasets continue to evolve — and the CHSR Authority's vulnerability analysis must evolve with them. PEC Water supports ongoing updates to the statewide vulnerability analysis as new flood data, updated climate model outputs, and revised sea level rise projections become available. This includes reviewing updated FEMA flood mapping, incorporating new California Department of Water Resources datasets, and assessing how emerging science on precipitation extremes and atmospheric river events affects the risk picture for the corridor.
Each vulnerability update feeds back into the Climate Adaptation Plan and into the design guidance provided to CHSR design teams — ensuring that the project's climate risk framework reflects the best available science at every stage of program delivery. For a project that will be in design and construction for decades, keeping the vulnerability analysis current is not a one-time deliverable but an ongoing program commitment.