How nature-based solutions can help protect railway infrastructure from the impacts of climate changeNovember 29, 2022
By Shelley Hazen – Climate Change Specialist
Author’s Note: This blog was adapted from my presentation: Planning for the Impacts of Climate Uncertainty and Extreme Weather Events, delivered at the 2022 Railroad Environmental Conference in Champaign, Illinois.
All transportation systems are climate sensitive. Rail transportation in particular faces a variety of unique risks due to changing climate conditions and more extreme weather events. These sensitivities can translate into infrastructure damage and deterioration, disruptions to transport operations, and unsafe conditions. Let’s explore how nature-based solutions can help keep your rail infrastructure “on track” and functioning in the face of climate challenges.
The impact of climate change comes with high financial, social, and environmental costs. According to the National Oceanic and Atmospheric Association (NOAA) in 2021, the US experienced 20 climate or weather-related disaster events with losses exceeding $1 billion each.
How do extreme weather events and climate physically impact rails?
- Extreme heat can lead to track buckling;
- Windstorms can spread debris, like trees, across tracks;
- Snow and ice storms can coat supporting overhead power lines; and
- Rain events can cause flooding, promote erosion, and reduce track infrastructure stability.
In this blog, I’m going to focus on how rainfall and flooding events impact rails. I’ll also cover the emerging science and research about nature-based solutions for better stormwater management. When I write “flooding events”, I’m referring to urban flooding, not coastal-related sea level rise, storm surge, or hurricane-induced flooding.
Why focus on flooding? According to the latest US climate assessment, studies show that the: “Expected increases in the severity and frequency of heavy precipitation events will affect inland infrastructure in every region.”
What are some of the indirect consequences and repercussions of flooding impacts (and other climate impacts) on rail service providers, owners, and operators?
- Disruption in the movement of goods and services, whether it’s people or goods.
- Reputational Risks. Major schedule delays, canceling scheduled trips, or not being able to provide for your clients when they need you to deliver.
- Financial risks resulting in the potential loss of customers, but also increased maintenance risk if there’s physical damage to the rail infrastructure.
So, we know these impacts are happening, they’re even increasing in frequency, intensity, and duration. How do we deal with it?
Forward-looking infrastructure design, planning, and operational measures and standards can reduce exposure and vulnerability to the impacts of climate change. This means planning for the future-projected climate, not continuing to plan and build based on the past, as we’ve done so many times.
The implementation of nature-based solutions, low impact development (LIDs), and green infrastructure along rail corridors, greenfields and brownfields, and at train stations is gaining popularity across North America.
These nature-based adaptations integrate natural processes, such as infiltration or evapotranspiration, into stormwater management practices through the displacement or storage of accumulated runoff. Nature-based solutions is really a blanket term and one that you’ll often hear being used interchangeably with terms like LID. But there are differences.
- Green infrastructure is an overarching term that includes LID and use of natural features and vegetated systems.
- LID tends to be a marriage between soft scaping and engineering, including features like bioretention, permeable pavements, bioswales, and green roofs.
What are examples of proactive adaptation that can assist in stormwater management to help reduce flood impacts for railways? We’re seeing examples of green solutions being integrated by other infrastructure providers into and along transportation and hydro corridors for example. As for railways, we’re seeing more examples of green solutions being integrated alongside and between rail tracks themselves.
Now, I know a solid ballast in a rail track base is extremely important, and we can’t just go around ripping it up and planting flowers. But we also know that ballast makes ground hard so that rainwater can’t drain away properly or quickly enough during a large rain event. See image below. What we’re starting to see more of is an application of ground cover on top of the ballast, which means we don’t have to disturb the underlaying structural integrity of the track. Green coverage can help capture rainfall and slowly release the water to surrounding areas; it can also promote greater evapotranspiration. In this way, a green train track contributes to the reduction of flooding, especially in cities where we have a greater amount of impermeable surfaces.
Solid ballast in a rail track base is extremely important, but we also know that ballast makes ground hard so that rainwater can’t drain away properly.
You’re probably thinking, this sounds great in theory, but how and where can we put it into practice? And how much is it going to cost to implement and maintain throughout the life of my rail asset?
It depends on where you implement your project and on the project size.
A recent article from the Canadian Climate Institute, Reducing the Costs of Climate Impacts, notes that investment returns on proactive measures that help us prepare for climate damages are multiples greater than the costs of implementing those measures. As a rule, for every one dollar spent on adaptation measures, there’s a return on investment of $13-15 dollars.
There are substantial resources available to help you estimate and budget the costs of implementing green infrastructure and LID technologies in support of stormwater management. Lifecycle costing tools are a great way to mock-up a site and test various LIDS and get relatively accurate costs of the LID infrastructure throughout its lifespan.
Beyond a financial return on investment, why else should you consider using nature-based solutions to bolster the resiliency of your rail infrastructure?
Lowering Project Costs
Nature-based solutions can provide both short- and long-term financial savings by lowering operations and maintenance (O&M) costs. Some solutions, such as constructed wetlands in lieu of wastewater treatment plants, can cost less to build up front. Other nature-based solutions may require more upfront costs but, over time, often provide financial savings due to their reduced O&M expenses.
Mitigating Physical Climate Impacts
Nature-based solutions can help reduce the damage that climate change inflicts on your infrastructure. Remember my mention of greening the tracks? Vegetation between rails lowers the temperature by as much as 50%, which can help reduce the risk of track buckling.
Achieving Sustainability Goals
Investing in nature-based solutions can help achieve corporate sustainability goals. You might think: “That sounds great, but I don’t really care about ‘fluffy’ sustainability goals.”
The fact is, at the end of the day, implementing nature-based solutions, achieving sustainability goals, and fulfilling climate change commitments demonstrate a company’s commitment to the environment. Studies show that, now more than ever, consumers intentionally choose brands and companies that demonstrate a commitment to sustainability.
Railways are already one of the greenest transportation modes from a mitigation standpoint. But in terms of adaptation, preparing for the impacts of climate change to reduce exposure, risks, and costs, there is a lot of great work that can still be done using nature-based solutions for proactive adaptation.
To learn how you can implement nature-based solutions into your rail infrastructure project, contact me.