Helping nature heal itself - Using natural infrastructure to strengthen shoreline resiliency

As engineers, we tend to enjoy constructing stationary structures in ever-changing surroundings. When we build a wall or a bridge, we can predict with relative certainty what will occur.

But we face a lot of unknowns in dynamic natural systems. Nature-based approaches are still somewhat experimental and require adaptive management. When engineers and asset managers become more comfortable with uncertainties and trust natural systems to adapt to changing environments with some intervention, the potential is limitless.

Even though the California Natural Resources Agency and California Coastal Commission encourage nature-based solutions, these projects are still considered innovative. Although natural shoreline infrastructure has been used successfully on the east coast, relatively few projects have been implemented in California. We’d like to change that.

As we think about coastal resiliency, the big hurdles are funding, permitting and feasibility. We’re finding creative ways to jump over those hurdles:

• Funding. Small, disadvantaged communities can be challenged to raise funding. Fortunately, we are seeing more grant funding for nature-based solutions. You just need to know where to look and how to present the business case.
• Permitting. Risk-averse permitting agencies are more likely to approve projects that provide multiple community wins (like the pedestrian trail and flooding prevention for the City of Encinitas) by stacking benefits and using hybrid approaches to make projects more appealing. For example, if we use hard armoring – the use of solid materials like concrete or rocks – to support building the natural shoreline, could it also be a bike path?
• Feasibility. The primary technical challenge is understanding the dynamics of natural systems at a specific location. It's not one size fits all; we can't do the same thing we did elsewhere. We need to consider how the project will evolve and adapt, accounting for natural processes. For example, if we implement a structure on the mud flats to quiet the hydraulics, we can bring in some sediment. Can the project start to create more sediment through the natural hydraulics? Natural infrastructure is an ongoing process that continues beyond the construction phase. These projects are far more dynamic, like nature.

Many tend to think in silos, like one solution for one challenge. When we propose projects that offer multiple benefits, skeptics may question why we would want to increase costs by including additional elements.

We’ve been successful in obtaining natural infrastructure grants for smaller or disadvantaged communities by presenting these projects as creative, multi-benefit solutions. We begin by examining the community's requirements and determining how we can maximize benefits to create a comprehensive project. In this way, both nature and the community can benefit.

By the end of the century, almost half of the world’s sandy beaches will have significantly eroded because of climate-driven coastal flooding and human interference. The way we have been treating the planet has had an impact on the resilience of our shorelines.

In California, 85 percent of the coast is eroding. According to the U.S. Geological Survey, up to 67 percent of Southern California beaches could disappear by 2100. Coastal communities will be vulnerable to flooding, wildlife will be endangered, and economies will suffer. The risk of doing nothing is serious.

For more healthy habitats, we need solutions that evolve over time and allow for natural processes to continue. For example, we proposed a nature-based design solution that restores salt marsh, sequesters carbon and reduces flood risk to more than 6,500 feet of California State Highway 101. The highway is becoming increasingly vulnerable to flood hazards because of rising sea levels and continued shoreline erosion. The project received funding from the California Ocean Protection Council and the National Fish and Wildlife Foundation.

Contact us if you would like to explore a natural shoreline infrastructure solution for your community. We can assist you in developing a strategy to effectively coordinate with multiple permitting agencies and funding sources to bring your project to fruition. And we can provide a template for communities to enhance the resilience of their coasts and beaches, thereby enabling them to better withstand future threats.