South Florida’s natural ecosystems can provide affordable protection from chronic flooding

As part of an op-ed series, FIU News shares the expertise and diverse perspectives of members of the university community. In this piece, Tiffany Troxler, director of  science of the Sea Level Solutions Center, offers her perspective on the need for collaboration to combat sea level rise. This piece first appeared in The Invading Sea, a collaboration of South Florida Sun Sentinel, Miami Herald, Palm Beach Post and WLRN Public Media. The opinions expressed in the piece are is his own.

Natural infrastructure can help reduce impacts from climate change and sea-level rise throughout South Florida.

But what does natural infrastructure even mean? It’s just a way of describing natural ecosystems such as the Everglades or mangrove forests in Coral Gables and around Miami-Dade County.

However, instead of considering their value from a habitat or an ecological perspective, we assess these ecosystems as social and economic assets. They’re an inexpensive way to defend the region from the potential financial damage of chronic flooding while preserving or enhancing the environment in which we live, work and play.

These systems help protect our drinking water, coastlines and recreational amenities, and reduce the threat of flooding and pollution.  As with the Everglades, natural infrastructure works best when it is managed to preserve or enhance its function and thus its benefits to society.

Long ago, Miami’s environment provided robust ecosystem services. That’s when freshwater springs bubbled up from the middle of Biscayne Bay, the airport was a wetland, and the Atlantic rock ridge (a.k.a. I-95 corridor) was the best way to travel. Mangroves lined much of our shores.

But population growth and development have changed all that.

Nowadays, in some of the areas we call home, persistent drainage with pumps, control structures and canals is the only way to keep some neighborhoods dry. We call this kind of flood control “gray infrastructure.”

However, that doesn’t always work and often comes with unintended social and environmental costs.

Comparing natural infrastructure with gray infrastructure is analogous to comparing a screwdriver to a multi-tool device with a screwdriver, pliers, a knife, a bottle opener, Allen wrench, etc.

For example, a seawall can help keep land from eroding, but it may cause subsequent damage to the environment.

However, a living shoreline of mangrove vegetation can help keep land from eroding, but also reduces heat and improves water and air quality. It provides habitat for fish and birds. It also increases recreational and educational value and even removes carbon dioxide from the atmosphere.

There are intermediate approaches too. Gray infrastructure can be combined with natural infrastructure to create “hybrid” infrastructure.

For example, engineers can use limestone boulders as a breakwater, creating wetlands immediately inland of the breakwater.

“Bioswales” are another hybrid. They feature trees and shrubs embedded into a stormwater network. They improve water quality, reduce heat and make the swales look better.

In some cases, natural infrastructure can make gray infrastructure work efficient. A variety of approaches will yield the greatest benefits.

These nature-based strategies have extraordinary economic benefits. Since 1980, coastal wetlands in the U.S. were determined to provide $23 billion per year in storm protection services.

Other benefits include saving money on water quality remediation and stormwater management, and raising money through increased property values and higher revenues from more tourists.

These kinds of natural or green infrastructure approaches are not a heavy lift. Ecologists have been studying natural ecosystems for a long time and landscape architects usually apply natural ecosystem concepts in their designs.

In fact, cities and counties have been implementing these strategies all over the world. In Miami-Dade County, 500 acres of wetlands have been restored and 8.5 miles of shoreline have been stabilized through natural approaches.

Miami and Miami Beach are incorporating natural infrastructure into their resiliency plans – another tool in the toolbox for adapting to sea-level rise.

Fortunately, the federal government has instituted policies that make some of these approaches appealing to homeowners, such as reduced flood insurance rates.

We can do more to make natural infrastructure work effectively for South Florida’s residents and businesses, enhancing opportunities for innovative approaches to adaptation. As we adapt to sea-level rise, we have many tools in the toolbox that can not only keep our communities safe, but also improve our quality of life.

Tiffany G. Troxler, Ph.D., is Director of Science for the Sea Level Solutions Center at Florida International University.