Miami, to cut heat and reduce flooding and pollution, let’s try this simple solution | Opinion

Nobody can deny the heat we feel. We are breaking records routinely. There’s saltwater flooding during king tides, the Bay is near dying, and endemic butterflies are on the brink of extinction. What a lot of people don’t know is that how we live can mitigate a lot of these problems. We need trees, bioswales and pollination corridors.

Miami is one of the hottest cities in the country, ranking third-worst in heat island effect out of the 44 largest cities in the United States, according to the Climate Central report released in July 2023. As concrete replaces natural landscape, the end result is surfaces that reflect and radiate heat instead of surfaces that absorb heat. The reduction in natural landscape also causes flooding, as evidenced in our downtown neighborhoods. Why?

Because water simply has no place to go. Concrete does not absorb rainwater! And the health of Biscayne Bay is in danger, in part due to pollution from stormwater runoff and fertilizers. According to the 2023 Biscayne Bay Economic Study Update, Biscayne Bay provides $64 billion in economic output in Miami-Dade County and generates 448,5000 total jobs.

The good news is we have a simple, affordable and immediate solution to help reduce our heat island effect, provide flood mitigation and filter pollutants and toxins before they enter Biscayne Bay: using swales as green infrastructure.

At the July 27 Miami city commission meeting, Commissioner Sabina Covo introduced an agenda item aimed at creating a process for homeowners to use certain native plants on swales, and other native and non-native plants after review. Discussion is set for Oct. 26.

A swale is the oldest, most used stormwater management method throughout the world. Swales collect rainwater, mitigate flooding, filter out pollutants, sediment and toxins, prevent erosion and provide a natural area for storm runoff. They must be maintained to function properly. Unplanted, eroded swales, which are extensive throughout Miami, not only fail to serve their important stormwater management purpose, they contribute to flooding and pollutants entering Biscayne Bay.

Planted swales capture and slow stormwater runoff, but grass swales offer less filtering and infiltration than swales planted with native plants. Native plants have a deeper root system and are easy to maintain. They require little or no fertilizer, pesticides or watering, and are adapted to our South Florida climate. They also help sustain our biodiverse ecosystem.

Let’s hope the city does right by our environment by establishing swale legislation that enables us to address our climate issues now, without requiring a complicated, lengthy permit process when planting native plants. Existing code already allows for native herbaceous plants, ground covers and other plants and requires 30% native plants in rights-of-way.

Planted swales may seem like a small contribution to water quality improvement, but every little thing we do adds up. Allowing residents to plant 100% native plants in the swales in front of their homes is one simple, effective way we can work together to better manage stormwater to reduce heat, limit flooding and help save our precious Biscayne Bay.

Sandy Moise is a Miami resident and director of policy and education for the Urban Paradise Guild.