Analyzing potential damage done by lowering our polluted canals into Biscayne Bay ahead of Hurricane Ian

MIAMI-DADE COUNTY, Fla. – It is the weekend after Hurricane Ian ravaged the southern Gulf Coast and while South Florida was spared from the storm’s devastation, scientists with Florida International University’s Institute of Environment are making sure water management didn’t unleash a different type of catastrophe.

To prevent potential flooding of neighborhoods, tens of thousands of gallons of water were discharged from 2200 miles of canals right into Biscayne Bay.

“We are preparing for Hurricane Ian by lowering our canals throughout the South Florida,” South Florida Water Management District Executive Director Drew Bartlett said in the days before Ian was set to arrive.

It is the most polluted water in all of Miami-Dade County and it was sent flowing into a bay already at a dangerous tipping point.

Early Saturday morning Local 10 News’ Louis Aguirre set out with the FIU research team to collect data and hope for the best.

“With them dumping the waters into the bay, we just want to make sure that those waters aren’t disrupting the nice conditions that are currently in our Biscayne Bay,” said FIU PhD chemistry student Kassidy Troxell.

They used a water probe that measures PH and chlorophyll levels and more importantly the amount of oxygen in the water.

“So we can really see the condition of the bay right now, in real time,” Troxell said.

It was the crash of oxygen levels in parts of northern bay that caused the unpresented fish kill of 2020, when more than 27,000 marine species suffocated to death during that hot week in August, spiked by an overload of deadly nutrients caused by too much pollution.

“The bay is very vulnerable,” said Miami Waterkeeper Executive Director Rachel Silverstein. “It’s very fragile right now because of all the pollution that’s already in it, and so adding any additional stress on the bay can push it over the edge.”

But Hurricane Ian brought more than eight inches of rain to Miami-Dade, as well as tropical storm force winds that cooled the bay water, and a strong Florida current that drove fresh ocean flows into the watershed.

“So with the hurricane, the winds, I feel like the water sloshing back and forth, the oxygen levels look, okay,” said Dr. Todd Crowl, Executive Director of FIU’s Institute of Environment.

Indeed, the bay caught a break, but not all of it.

A map from the data collected Saturday shows two recurring hotspots with consistently lower oxygen levels: the Biscayne Canal and the Little River.

The Little River Canal is one of the dirtiest bodies of water in all Miami-Dade County, full of deadly nutrients that cause those dissolved oxygen levels to crash at the mouth of the outfall, and every time SFWMD has to open the flow into the bay, there is the potential for devastating consequences.

“Oxygen here in the Little River is 25 percent,” said Troxell. “This type of dissolved oxygen is not sustainable for our bay.”

Sewage breaks, fertilizer runoffs and dirty storm water in the Little River contribute to the nutrient load causing low oxygen, but it is the 300 homes along the river on septic tanks that are the real killers.

Miami-Dade has 120,000 septic tanks in the county, and 9000 of them are already failing due to sea level rise, spewing all that untreated effluent into our ground water and canals.

“We all have to say, ‘Yes, we’re willing to have our roads torn up or willing to make a sacrifice to get off of our septic systems into sewer systems and clean up the Bay,’” said Crowl.

With both federal and state grants to help absorb some of the costs, Miami-Dade launched its Connect to Protect program in January to urgently get the county’s most vulnerable properties off septic and connected to sewer laterals as soon as possible, but it will take years and billions of dollars to complete.

So for now, constant monitoring of the bay is the best defense we have.

“It’s getting hotter again,” said FIU Institute of Environment Program Director Brad Schonhoff. “And this could be the thing that could with those nutrients that were brought out, this could spark something to happen, and so we’re just making sure that we keep an eye on it.”

This is on all of us.

Everything we do on land impacts our water, from the trash that gets dumped on the street or out of our car windows, the fertilizer some residents put on their lawn during the rainy season, the pet waste some animal owners don’t pick up, every time it rains all that flows into our canals that empty out into the watershed. It’s all another dagger straight through the heart of a dying Biscayne Bay.

For more information on Miami-Dade County’s Connect to Protect program, click here.


About the Author:

Louis Aguirre is an Emmy-award winning journalist who anchors weekday newscasts and serves as WPLG Local 10’s Environmental Advocate.