When Ariella Deutsch’s toddler accidentally ran into Prospect Park Lake, it was impossible to see him through the duckweed, which can make the water’s surface look like a field of solid grass.
“It happened really fast,” Deutsch recalled of the July 12 incident near the park’s Boathouse. “I was terrified.”
Her husband and an onlooker charged into the murky waters to pluck out the fully submerged 3½ -year-old. The mom consulted with a doctor who told her to watch her son for symptoms of poisoning from the toxic blue-green algae. The boy was OK.
But Deutsch and fellow parents fear other children may not be as fortunate — especially when the 526-acre Brooklyn oasis is more popular than ever as a pandemic refuge and as algae spread peaks in the summer.
They are doing everything possible to warn others about the dangers and push the group overseeing the park to take more precautions, as they recall a 2014 summertime tragedy still fresh in the minds of many parkgoers.
Six years ago, the green grass-like duckweed contributed to a toddler’s drowning in the 55-acre lake. The vegetation on top of the water made it difficult for first responders to find 2-year-old Ruhshona Kurbonova, who had wandered off with her 3-year-old cousin during a family get-together at the park.
Police called in a helicopter to cruise over the lake in a desperate attempt to push away the duckweed and thick algae.

Park staffers now use a $140,000 weed harvester dubbed “The Floating Goat” to minimize the spread of the duckweed and water primrose. The piloted vessel goes over the once pristine blue lake about once a week, according to Megan Moriarty, a Parks Department spokesperson, who noted that swimming in the lake is prohibited.
But young children who play near the lake often have no idea where the grass ends and the water starts. Further compounding the hazard, the grass near the walkway slopes downward, which can lead rambunctious kids to zoom right into the gooey water.
Like ‘Sliding into Home Plate’
That’s what happened to Elona Litvintchouk’s then-5-year-old son Yechial in 2017.
“I told the kids to go play on the grass,” Litvintchouk recalled. “He ran into the water like someone sliding into home plate.”
In an instant, he was underwater and out of sight beneath the grassy green layer atop the water, she said.
“I was in shock,” Litvintchouk said. “I started panicking and going in.”
Her husband also raced into the water and quickly scooped the frightened kid out.
In the chaos, their youngest child, Yehudis, who was 3 at the time, began to roll down into the lake as she sat in a stroller. Litvintchouk ran back to stop the stroller just before it hit the water.

Afterward, the Midwood mother reported the near drowning to 311 and reached out to police in her neighborhood.
The cops said there was nothing they could do, she said. The 311 report was closed out, with a note that the city Parks Department “corrected the problem.”
“As per park manger (sic), Prospect Park Senior Staff will take the matter under advisement to consider additional precautions,” the response said.
But the algae and duckweed remain.
And last December the water tested positive for “high toxins,” according to the state’s Department of Environmental Conservation. People and dogs exposed to the algae can become sick with diarrhea and vomiting or struggle to breathe and have convulsions, according to the state Department of Health.
Filtration System Tested
In 2019, the Prospect Park Alliance, which operates park maintenance, announced that it began construction of a natural filtration system, known as an ecoWEIR, to reduce cyanobacterial harmful algal blooms, known as CyanoHABs or HABS for short.
The algae explodes when the weather warms up and grows on the phosphorus that comes in with the municipal water that feeds the lake — as well as from the decomposition of other algae that bloom and die.
The filtration system holds the incoming water about a foot below the surface of the soil and just underneath the plant root zone. There it undergoes a sort of natural cleansing to rid it of phosphorus, which the bacteria feeds on like a buffet.
‘Words do not do justice to how insane this part of the park is.’
But the $394,473 pilot program, to be launched near the water feeding into the Prospect Park Dog Beach, is not expected to have much of an effect on the water by the Boathouse.
Construction on the “underground Brita system” was delayed by the pandemic, according to Prospect Park Alliance, but is expected to be operational soon.
The results from the system will be assessed and may be expanded to other parts of the park — and even playing fields — if deemed a success.
“It’s a win-win type of solution: Using natural systems to address the problem,” said Jennifer Cherrier, a Brooklyn College professor who invented and patented the ecoWEIR system. “Nature is pretty cool. It just needs a boost.”
But Deutch is worried what will happen in the interim. She wonders why the Parks Department doesn’t cordon off the area where it slopes down or at least put up signs warning parkgoers.
“Words do not do justice to how insane this part of the park is,” she said. “It’s a totally open body of water with no barrier and it’s covered in algae so it looks like a field.”