Maria Diaz is filing a wrongful death lawsuit for the August 22 incident at Pratt Pier.
Witnesses say they heard Miguel Cisneros screaming for help but they could not find a floatation device to toss to him.
The victim's mother is calling on the park district to take immediate action and install life rings so another incident does not occur.
Her attorney, Jeffery Kroll, said Wednesday that Cisneros' death could have been prevented.
"If you think about this, this was preventable. It was an obvious problem and it was predictable," Kroll said. "And this was a recipe for disaster and they just, they buried their head. They wanted nothing to do with this and it took yet another drowning death for them to do something. But they're doing it at one location, not the hundreds that they talked about originally."
Since 2010, over 1,000 people have drowned in Lake Michigan.