Dudley Johnson Park is popular spot for families looking to cool off from the Texas heat.
It's one of many designated areas along the five-mile stretch of the Blanco River. Hays County Sheriff Gary Cutler said his office has seen seven drownings since 2003.
"Know your swimming capabilities when you go swimming if you are not a good swimmer you should never swim alone," Sheriff Cutler said.
On Wednesday afternoon, first responders found 15-year-old Wyatt Kunze along the river.
Kunze's family said he was attempting to cross the river with his sister and two of his cousins when he began to struggle and drowned.
Kunze's older sister Cheryl Patterson said Kunze wasn't a strong swimmer, she attempted to swim out to help him but it was too late. After an hour and a half the rescue team found him.
Sheriff Cutler said the weather was not a factor.
"The weather was good it was clear things were calm, the river was up just a little because of recent rains but it was not swift for this area," Cutler said. "It was a normal flow this time of year."
Parts of the river can be tricky to navigate with steep drop offs.
Patterson said they weren't aware the river could be dangerous.
"If you have someone close to you hold onto them you never know when you are going to lose somebody," Patterson said.
Kunze was from Lockhart attended Prairie Lea ISD as a sophomore, loved football and fixing up cars.
Kunze's family set-up a GoFundMe to assist with funeral arrangements.