Las Cruces park officials estimate it will cost $300,000 to replace bathrooms at Young Park after the building was set on fire.
Marcus Garcia, 16, his brother, Daniel Garcia, 14, and their cousin, Chris Reed, 17, were arrested last Friday and charged with intentionally starting the fire.
Officials said the money for repairs will be coming out of taxpayers' pockets.
City Parks District Manager Rudy Treviño told ABC-7 the bathrooms are so damaged they're not worth repairing.
Instead, they will have to tear down the building and start from scratch.
"These playgrounds and these public restrooms, they're not cheap. The city has to pay for them. The city gets its funding from the taxpayers, so it all comes back to the taxpayers having to foot the bill," Las Cruces Police Department spokesman Dan Trujillo said.
Trujillo said the three teenagers lit toilet paper on fire and stuffed it in a trash can inside the bathroom.
The fire left the building charred and beyond repair.
"This is definitely the most I've seen in a short period of time. This is a big dollar amount. In a couple years' time, that's the most we've seen," Treviño said.
Hundreds of people enjoy Young Park every month. Many of them said they're not happy to find the bathrooms destroyed and locked up.
"I feel sad because the restroom every day when we come here, we use it for the kids right away. He needs to go to the restroom," Blanca Madrid, a Las Crucen strolling through the park, said.
"It's sad because we're the ones that enjoy it but we take care of it. We pick up our trash when we leave. It's just sad that now we have to pay out of pocket and we can't enjoy it," Las Crucen Ruben Lucero said.
Treviño said the $300,000 estimate for Young Park will be added to a long list including repairs for the burnt playground at Lion's Park costing about $15,000.
In the meantime, the parks are still open for business.
"We have a car show on Sunday and the Renaissance Crafts Fair, which is gonna bring in about 20,000 people. Obviously we will not have these bathrooms repaired in that time frame," Treviño said.
Park officials brought in extra portable toilets to accommodate the crowds.
Treviño said people vandalize the parks every day, but this much damage is upsetting.
"It's a lot of money and it could be used on other facilities or for different parts of the organization," he told ABC-7.
Treviño said it could anywhere from six to nine months to have the bathrooms replaced.