Kaka'ako Waterfront Park is one of three that re-opened Monday after the park was closed for maintenance and repair the past few months.
Now, the Hawaii Community Development Authority is stepping-up enforcement.
Just as the "No Trespassing" notices came down, new signs are up at the Hawaii Community Development Authority's parks in Kakaako, and more security as well.
"They're doing their best... If this doesn't work, then I don't know what the answer is," Richard Johnson, Honolulu resident said.
After being off-limits to allow for repairs and renovations, Kakaako's Gateway Parks and Kakaako Waterfront Park are back open.
The popular oceanfront park closed last October for health and safety reasons after HCDA says illegal campers tapped into the park's irrigation and electrical system, resulting in $200,000 in damages.
"There are some things that we sealed up and didn't actually fix but we made it safe and that's really our goal right now cause we really wanted to open this resource to the public," Garret Kamemoto, Hawaii Community Development Authority said.
Johnson says Kakaako Waterfront Park is part of his walking route for the past 25-years, and he's glad to see it is finally back open.
"We've got our park back again... big smile on my face now," Johnson said.
The new signs remind park users littering, camping and tampering with any irrigation system equipment is prohibited.
HCDA says it has also hired a private security team to enforce the list of rules and the park's closure time of 10 p.m.
"We're hoping that will prevent these big build ups of encampments," Kamemoto said.
Meanwhile, Hawaii's homeless coordinator, Scott Morishige, says there are on-going outreach efforts to educate the homeless about the park rules and their options through shelters and service providers.
"We're really building a relationship... It's not just handing somebody a card, it's really getting to know what were their needs are," Morishige said.
HCDA says state sheriffs, as well as Honolulu police, will also be out patrolling the area to ensure park users are following the rules.