Albizia trees that fell wrongly in February at Akaka Falls State Park caused nearly $300,000 in damage during invasive species removal — and it will be December before repairs are complete.

Albizia trees that fell wrongly in February at Akaka Falls State Park caused nearly $300,000 in damage during invasive species removal — and it will be December before repairs are complete.

The state Department of Land and Natural Resource made that announcement Wednesday.

Akaka Falls “plunges 442 feet into a stream-eroded gorge,” the DLNR’s announcement says. It’s a major draw for tourism.

Albizia in the park had grown to a towering 150-180 feet and posed a danger to passing tourists because the trees are notorious for sporadically dropping limbs. During removal of the trees, estimated to be only about 12-15 years old, the trees fell the wrong direction and damaged sidewalks, railings and steps.

The tree removal company’s insurance is covering repair costs, the state said in June.

The park’s longest — and most intense — trail has been closed since February. But the park continues to see a steady stream of visitors taking the short route to view Akaka Falls daily. They pile from tour buses and private vehicles to traipse to the viewing area.

Repairs already began along the short route, where sidewalk was damaged and railings knocked down. The DLNR named Site Engineering as the contractor for repairs, with an estimated total cost of $297,400.

Initial repair work began last week on the longer trail section that leads to the scenic view of Kuhuna Falls, the DLNR statement says.

The entire park will be closed Oct. 16-20 for work on the short route.

“Hopefully, this will be the only time the park will need to be closed,” the DLNR announcement says. “If additional closure is needed, an announcement will be posted on the Division of State Parks website and in local news media.”

How can the park prevent new albizias from causing similar damage in the future?

“We will continue to monitor the park for any potential problems that may occur due to invasive trees and plants,” said Hawaii Island State Parks Superintendent Dean Takebayashi.

He recommends property owners concerned about albizia on their own land visit the Big Island Invasive Species Committee website at www.biisc.org/albizia.

BIISC project manager Springer Kaye said the key to preventing albizia from getting out of hand is to replant the area with tropical ornamental plants once albizias are removed. Homeowners can mow regularly to keep them from starting in their yards, she said.

Getting the forest floor shaded will be essential at Akaka Falls, Kaye said, because that will help prevent growth of the invasive trees.

“Albizia seedlings are really poor competitors, as long as there’s shade or really dense ground cover,” Kaye said.

Forest Service research in Hawaii has shown “up to 1,200 seedlings will come up in one square meter of bare soil,” she said. But just a handful of seedlings will grow when a similar square meter is covered in shade.

Regardless of whether you’re a state park or a private landowner, Kaye said, regularly cutting down albizia trees is important.

“You want to take care of them every year,” she said.

Takebayashi suggested it be even more often.

“Be diligent in monitoring your properties for young trees and remove them as soon as they are discovered,” he said.

Within a year, an albizia tree can grow to a height of 15 feet, Kaye said. Most physically fit people can cut down one at that height.

“Once it gets bigger than that, it gets to be a real cost,” Kaye said.

Cutting down albizia trees from parks and private landowner property, she said, should be considered a “civic duty.”

“We were so sorry to see what happened up at Akaka Falls.”

Email Jeff Hansel at jhansel@hawaiitribune-herald.com.