Teams of volunteers are moving boulders, spreading gravel and rebuilding the damaged Manoa Falls trail after a devastating flood last October washed away trail sections, leaving behind a rutted and slippery path.

Upwards of 200 tourists and residents a day hike the 0.8-mile novice-rated trail to see the 100-foot waterfall at the back of the valley. It is one of the five most popular hikes in the state and takes visitors through lush rain forest and across a small stream.

Using $25,000 in federal money for flood-damaged areas, the state's Na Ala Hele trails program is focusing on restoring the trail and protecting the water quality of Manoa Stream, which the trail follows.

Kyle Clark, on vacation here from Florida, hiked the falls last week and said the new gravel makes the walk much safer.

"Up near the top it was real muddy and that is where everybody started to slip," he said. "There was no gravel up there at all. The gravel gives you much better traction and is easier to walk on."

His wife, Debbie, wanted to thank the volunteers for their labor. "Whoever is doing this work, it is incredible," she said. "It's very nice. It makes it so you can bring your family up."

The repair effort includes Sierra Club of O'ahu volunteers, who have been spreading 100 tons of gravel three inches thick along the entire trail, and low-risk prisoners, who have been moving boulders and installing recycled plastic edging along the trail.

Traffic on the trail increased after a 1999 rockslide closed the Sacred Falls trail on the island's Windward side.

Randy Ching, an outings leader with the Sierra Club, is coordinating the group's volunteers. Most days, Ching works by himself, moving gravel from where it was dumped by trucks near Lyon Arboretum to the trail head.

"The gravel will keep most of the dirt on the trail instead of running off into Manoa stream," Ching said. "It will also be very good for the hikers. They will be able to wear white shoes in and come out with white shoes."

Ching has held two volunteer work days this month and more are planned, for Sept. 3 and 18, and Oct. 1 and 23.

(To volunteer, contact Ching at 942-0145 or oahurandy@ya hoo.com.)

The volunteers use wheelbarrows to move gravel to the trail head and then shovel it into buckets and backpacks for others to carry down the trail. More volunteers spread the gravel, filling in holes to make an even walkway.

"It's hard, dirty, sweaty, stinky work," he said. "But it is worth it."

The trail was closed for three months in 2002 after a landslide near the falls. The state repaired the trail and built an area from which to view the waterfall safely. Signs were put up warning hikers to stay away from the landslide area, including the pool at the base of the waterfall.

Aaron Lowe, the Na Ala Hele program specialist coordinating the effort, said the project will include increasing the size of the viewing area to accommodate more people: "We've continued our risk assessment of the falls with our geologists. We are fairly comfortable that the slide is secure, but would prefer people stay within the viewing area."

Reach James Gonser at jgonser@honoluluadvertiser.com.