About two dozen friends, neighbors and church group volunteers joined 10 state employees to form a circular bucket brigade around a mud-drenched Manoa house yesterday.

Bucket slingers worked feverishly to clear out tons of debris from the fourth and worst mudslide in one week to hit the half-century-old, contemporary-style home at 2750 Pu'uhonua St.

"If we don't remove it, when it rains again the water will get up high and overflow the barriers we've put up and go into the house," said Pat Costales, branch manager for the Division of Forestry and Wildlife in the state Department of Land and Natural Resources.

The National Weather Service was predicting potential thunderstorms over O'ahu last night, and even more rain tonight and tomorrow.

Meanwhile, yesterday crews were clearing a mudslide on Round Top Drive on Tantalus and trying to stem a sewer break that was pouring wastewater into the Ala Wai Canal. There were no new reports of flooding on O'ahu yesterday, officials said.

At the Manoa project, Aaron Lowe, the O'ahu trails and access specialist for the DLNR, who helped coordinate yesterday's cleanup, said one problem was that workers would labor on the site in the day, "and the mountain takes it out during the night."

While some volunteers moved buckets, others shoveled dirt into bags used to construct a barrier wall around the back of the house.

Out front, Red Cross Disaster Services volunteer Yesid Romero stood by with food, water, and an emergency vehicle in case one were needed.

By yesterday, the bucket brigade had been enhanced by a makeshift wooden chute stationed down the hill along the right side of the house and leading to the top of the home's carport. There, catchers poured the contents into a dump truck parked below.

"We're using gravity to our advantage," Lowe said. "Before, it was buckets up and down the staircase. Now, we're going empty buckets up the stairs, and full buckets down the flue, so the whole thing moves clockwise around the house."

Linda Green, who along with Michael Hofmann has owned the home for two years, said the debris fall started directly behind the home on Tuesday night.

Green said that on the first and second nights, a layer of mud went through the house and seeped through the hardwood floor to a small guest- apartment below. "There was just mud everywhere. Thick cakes of mud," said Green, who expressed gratitude to all who helped in the cleanup effort.

"We don't know what the damage is. We don't know how the water has worked its way through the walls or anything below. It's in the electrical system."

Yesterday's debris fall was confined to the back of the house or diverted around the sides, Green said.

"But if it comes down and gets filled up again, we'll need a whole crew to come in and dig it out again."

Hofmann said neighbors who have lived in surrounding homes for decades said nothing like this has happened before. "Rocks and gravel will come down sometimes," he said. "But this is the first time there's ever been a mud event."

National Weather Service forecaster Tom Birchard said the Islands have never before experienced the kind of heavy downpours they've received lately. "We're sort of in an unprecedented type of regime here as far as the amount of rainfall we received over the last 30 to 40 days," Birchard said. "And some of our records go back pretty far."

Lowe said engineers were still looking to find the source of the water flow causing the debris fall. "We've got guys up on the mountain trying to figure it out and negotiate where it's coming from and do an evaluation," he said.

Meanwhile, bucket brigade volunteers said they were happy to help.

David Merkel and his 11-year-old daughter, J'aime, were on their way to do volunteer landscaping work at the Makiki watershed when Merkel spoke to Lowe by phone.

Soon the two were headed for the Manoa bucket brigade instead.

"The reward is the personal satisfaction," Merkel later explained as he paused for a lunch break by the side of the road.

"And I learned that you need to help others," added J'aime as she polished off a piece of Red Cross chicken.

Reach Will Hoover at whoover@honoluluadvertiser.com.