Heavy October rain in Manoa has again caused water damage at the University of Hawai'i's Hamilton Library, this time gushing through three floors, wrecking ceiling tiles and soaking nearly 1,000 books.

Most of the damage occurred on the library's second floor, where ceiling tiles crumpled because of water that gushed through like "waterfalls at an amusement park," said Kyle Hamada, a conservation technician at the library.

"From the amount of water coming down, it was kind of surprising that nothing got really wet," Hamada said.

The latest damage occurred while contractors were in the middle of a months-long reroofing project. The $250,000 project began in mid-August, and those repairs are not expected to be completed for another month and a half, barring more rainy days, acting head librarian Alan Grosenheider said.

Debris from the repair work apparently clogged drain pipes during the weekend rain, causing water to pool on the ceiling and trickle from the library's third floor down to the first floor, officials said.

Officials were assessing the damage.

"We believe we were able to prevent serious damage because (library workers) were able to respond so quickly," UH-Manoa spokesman Gregg Takayama said.

A disaster response team leapt into action Sunday morning after it was discovered that water was pooling inches deep on three floors of the library. Workers scooped away buckets of water as others removed books from the shelves, out of the water's path.

Portions of the library are now covered by tarps, and there are buckets where water leaked through.

An estimated 1,000 books from the European history and literature collections are now being housed in the library's Preservation Department, where fans and dehumidifiers are drying them out, library officials said.

Most of the books will be OK once they've dried, they said.

"Because they caught it early, there shouldn't be any permanent damage to the books," Takayama said.

It was the third time in four years that the library has suffered during fall rains.

"It seems like every year around this time," Hamada said.

About a year ago, Hamilton Library suffered about $500,000 worth of damage when thousands of books and rare documents were wrecked by heavy rain.

Dozens of rare Tibetan scrolls, books and other rare items in the library's Asian collection were soaked when water leaked into the third floor of the building.

Seriously damaged books were put in large freezers in the library's Preservation Department, where they were freeze-dried, allowing many to be salvaged.

Thousands of other books were packed into boxes and stored in 40-foot refrigerated shipping containers.

The library continues to recover from damage caused in 2004 during flooding on Halloween.

That flood damaged about $34 million in rare documents, maps and books in the basement — more than 3 million items — and forced faculty, students and several departments to move.

Hamada said the Preservation Department continues to slowly restore drawers of maps covered in mud during that flood. Containers of other documents still remain to be restored, he said.

The library also is in the midst of a $30 million reconstruction project for its one-acre basement space.