KALAPAKI, Kaua'i — The Kaua'i Marriott resort was cleaning up yesterday from a powerful rain Saturday morning that flooded 25 rooms and dozens of cars, overwhelmed a sewage pump station, cut canyons through coastal lawns and Kalapaki Beach, and severely damaged shoreline rock walls and foundation slabs.

A stream that had been diverted underground as part of the resort development gushed over diversions and flowed several feet deep through the hotel.

"This was a disaster, but not a natural disaster. It was a man-made disaster" due to the stream diversion, said aquatic biologist Don Heacock.

The state Department of Health closed Kalapaki Beach, which lies in front of the hotel, because of sewage in the water.

"I think all the water on Kaua'i tried to get through the property," said hotel general manager Bill Countryman.

Gov. Linda Lingle viewed the damage before a function at the resort Saturday night.

Several dozen cars parked in the lot below the hotel's old Japanese garden area were flooded and were being cleaned. Countryman said he expects it to take about a month to bring the 25 flooded rooms back on line. The affected rooms are in the newest of the resort's three towers — one built by developer Chris Hemmeter immediately below the stream valley.

The mud-filled hotel pool was drained and cleaned. It was being refilled yesterday morning and Countryman said it would be available to guests by yesterday afternoon.

Cleaning crews from several Kaua'i companies, supplemented by crews flown in from O'ahu, were working on the property.

"Our engineers are coordinating efforts with county officials to address the damages to Kalapaki Beach," Countryman said.

Longtime Kaua'i resident Patrick Childs said that when he was young, he recalls a large wetland behind the east end of Kalapaki Beach, which was later filled.

Holbrook Goodale, whose parents had a beach house on Kalapaki Beach before resorts were built there, said there was extensive filling of stream beds and blocking of old springs by resort operators over the years during development of the old Kaua'i Surf Hotel and then the Westin, which later became the Marriott.

"I told them, you don't go messing around with old Hawaiian streams. Eventually, they're going to find their way back to the ocean," he said.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.