Heavy rains are expected to pound the Big Island today and then make their way up the island chain as the remnants of Hurricane Kenneth, now a tropical depression, roll across the state.

Most areas of the state can expect 1 to 2 inches of rain, but some parts could get up to 6 inches, said Bob Farrell, lead forecaster with the National Weather Service in Honolulu.

"It looks like all islands will see heavy rainfall," especially on the windward sides, he said.

The weather service has issued a flash flood watch for the entire state through Sunday, he said.

Light to medium showers hit much of O'ahu last night. There were no reports of flooding as of 10:30 p.m., a fire department official said. The rain was from a system largely unrelated to Kenneth, weather forecaster Henry Lau said.

Kenneth was weakening rapidly yesterday, Farrell said. "But all that moisture associated with the depression will still be carried across the islands," he said.

O'ahu Civil Defense has been bracing for hurricanes and storms for weeks, said John Cummings III, agency spokes-man.

"At the city we started looking at the potential for flooding and storm-related problems when (Hurricane) Jova first popped on the screen," Cummings said.

While Kenneth has been consistently downgraded for the past week, "this is a sizable system, dragging a lot of water," Cummings said.

Residents living in areas that have experienced severe flooding in the past are asked to be vigilant and possibly be prepared to leave, he said.

Public works crews on the Big Island have been working to clear stream beds and drainage canals in preparation for the storm, said Dixie Kaetsu, Hawai'i County managing director.

Heavy rain isn't expected to cause too many difficulties, at least in Hilo, Kaetsu said. But the Kona side of the island is drier and more prone to flooding. "We will be keeping a close eye on those areas," she said.

The heavier showers and thunderstorms more associated with the core of the system could begin to affect the Big Island as early as this afternoon and last through tomorrow morning, Farrell said. Those showers could begin to affect the rest of the island chain tonight, he said.

The storm should clear out by Sunday with a return of trade winds and more normal weather conditions, Farrell said.

On O'ahu, city crews have been clearing debris from drainage ditches and streams for nearly two weeks, since Jova, the first storm to threaten the Islands, popped on the screen, said Laverne Higa, director of the city Department of Facility Maintenance.

"That is our standard operating procedure during hurricane season," Higa said.

Reach Loren Moreno at lmoreno@honoluluadvertiser.com.