The weather forecast says the entire state will be hit with many showers and isolated thunderstorms today as a flash flood watch remains in effect through tomorrow on all major islands.

Areas other than Kaua'i were relatively dry yesterday, but sporadic showers hit O'ahu's North Shore and Maui's east side and Kula in the late afternoon, the National Weather Service said.

"We (on O'ahu) are very dry by comparison to what they had on Kaua'i," said Andy Nash, director of operations at the National Weather Service in Honolulu. "(Kaua'i) can't take any more rain, but there's still going to be more rain to come."

Central O'ahu's relatively dry weather has allowed the water level in the Lake Wilson reservoir to continue to recede, said John Cummings of the O'ahu Civil Defense Agency. He said there were no reports of flooding or evacuation requests yesterday.

One bright spot on O'ahu was the improving water quality at some popular beaches. The state removed 11 warning signs from beaches and waterways — signs that had been posted because of high bacterial counts after sewage spills caused by heavy rain.

The state Department of Health has removed warning signs from Kailua, Waimanalo and He'eia, but longtime residents say people should still wait before going into the ocean and streams that were closed because of sewage contamination.

"The pilau (pollution) is still there," said longtime Waimanalo resident Haywood Kalima, 59, president of the Waimanalo Ramp Fisherman Club. "You should wait two weeks after it clears."

Kalima said the sewage spills are killing reefs, limu and octopus, and people shouldn't be eating seafood caught in contaminated areas. He wondered about the spills that haven't been a problem until the last four or five years.

The state Department of Health said bacteria counts in the water have dropped, and they removed warning signs from Kailua Bay, Waimanalo Beach and Nahiku Street in Kane'ohe after water samples collected over the weekend showed diminished bacteria counts.

Still, the Department of Health issued a brown-water advisory, warning people to stay out of murky and dirty waters. Those waters may contain chemical pollutants or harmful microorganisms from overflowing cesspools or septic tanks as well as animal feces washed into streams and storm drains, the DOH advisory said.

Kurt Tsue, DOH spokesman, said several areas on O'ahu remain posted and will most likely stay up for the weekend.

But Whitney Schmiedeknecht, 25, said it was good news to learn that the signs have been removed from Kailua because she's stayed clear of the beach for several weeks.

"I'm glad that it's cleared up and I'm just waiting for a sunny day so I can go back," she said.

Meanwhile, Troy Kindred, with the Hawaii County Civil Defense, said the Big Island had about 2 inches of rain in 24 hours that ended yesterday. The agency is focusing on helping Kaua'i by locating and sending pumps.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.