LIHU'E, Kaua'i — Engineers yesterday launched an unprecedented inspection tour of every one of Kaua'i's 54 reservoir dams, going in by foot, four-wheel-drive and even helicopter.

The urgency of the survey follows last week's Kaloko Reservoir dam failure that left three people known dead and four missing — and by the revelation from state land board director Peter Young that some dams, including Kaloko, may never have been checked by state inspectors.

Mayor Bryan Baptiste yesterday echoed that.

"They've been in place for 100 years, and some of them probably haven't been inspected since they were built," Baptiste said.

A point of confusion is that all the dams have danger ratings — but authorities learned that these ratings reflect the amount of potential development downstream from the dams that could be destroyed by a failure.

They were not indications of the condition of the dams themselves.

Baptiste said that Kaloko's low-danger rating was an old one, dating to before the agricultural valley and stream below it were developed into rural home sites.

County planning officials are being prevented from inspecting whether some structures were built illegally within the flood zone until after the search for victims of the flood is complete.

Four multiagency dam inspection teams have divided the island into sectors, and are expected to complete their islandwide survey by Friday. They will fill out a seven-page report in a format designed specifically for this project, said Bob Masuda, deputy director of the state Department of Land and Natural Resources.

Masuda said the owners of the Pu'u Ka Ele dam, which is immediately to the west of Kaloko, consulted with state engineers before removing concrete features on their dam's spillway that could have obstructed the flow of water from the reservoir.

"We didn't require them to do it, but we agreed with them that it seemed appropriate," Masuda said.

He said that engineers have installed water-level sensors at Kaloko, Waita and Pu'u Ka Ele dams and intend to also put one at Alexander Dam. The sensors automatically report water height to satellites, he said.

Meanwhile, engineers conducting investigations at Kaloko have concluded that the dam's breach March 14 dumped far more than the 300 million gallons that has been estimated.

"We're estimating that 420 million gallons was released," Masuda said. Investigators have concluded that Kaloko could have been holding 1,400 acre-feet of water before its failure — close to 460 million gallons. A crew using satellite location measuring equipment and depth finders has determined that only about 10 percent of that amount is left in the reservoir, he said.

The water swept down Wailapa Stream before dawn, ripping out acres of trees, and tumbling them before it. The flood critically damaged the downstream Morita Reservoir, whose dam has now been intentionally breached to prevent further flooding. It destroyed several buildings, including at least two where seven people slept. All seven were reported missing in the flood, and the bodies of three have been found and identified.

Kaua'i Fire Chief Bob Westerman said a team of 39 searchers was walking Wailapa Stream looking for signs of the remaining missing people. County lifeguards and state Department of Land and Natural Resources personnel used boats to search Kilauea River, into which Wailapa flows.

The search goes into its seventh day today, and has not yielded results since Friday. Baptiste was to meet yesterday afternoon with the families of the missing to review with them the progress of the search and its future.

"We're committed to at least two more days" of searching, Baptiste said.

Officials will reassess the search effort tomorrow, said county public information officer Mary Daubert.

Meanwhile, as the island dried up a little under the first full day of sunshine in weeks, the effects of the drenching continued. Sharks were reported sighted off Kekaha, just a few days after two sightings of sharks at Kealia.

Officials have suggested that they may be attracted to the carcasses of animals that washed into the ocean during the flooding.

A boulder described as Volkswagen-sized rolled onto Kuhio Highway above Hanalei Bridge yesterday morning, limiting traffic to one lane. Koke'e Road in Kekaha remained closed due to heavy mud.

The devastation led Gov. Linda Lingle on Friday to request an emergency $14.3 million appropriation.

The House Finance Committee is scheduled to hold a hearing on the request today at 2 p.m. in Room 308 of the state Capitol.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.