New studies of 10 dams and reservoirs that sit above populated areas — most of them on Kaua'i — show no immediate threats of failure, according to an initial review.

But engineers with the state Department of Land and Natural Resources are still poring over the reports commissioned by the U.S. Army Corps of Engineers to see if the owners of the dams and reservoirs need to make improvements, said Laura H. Thielen, DLNR chairwoman.

"We just received these reports ourselves," Thielen said late yesterday. "Our engineers are reviewing the corps' study. If there is information that requires immediate action, we will be working with the owners on that."

The $2 million worth of studies — ordered by the U.S. Senate Appropriations Committee — are part of the state's program to inspect and monitor 136 dams and reservoirs following the catastrophic collapse of Kaua'i's Kaloko Dam on March 14, 2006, which killed seven people.

The 10 dams were primarily picked for review because they are "upstream from urban development," Thielen said.

The Army Corps of Engineers commissioned a Mainland contractor to conduct the studies. Both the corps and the contractor, Seattle-based Tetra Tech, declined to comment yesterday. The results of an 11th study are expected in March.

The most alarming report concerned the Twin Reservoir on Kaua'i, which has several critical problems, such as debris that is clogging spillways, according to the study.

"These items require immediate attention by the dam owner," the report said.

Representatives for the Twin Reservoir — listed as East Kaua'i Irrigation Co. — could not be reached for comment yesterday.

But Thielen said the owners already have drained the reservoir and it poses no immediate threat.

The owners are considering what to do next with the reservoir, she said.

"Other owners are talking about the possibility of decommissioning their dams as well," Thielen said.

REPORTS RELEASED

The reports on six dams and reservoirs on Kaua'i and four more on Maui, O'ahu and Moloka'i use computerized modeling to project dangerous situations that could result in breaching and failure.

The Army Corps of Engineers gave the reports to DLNR on Feb. 8. DLNR spokeswoman Deborah Ward said the agency wanted to review them and forward them to the owners of the dams and reservoirs before making them public. The studies appeared Wednesday night on a Web site set up by DLNR.

But yesterday, some of the owners said they had not been given the reports and that they could not access the Web site.

Thielen said her engineers were continuing to review the reports.

Representatives of some of the property owners who own the dams and reservoirs yesterday wondered what they are supposed to do with the information when they eventually receive it.

"Once we obtain it, I suppose we need to be proactive with DLNR and find out exactly what it means for us," said Mike Tresler, vice president of land management and renewable energy for Grove Farm, which owns Kaua'i's Waita Reservoir. "My understanding of this study is it's basically a simulation of a worst-case scenario of what could possibly happen. It's very technical. What is the value? It's very concerning if they put stuff out like this and don't explain what it really means. I would hate for it to cause any panic."

FUNDED BY CONGRESS

Mary Daubert, spokeswoman for Kaua'i County, said in an e-mail: "This is the first time I heard of the study. We haven't had a chance to review it yet. Certainly, the safety of our residents is of utmost importance to us."

Like others, Daubert yesterday said that county officials could not immediately access the DLNR Web site that posted the studies, after being contacted for comment by The Advertiser.

U.S. Sen. Daniel K. Inouye, D-Hawai'i, a member of the Appropriations Committee that funded the Army Corps of Engineers' studies, said in a statement that they "will play a significant safety-related role because their purpose is twofold: To determine the downstream impact if a dam were to fail, and to be part of the evaluation process if a danger declaration needs to be issued for a particular dam.

"The state of Hawai'i will use the findings from the dam-break studies to work with dam owners and managers on preparing emergency action plans, while it continues to work with them on correcting any possible problems with the dams."

'CONTINUING PRIORITY'

In addition to the Army Corps of Engineers studies, federal and state inspectors inspected dams after the Kaloko disaster and again following the October 2006 earthquakes that rattled the Islands and knocked out power across O'ahu.

Another round of inspections is being conducted this year. The reports are expected to be delivered in the middle of this year, Thielen said.

"The state's dam safety inspection program is pretty complex," Thielen said.

"Frankly, the dam safety inspections are going to be a continuing priority. It's pretty unprecedented nationwide to have annual inspections of every dam in the state and we've done more than that."

Reach Dan Nakaso at dnakaso@honoluluadvertiser.com.