And while the report does not attempt to assign blame for the dam failure, it does address problems of lack of maintenance, and the filling in of an emergency overflow that has been a controversial topic in post-disaster probes.

The report concludes that the overflow or spillway was filled about 1997, and that the "lack of a spillway at Ka Loko Dam, as well as other circumstantial evidence, would indicate that the dam likely failed by overtopping."

But it says it is also possible the failure was caused by other things, including internal erosion caused by persistent seepage within the dam wall.

The dam breached March 14, 2006, and the resulting flood swept through the rural Wailapa Stream community, destroying property and killing seven people living in a streamside home. The state attorney general is conducting a criminal investigation into the case, and families of the victims have filed suit against the dam's owners, the state and county, and others.

Godbey was hired on a $250,000 contract after the Legislature demanded a civil investigation by an independent party. His goal, he said, was not to assign blame, but to study the practices that may have led to the failure and make recommendations to the Legislature on how to improve dam safety statewide.

"The principal goal of the investigation has been to provide constructive recommendations that may help avoid a similar tragedy in the future," Godbey's report said.

Godbey worked on the report with a staff of experts, including: attorneys Jess Griffiths and Chad Iida, who like Godbey is also an engineer; University of Hawai'i law students Cameron Black, who has experience in environmental health and safety; and Joshua Strickler, a mechanical engineer; cultural anthropologist Deborah Ball; and attorney Heather Gamache.

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