Construction crews have nearly finished rebuilding Utah County's Murdock Canal, but the waterway's operators still are not sure why it failed last month, causing an estimated $1 million in flood damage in Lindon.

There likely will be at least two investigations into the accident May 22 that damaged 40 homes, streets, highways and a Lindon city park, said Jack Gardner, superintendent of the Provo River Water Users Association, which operates the canal.Gardner said the association's liability insurance policy may have to pay for the damage caused by the canal break, but the insurance carrier will investigate the cause of the failure before paying claims.

The association, a non-profit corporation whose stockholders are canal water users, probably will hire an engineering firm to make an independent investigation, Gardner said.

Water could be flowing at capacity through the rebuilt canal within a week if all goes well.

Crews have been rebuilding the failed 30-foot section for nearly a week. Stormy weather kept workers from the canal Monday, the only day construction work has been halted.

"The bottom of the canal has been filled in to the original (depth)," Gardner said. "Only the bank is left to fill in, and that should take three or four days." The reconstruction will cost about $70,000, he said.

The Pleasant Grove Police Department, which coordinated the emergency response to the canal failure, estimated damage at more than $1 million. However, damage claims are still being filed and the total could go higher.

Gardner has denied that the canal was carrying more water than its normal flow of 300 second-feet at the time of the failure.

Only one minor injury was attributed to the incident, and authorities say warnings to those whose homes were in the path of the flood by emergency personnel and volunteers kept that toll from being higher.

The canal, built in 1938 by the U.S. Bureau of Reclamation, supplies irrigation water to Salt Lake and northern Utah counties.