MIAMI (CBSMiami) – The party responsible for $5 million in damage to the Adrienne Arsht Center last summer is the builder and its contractors, according to a forensic engineering group’s report released Thursday.

CBS4 news partner The Miami Herald reports the Slider Engineering Group said installation deficiencies “fell below the reasonable standard of care for experienced mechanical/plumbing contractors in the Florida construction industry.”

The report went on to say “that this substandard installation work was the direct cause of the May 20, 2012 storm water drainage system failure at the ZBOH [Ziff Ballet Opera House], resulting in significant water intrusion and the subsequent damage to the facility.”

Slider blamed the damage to the ballet center’s ceiling, light fixtures, carpeting and several other sections of the building’s interior on reinforcement and braces that were never installed on the water drainage pipe, as well as pipe supporters and couplings that were improperly installed.

A Miami-Dade commission agreed in July to pay for the $5 million repairs to the Center.

County Mayor Carlos Gimenez said staff has discussed the findings with Odebrecht USA., The Haskell Co., and Ellis Don Construction Inc., the joint venture that built the performing arts center, as well as subcontractors The Poole and Kent Co., and Fred McGilvray Inc., which were hired to install the roof rainwater drainage system.

“While we have not achieved resolution of these issues yet, we will continue to take any necessary actions to protect our interests,” Gimenez wrote in the cover letter to the report released to county commissioners.

So far, the county has spent $4.3 million replacing damaged fixtures, removing humidity and, in some places, demolishing damaged sections of the opera hall. It has only been reimbursed $535,000 by the insurance provider.

Odebrecht said it has worked closely with the county, and expects that to continue. In a prepared statement, the company said “Today we received the final Slider Engineering report about the leak event, and we will continue to cooperate fully with the county and its consulting engineer as the remediation program is finalized and implemented.”

The county expects full reimbursement of the $4.3 million, and of about an additional $2 million it expects to spend on still-needed repairs pinpointed in the report.

“We’ve been very targeted in fixing what broke, but some long-term fixes must be done,” said Lester Sola, the county’s director of Internal Services. “The memo from the county is very clear: We are looking for reimbursement.”

It was a May 20, 2012, deluge that soaked many of the 2,500 patrons who were attending a Sunday evening performance of The Lion King. As a pipe in the ceiling burst, water gushed from the ceiling and light fixtures in the hall’s lobby, corridors and four-floor atrium. The show halted, and the crowd, moving through ankle-deep water, quickly sloshed its way outside.

With the facility closed for only one night, the damage was much worse than at first expected. In July, Gimenez went before county commissioners asking them to approve a $5 million request for reparations, and promising to try and retrieve the money from the builder or subcontractors. After much debate, the move was approved.

The county has not received any money from the builder or its contractors for the work that has already been done. More work is needed to completely repair the facility.

“Our goal remains to secure the reimbursements of all costs incurred to date on these repairs … and to pursue all necessary avenues to recover these additional costs,” Gimenez wrote.

The $470 million Arsht Center opened in 2006. Warranties that would have covered the cost of the damage have expired. Each year the county pays the Arsht Center a $7.65 million subsidy to cover operations. Though the $5 million comes from county coffers, the independent Performing Arts Center Trust has been charged with hiring the contractors to make the repairs.

(TM and © Copyright 2013 CBS Local Media, a division of CBS Radio Inc. CBS RADIO and EYE Logo TM and Copyright 2013 CBS Broadcasting Inc. Used under license. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. CBS4 news partner The Miami Herald contributed to this report.)