Heavy rain that caused pockets of flash flooding in the southern and eastern areas of Oahu on Sunday soaked through the Hawai‘i Convention Center roof, affecting the Kawaii Kon event and removing another five meeting rooms from service.

Hawai‘i Convention Center General Manager Teri Orton said the final ceremony for Kawaii Kon was taking place when rain penetrated the third-floor ceiling, forcing staff to enter the event to put out several plastic bins to catch the rain — an embarrassing end to an otherwise successful event. Orton said Kawaii Kon drew some 20,000 attendees during the three-day event, which celebrated Japanese anime, gaming and illustration.

The new damage occurred as rain was falling on Oahu at a rate of 2 to 3 inches per hour, causing flooding in drainage areas, streams, rivers, roads, properties and other low-lying areas. Public road closures also occurred before Oahu’s flash flood warning and flood advisory expired early Monday morning.

Orton said the fact that Sunday’s rain event caused so much damage and wasn’t even one of Oahu’s worst storms shows how years of deferred maintenance are exacerbating the center’s problems, and why she has asked the state Legislature for $64 million to fix the center’s leaky roof. She said the rooftop terrace deck repair isn’t even part of a separate $80 million capital improvement plan that includes repairs for damage from other leaks, such as the third-floor planters from which water is pouring into the center’s back-of-the-house storage.

“This was a minor rain on Sunday, but it’s still costing taxpayer dollars to do the repairs. We’ve done them over and over again. We need to address the source of the leaks,” she said. “We added an indoor water feature yesterday — one that we didn’t want.”

So far, state lawmakers have allocated just $15 million for a temporary fix for the rooftop terrace deck. Gov. Josh Green released those funds Feb. 17, and they have been posted in the state Financial Accounting and Management Information System by the state Department of Accounting and General Services.

Daniel Naho‘opi‘i, Hawaii Tourism Authority chief administrative officer, said, “We appreciate the governor releasing the $15 million allocated by the Legislature last session for temporary repairs to the Hawai‘i Convention Center roof.”

Naho‘opi‘i said HTA had made a legislative budget request for a $28.5 million annual expenditure ceiling for the Convention Center Enterprise Special Fund “to enable us to access the resources already in that fund to address immediate repair and maintenance needs. The House finance committee did not concur with that request.”

He added, “We are also in discussions with the House and Senate tourism committees on the needs for more permanent roof repairs, and those conversations have been positive.”

Orton said the center hopes that the state will find a way to fund the permanent repairs, and in the interim is moving ahead with the temporary fix to remove the rooftop’s plastic square flooring and planters and paint on a leak-proof barrier.

She said the center recently went through procurement for a project manager for the temporary repair and that RLB was awarded the contract. Orton said construction would likely start in the fall of 2024 and would run about 10 months as the schedule would have built-in starts and stops to accommodate center business.

Orton said the temporary repair would render the popular rooftop deck unusable and would not stop the worsening of underlying rust or corrosion, which over time could further weaken the facility’s support structure. She said eventually the permanent repairs would have to be done anyway, and delaying them another three years is projected to increase the cost to at least $88 million.

Repairs and the cost to fix them have been mounting at the center for some time. For years, water has been penetrating the center’s rooftop terrace deck, causing water leaks into other parts of the building where there are now cracks, rust and calcium leaching from the concrete. Mold and mildew are a constant worry.

Orton said the center already has spent about $300,000 to make repairs after rain events in November and earlier this year, and each storm brings new worries and costs.

Grant Castillo, the center’s director of engineering, said the leak that affected Kawaii Kon on Sunday is a new one stemming from the metal roof above the ballroom and is unrelated to the center’s leaky rooftop terrace deck. He estimates it could cost another $200,000 to fix the metal roof, and more if the scope of the damage goes beyond a coating to fix.

In addition to the ballroom leak, Castillo said this latest rain caused damage to four other third-floor meeting rooms. He said one of the rooms already has been fixed twice since November, and now has incurred enough new water damage to cause 160 square feet of ceiling tile to fall.

He said the Sunday storm also caused a rain bladder, an earlier temporary fix to stop rain from leaking into the parking garage, to overflow in one of the meeting rooms. On Monday, water was still coming out of the carpet with every step in that room, and it had a musty odor like several of the other damaged rooms.

Orton said center staff were up until midnight Sunday responding to the latest water damage and figuring out how to accommodate the Pacific Risk Management ‘Ohana (PRiMO) conference, which was taking place at the center Monday, and an event today for Nuuanu Congregational Church.

“We had to figure out what rooms to move and how to change the event floor plans,” Orton said. “We also had to start contacting remediation professionals.”

Jeff Carbaugh, center operations manager, said the new damage is expected to remove five of the center’s 47 meeting rooms from service for at least two weeks. Generally, it takes about five to 10 days for the leaks to stop after a rain event, and then the center must ensure that the rooms are completely dried to avoid mildew or mold before they can begin repairs.

Orton said after every damaging rain event, extensive remediation is required, which includes tests for air quality and moisture checks. She said in addition to ceiling repairs, carpet and furniture may have to be treated.