HONOLULU (KHON2) — The Kaupakalua Dam in the Haiku is scheduled to be removed during the summer of 2021 after heavy rains caused it to overtop on Monday, March 8, prompting residents to evacuate.

The 138-year-old earthen dam was deemed to be in “unsatisfactory” overall condition.

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Records show that state inspectors issued a Notice of Deficiency to the owners in 2020.

The State sent the owners, Mahi Pono and East Maui Irrigation a notice of deficiency. The State also cited the owners in February, 2021, for failure to install a water level gauge that is accessible on the internet.

The owners had agreed to keep the dam empty except during storm events. Mahi Pono said in a statement, “Prior to yesterday’s rainstorm, the reservoir was empty… and is not being used to collect water for irrigation purposes.”

The owners say they submitted a permit to the State to remove the dam in October, 2020.
“It was determined that removing the dam and decommissioning the reservoir was the best option.”

Kaupakalua Dam can hold up to 68 million gallons of water. Experts say downpours like the one inn Maui on Monday can accumulate fast.

“It can happen that fast. Remember back in 2018, even though we were not in danger of over topping that dam, we were getting close to a few feet below the spillway elevation,” said Ernest Lau, manager at Honolulu Board of Water Supply.

Heavy rains forced the Honolulu Board of Water Supply to pump water out of Nuuanu Reservoir #1. It was getting close to within a foot below the crest, which would have forced nearby residents to evacuate. Lau says both Nuuanu dams are well below emergency levels. Crews are already taking preventative measures during these rainy days.

“We try to keep it dry as much as we can and keep the water levels low in case a big storm that may come by,” said Lau.

The Emergency Action Plan for Kaupakalua is what resulted in Monday’s immediate public safety alerts and the evacuation of people downstream of the dam. 

Our Dam and Reservoir Safety Program works continuously with private and public owners of dams and reservoirs to bring them into compliance with all required safety regulations. Yesterday’s overtopping of water over this dam certainly indicates the removal is necessary to protect people and property. We will continue to work with the dam owners around the state to ensure the optimum level of safety and awareness possible.

DLNR Chair Suzanne Case