Haiku flood
Dam was slated for removal
Before a warning of “imminent failure” of Kaupakalua Dam in Haiku during heavy rainfall and flooding Monday, a plan was underway to remove the dam this summer, following a state report that found the structure in “unsatisfactory” overall condition.
The reservoir was empty before the heavy rain started falling Monday, according to Mahi Pono, which is halfowner of the dam and reservoir built in 1885 and owned and managed by East Maui Irrigation Co.
The reservoir isn’t being used to collect water for irrigation and is dry under normal conditions, the company reported. A valve is kept open to allow water entering the reservoir during typical rainfall to quickly exit and flow downstream, according to the company.
The dam had an emergency action plan filed with the state Department of Land and Natural Resources. That resulted in immediate public safety alerts Monday afternoon and the evacuation of residents in areas of Haiku and Peahi downstream of the dam and reservoir, after Mahi Pono reported that water was starting to top the dam embankment.
Shan Tsutsui, chief operating officer of Mahi Pono, said the overtopping stopped at about 5 p.m. Monday and didn’t recur overnight. Tsutsui said he inspected the reservoir and dam at about 10 a.m. Tuesday.
“At that time, water levels are still high but overtopping has stopped,” Tsutsui said. “We will continue to monitor the situation until it returns to a safe level.
“At this time, we are not aware any property damage that occurred due to the overtopping,” he said. “However, this does not diminish the damage caused in the surrounding community located mauka of the reservoir by the overwhelming and unprecedented rainfall here on Maui.”
In a news release Tuesday, the state Department of Land and Natural Resources said East Maui Irrigation has been working with the state on complying with a Feb. 18, 2020, notice of deficiency letter that set a compliance schedule to remediate the dam’s deficiency.
In October, the owner applied for a permit to remove the dam, with the work planned for this summer. The permit application is still pending, Mahi Pono reported Tuesday.
About two weeks ago, on Feb. 24, a DLNR violation notice said the dam owner had failed to comply with the notice of deficiency by failing to install a real-time reservoir water level gauge with readings accessible on the internet by May 30, as required by state law, the department said. A water level gauge previously installed at the dam was stolen in 2018.
The owner is working with the state to have the gauge replaced and to install gauges at three other Maui reservoirs — Kapalaalaea, Haiku and Reservoir 24, the department said.
In 2017, East Maui Irrigation received a notice of deficiency for Kaupakalua Reservoir for three items — topography, hydraulics and realtime gauge, according to Mahi Pono. The company said the first two items have been resolved and the third was in the process of being resolved.
Mahi Pono said a review and study of the dam was commissioned and it was determined that removing the dam and decommissioning the reservoir was the best option. EMI is responsible for costs associated with the removal.
DLNR Chairwoman Suzanne Case said the department’s Dam and Reservoir Safety Program works with owners of dams and reservoirs to bring them into compliance with safety regulations.
“Yesterday’s overtopping of water over this dam certainly indicates the removal is necessary to protect people and property,” she said in the news release. “We will continue to work with the dam owners around the state to ensure the optimum level of safety and awareness possible.”