LIHU'E, Kaua'i — Landowners across the state are closely examining reservoirs and dams they own after the March 14 Kaloko Dam collapse that killed seven people living along the Wailapa Stream.

For example, A&B's Kaua'i Coffee Co. has drained its Aepo Reservoir in Lawa'i and other reservoirs it operates in the area. While it is standard practice for the company to lower water levels during heavy rains, it took an extra step in this situation.

"We did it out of an abundance of caution. We've never had this kind of rain before," said Frank Kiger, president of Kaua'i Coffee. The basins will be allowed to refill when the state's pattern of heavy rain and flooding appears to have ended, and the coffee plantation is likely to need the water, he said.

Some owners, including the state, are reviewing how much reservoir storage is actually needed, and some operators already have reduced the capacities maintained in reservoirs to reflect smaller demand. One point is clear: Hawai'i reservoirs are not just for irrigating sugar anymore.

For example, the Maha'ulepu Reservoir in south Kaua'i is kept at a level far below its design capacity because the needs of cattle ranching in the area are much less than the former demand of sugar growers.

Several reservoirs across the state had already been shut down before the Kaloko disaster — either with their intakes entirely shut off, or with their drainage valves open so water flows through and cannot be stored. This was done generally because there were no longer agricultural uses for the water they stored. And reservoir owners indicated they will review the necessity of keeping reservoirs open.

Kamehameha Schools has five of its nine reservoirs in flow-through condition — two in Kohala on the Big Island and three in Waiawa on O'ahu, said Kekoa Paulsen, information officer for Kamehameha Schools.

"We no longer had users, and we have not been allowing them to fill," Paulsen said. For the estate, that means less demand for frequent inspections and maintenance, he said.

Kamehameha Schools launched a review of its reservoirs last summer, he said. That review is not complete, but all the estate's reservoirs have recently been inspected by the school, and will be inspected again over the next few days by a team of state, federal and contractual dam engineers, he said.

Joint state-federal dam inspection crews have completed studies of all of Kaua'i's reservoir dams, and plan to look at every dam in the state during the next four days.

VARIED ATTENTION

Active reservoirs require active and frequent attention, which they generally get where agriculture remains active and the farmers control the water supply.

"Reservoirs are visited every day and water levels recorded, routine inspection and maintenance conducted, and active water management practices undertaken to control water flow in and out of the reservoirs accordingly. Some of these reservoirs have been in existence for over 100 years, and none have ever failed," said Stephen Holaday, A&B's president for agribusiness and general manager of the state's largest surviving sugar plantation, Maui's HC&S.

The plantation operates 55 reservoirs on Maui, 30 of which are large enough to fall under state oversight.

"Because these reservoirs are in active use as part of our agricultural operation, they are actively operated, monitored and maintained on a regular and ongoing basis," Holaday said.

On Kaua'i, Grove Farm Co. is paying special attention to Waita Reservoir, which has the largest surface area of any manmade body of fresh water in the state, at 424 acres.

"At Waita, we did open one of the outlet valves" to reduce water levels, said Kathy Thompson, a spokeswoman for Grove Farm, which operates about a dozen reservoirs that once were part of Grove Farm and Lihu'e Plantation sugar operations.

One of its reservoirs, at Ahukini Road and Kapule Highway, has been dry for many years and is being dismantled. The company has no plans to decommission any of its other water storage facilities, but, "we're evaluating all our reservoirs," Thompson said.

Another Grove Farm reservoir, the Kapaia Reservoir, also known as Tanaka Pond, has been outfitted with a sophisticated filtration plant that converts the plantation ditch water into drinking water that is fed into the county Department of Water's Lihu'e water system.

NO PROBLEMS FOUND

The state itself owns 19 reservoirs — 13 on Kaua'i, four on Hawai'i, and one each on Maui and O'ahu.

Peter Young, chairman of the Board of Land and Natural Resources, said preliminary inspections do not indicate problems with any of the state reservoirs.

But Young said that in addition to checking on reservoirs for structural safety, the state plans to review their use. For example, some reservoirs remain primarily for irrigation, but some — like Lake Wilson on O'ahu — are dual-use, including recreational fishing and irrigation among their functions. A few are now used primarily for fishing.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.