Hawaii County is moving forward with plans to construct a 10 million gallon water reservoir to serve coastal areas of South Kohala.
The Hawaii County Department of Water Supply proposes to build the 36-foot-tall prestressed concrete water tank on property currently owned by Parker Ranch. Also included in the project are accessory waterlines and a gate, access road, security lighting and fence.
A final environmental assessment for the project, released Sept. 8, concluded building the capped reservoir to provide additional water storage in the Lalamilo Water System would have no significant impact.
Estimated to cost approximately $12 million, the new 222-foot diameter reservoir will take about 21 months to construct, providing well-paying construction jobs, according to the Department of Water Supply. The cost will be split between state general obligation bonds and DWS capital improvement project funds.
Filling of the reservoir, which would be situated at about 1,200 feet elevation just mauka of Lalamilo Parker Access Road between Parker Wells No. 2 and 3, would occur when wind power from the nearby 3.3-megawatt Lalamilo Windfarm Repowering Project becomes available.
“When completed, this important project will improve the Lalamilo Water System by adding another 10MG of available storage. A key benefit will be greater and more efficient use of clean electricity generated at the nearby Lalamilo Windfarm Repowering Project,” said Jason Armstrong, Department of Water Supply information and education specialist. “The intent of using more renewable wind energy when available is to lower both pumping costs to refill the water system’s storage tanks and fossil fuel consumption. DWS passes energy costs on to water customers, who benefit financially when savings occur.”
The Lalamilo Water System serves the coastal areas of South Kohala. Originally implemented to serve the small village of Kawaihae in the early 1900s, the system grew to include wells on state and private lands that allowed the development of the Mauna Kea and Mauna Lani resorts, which remain the largest consumers of water.
Today, the system is supplied by six wells and serves Mauna Lani Resort, Puako, Waialea, Mauna Kea Resort and Kawaihae communities through two booster pump stations, nine storage tanks and transmission lines.
In 2019, prior to the COVID-19 pandemic, the system served a population of about 1,975, utilizing about 4.38 million gallons per day.
The proposed work may produce minor, localized construction equipment noise, emissions and dust. However, because of the isolated location of the proposed project, these effects would be minimal to the public.
The project site has long been used as cattle, goat and sheep pasture. Botanical surveys found mainly non-native species and no rare or endangered flora. Vegetation removal will be restricted to minimize impacts to endangered Hawaiian hoary bats. An archaeological survey found no historical sites.
The area is part of the Waimea Maneuver Area, a large military training site, and unexploded ordnance will be surveyed and removed.
