Irrigation Systems

Irrigation Systems are the lifeline for any agricultural operation. The Hawai`i Department of Agriculture, through its Agricultural Resource Management Division (ARMD) manages five irrigation systems, two on O`ahu (Kahuku and Waimanalo), two on the Island of Hawai`i (Waimea and Honoka`a-Paauilo), and one on Moloka`i (Ho`olehua).

The ARMD also manages the following reservoirs:

  • Honokaia Reservoir located in Honokaia, Island of Hawai`i
  • Paauilo Reservoir located in Paauilo, Island of Hawai`i
  • Puu Pulehu Reservoir located in Waimea, Island of Hawai`i
  • Waimea 60 MG Reservoir located in Waimea, Island of Hawai`i
  • Kualapuu Reservoir located in Kualapuu, Island of Moloka`i
  • Waimanalo 60 MG Reservoir located in Waimanalo, Island of O`ahu

All recreational activities, including swimming and fishing, in the above-listed reservoirs are prohibited.  These reservoirs are not open to the public.  Trespassers will be prosecuted in accordance with §708-814, Hawaii Revised Statutes.


Waimanalo Irrigation System

View the current water level of the Waimanalo Irrigation System

    • length: 15 miles
    • acres served: 1,174 acres
    • transports: 150.0 million gallons per year

Kahuku Irrigation System

    • length: 3 miles
    • acres served: 445 acres
Updated Feb. 1, 2022

Kahuku Irrigation System Mandatory Water Conservation Reduced to 10% from 30%

In accordance with §4-157-4, Hawaii Administrative Rules, the administrator-chief engineer has deemed that special conservation measures continue to be necessary to address a water shortage emergency.  Effective February 1, 2022, however, the Kahuku Irrigation System shall reduce the conservation measures from a mandatory 30% to a mandatory 10% cutback in the monthly consumption of irrigation water for all water customers.

Emergency repair work to the irrigation pumps continues and interruptions of water delivery and/or low water pressure may occur.

Irrigation staff will monitor water meters for compliance with the mandatory 10% conservation.  Consumers shall be assessed a surcharge of thirty cents per thousand gallons of water consumed in excess of ninety per cent of their average use as calculated by the administrator-chief engineer.  Non-compliance for overuse may result in water service being turned off.

If you have any questions, please contact our office at (808) 973-9473.


Waimea Irrigation System

View the current water level of the Waimea Irrigation System

    • length: 15 miles
    • acres served: 566 acres
    • transports: 307.2 million gallons per year

Lower Hamakua Irrigation System (Honoka`a-Paauilo)

View the current water levels of the Lower Hamakua Irrigation System

    • length: 26 miles
    • acres served: 4,755 acres


Moloka`i Irrigation System

View the current level of the Moloka`i Irrigation System

    • length: 25 miles
    • acres served: 3,160 acres
    • transports: 1.2 billion gallons per year

View more information on the administration of the Moloka`i Irrigation System


To Apply for Irrigation Services

To apply for irrigation water services, you may download the Application for Irrigation Water Service form (in pdf format on legal sized paper)

or obtained by writing or calling the Agricultural Resource Management Division below.

Changing an Acreage Assessment

Information on the procedure to request to change an acreage assessment


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Hawai`i Department of Agriculture
Agricultural Resource Management Division
1428 South King Street
Honolulu, HI 96814-2512
Phone: (808) 973-9473

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