Launiupoko Irrigation Company
Launiupoko Irrigation Company, LLC (LIC) was established in 2002 by Makila Land Company, LLC. The purchase by Makila Land included the irrigation water system built by and utilized by Pioneer Mill for 150 years of growing sugar cane. LIC was formed to provide irrigation water service to the agricultural subdivisions and Kuleana lands. The LIC received a Certificate of Public Convenience and Necessity from the State of Hawaii Public Utilities Commission to provide water service to this area in October of 2003. You are invited to see the virtual tour that was created for the PUC Rate Case: https://www.youtube.com/watch?v=IrRH5QfGL2M
Up until March of 2018, the water source for LIC’s water system derived from two stream diversions, with intakes at Kauaula and Launiupoko streams. Both streams collect their water from watersheds of two separate valleys within the conservation zoned land owned by Makila Land Co., LLC. After the sugar cane industry shut down the existing infrastructure was redesigned by LIC to accommodate small farm plots using gravitational flow to assist in distribution.
The redesigned infrastructure allows water to be transported by ditch, tunnel or pipe and collected in reservoirs then filtered and distributed through new PVC infrastructure into subdivisions of the agricultural lands below.
Currently, LIC must be able to provide approximately 2 million gallons per day for their customers. Once stream flow restrictions were created, the available source wasn’t enough to supply the demand for the current customers. LIC is utilizing two wells in the Pu’unoa area to pump water up to homes in higher elevations in addition to the Kaua’ula reservoir so that it can be distributed as needed. LIC is also mixing potable with non-potable water as a short-term solution to meet the current water demands of its customers.
Details of Launiupoko Stream System
The Launiupoko Intake dam (1,280ft elev.) diverts water from a 742-acre watershed into a cut stone ditch with an 8-inch PVC pipe along a transmission ditch approximately 1 mile long. The pipe and ditch deliver the water to the Launiupoko Reservoir (900ft elev.). The reservoir has a capacity of 2 million gallons. The outlet works from the reservoir connects a 10” PVC pipe and delivers the water to a filter station.
After the filter station the transmission lines split allowing the water to service the Mahanalua Nui and Makila Nui subdivisions to the south and the Pu’unoa and Makila Plantation subdivisions to the North. This source can only supply approximately 10-15% of the daily demand.
Total Flows diverted by this system as expressed by statistical parameters are as follows:
Mean = .78 MGD
Median = .60 MGD
Mode = .55 MGD
Max. = 4.75 MGD
Period of Record 1956 to 1975 (20 Years)
Details of Kauaula Stream System
The Kauaula Intake diversion dam is at an elevation of 1529 feet, which diverts water from a 1200-acre watershed through a rocktrap with flushing gate, across an inclined grating and then into a .8-mile transmission tunnel. At the end of the tunnel the water flows into a forebay and then penstock that runs the Kauaula Hydroelectric plant. From the hydro plant the water enters a ditch then to a siphon and back to a ditch, which flows to the Kauaula reservoir, a 4 million gallon reservoir at 750 feet. From the reservoir a 12 PVC delivers the water to a filter station located at approximately 650 feet. After the filter station the transmission lines split allowing the water to service the Makila plantation subdivision the to the south and to Pu’uanoa subdivision to the west.
There is one known development tunnel above the intake. The location of the tunnel is about 1.4 miles upstream from the intake on the north side of the valley at an elevation of 2920 feet. The tunnel is 656 feet long, cuts 194 dikes and reportedly delivers about 2.0 MGD to the total stream flow
Total Flows diverted by this system as expressed by statistical parameters are as follows:
Mean = 5.22 MGD
Median = 4.50 MGD
Mode = 3.45 MGD
Max. = 25.5 MGD
Period of Record 1956 to 1975 (20 Years)
* Flow data taken from a report called Hydromania written by Bert Hatton Civil Engineer for Pioneer Mill.