East Maui Irrigation | Page 2 | Images of Old Hawaiʻi

The early Polynesians brought sugar cane with them and demonstrated that it could be grown successfully in the islands. The first commercially-viable sugar plantation, Ladd and Co, was started at Kōloa on Kauai in 1835. Others followed, including on Maui.

Sugar became part of the Maui landscape. More than 30-plantations of various sizes popped up on Maui. Over time, consolidations and closures gradually reduced the number to fewer, but larger, plantations. (Sugar Museum)

Sugar is a thirsty crop; in order to irrigate, in 1876 the initial Hāmākua Ditch was built, bringing water from streams from the windward and wet East Maui. A total of ten ditches were constructed between 1879 and 1923; this system makes up what is known today as East Maui Irrigation (EMI.)

Under natural conditions, most surface water would flow to the ocean; instead, this water has been diverted and artificially applied to the plant-soil system, creating a net increase in ground-water recharge. Irrigation-enhanced recharge greatly affects the groundwater system in central Maui.

Ground water is one of Hawai‘i’s most important natural resources. It is used for drinking water, irrigation, and domestic, commercial, and industrial needs. Ground water provides about 99% of Hawai‘i’s domestic water and about 50% of all freshwater used in the State.

The amount of recharge available to enter the aquifers is the volume of rainfall, fog drip, and irrigation water that is not lost to runoff or evapotranspiration or stored in the soil. (USGS)

The period 1926–79 had the highest estimated recharge; irrigation rates during this period were at least 50% higher than in any other period considered.

Prior to the early-1970s, about 190-million gallons per day (Mgal/d) of water diverted by East Maui ditches and 170-Mgal/d of groundwater withdrawn from shafts and wells was used to irrigate sugarcane fields in central Maui.

Groundwater recharge concerns have gone from bad to worse. Overall irrigation rates have been steadily decreasing since the 1970s, when large-scale sugarcane plantations began a conversion from furrow to more efficient drip irrigation methods and a reduction in the amount of acreage dedicated to sugarcane production.

Estimated recharge for central and west Maui declined 44% during the period 1979–2004. During this period, on the leeward (Lāhainā) side of West Maui Mountain, sugarcane cultivation ceased altogether.

The decrease in irrigation has coincided recently with periods of below-average rainfall, creating the potential for substantially reduced recharge rates in many areas. (USGS)

The period 2000–04 had the lowest estimated recharge; irrigation rates during this period were 46 percent lower than during 1926–79, and rainfall was the lowest of any period.

With the closure of HC&S’ sugarcane fields in central Maui, and subsequent stoppage of irrigation over the groundwater aquifer, recharge will be reduced and the groundwater flow system will be affected. (USGS)

Population growth on the Island of Maui has led to an increase in ground-water demand. The resident population on the island increased more than 300% percent during the period 1960–2010: from 35,717 to 144,444 (Maui County)

The ‘Ïao aquifer system is the principal source of domestic water supply for the Island of Maui. Ground-water withdrawals from this aquifer system increased from less than 10-Mgal/d during 1970 to about 17-Mgal/d during 2005.

So, there is concern surrounding declines in ground-water levels and an increase in the chloride concentration of water pumped from wells in the ‘Ïao aquifer system.

Even before the contemplated, and later announced, closure of HC&S sugar cultivation, the State Water Commission designated ‘Īao as a groundwater management area because the 12-month moving average pumping withdrawals exceeded the Commission-established trigger.

The effect of changes in irrigation-enhanced recharge was illustrated on a small scale in Wailua on Kauai, and the drying up of ‘Fern Grotto’ was the result. There, the Kapa‘a irrigation system was built in the 1920s to provide water for approximately 6,000 acres of land under sugar cane.

Up until the sugar company closing, the lower portion has been fed by the Hanamaulu Ditch, which ended at ‘Reservoir 21,’ directly above Fern Grotto. The ferns began growing only after sugar was grown on the land 150 feet above the cave.

Plantation workers built a catch basin for storm runoff that became known as Reservoir 21. Water from the reservoir percolated through the ground and came out on the roof and walls of the cave.

The shutting down of the Hanamaulu Ditch has undoubtedly contributed or even was the principal cause of the drying up on the Fern Grotto. The lack of irrigation water caused the cliff-side ferns to dry up.

A 9-month rejuvenation project involved creation of a second waterfall in the grotto and installation of solar panels to power pumps to bring water from the Wailua Reservoir to the Fern Grotto.

Now, the Fern Grotto is back. Solutions in the central Maui isthmus, the principal source of domestic water supply for the Island of Maui, are not as simple.

A century after Captain James Cook’s arrival in Hawaiʻi, sugar plantations started to dominate the landscape. Sugar changed the social fabric of Hawaii. Hawai`i’s economy turned toward sugar in the decades between 1860 and 1880.

The industry came to maturity by the turn of the century; the industry peaked in the 1930s. Hawaiʻi’s sugar plantations employed more than 50,000 workers and produced more than 1-million tons of sugar a year; over 254,500-acres were planted in sugar. (That plummeted to 492,000-tons in 1995; a majority of the plantations closed in the 1990s.)

So, the Islands have not just lost that last remnant of generations of economic and agricultural activity; Maui must now look at ways to manage and provide for water needs and demands, given the loss of irrigation-enhanced recharge. (Lots of information here is from several USGS reports.)

I was fortunate to have served as the Chair and Director of the Department of Land and Natural Resources and the Chair of the Water Commission, working on these and other related issues.

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maui-sugar-cane-ron-dahlquist

Central Maui Isthmus-sugarcane

EMI_System-map

EMI_Intake

EMI-Ditch

Installation of a pipeline for Haiku ditch water under the steel railroad bridge crossing the Maliko Gulch-1909

Iao Aquifer-Ditches-USGS

Fern Grotto

At the time of Haiku Sugar Company’s charter in 1858, there were only ten sugar companies in the Kingdom of Hawaiʻi. Five of these sugar companies were located on the island of Maui: East Maui Plantation at Kaluanui; Brewer Plantation at Haliʻimalie; LL Torbert and Captain James Makee’s plantation at Ulupalakua; Haiku Plantation; and Hana.

In 1871, Samuel T Alexander became manager of the Haiku mill on Maui. Alexander and his partner, Henry Perrine Baldwin, saw the need for a reliable source of water, and to this end undertook the construction of the Hāmākua ditch in 1876.

The first part of the work was completed in the summer of 1877; the Pacific Commercial Advertiser, on July 14, 1877, noted: “The great display of the day was at Haiku, where several hundred Natives and Foreigners assembled to celebrate the completion of the Big Ditch, and to see for themselves, the water from the mountain gushing through great iron pipes, emptying itself into the ditch, and rolling on to the valley, and spreading over the cane fields, making the earth glad with its presence. The motto, “The Grass Grows And Water Runs,” was pointed on canvas and stretched across the principal avenue; flags were flying apparently from every bush,—the Wailuku brass band was in attendance and discoursed screech music. Too much credit cannot be bestowed upon Messers. Alexander and Baldwin for their perseverance and energy in completing so great and valuable an enterprise.” (Kuykendall)

The completed Old Hāmākua Ditch was 17-miles long and had a capacity of 60-million gallons per day. A second ditch was added, the Spreckels Ditch; when completed, it was 30-miles long with a capacity of 60-million gallons per day. Before World War I, the New Hāmākua, Koʻolau, New Haiku and Kauhikoa ditches were built.

A total of ten ditches were constructed between 1879 and 1923; this system makes up what is known today as East Maui Irrigation (EMI.)

This privately financed, constructed and managed irrigation system was one of the largest in the United States. It demonstrated the feasibility of transporting water from steep tropical forested watersheds with high rainfall across difficult terrain to fertile and dry plains.

East Maui Irrigation system consists of 388-separate intakes, 24-miles of ditches and 50-miles of tunnels, as well as inverted siphons, numerous small dams, pipes, flumes and 8-reservoirs, spanning 39 drainage basins.

The aqueducts bring water from the steep, wet eastern slopes of Haleakalā to the fertile semi-arid central Maui plain. They provide half the irrigation water to the sugar growing area of Maui.

Sugar production dramatically increased with irrigation and improved cultivation practices. Sugar yields increased from 2-tons per acre to over 13-tons per acre grown with 2-year crop cycles.

Eventually sugar production from the Islands exceeded 1.2-million tons per year, comprising the major economic sector of Hawaii for 100-years.

Over the years of the development of this system, many engineers gained experience in building irrigation systems. They used what they learned from the East Maui Irrigation System to develop other irrigation systems; EMI System was the forerunner of major aqueducts in the Western United States by the Bureau of Reclamation for irrigation districts and regional domestic supplies.

In 2003, the East Maui Irrigation System was designated as an ASCE National Historic Civil Engineering Landmark. It is the third National Historic Civil Engineering Landmark in the State of Hawaiʻi. The other two landmarks are the Kamehameha V Post Office Building, dedicated in 1987, and the Red Hill Underground Fuel Storage Facility, dedicated in 1994.

Today, the EMI System conveys billions of gallons per year from high rainfall slopes on the Windward side of Haleakalā to the semi-arid region between east and west Maui for sugar cane cultivation. In addition, some of the water diverted serves 10,000 Upcountry customers.

The issue of stream diversion, at EMI and elsewhere, however, is not simply engineering success and diversion on one part of the island to irrigate crops on another part of the island. Taking too much from a stream can impact the stream ecosystem.

This relates to Instream Flow Standard which is “a quantity or flow of water or depth of water which is required to be present at a specific location in a stream system at certain specified times of the year to protect fishery, wildlife, recreational, aesthetic, scenic, and other beneficial instream uses.”

The technical language of the law is complicated; I simplify this to say that the instream flow standard simply allows a stream to be a stream.

Because ground and surface waters of the state are held in public trust for the benefit of the citizens of the state, the people of the state are beneficiaries and have a right to have the waters protected.

The object of the public trust is not maximum consumptive use, but rather the most equitable, reasonable and beneficial allocation of state water resources, with full recognition that resource protection and natural processes also constitute “use.”

Adequate provisions must also be made for the protection of traditional and customary Hawaiian rights, the protection and procreation of fish and wildlife, the maintenance of proper ecological balance and scenic beauty, and the preservation and enhancement of water of the state for municipal uses, public recreation, public water supply, agriculture, and navigation. Such objectives are declared to be in the public interest.

Related to this, EMI and other diversion systems have been the subject of conflict, litigation and contested case hearings before the Department of Land and Natural Resources and the State Commission on Water Resource Management (CWRM.) In the past few years, CWRM adopted interim instream flow standards for 27 of the EMI streams. The saga continues.

While taking water for appropriate off-stream uses, at issue with diversions are the fundamental principles of letting a stream be a stream (don’t divert too much to cause ecological changes in the stream) and protection of downstream user rights (allowing downstream users to also use the water resource – especially for taro cultivation.)

I was fortunate to have served as the Chair and Director of the Department of Land and Natural Resources and the Chair of the Water Commission, working on these and other related issues.

The image shows a map of the East Maui Irrigation system. In addition, I have added other images in a folder of like name in the Photos section on my Facebook and Google+ pages.

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