U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2007–1157

Prepared in cooperation with the Office of Hawaiian Affairs, State of Hawai‘i

Water Use in Wetland Kalo Cultivation in Hawaiÿi
COVER

Kalo or taro (Colocasia esculenta (L.) Schott) typically in Hawai‘i is grown in wetland patches (lo‘i) 

directly irrigated with water from rivers or streams. Nearly 300 forms of Hawaiian kalo have been 

recorded. As a food source it was so important that it was referred to simply as ‘ai, which means 

food in Hawaiian. Practically the entire plant is edible.

Photo by Chiu W. Yeung, U.S. Geological Survey.
Water Use in Wetland Kalo 

Cultivation in Hawaiÿi

By Stephen B. Gingerich, Chiu W. Yeung, Tracy-Joy N. Ibarra, and 

John A. Engott

Prepared in cooperation with the 

Office of Hawaiian Affairs, State of Hawai‘i

Open-File Report 2007–1157

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

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copyright owners to reproduce any copyrighted materials contained within this report.

Suggested citation:

Gingerich, S.B., Yeung, C.W., Ibarra, T.N., and Engott, J.A., 2007, Water use in wetland kalo cultivation in Hawai‘i: U.S. Geological Survey Open-File Report 2007-1157, 68 p.
iii

Contents

Abstract ..........................................................................................................................1

Introduction ....................................................................................................................1

Site Selection ..........................................................................................................3

Acknowledgments ...................................................................................................4

Discharge, Water-Temperature, and Area Data-Collection Methods..............................4

Discharge Measurements .......................................................................................5

Water-Temperature Measurements.........................................................................5

Area Measurements................................................................................................5

Discharge and Water-Temperature Data ........................................................................6

Kaua‘i ......................................................................................................................7

O‘ahu ....................................................................................................................25

Maui ....................................................................................................................43

Hawai‘i...................................................................................................................59

Summary ......................................................................................................................59

References Cited..........................................................................................................59

Figures

1. General movement of irrigation water in a lo‘i kalo...........................................2

2. Location of significant areas of kalo cultivation, State of Hawai‘i......................4

3. Flow measured by U.S. Geological Survey staff in loÿi kalo ÿauwai with (A)

an acoustic Doppler velocimeter and (B) the volumetric method......................5

4. Thermistor and PVC housing used for collecting temperature 

measurements ..................................................................................................6

5. Wai‘oli lo‘i complex, Island of Kaua‘i ...............................................................10

6. Water temperature in Wai‘oli lo‘i complex, Island of Kaua‘i.............................11

7. Daily pattern of water temperature in Wai‘oli lo‘i complex, 

Island of Kaua‘i ...............................................................................................15

8. Hanalei lo‘i complex, Island of Kaua‘i .............................................................19

9. Water temperature in Hanalei lo‘i complex, Island of Kaua‘i...........................20

10. Daily pattern of water temperature in Hanalei lo‘i complex, 

Island of Kaua‘i ...............................................................................................21

11. Makaweli lo‘i complex, Island of Kaua‘i...........................................................22

12. Water temperature in Makaweli lo‘i complex, Island of Kaua‘i ........................23

13. Daily pattern of water temperature in Makaweli lo‘i complex, Island of

Kaua‘i..............................................................................................................24
iv

14. Waiähole lo‘i complexes, Island of O‘ahu........................................................28

15. Water temperature in Waiähole lo‘i complexes, Island of O‘ahu .....................29

16. Daily pattern of water temperature in Waiähole lo‘i complexes, Island of

O‘ahu ..............................................................................................................32

17. Waihe‘e lo‘i complex, Island of O‘ahu .............................................................35

18. Water temperature in Waihe‘e lo‘i complexes, Island of O‘ahu .......................36

18. Continued .......................................................................................................37

19. Daily pattern of water temperature in Waihe‘e lo‘i complex, 

Island of O‘ahu................................................................................................38

20. Hale‘iwa lo‘i complex, Island of O‘ahu ............................................................40

21. Water temperature in Hale‘iwa lo‘i complexes, Island of O‘ahu ......................41

22. Daily pattern of water temperature in Hale‘iwa lo‘i complex, Island of

O‘ahu ..............................................................................................................42

23. Waihe‘e lo‘i complexes, Island of Maui ...........................................................46

24. Water temperature in Waihe‘e lo‘i complexes, Island of Maui.........................47

25. Daily pattern of water temperature in Waihe‘e lo‘i complexes, Island of

Maui ................................................................................................................48

26. Wailua (Lakini) lo‘i complex, Island of Maui ....................................................49

27. Water temperature in Wailua (Lakini) lo‘i complex, Island of Maui..................50

28. Daily pattern of water temperature in Wailua (Lakini) lo‘i complex, Island of

Maui ................................................................................................................51

29. Wailua lo‘i complex, Island of Maui.................................................................52

30. Water temperature in Wailua lo‘i complex, Island of Maui...............................53

31. Daily pattern of water temperature in Wailua lo‘i complex, Island of Maui......53

32. Wailua (Waikani) lo‘i complex, Island of Maui.................................................54

33. Water temperature in Wailua (Waikani) lo‘i complex, Island of Maui...............55

34. Daily pattern of water temperature in Wailua (Waikani) lo‘i complex, Island

of Maui ............................................................................................................56

35. Ke‘anae lo‘i complex, Island of Maui...............................................................57

36. Water temperature in Ke‘anae lo‘i complex, Island of Maui ............................58

37. Daily pattern of water temperature in Ke‘anae lo‘i complex, Island of Maui....58

38. Waipi‘o (A) lo‘i complex, Island of Hawai‘i.......................................................62

39. Waipi‘o (B) lo‘i complex, Island of Hawai‘i.......................................................63

40. Water temperature in Waipi‘o (A) lo‘i complex, Island of Hawai‘i ....................64

41. Daily pattern of water temperature in Waipi‘o (A) lo‘i complex, Island of

Hawai‘i ............................................................................................................65

42. Water temperature in Waipi‘o (B) lo‘i complex, Island of Hawai‘i ....................66

43. Daily pattern of water temperature in Waipi‘o (B) lo‘i complex, Island of

Hawai‘i ............................................................................................................67
Tables

1. Selected temperature conversions. ..................................................................6

2. Summary of discharge measurements and areas for selected lo‘i

complexes, Island of Kaua‘i ..............................................................................8

5. Water-temperature statistics based on measurements collected at

15-minute intervals for lo‘i complexes on the Island of O‘ahu.........................27

6. Summary of discharge measurements and areas for selected lo‘i

complexes, Island of Maui...............................................................................44

7. Water-temperature statistics based on measurements collected at

15-minute intervals for lo‘i complexes on the Island of Maui. .........................45

8. Summary of discharge measurements and areas for selected lo‘i

complexes, Island of Hawai‘i...........................................................................60

9. Water-temperature statistics based on measurements collected at

15-minute intervals for lo‘i complexes on the Island of Hawai‘i. .....................61

10. Summary of water use calculated for lo‘i and lo‘i complexes by island,

State of Hawai‘i..............................................................................................68

3. Water-temperature statistics based on measurements collected at 

15-minute intervals for lo‘i complexes on the Island of Kaua‘i ..........................9

4. Summary of discharge measurements and areas for selected lo‘i 

complexes, Island of O‘ahu ...........................................................................26
vi

Conversion Factors

Multiply By To obtain

Area

acre 4,047 square meter (m2

)

Volume

million gallons (Mgal) 3,785 cubic meter (m3

)

Flow rate

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3

/s)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as 

follows:

°F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as 

follows:

°C=(°F-32)/1.8

Vertical coordinate information is referenced to mean sea level.

Horizontal coordinate information is referenced to the North American Datum of 1983 

(NAD 83).
Abstract

Ten cultivation areas (8 windward, 2 leeward) 

were selected for a kalo water-use study, primarily 

on the basis of the diversity of environmental and 

agricultural conditions under which wetland kalo is 

grown and landowner permission and availability. 

Flow and water-temperature data were collected 

at the lo‘i complex level and at the individual lo‘i 

level. To ensure that flow and temperature data 

collected at different lo‘i reflect similar irrigation 

conditions (continuous flooding of the mature crop), 

only lo‘i with crops near the harvesting stage were 

selected for water-temperature data collection. The 

water need for kalo cultivation varies depending 

on the crop stage. In this study, data were collected 

during the dry season (June - October), when water 

requirements for cooling kalo approach upper 

limits. Flow measurements generally were made 

during the warmest part of the day, and temperature 

measurements were made every 15 minutes at each 

site for about a 2-month period.

Flow and temperature data were collected from 

kalo cultivation areas on four islands—Kaua‘i, 

O‘ahu, Maui, and Hawai‘i. The average inflow 

value for the 19 lo‘i complexes measured in this 

study is 260,000 gallons per acre per day, and the 

median inflow value is 150,000 gallons per acre per 

day. The average inflow value for the 17 windward 

sites is 270,000 gallons per acre per day, and the 

median inflow value is 150,000 gallons per acre per 

day. The average inflow value for the two leeward 

sites is 150,000 gallons per acre per day. The aver- age inflow value measured for six individual lo‘i is 

350,000 gallons per acre per day, and the median 

inflow value is 270,000 gallons per acre per day. 

The average inflow value for the five windward 

lo‘i is 370,000 gallons per acre per day, and the 

median inflow value is 320,000 gallons per acre 

per day. The inflow value for the one leeward lo‘i is 

210,000 gallons per acre per day. These inflow values are consistent with previously reported values 

for inflow and are significantly higher than values 

generally estimated for water consumption during 

kalo cultivation. These measurements of inflow are 

important for future considerations of water-use 

requirements for successful kalo cultivation. 

Of the 17 loÿi complexes where water inflow 

temperature was measured, only 3 had inflow 

temperatures that rose above 27°C, the threshold 

temperature above which wetland kalo is more 

susceptible to fungi and associated rotting diseases. 

The coldest mean inflow temperature was 20.0°C 

and the warmest inflow temperature was 24.9°C. 

All 15 of the sites where outflow temperatures were 

measured had some temperatures greater than 27°C. 

Outflow temperatures exceeded 27°C between 2.5 

percent and about 40 percent of the time. Mean outflow temperatures ranged from 23.0°C to 26.7°C.

Introduction 

Wetland kalo or taro (Colocasia esculenta (L.) 

Schott) is a vital part of the cultural and agricul- tural traditions of native Hawaiians. In some loca- tions in Hawai‘i, significant competition between 

instream and offstream uses for limited surfacewater resources has led to litigation about rights to 

water for kalo cultivation and other uses. Appurte- nant water rights of kuleana (private land awards 

to commoners) and kalo lands are preserved under 

the State Water Code, Hawai‘i Revised Statutes Ch. 

174C. Although irrigation flows for kalo cultiva- tion have been measured with varying degrees of 

scientific accuracy, there is disagreement regarding 

the amount of water used and needed for successful 

kalo cultivation, with water temperature recognized 

as a critical factor. Most studies have focused on the 

amount of water consumed rather than the amount 

needed to flow through the irrigation system for 

successful kalo cultivation. In 2002, the Office of 

Hawaiian Affairs, State of Hawai‘i, cosponsored the 

“No Ka Lo‘i Conference” at the Kamakaküokalani 

Center for Hawaiian Studies, University of Hawai‘i 

at Mänoa. One of the outcomes of the conference 

was kalo farmers’ expressed desire to document 

current water use and to protect and enhance kalo 

Water Use in Wetland Kalo Cultivation in Hawaiÿi

By Stephen B. Gingerich, Chiu W. Yeung, Tracy-Joy N. Ibarra, and John A. Engott
cultivation. The study documented in this report was 

pursued to help fulfill the priorities identified during 

that conference.

Wetland kalo is cultivated throughout Hawai‘i 

in groups of shallow, watery terraces and pondfields, which native Hawaiians call lo‘i kalo (fig.1). 

In this report, lo‘i refers to an individual pondfield 

and lo‘i complex refers to a group of lo‘i. Wetland 

cultivation is the primary and preferred source for 

kalo corms (food-bearing underground stem), which 

are processed into poi, a popular Hawaiian staple 

food. Wetland kalo requires cool water flowing 

over its roots to ensure the health and productivity 

of the crop. Irrigation, therefore, needs to provide 

more water than just what is consumed in the lo‘i 

through evaporation from open water, transpiration 

through the kalo leaves, and percolation through 

the lo‘i bottom and sides. Irrigation flow must be 

controlled to provide enough cold water to keep the 

lo‘i adequately cool throughout the growing cycle. 

Water-temperature management in individual lo‘i is 

recognized as a water-management priority. Water 

temperature is generally considered the most critical physical factor in kalo cultivation water use, but 

rarely is it systematically measured or analyzed. 

Various studies suggest that it is best to keep lo‘i 

water temperatures at about 25oC (77oF) or lower 

(Reppun v. Board of Water Supply, 1982; Penn, 

1997). In general, a higher irrigation rate should 

dampen water heating and lower irrigation outflow 

temperature (Penn, 1997).

In cooperation with the Office of Hawaiian Affairs, State of Hawai‘i, the U.S. Geological Survey (USGS) undertook an investigation to 

evaluate current water use for commercial wetland 

kalo cultivation in Hawai‘i. The objectives of this 

2-year study are (1) to document current water use 

for selected lo‘i complexes of various sizes on the 

islands of Kaua‘i, O‘ahu, Maui, and Hawai‘i; and 

(2) to monitor the variation in inflow and outflow water temperatures of selected lo‘i and lo‘i 

complexes. Water-use and water-temperature data 

collected as part of this study provides baseline 

information on wetland kalo irrigation practices 

Evaporation

Solar heating

Transpiration

Outflow

of solarheated

water

Inflow of

cold water

from ‘auwai

Percolation

through sides

Percolation through bottom

Figure 1. General movement of irrigation water in a lo‘i kalo.

2
for a variety of geographic settings in the Hawaiian 

Islands. 

The ‘auwai, or irrigation ditch system, constructed at each lo‘i complex transports water from 

streams to flood each lo‘i. The design of the ‘auwai 

and lo‘i complexes varies from place to place, and 

from simple to complicated. An example of a simple 

lo‘i complex design is where an ‘auwai supplies 

water to a lo‘i and flow is returned directly back 

to the stream. An example of a more complicated 

design exists in Ke‘anae, Maui, where an ‘auwai 

distributes water to multiple lo‘i staggered along 

the ‘auwai, and most lo‘i throughflow is returned to 

the ‘auwai and mixed for reuse in downstream lo‘i 

irrigation. Flow is ultimately released to the ocean 

at various locations around the Ke‘anae Peninsula 

and is too diffuse to accurately measure.

The most rigorous documented measurements 

of water used for wetland kalo cultivation were 

made in the 1930s at Hanapëpë, Kaua‘i, by the University of Hawai‘i and McBryde Sugar Company 

(Miles, 1931). Various water uses were measured 

including percolation in the lo‘i and ‘auwai, transpiration, and evaporation. The highlighted results 

of 50,000 to 80,000 gallons per acre per day (gad) 

represent net loss or consumption (the difference 

between the amount of water flowing into a lo‘i 

complex and the amount flowing out) in the lo‘i 

and the researchers recognized “that a consider- ably greater amount would have to be diverted in 

order to successfully grow taro [kalo] with proper 

circulation of water.” This statement is based on 

inflow measurements that ranged from 290,000 

to 1,100,000 gad (Penn, 1997). The results of this 

Hanapëpë study were used by the Hawai‘i courts 

to determine the water rights in connection with 

the various lands involved in the case. This was the 

last time that a final court decision was reached on 

this water rights issue. Some of the most frequently 

relied on flow-rate measurements were made by 

Watson (1964) and were presented as evidence in 

several seminal water-rights cases (Reppun v. Board 

of Water Supply, 1982; State of Hawaiÿi, 2000). 

Watson reported kalo water requirements of 40,000 

gad, a figure also arrived at through a net loss determination. No consideration was given to the amount 

of throughflow needed to meet the cooling requirements of the lo‘i. Penn (1997) reinterpreted Watson’s findings to suggest that throughflow results 

for that study would be 100,000 to 250,000 gad. At 

Hanalei, Kaua‘i, the U.S. Forest Service measured 

average inflow rates to a lo‘i complex of 87,500 gad 

and estimated consumptive use for 220 acres in kalo 

production to be about 23,600 gad (Berg and others, 

1997). 

Site Selection

Twenty-eight geographic areas with significant 

kalo cultivation on the islands of Kaua‘i, O‘ahu, 

Moloka‘i, Maui, and Hawai‘i were initially identified (fig. 2). Each of the islands can be divided into 

two primary physiographic zones, windward and 

leeward, which relate to the exposure of these areas 

to the northeasterly trade winds and orographic 

rainfall. In general, windward areas receive higher 

rainfall than leeward areas. Twenty-one of the identified kalo cultivation areas receive rainfall consistent with the windward sides of the islands and 

seven cultivation areas receive rainfall consistent 

with the leeward sides of their respective islands. 

Of these areas, 10 were selected for this study (8 

windward, 2 leeward), primarily on the basis of the 

diversity of environmental and agricultural conditions under which wetland kalo is grown and on the 

basis of landowner availability. In some areas, more 

than one complex was studied. Final site selection 

was made in consultation with the Office of Hawaiian Affairs, State of Hawai‘i, Onipa‘a Nä Hui Kalo, 

and the State of Hawai‘i Department of Health.

The USGS collected flow and water-temperature data at the loÿi complex level and at the lo‘i 

level. Data collection was designed to measure 

and document the amount of water being used by 

kalo farmers in a variety of geographic areas. The 

study was not designed to measure the consump- tion of water during kalo growth, but rather the 

throughflow of water used in loÿi complexes where 

commercial cultivation generally is viable. For 

consistency in site selection, lo‘i with crops near 

harvesting stage were selected for the lo‘i watertemperature data collection. Farmers stagger planting dates to obtain year-round production. Due to 

differences in water availability and irrigation-system configuration, irrigation practices vary. Farmers generally allocate a greater amount of water to 

lo‘i with crops at harvesting stage and less water 

to lo‘i with crops at earlier stages to maximize the 

use of limited water resources. The selection of lo‘i 

with crops at harvesting stage ensured that flow and 

temperature data collected at different lo‘i reflect 

similar irrigation conditions (continuous flooding 

of the mature crop). During field visits, farmers 

were interviewed about their irrigation practices 

and about their perceptions of their water supply. 

In general, most farmers believed that their supply 

of irrigation water was insufficient for proper kalo 

cultivation.

3
Acknowledgments

The authors wish to thank the stakeholders who helped to initiate and define the scope of 

this study—Dr. Jonathan Scheuer of the Office of 

Hawaiian Affairs, State of Hawai‘i, Charlie and 

Paul Reppun and other members of Onipa‘a Nä 

Hui Kalo, and David Penn of the State of Hawai‘i 

Department of Health. We also thank the many 

kalo farmers who provided lodging (and sometimes 

food), access to their lo‘i, knowledge of their irrigation systems, descriptions of their farming practices, 

and aloha during this study. We owe a special debt 

of gratitude to Charlie and Paul Reppun for providing volunteer help during visits to all of the study 

areas, for being the liaisons to all the kalo farmers, 

and for their general insight from more than 30 

years of experience in kalo farming. David Reppun 

also provided volunteer help during the initial visits 

to Maui and Hawai‘i.

Discharge, Water-Temperature, 

and Area Data-Collection 

Methods

Data collection was done during the dry season (June–October) when water requirements for 

cooling kalo are higher. In general, surface-water 

temperatures in the Hawaiian Islands begin to rise 

in April and remain elevated through September, 

mainly due to increased solar heating (Brasher and 

others, 2004; Gingerich and Wolff, 2005; Oki and 

others, 2006). Flow measurements generally were 

made during the warmest part of the day; temperature measurements were made every 15 minutes at 

each site for about a two-month period.

22°

20°

160° 158° 156°

Kaua‘i

Ni‘ihau

O‘ahu

Maui

Moloka‘i

Läna‘i

Kaho‘olawe

Hawai‘i

HAWAI‘I

Pacific Ocean

a

aa

a

a

a

d

a

dd a

d

d

a

aa a a

a

aa

a a Wai‘äpuka

Kohala Waipi‘o

Kïpahulu

Waikapü Wailua

Waihe‘e

Ka‘amola

Wailau Hälawa

Wailua

Honouliwai

Kahakuloa

Honoköhau

Waiähole

Känewai

Waihe‘e

Hale‘iwa Kahana

Ka‘ala

Ke‘anae

ddd

Limahuli aaaaHanalei

Waipä Wai‘oli

Hanapëpë

Makaweli

Waimea

EXPLANATION

WINDWARD SITE

LEEWARD SITE

Sites in red were included in this study

Figure 2. Location of significant areas of kalo cultivation, State of Hawai‘i.

4
Discharge Measurements

Measurements of the amount of water flowing into or out of the lo‘i complexes were made by 

using current-meter, volumetric-flow, or portable 

Parshall flume methods. Where channel conditions in the ÿauwai permitted (for example, straight 

channels, non-turbulent flow, and relatively greater 

flow volumes), current-meter measurements were 

made. In the current-meter method, observations of 

width, depth, and velocity are collected at intervals 

in a cross section of the channel while the measurer 

wades in the channel (Rantz and others, 1982). 

Velocity measurements were made by using an 

acoustic Doppler velocimeter attached to a top-setting wading rod (fig. 3). Volumetric measurements 

were made where channel conditions did not permit 

current-meter measurements, where flow volumes 

were relatively low, or where volumetric measurements were more convenient than current-meter 

measurements. Volumetric measurements were 

made by repeated timed fillings of a calibrated 

five-gallon bucket and averaging the results (fig. 3). 

Typically, 10 independent measurements were made 

by using the calibrated bucket. Although relatively 

simple, the volumetric measurement is considered 

the most accurate way to measure low flows (Rantz 

and others, 1982). Parshall flume measurements 

were made in selected ‘auwai where flow was too 

low for current-meter measurements but where the 

channel was narrow and flow was uniform. At these 

sites, the Parshall flume was installed and leveled, 

and repeated measurements were made in the flume 

stilling well after flow in the flume stabilized. At 

all sites, regardless of the method of measurement, 

a reference mark was set and checked at the beginning and ending of each workday to determine if the 

overall flow conditions changed during the day.

Water-Temperature Measurements

Water temperatures were measured every 15 

minutes by using StowAway® Tidbit® thermis- tors from Onset Computer Corporation that were 

designed to operate in the -20°C–50°C temperature 

range. Each thermistor was calibrated in the laboratory following USGS procedures (U.S. Geological 

Survey, 1997 to present) before installation in the 

field. Each thermistor was installed inside a 6-in. 

length of 1.25-in. diameter PVC pipe staked below 

the lowest expected water level in the ÿauwai or loÿi 

being monitored (fig. 4). Monitoring locations were 

in the shade, where possible, and chosen to avoid 

potentially stagnant flow. Each thermistor was field 

checked in place when deployed and again when 

retrieved by using a laboratory-calibrated field 

thermistor. Because field checks of the thermistors 

were within acceptable tolerances, no adjustments 

to the data were needed. A table showing equivalent 

temperature values in °C and °F is included (table 

1).

Area Measurements

Measurements of the selected loÿi and lo‘i 

complex areas were made by walking the perim- eter of each lo‘i complex while recording the track 

with a handheld Global Positioning System (GPS) 

unit. Each perimeter track was uploaded from the 

GPS unit to a geographic information system (GIS) 

program and, where necessary, adjusted to overlay 

aerial images showing the appropriate lo‘i com-

(A)

(B)

Figure 3. Flow measured by U.S. Geological Survey staff 

in loÿi kalo ÿauwai with (A) an acoustic Doppler velocimeter 

and (B) the volumetric method.

5
plexes. The areas, determined from the GIS program, include the cultivated and fallow lo‘i banks, 

pathways, and ‘auwai inside the perimeter of the 

track. Removing the area of these non-water-covered parts of the lo‘i complexes from the total area 

was determined to be too difficult and subjective. 

The emphasis was, therefore, directed toward treating each lo‘i complex consistently.

Discharge and WaterTemperature Data

As part of this study, 62 flow measurements and 

46 sets of temperature data were collected from kalo 

cultivation areas on four islands—Kaua‘i, O‘ahu, 

Maui, and Hawai‘i. The flow and temperature 

measurement data collected as part of this study are 

available on the World Wide Web. Data from each 

station listed in the following tables can be retrieved 

Figure 4. Thermistor and PVC housing used for collecting 

temperature measurements.

Table 1. Selected temperature conversions. 

Temperature

(degrees Celsius)

Temperature

( degrees Fahrenheit)

18.0 64.4

18.5 65.3

19.0 66.2

19.5 67.1

20.0 68.0

20.5 68.9

21.0 69.8

21.5 70.7

22.0 71.6

22.5 72.5

23.0 73.4

23.5 74.3

24.0 75.2

24.5 76.1

25.0 77.0

25.5 77.9

26.0 78.8

26.5 79.7

27.0 80.6

27.5 81.5

28.0 82.4

28.5 83.3

29.0 84.2

29.5 85.1

30.0 86.0

30.5 86.9

31.0 87.8

31.5 88.7

32.0 89.6

32.5 90.5

33.0 91.4

33.5 92.3

34.0 93.2

34.5 94.1

35.0 95.0

35.5 95.9

36.0 96.8

36.5 97.7

37.0 98.6

37.5 99.5

38.0 100.4

38.5 101.3

39.0 102.2

39.5 103.1

40.0 104.0

6
from the USGS National Water Information System 

database (NWIS) by clicking on the linked station 

name. 

The flow and area tables in the following sections, presented by island, provide dates and times 

of measurements, flow rates in ‘auwai irrigating the 

loÿi and lo‘i complexes, the GPS-measured areas of 

the selected loÿi and loÿi complexes, and water use 

based on the flow and area measurements. The temperature tables summarize (1) the dates of temperature-logger deployment; (2) the mean, maximum, 

and minimum temperature over the entire period 

of measurement; (3) the mean of the daily range 

in temperatures; (4) the range of times the highest 

temperature in any day occurred; (5) the percentage of measurements greater than 27°C; and (6) 

the earliest and latest times during the day that the 

temperatures were greater than 27°C. A temperature 

of 27°C is cited as the threshold temperature above 

which wetland kalo is more susceptible to fungi 

and associated rotting diseases (Ooka, 1994, Penn, 

1997).

Two plots are presented for each temperature 

record collected in the study. One plot shows the 

entire record of 15-minute temperature data measurements for the length of time each temperature 

thermistor was deployed. These plots are useful 

for displaying how the temperature changed over 

time due to factors such as a period of cloudiness, 

increased or decreased irrigation caused by rainfall, 

or ‘auwai problems. The other temperature plots 

provided show all of the temperature data plot- ted against the time of day each measurement was 

recorded. These plots indicate the daily pattern of 

temperature variation and are also useful for dis- playing the earliest and latest times of the day when 

the temperature reached the 27°C threshold.

Kaua‘i

Three areas were measured on Kaua‘i—Wai‘oli 

and Hanalei (windward sites) and Makaweli (leeward site). Flow measurements were made on 

August 7-9, 2005, when the temperature loggers 

were deployed, and on September 21-23, 2005, 

when the temperature loggers were removed (tables 

2 and 3). The Wai‘oli area is supplied through the 

Wai‘oli ‘Auwai with water diverted from the Wai‘oli 

River (fig. 4). Of the numerous lo‘i complexes 

supplied by the Wai‘oli ‘Auwai, four independent 

loÿi complexes were studied. Twelve flow measurements were made, and ten temperature loggers were 

deployed at selected inflow and outflow locations 

(figs. 5 and 6). 

The Hanalei area is supplied through the “China 

Ditch” with water diverted from the Hanalei River 

(fig. 7). One lo‘i complex was studied in this area. 

Four flow measurements were made, and three temperature loggers were deployed in the Hanalei area 

(figs. 8 and 9). 

The Makaweli area is supplied through the 

Pu‘ulima Ditch with water diverted from the 

Makaweli River; one lo‘i complex was studied 

in this area (fig. 10). One flow measurement was 

made, and three temperature loggers were deployed 

in the Makaweli area (figs. 11 and 12). A flow measurement was not made during the second visit to 

the Makaweli area because of damage to the diver- sion structure.

7
Table 2. Summary of discharge measurements and areas for selected lo‘i complexes, Island of Kaua‘i.

[Mgal/d, million gallons per day; gad, gallons per acre per day; --, not available; average water use is determined by summing the averages of each lo‘i or lo‘i complex and dividcomplexes]

Complex Lo‘i

Geographic

designation Area Station

Irrigation 

area

(acre)

Date Measurement time Discharge (Mgal/d) Water use (gad) Station Irrigation area (acre) Date Measurem

time 

Windward Wai‘oli Ka01A-CI 32.39 8/8/2005 0850 4.2 130,000

9/21/2005 1147 4.2 130,000

Ka01B-CI 2.98 8/8/2005 1000 0.36 120,000 Ka01B-LI 0.21 8/8/2005 1400 

9/21/2005 1246 0.55a 180,000 9/21/2005 1337 

Ka01C-CI 5.46 8/8/2005 1132 0.54 100,000 Ka01C-LI 0.16 8/8/2005 1030 

9/22/2005 1211 0.38b 70,000 9/22/2005 1255 

Ka01D-CI 4.18 8/8/2005 1505 0.15 36,000

9/22/2005 1510 0.25 60,000

Windward Hanalei Ka02-CI 53.63 8/7/2005 1708 3.7c 69,000 Ka02A-LO 0.51 8/9/2005 0910 

9/21/2005 1604 4.2d 78,000 9/21/2005 1722 

Leeward Makaweli Ka03-CI 0.68 8/9/2005e 1241 0.090 260,000

9/23/2005f -- -- --

number 6 6 3 

minimum 0.68 36,000 0.16 

maximum 53.63 260,000 0.51 

average 16.55 120,000 0.29 

aFlow higher than normal due to leakage at field inlet gate.bFlow lower than normal due to damaged upstream diversion dam.cIntake gate was not fully open.dHigher flow because intake gate was fully open.eTwo intake pipes (4-inch and 3-inch diameter) are used to divert water from the ‘auwai to the loÿi. Flow measurement only was made at the the 4-inch-intake pipe on 8/9/2005

inch-pipe will be replaced eventually with a 4-inch-pipe, so two times the 4-inch-pipe measurement would be a reasonable estimate of typical flow to the loÿi.

fFlow was not measured because flow in the ‘auwai was much lower than normal due to damaged upstream diversion dam.

8
Temperature (o

C)

Mean Mean daily 

range

Percent Earliest 

time of day

Latest time 

of day

Windward Wai‘oli Ka01A-LI 8/8/05 – 9/22/05 21.4 19.5 – 23.3 1.2 1315 – 1830 0.0 na na

Ka01A-LO 8/8/05 – 9/22/05 25.5 19.7 – 34.1 5.5 1200 – 1700 32.6 0930 2045

Ka01B-CI 8/8/05 – 9/22/05 21.4 19.5 – 23.6 1.2 1315 – 1815 0.0 0000 0000

Ka01B-LI 8/8/05 – 9/22/05 22.6 19.6 – 28.1 2.8 1130 – 1645 0.8 1415 1700

Ka01B-LO 8/8/05 – 9/22/05 24.7 20.5 – 30.7 3.5 1330 – 1845 16.8 1215 2045

Ka01C-LI 8/8/05 – 9/22/05 23.5 19.7 – 30.6 3.1 1145 – 1645 8.1 1045 1800

Ka01C-LO 8/8/05 – 9/22/05 25.9 20.0 – 33.5 4.3 1145 – 1545 31.3 1000 2100

Ka01D-CI 8/8/05 – 9/22/05 21.8 19.5 – 24.1 1.5 1130 – 1745 0.0 na na

Ka01D-LI 8/8/05 – 9/22/05 23.5 19.2 – 31.8 4.6 1145 – 1630 14.9 1130 1815

Ka01D-LO 8/8/05 – 9/22/05 26.2 22.1 – 30.8 3.3 1400 – 1730 33.5 1115 2245

Windward Hanalei Ka02-CI 8/8/05 – 9/21/05 23.7 21.3 – 26.9 2.2 1445 – 2030 0.0 0000 0000

Ka02-LI 8/8/05 – 9/21/05 24.2 21.5 – 27.4 2.3 1245 – 1815 0.2 1445 1600

Ka02-LO 8/8/05 – 9/21/05 26.7 21.9 – 33.5 6.3 1215 – 1700 40.4 1045 2345

Leeward Makaweli Ka03-CI 8/9/05 – 9/23/05 24.8 21.5 – 28.3 2.6 1400 – 1815 9.0 1330 2115

Ka03-LI 8/9/05 – 9/23/05 25.8 21.3 – 36.9 3.8 1030 – 1930 23.8 0830 2330

Ka03-LO 8/9/05 – 9/23/05 24.5 19.7 – 35.7 3.9 0945 – 2045 10.5 0930 1930

Table 3. Water-temperature statistics based on measurements collected at 15-minute intervals for lo‘i complexes on the Island of Kaua‘i. 

[

o

C, degrees Celsius; na, not applicable]

Range of times 

daily peak 

temperatures 

occurred

Period of record Geographic

designation Area Station

Range

 Temperature measurements

greater than 27o

C

9
A-CI

A-LI A-LO

C-CI

D-CI

D-LO

D-

B-LI

B-LO

C-LI

C-LO

B-CI

0.33 acres

0.26 acre

0.16 acres

 0.21 acres

159°30'15"W 159°30'0"W 159°29'45"W

Wai‘oli River

0 500 1,000 

0 150 300 M

Wai‘oli ‘Auwai

Selected lo‘iComplex A (32.39 acres)

Complex B (2.98 acres)Complex C (5.46 acres)Complex D (4.18 acres)

STATION AND ABBREVIATED ID--Complete ID is preceeded 

A-CI by island and area codes, Ka and 01

 AbbreviationsKa - Kaua‘i C - Complex I - Inflow01 - Wai‘oli L - Lo‘i O - Outflow 

d

dd

aaaa

Wai‘oli

Kaua‘i

Figure 5. Wai‘oli lo‘i complex, Island of Kaua‘i.

10
DATE

 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

270C

270

C

AUGUST 2005 SEPTEMBER 2005

 

18

20

22

24

26

28

30

32

34

36

A complex, lo‘i inflow (Ka01A-LI), Wai‘oli, Island of Kaua‘i, 

A complex, lo‘i outflow (Ka01A-LO), Wai‘oli, Island of Kaua‘i,

Highlighted periods indicate atypical irrigated conditions. During September 14-15, 2005, a heavy rainstorm 

flooded the complex and caused damage in the Wai‘oli irrigation system by depositing heavy debris around 

the diversion dam and ‘auwai. During the following period, the diversion dam and the ‘auwai were being 

repaired, which significantly altered flow conditions in the irrigation system. During September 18-22, 2005, 

the farmer indicated that inflow to the selected lo‘i was reduced because the kalo was ready to be 

harvested. 

Figure 6. Water temperature in Wai‘oli lo‘i complex, Island of Kaua‘i.

11
 

18

20

22

24

26

28

30

32

34

36

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

270C

270

C

270

C

AUGUST 2005 SEPTEMBER 2005

B complex, complex inflow (Ka01B-CI), Wai‘oli, Island of Kaua‘i

B complex, lo‘i inflow (Ka01B-LI), Wai‘oli, Island of Kaua‘i

B complex, lo‘i outflow (Ka01B-LO), Wai‘oli, Island of Kaua‘i

Highlighted periods indicate atypical irrigated conditions. During September 14-15, a heavy rainstorm 

flooded the complex and caused damages in the Wai‘oli irrigation system by depositing heavy debris around 

the diversion dam and ‘auwai. Afterward, the diversion dam and the ‘auwai were being repaired, which 

significantly altered flow conditions in the irrigation system. 

Figure 6. Continued.

12
 

18

20

22

24

26

28

30

32

34

36

DATE

 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

270C

270

C

AUGUST 2005 SEPTEMBER 2005

C complex, lo‘i inflow (Ka01C-LI), Wai‘oli, Island of Kaua‘i

C complex, lo‘i outflow (Ka01C-LO), Wai‘oli, Island of Kaua‘i

Highlighted periods indicate atypical irrigated conditions. During August 16-19, lo‘i was dried out. During 

September 14-15, a heavy rainstorm flooded the complex and caused damages in the Wai‘oli irrigation 

system by depositing heavy debris around the diversion dam and ‘auwai. During the following period, the 

diversion dam and the ‘auwai were being repaired which significantly altered flow conditions in the irrigation 

system. 

Figure 6. Continued.

13
 

18

20

22

24

26

28

30

32

34

36

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

270C

270

C

270

C

AUGUST 2005 SEPTEMBER 2005

D complex, complex inflow (Ka01D-CI), Wai‘oli, Island of Kaua‘i

D complex, lo‘i inflow (Ka01D-LI), Wai‘oli, Island of Kaua‘i

D complex, lo‘i outflow (Ka01D-LO), Wai‘oli, Island of Kaua‘i

Highlighted periods indicate atypical irrigated conditions. During September 14-15, a heavy rainstorm 

flooded the complex and caused damages in the Wai‘oli irrigation system by depositing heavy debris around 

the diversion dam and ‘auwai. During the following period, the diversion dam and the ‘auwai were being 

repaired which significantly altered flow conditions in the irrigation system. 

Figure 6. Continued.

14
TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

18

20

22

24

26

28

30

32

34

36

270C

270

C

A complex, lo‘i inflow (Ka01A-LI), Wai‘oli, Island of Kaua‘i

A complex, lo‘i outflow (Ka01A-LO), Wai‘oli, Island of Kaua‘i

Figure 7. Daily pattern of water temperature in Wai‘oli lo‘i complex, Island of Kaua‘i. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

15
TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

18

20

22

24

26

28

30

32

34

36

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

270C

270

C

270

C

B complex, complex inflow (Ka01B-CI), Wai‘oli, Island of Kaua‘i

B complex, lo‘i inflow (Ka01B-LI), Wai‘oli, Island of Kaua‘i

B complex, lo‘i outflow (Ka01B-LO), Wai‘oli, Island of Kaua‘i

Figure 7. Continued.

16
TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

18

20

22

24

26

28

30

32

34

36

270C

270

C

C complex, lo‘i inflow (Ka01C-LI), Wai‘oli, Island of Kaua‘i

C complex, lo‘i outflow (Ka01C-LO), Wai‘oli, Island of Kaua‘i

Figure 7. Continued.

17
TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

18

20

22

24

26

28

30

32

34

36

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

270C

270

C

270

C

D complex, complex inflow (Ka01D-CI), Wai‘oli, Island of Kaua‘i

D complex, lo‘i inflow (Ka01D-LI), Wai‘oli, Island of Kaua‘i

D complex, lo‘i outflow (Ka01D-LO), Wai‘oli, Island of Kaua‘i

Figure 7. Continued.

18
Figure 8. Hanalei lo‘i complex, Island of Kaua‘i.

159°29'0"W 159°28'45"W 159°28'30"W

0 610 1,

0 180 36

CI

LO LI

China Ditch

Selected lo‘i (0.51 acres)Hanalei complex (53.6 acres)

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ka and 02

 AbbreviationsKa - Kaua‘i C - Complex I - Inflow02 - Hanalei L - Lo‘i O - Outflow 

CI

d

dd

aaaa

Hanalei

19
Figure 9. Water temperature in Hanalei lo‘i complex, Island of Kaua‘i.

 

18

20

22

24

26

28

30

32

34

36

38

40

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

AUGUST 2005 SEPTEMBER 2005

1 6 11 16 21 26 31 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

38

40

Hanalei complex, complex inflow (Ka02-CI), Hanalei, Island of Kaua‘i 

Hanalei complex, lo‘i inflow (Ka02-LI), Hanalei, Island of Kaua‘i

Hanalei complex, lo‘i outflow (Ka02-LO), Hanalei, Island of Kaua‘i

DATE

Highlighted periods indicate atypical irrigation conditions. During August 18-23, the selected lo‘i was dried 

out for fertilization. During September 14-15, entire complex was flooded by heavy rainstorm. 

20
Figure 10. Daily pattern of water temperature in Hanalei lo‘i complex, Island of Kaua‘i. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded. TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

18

20

22

24

26

28

30

32

34

36

38

40

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

Hanalei complex, complex inflow (Ka02-CI), Hanalei, Island of Kaua‘i 

Hanalei complex, lo‘i inflow (Ka02-LI), Hanalei, Island of Kaua‘i

Hanalei complex, lo‘i outflow (Ka02-LO), Hanalei, Island of Kaua‘i

21
Pu‘ulima Ditch

Selected lo‘i (0.17 acres)Makaweli complex (0.68 acres)

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ka and 03

 AbbreviationsKa - Kaua‘i C - Complex I - Inflow03 - Makaweli L - Lo‘i O - Outflow 

CI

159°39'2"W 159°39'0"W

CI

LI

LO

0 60 120 Feet

dd

d 0 20 40 Me

aaaa

Makaweli

Kaua‘i

Figure 11. Makaweli lo‘i complex, Island of Kaua‘i.

22
 

16

18

20

22

24

26

28

30

32

34

36

38

 

TEMPERATURE, IN DEGREES CELSIUS

16

18

20

22

24

26

28

30

32

34

36

38

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 

16

18

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

AUGUST 2005 SEPTEMBER 2005

Makaweli complex, complex inflow (Ka03-CI), Makaweli, Island of Kaua‘i 

Makaweli complex, lo‘i inflow (Ka03-LI), Makaweli, Island of Kaua‘i 

Makaweli complex, lo‘i outflow (Ka03-LO), Makaweli, Island of Kaua‘i 

Highlighted periods indicate atypical irrigated conditions. On August 9, at the time of first visit, no flow was 

going into the selected lo‘i. During September 14-15, a rainstorm deposited heavy debris upstream of the 

main diversion dam which significantly reduced flow in the ‘auwai for the following period. 

Figure 12. Water temperature in Makaweli lo‘i complex, Island of Kaua‘i.

23
TEMPERATURE, IN DEGREES CELSIUS

16

18

20

22

24

26

28

30

32

34

36

38

16

18

20

22

24

26

28

30

32

34

36

38

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

16

18

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

Makaweli complex, complex inflow (Ka03-CI), Makaweli, Island of Kaua‘i 

Makaweli complex, lo‘i inflow (Ka03-LI), Makaweli, Island of Kaua‘i 

Makaweli complex, lo‘i outflow (Ka03-LO), Makaweli, Island of Kaua‘i 

Figure 13. Daily pattern of water temperature in Makaweli lo‘i complex, Island of Kaua‘i. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

24
O‘ahu

Three areas were measured on O‘ahu—

Waiähole and Waihe‘e (windward sites) and 

Hale‘iwa (leeward site). Flow measurements were 

made in Waiähole on August 15, 2005, when the 

temperature loggers were deployed, and on October 17, 2005, when the temperature loggers were 

removed (tables 4 and 5). The Waiähole area is 

supplied through an unnamed ‘auwai with water 

diverted from Waianu Stream (fig. 13). Two independent complexes were studied. Ten flow measurements were made, and seven temperature loggers 

were deployed at selected inflow and outflow locations (figs. 14 and 15). 

Flow measurements were made in Waihe‘e on 

August 23, 2005, when the temperature loggers 

were deployed, and on October 18, 2005, when the 

temperature loggers were removed (tables 4 and 5). 

The Waihe‘e area is supplied through the Waihe‘e 

Ditch with water diverted far upstream from 

Waihe‘e Stream (fig. 16). Two lo‘i complexes were 

available for study in this area. Eight flow measurements were made, and four temperature loggers 

were deployed in the Waihe‘e area (figs. 17 and 18). 

The Hale‘iwa area is supplied by ground water 

pumped from nearby springs and was considered 

to be one lo‘i complex for this study (fig. 19). No 

flow measurements were made because of difficulty 

finding places to make measurements, but the kalo 

farmer estimated the flow to be 1.08 Mgal/d (table 

4). Three temperature loggers were deployed in the 

Hale‘iwa area from August 10, 2006, to September 

26, 2006 (table 5; figs. 20 and 21).

25
Table 4. Summary of discharge measurements and areas for selected lo‘i complexes, Island of O‘ahu.

[Mgal/d, million gallons per day; gad, gallons per acre per day; na, not applicable, average water use is determined by summing the averages of each complex or lo‘i and dividinlo‘i]

Complex Lo‘i

Geographic

designation Area Station

Irrigation 

area

(acre)

Date Measurement time Discharge (Mgal/d) Water use (gad) Station Irriga- tion area (acre) Date Measu

ment t

Windward Waiãhole Oa04A-CI 1.00 8/15/2005 1019 0.35 350,000 Oa04A-LI 0.12 8/15/2005 104

10/17/2005a 0932 0.25 250,000 10/17/2005 100

Oa04B-CI 0.71 8/15/2005 1325 0.42 590,000 Oa04B-LI 0.12 8/15/2005 142

10/17/2005b 1252 0.72 1,000,000 10/17/2005 132

Oa04B-LO 8/15/2005 151

10/17/2005 134

Windward Waihe‘e Oa05A-CI 1.94 8/23/2005 1340 0.59 300,000 Oa05B-LI 0.21 8/23/2005 125

10/18/2005 1439 0.52 270,000 10/18/2005 104

Oa05B-CI 1.02 8/23/2005 1318 0.15 150,000 Oa05B-LO 8/23/2005 1204 

10/18/2005 1021 0.12 120,000 10/18/2005 1604 

Leeward Hale‘iwa Oa06-CI 25.14 na na 1.08c 44,000 Oa06-LI 0.70 9/26/2006 102number 5 5 4 

minimum 0.71 44,000 0.12 

maximum 25.14 1,000,000 0.70 average 1.17 310,000 0.29 

aÿauwai overflow upstream of measurement site resulting from backwater conditions caused by debris in the ÿauwai; reason for lower flow.bÿauwai had just been cleaned; reason for higher flow.cEstimated pumping rate of 750 gal/min (by farmer) from nearby spring to irrigate loÿi complexes

26
Table 5. Water-temperature statistics based on measurements collected at 15-minute intervals for lo‘i complexes on the Island of O‘ah

[ ̊C, degrees Celsius; na, not applicable]Geographicdesignation Area Station Period of record

Temperature ( ̊C) Range of times daily 

peak temperatures 

occurred

 Tempe

g

Mean Range Mean daily range Percent E

Windward Waiãhole Oa04A-CI 8/15/2005 – 10/17/2005 21.4 20.5 – 23.3 1.4 1030 – 2345 0.0 

Oa04A-LI 8/15/2005 – 10/17/2005 21.5 20.4 – 23.4 1.5 0945 – 2345 0.0 

Oa04A-LO 8/15/2005 – 10/17/2005 24.6 20.8 – 35.7 8.5 1100 – 1730 21.6 

Oa04B-CI 8/15/2005 – 10/17/2005 21.7 20.5 – 24.2 1.5 1100 – 2345 0.0 

Oa04B-LI 8/15/2005 – 10/17/2005 21.9 20.5 – 24.5 1.7 1100 – 1730 0.0 

Oa04B-LO 8/15/2005 – 10/17/2005 24.5 20.5 – 35.3 7.6 1015 – 1530 21.4 

8/15/2005 – 10/17/2005 23.0 20.5 – 29.7 4.1 1045 – 1600 2.5 

Windward Waihe‘e Oa05A-CI 8/23/2005 – 10/18/2005 21.6 20.7 – 22.7 0.7 1045 – 2345 0.0 

Oa05B-CI 8/23/2005 – 10/18/2005 21.8 20.7 – 23.9 1.2 1030 – 1545 0.0 

Oa05B-LI 8/23/2005 – 10/18/2005 22.0 20.7 – 24.9 1.5 1030 – 1500 0.0 

Oa05B-LO 8/23/2005 – 10/18/2005 25.0 21.4 – 35.3 4.9 1030 – 1700 22.3 

Leeward Hale‘iwa Oa06-CI 8/10/2006 – 9/26/2006 23.2 22.6 – 24.2 0.7 0700 – 1800 0.0 

Oa06-LI 8/10/2006 – 9/26/2006 25.2 21.7 – 31.0 4.1 0930 – 1830 23.2 

Oa06-L 8/10/2006 – 9/26/2006 26.3 21.9 – 35.1 5.4 1315 – 1730 34.5 

27
Waianu Stream

157°51'54"W 157°51'48"W

A-CI

A-LO

A-LI

B-CI (flow)

B-LI

B-CI (temperature)

0.12 acres

0.12 acres

0 170 340 

0 50 100 M

‘Auwai

Selected lo‘i

Complex A (1.00 acres)Complex B (0.71 acres)

A-CI

 AbbreviationsOa - O‘ahu C - Complex I - Inflow01 - Waiähole L - Lo‘i O - Outflow 

STATION AND ABBREVIATED ID--Complete ID is preceeded by island and area codes, Oa and 04

a

d

d a

d

a

Waiähole

O‘ahu

Figure 14. Waiähole lo‘i complexes, Island of O‘ahu.

28
 

18

20

22

24

26

28

30

32

34

36

38

40

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

AUGUST2005 SEPTEMBER 2005 OCTOBER 2005

A complex, complex inflow (Oa04A-CI), Waiähole, Island of O‘ahu

A complex, lo‘i inflow (Oa04A-LI), Waiähole, Island of O‘ahu

A complex, lo‘i outflow (Oa04A-LO), Waiähole, Island of O‘ahu

Highlighted periods indicate atypical irrigated conditions. On September 23, a heavy rainstorm flooded the 

complex and deposited debris around diversion dam and ‘auwai which significantly reduced inflow on the 

following day and caused the water temperature to rise. 

Figure 15. Water temperature in Waiähole lo‘i complexes, Island of O‘ahu.

29
 

18

20

22

24

26

28

30

32

34

36

38

40

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

AUGUST2005 SEPTEMBER 2005 OCTOBER 2005

B complex, complex inflow (Oa04B-CI), Waiähole, Island of O‘ahu

B complex, lo‘i inflow (Oa04B-LI), Waiähole, Island of O‘ahu

B complex, lo‘i outflow (Oa04B-LO), Waiähole, Island of O‘ahu

Highlighted periods indicate atypical irrigated conditions. On August 16, 21-23, farmer noted that intake pipe 

to the selected lo‘i was shut off for weeding. On August 28, field inflow was lower than normal. On 

September 23, heavy rainstorm flooded the complex and deposited debris around diversion dam and ‘auwai 

which significantly reduced inflow on the following day and caused water temperature to rise. 

Figure 15. Continued.

30
DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

270C

AUGUST2005 SEPTEMBER 2005 OCTOBER 2005

B complex, complex outflow (Oa04B-CO), Waiähole, Island of O‘ahu

Highlighted periods indicate atypical irrigated conditions. On August 16, 21-23, farmer noted that intake pipe 

to the selected lo‘i was shut off for weeding. On August 28, field inflow was lower than normal. On 

September 23, heavy rainstorm flooded the complex and deposited debris around diversion dam and ‘auwai 

which significantly reduced inflow on the following day and caused water temperature to rise. 

Figure 15. Continued.

31
TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

18

20

22

24

26

28

30

32

34

36

38

40

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

A complex, complex inflow (Oa04A-CI), Waiähole, Island of O‘ahu

A complex, lo‘i inflow (Oa04A-LI), Waiähole, Island of O‘ahu

A complex, lo‘i outflow (Oa04A-LO), Waiähole, Island of O‘ahu

Figure 16. Daily pattern of water temperature in Waiähole lo‘i complexes, Island of O‘ahu.

32
TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

18

20

22

24

26

28

30

32

34

36

38

40

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

B complex, complex inflow (Oa04B-CI), Waiähole, Island of O‘ahu

B complex, lo‘i inflow (Oa04B-LI), Waiähole, Island of O‘ahu

B complex, lo‘i outflow (Oa04B-LO), Waiähole, Island of O‘ahu

Figure 16. Continued.

33
TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

270C

B complex, complex outflow (Oa04B-CO), Waiähole, Island of O‘ahu

Figure 16. Continued.

34
Waihe‘e Ditch

Selected lo‘i (0.21 acres)

 Complex A (1.94 acres)

Complex B (1.02 acres)

A-CI

A-CI

B-CI

B-LI

B-LO

0 40 80 Me

0 140 280 

157°50'57"W 157°50'54"W

a

d

d a

d

aWaihe‘e

O‘ahu

STATION AND ABBREVIATED ID--Complete ID is preceeded by island and area codes, Oa and 05

 AbbreviationsOa - O‘ahu C - Complex I - Inflow05 - Waihe‘e L - Lo‘i O - Outflow 

Figure 17. Waihe‘e lo‘i complex, Island of O‘ahu.

35
DATE

15 20 25 30 4 9 14 19 24 29 4 9 14 19 24 29 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

270C

AUGUST 2006 SEPTEMBER 2006 OCTOBER 2006

A complex, complex inflow (Oa05A-CI), Waihe‘e, Island of O‘ahu, 

Highlighted periods indicate atypical irrigated conditions. Heavy rain, prior to September 17-20, probably 

clogged intake and reduced flow to complex which caused the rise in water temperatures. On September 

23, heavy rainstorm flooded the complex and deposited debris to upstream diversion dam and ‘auwai which 

significantly reduced inflow to complex and caused water temperatures to rise. During October 1-4, 

upstream diversion dam was being repaired which probably caused the reduction in flow and rise in water 

temperatures. 

Figure 18. Water temperature in Waihe‘e lo‘i complexes, Island of O‘ahu.

36
 

18

20

22

24

26

28

30

32

34

36

38

40

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

DATE

15 20 25 30 4 9 14 19 24 29 4 9 14 19 24 29 

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

AUGUST 2006 SEPTEMBER 2006 OCTOBER 2006

B complex, lo‘i inflow (Oa05B-LI), Waihe‘e, Island of O‘ahu

B complex, lo‘i outflow (Oa05B-LO), Waihe‘e, Island of O‘ahu

B complex, complex inflow (Oa05B-CI), Waihe‘e, Island of O‘ahu

Highlighted periods indicate atypical irrigated conditions. Heavy rain, prior to September 17-20, probably 

clogged intake and reduced flow to complex which caused the rise in water temperatures. On September 

23, heavy rainstorm flooded the complex and deposited debris to upstream diversion dam and ‘auwai which 

significantly reduced inflow to complex and caused water temperatures to rise. During October 1-4, 

upstream diversion dam was being repaired which probably caused the reduction in flow and rise in water 

temperatures. 

Figure 18. Continued.

37
TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

270C

A complex, complex inflow (Oa05A-CI), Waihe‘e, Island of O‘ahu, 

Figure 19. Daily pattern of water temperature in Waihe‘e lo‘i complex, Island of O‘ahu. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

38
TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

18

20

22

24

26

28

30

32

34

36

38

40

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

B complex, lo‘i inflow (Oa05B-LI), Waihe‘e, Island of O‘ahu

B complex, lo‘i outflow (Oa05B-LO), Waihe‘e, Island of O‘ahu

B complex, complex inflow (Oa05B-CI), Waihe‘e, Island of O‘ahu

Figure 19. Continued.

39
LI2

Selected lo‘i (0.70 acres)Hale‘iwa complex (25.14 acres)

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Oa and 06

 AbbreviationsOa - Oah‘u C - Complex I - Inflow06 - Hale‘iwa L - Lo‘i

L LI2

CI

LI

Note: average complex inflow estimated to be 1.1 Mgal/d.

158°6'19"W 158°6'4"W

0 490 980 

0 150 300 

a

d

d a

d

a

Hale‘iwa

O‘ahu

Figure 20. Hale‘iwa lo‘i complex, Island of O‘ahu.

40
X Data

 

20

22

24

26

28

30

32

34

36

38

X Data

 

TEMPERATURE, IN DEGREES CELSIUS

20

22

24

26

28

30

32

34

36

38

DATE

1 6 11 16 21 26 31 5 10 15 20 25 30 

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

AUGUST 2006 SEPTEMBER 2006

Hale‘iwa complex, complex inflow (Oa06-CI), Hale‘iwa, Island of O‘ahu

Hale‘iwa complex, lo‘i (Oa06-L), Hale‘iwa, Island of O‘ahu

Hale‘iwa complex, lo‘i inflow (Oa06-LI), Hale‘iwa, Island of O‘ahu

Figure 21. Water temperature in Hale‘iwa lo‘i complexes, Island of O‘ahu.

41
TEMPERATURE, IN DEGREES CELSIUS

20

22

24

26

28

30

32

34

36

38

20

22

24

26

28

30

32

34

36

38

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

Hale‘iwa complex, complex inflow (Oa06-CI), Hale‘iwa, Island of O‘ahu

Hale‘iwa complex, lo‘i (Oa06-L), Hale‘iwa, Island of O‘ahu

Hale‘iwa complex, lo‘i inflow (Oa06-LI), Hale‘iwa, Island of O‘ahu

Figure 22. Daily pattern of water temperature in Hale‘iwa lo‘i complex, Island of O‘ahu. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

42
Maui

Three areas were measured on Maui—Waihe‘e, 

Wailua, and Ke‘anae, all windward sites. Flow 

measurements were made July 29-31, 2006, when 

the temperature loggers were deployed, and September 21-22, 2006, when the temperature loggers 

were removed (tables 6 and 7). The Waihe‘e area 

gets water through an ‘auwai supplied by Spreckel’s 

Ditch with water diverted from the Waihe‘e River 

(fig. 22). The Waihe‘e area was considered to be 

two loÿi complexes (an upper and a lower complex), 

both of which were studied. Eight flow measurements were made, and three temperature loggers 

were deployed at selected inflow and outflow locations (figs. 23 and 24). 

The Wailua area contains numerous loÿi 

complexes, three of which were available for 

study—Lakini, Wailua, and Waikani. The Lakini 

loÿi complex is supplied through an ‘auwai with 

water diverted from Hamau Stream. Hamau Stream 

receives diverted water from Waiokomilo Stream 

further upstream (fig. 25). The Lakini area was 

considered to be one loÿi complex in this study. 

Eight flow measurements were made, and two 

temperature loggers were deployed in the Lakini 

area (figs. 26 and 27). In addition to the five flow 

measurements made to determine flow directly into 

the complex, two measurements were made in the 

‘auwai upstream of all loÿi complexes to determine 

the amount of flow available for all downstream lo‘i 

complexes (July 30, 2006, 2.31 Mgal/d and September 21, 2006, 1.37 Mgal/d), and one measurement 

was made in Hamau Stream (NWIS link) downstream of the ‘auwai diversion to determine how 

much water remained in the stream (July 30, 2006, 

0.54 Mgal/d). 

The lo‘i complex named Wailua in this study 

is supplied through an ‘auwai with water diverted 

from Waiokomilo Stream (fig. 28). Two flow measurements were made, and one temperature logger 

was deployed in the Wailua area (figs. 29 and 30). 

The Waikani area is supplied through an ‘auwai 

with water diverted from Wailuanui Stream (fig. 

31). Two flow measurements were made, and two 

temperature loggers were deployed in the Waikani 

area (figs. 32 and 33). 

The Ke‘anae area has numerous lo‘i and all 

active lo‘i were treated as one loÿi complex supplied 

by the Ke‘anae Flume, which diverts water from 

Pälauhulu Stream (fig. 34). Two flow measurements 

were made, and two temperature loggers were 

deployed in the Ke‘anae area (figs. 35 and 36) but 

the loÿi complex outlet temperature logger (Ma12-

CO) failed to collect data during the deployment. 

Flow measurements were made near the flume 

intake at the site of a former USGS streamflow 

gaging station (Taro patch feeder ditch at Ke‘anae, 

Maui, station 16522000) where the median flow 

from 1934 to 1968 was 2.2 Mgal/d.

43
Table 6. Summary of discharge measurements and areas for selected lo‘i complexes, Island of Maui.

[Mgal/d, million gallons per day; gad, gallons per acre per day; na, not applicable; average water use is determined by summing the averages of each complex or lo‘i and dividinlo‘i]Geographicdesignation Area

Complex

Station

Irrigation 

area

(acre)

Date Measurement time Discharge (Mgal/d) Water use (gad) Rem

Windward Waihe‘e Ma08A-CI 2.30 7/29/2006 1501 0.34 150,000 total flow for upper and low

9/22/2006 1158 0.30 130,000 total flow for upper and low

Ma08B-CIR na 7/29/2006 1500 0.025

Ma08B-CIL na 0.060

0.76 na 0.085 110,000 combined right and left co

Ma08B-CIR na 9/22/2006 1150 0.058

Ma08B-CIL na 1055 0.067

0.76 na 0.13 160,000 combined right and left co

Windward Wailua (Lakini) Ma09-CIR na 7/30/2006 1004 0.26

Ma09-CIL na 0947 0.30

0.74 na 0.56 750,000 combined right and left co

Ma09-CIR na 9/21/2006 1015 0.16

Ma09-CIL na 1049 0.058

Ma09-CIM na 1206 0.19

0.74 na 0.41 550,000 combined right, left, and m

Windward Wailua Ma10-CI 3.32 7/30/2006 1136 0.59 180,000

9/21/2006 0845 0.46 140,000

Windward Wailua (Waikani) Ma11-CI 2.80 7/30/2006 1236 0.54 190,000

9/21/2006 1608 0.26 93,000

Windward Ke‘anae Ma12-CI 10.53 7/31/2006 0836 1.9 180,000 former U.S. Geological Su

station

9/21/2006 1415 1.6 150,000

number 6 6

minimum 0.74 93,000

maximum 10.53 750,000

average 3.41 230,000

44
Table 7. Water-temperature statistics based on measurements collected at 15-minute intervals for lo‘i complexes on the Island of Mau

[ ̊C, degrees Celsius; na, not applicable]Geographicdesignation Area Station Period of record

Temperature ( ̊C) Range of times daily 

peak temperatures 

occurred

 Tempe

g

Mean Range Mean daily range Percent 

Windward Waihe‘e Ma08A-CI 7/29/2006 – 9/22/2006 21.6 19.9 – 24.0 2.0 1015 – 1845 0.0 

Ma08B-CIL 7/29/2006 – 9/22/2006 24.9 20.3 – 34.0 7.6 1130 – 1615 25.4 

Ma08B-CO 7/29/2006 – 9/22/2006 25.5 20.0 – 35.5 5.7 1115 – 1645 27.0 

Windward Wailua (Lakini) Ma09-CIT 7/30/2006 – 9/21/2006 20.7 18.5 – 23.4 2.3 1300 – 1815 0.0 

Ma09-CO 7/30/2006 – 9/21/2006 23.2 18.4 – 31.7 7.4 1130 – 1645 16.9 

Windward Wailua Ma10-CI 7/30/2006 – 9/21/2006 22.5 20.5 – 25.9 1.9 1200 – 1900 0.0 

Windward Wailua (Waikani) Ma11-CI 7/30/2006 – 9/21/2006 22.2 21.0 – 24.0 0.7 0700 – 2345 0.0 

Ma11-CO 7/30/2006 – 9/21/2006 26.1 22.1 – 31.8 3.3 1400 – 2045 29.1 

Windward Ke‘anae Ma12-CI 7/31/2006 – 9/21/2006 20.0 19.0 – 21.9 1.0 1345 – 2330 0.0 

Ma12-CO equipment malfunction na na na na na 

45
Figure 23. Waihe‘e lo‘i complexes, Island of Maui.

Waihe‘e Rive

Complex B (0.76 acres)

A-CI

Complex A (1.54 acres)

‘Auwai

STATION AND ABBREVIATED ID--Complete ID is preceeded by island and area codes, Ma and 08

 Abbreviations

Ma - Maui C - Complex I - Inflow L - Left08 - Waihe‘e O - Outflow R - Right

A-CI

B-CIR

B-CIL

156°31'9"W 

0 125 250 Fee

0 40 80 M

aa

a

aa

aaWaihe‘e

Maui

46
Figure 24. Water temperature in Waihe‘e lo‘i complexes, Island of Maui.

X Data

 

18

20

22

24

26

28

30

32

34

36

38

X Data

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

DATE

22 27 1 6 11 16 21 26 31 5 10 15 20 25 30 

18

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

JULY 2006 AUGUST 2006 SEPTEMBER 2006

A complex, complex inflow (Ma08A-CI), Waihe‘e, Island of Maui

B complex, complex inflow left (Ma08B-CIL), Waihe‘e, Island of Maui

B complex, complex outflow (Ma08B-CO), Waihe‘e, Island of Maui

47
Figure 25. Daily pattern of water temperature in Waihe‘e lo‘i complexes, Island of Maui. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded. TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

18

20

22

24

26

28

30

32

34

36

38

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

270C

270

C

270

C

A complex, complex inflow (Ma08A-CI), Waihe‘e, Island of Maui

B complex, complex inflow left (Ma08B-CIL), Waihe‘e, Island of Maui

B complex, complex outflow (Ma08B-CO), Waihe‘e, Island of Maui

48
Figure 26. Wailua (Lakini) lo‘i complex, Island of Maui.

CO

CIT

CIL

ClR

Hämau Stream

0.54 Mgal/d

on 7/30/06

ClM

CIR

Wailua (Lakini) complex (0.74 acres)

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ma and 09

 Abbreviations

Ma - Maui C - Complex O - Outflow R - Right T - Total

09 - Wailua (Lakini) I - Inflow L - Left M - Middle

156°8'25"W 156°8'23"W 156°8'21"W

0 60 120 F

0 20 4

‘Auwai

aa

a

aa

aa

Lakini

Maui

49
Figure 27. Water temperature in Wailua (Lakini) lo‘i complex, Island of Maui.

X Data

 

18

20

22

24

26

28

30

32

34

DATE

 22 27 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

270C

270

C

JULY 2006 AUGUST 2006 SEPTEMBER 2006

Lakini complex, complex inflow total (Ma09-CIT), Wailua, Island of Maui 

Lakini complex, complex outflow (Ma09-CO), Wailua, Island of Maui

50
Figure 28. Daily pattern of water temperature in Wailua (Lakini) lo‘i complex, Island of Maui. Plot shows 

all temperature data plotted against the time of day that each measurement was recorded.

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

18

20

22

24

26

28

30

32

34

270C

270

C

Lakini complex, complex inflow total (Ma09-CIT), Wailua, Island of Maui 

Lakini complex, complex outflow (Ma09-CO), Wailua, Island of Maui

51
Figure 29. Wailua lo‘i complex, Island of Maui.

CI

Wailua complex (3.32 acres)

‘Auwai

Discharge measurement location

Temperature measurement location

CI

CI

156°8'9"W 156°8'3"W

0 150 300 Feet

0 40 80 Meters

aa

aa

aa

Wailua

Maui

STATION AND ABBREVIATED ID--Complepreceeded by island and area codes, Ma a

 Abbreviations

Ma - Maui C - Complex 10 - Wailua I - Inflow

52
Figure 30. Water temperature in Wailua lo‘i complex, Island of Maui.

DATE

22 27 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

270C

JULY 2006 AUGUST 2006 SEPTEMBER 2006

Wailua complex, complex inflow (Ma10-CI), Wailua, Island of Maui, 

Figure 31. Daily pattern of water temperature in Wailua lo‘i complex, Island of Maui. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

270C

TEMPERATURE, IN DEGREES CELSIUS

Wailua complex, complex inflow (Ma10-CI), Wailua, Island of Maui, 

53
Figure 32. Wailua (Waikani) lo‘i complex, Island of Maui.

‘Auwai

CI

Wailua (Waikani) complex (2.80 acres)

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ma and 11

 Abbreviations

Ma - Maui C - Complex I - Inflow11 - Wailua (Waikani) O - Outflow 

CI

CO

156°8'14"W 156°8'9"W

0 150 300 F

0 40 80 Meters

aa

aa

Wa

Maui

54
Figure 33. Water temperature in Wailua (Waikani) lo‘i complex, Island of Maui. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

X Data

 

20

22

24

26

28

30

32

34

DATE

 22 27 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

20

22

24

26

28

30

32

34

270C

270

C

JULY 2006 AUGUST 2006 SEPTEMBER 2006

Waikani complex, complex inflow (Ma11-CI), Wailua, Island of Maui

Waikani complex, complex outflow (Ma11-CO), Wailua, Island of Maui

55
Figure 34. Daily pattern of water temperature in Wailua (Waikani) lo‘i complex, Island of Maui.

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

18

20

22

24

26

28

30

32

34

270C

270

C

Waikani complex, complex inflow (Ma11-CI), Wailua, Island of Maui

Waikani complex, complex outflow (Ma11-CO), Wailua, Island of Maui

56
Figure 35. Ke‘anae lo‘i complex, Island of Maui.

Pi‘ina‘au StreamPalauhulu Stream

P A C I F I C O C E A N

P A C I F  O C E 

Waialohe Pond 

CO

CI (flow)

CI (temperature)

CI

Ke‘anae complex (10.53 acres)

Ke‘anae Flume

STATION AND ABBREVIATED ID--Complete ID is preceeded by island and area codes, Ma and 06

 Abbreviations

Ma - Maui C - Complex I - Inflow06 - Ke‘anae O - Outflow 

156°8'55"W 156°8'44"W

0 300 600 Feet

0 100 200 Meters

aa

a

aa

aa

Ke‘anae

Maui

57
Figure 36. Water temperature in Ke‘anae lo‘i complex, Island of Maui.

Figure . Daily pattern of water temperature in Ke‘anae lo‘i complex, Island of Maui. Plot shows all 

temperature data plotted against the time of day that each measurement was recorded.

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

TE

MPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

270C

Ke‘anae complex, complex inow (Ma12-CI), Ke‘anae, Island of Maui, 

DATE

22 27 1 6 11 16 21 26 31 5 10 15 20 25 30 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

270C

JULY 2006 6002 TSUGUA 6002 REBMETPES

Ke‘anae complex, complex inow (Ma12-CI), Ke‘anae, Island of Maui, 

 37

58
Hawai‘i

On the Island of Hawai‘i, the windward site 

of Waipi‘o had two complexes available for study. 

Flow measurements were made on June 11, 2006, 

when the temperature loggers were deployed, and 

on August 8, 2006, when the temperature loggers 

were removed (tables 8 and 9). The Waipi‘o area is 

supplied through several ‘auwai with water diverted 

from Wailoa Stream (figs. 37 and 38). Five flow 

measurements were made, and six temperature loggers were deployed at selected inflow and outflow 

locations (figs. 39–42).

Summary

Ten kalo cultivation areas (out of an initial 

count of 28 areas) were selected for study (8 wind- ward areas, 2 leeward areas), mainly on the basis 

of the diversity of environmental and agricultural 

conditions under which wetland kalo is grown and 

on the basis of landowner permission and availabil- ity. Flow and water-temperature data were collected 

at the loÿi and loÿi complex level. For consistency in 

site selection, lo‘i with crops near harvesting stage 

were selected for the lo‘i water-temperature data 

collection to ensure that flow and temperature data 

collected at different lo‘i reflect similar irrigation 

conditions (continuous flooding of the mature crop). 

Data collection was done during the dry season 

(June–October), when water requirements for cooling kalo are higher. Flow measurements generally 

were made during the warmest part of the day, and 

temperature measurements were made every 15 

minutes at each site for about a 2-month period.

As part of this study, 62 flow measurements 

and 46 sets of temperature data were collected from 

kalo cultivation areas on four islands—Kaua‘i, 

O‘ahu, Maui, and Hawai‘i. (the data summarized 

in this report are available on the World Wide Web 

at http://waterdata.usgs.gov/hi/nwis/sw. The average inflow for the 19 lo‘i complexes measured in 

this study is 260,000 gad, and the median inflow is 

150,000 gad (table 10). The average inflow for the 

17 windward sites is 270,000 gad, and the median 

inflow is 150,000 gad. The average inflow for the 

two leeward sites is 150,000 gad. The average 

inflow measured for 6 lo‘i is 350,000 gad, and the 

median inflow is 270,000 gad. The average inflow 

for the 5 windward lo‘i is 370,000 gad, and the 

median inflow is 320,000 gad. The inflow value 

for the 1 leeward lo‘i is 210,000 gad. These values 

are consistent with previously reported values for 

inflow and are significantly higher than values generally estimated for consumption during kalo cultivation. These measurements of inflow are important 

for future considerations of water-use requirements 

for successful kalo cultivation.

Of the 17 loÿi complexes where water inflow 

temperature was measured, only 3 loÿi complexes 

had inflow temperature values greater than 27°C. 

These sites were Makaweli, Kaua‘i (9 percent of 

time), Waihe‘e, Maui (about 25 percent of time 

at the lower loÿi complex), and Waipi‘o, Hawai‘i 

(about 8 percent of time at B site). The coldest mean 

inflow temperature was at the Ke‘anae complex 

(20.0°C), and the warmest mean inflow temperature 

recorded was at the lower Waihe‘e loÿi complex 

(24.9°C), both on Maui. The loÿi complexes with 

the most stable inflow temperatures were Waihe‘e 

and Hale‘iwa on O‘ahu, and Waikani on Maui 

(0.7°C mean daily range). The complex with the 

most variable inflow temperature value was the 

Waihe‘e lower (B) loÿi complex on Maui (7.6°C 

mean daily range). All 15 of the sites (11 lo‘i sites, 4 

loÿi complex sites) where outflow temperature was 

measured had some temperature values greater than 

27°C. The percentage of time that outflow temperature values exceeded 27°C ranged from 2.5 percent 

(Waiähole loÿi complex, O‘ahu) to about 40 percent 

(Hanalei lo‘i, Kaua‘i). Mean outflow temperature 

values ranged from 23.0°C (Waiähole loÿi complex, 

O‘ahu) to 26.7°C (Hanalei lo‘i, Kaua‘i).

References Cited

Berg, N., McGurk, B., and Calhoun, R.S., 1997, 

Hydrology and land use effects in the Hanalei 

National Wildlife Refuge, Kaua‘i, Hawai‘i (Final 

Report, Interagency Agreement 14-48-0001-

94588): Albany, California, United States Department of Agriculture Forest Service, Pacific Southwest Research Station, 62 p.

Brasher, A.M.D., Wolff, R.H., and Luton, C.D., 

2004, Associations among land use, habitat char- acteristics, and invertebrate community structure 

in nine streams on the Island of O‘ahu, Hawai‘i: 

U.S. Geological Survey Water-Resources Investi- gations Report 03-4256, 47 p.

Gingerich, S.B. and Wolff, R.H., 2005, Effects of 

surface-water diversions on habitat availability for 

native macrofauna, northeast Maui, Hawaii: U.S. 

Geological Survey Scientific Investigations Report 

2005-5213, 93 p.

59
Table 8. Summary of discharge measurements and areas for selected lo‘i complexes, Island of Hawai‘i.

[Mgal/d, million gallons per day; gad, gallons per acre per day; average water use is determined by summing the averages of each complex or lo‘i and dividing 

by the number of lo‘i or lo‘i complexes ]

Complex

Geographic

designation Area Station

Irrigation 

area

(acre)

Date Measurement 

time

Discharge

(Mgal/d)

Water use

(gad)

Windward Waipi‘o (A) Ha07A-CI 7.66 6/11/2006 1022 8.5 1,100,000

8/8/2006 1325 6.3 820,000

Windward Waipi‘o (B) Ha07B-CI 5.47 6/11/2006a 1335 0.56 100,000

8/8/2006b 0906 1.7 310,000

8/8/2006c 1021 1.5 270,000

number 2 2

minimum 5.47 100,000

maximum 7.66 1,100,000

average 6.57 710,000

a

Farmer indicated that flow was substantially less than normal because upstream diversion was damaged by recent flooding.

b

Upstream diversion remained unrepaired, but the flow was increased due to rain over night.

c

Second measurement.

Miles, K., 1931, Report on study of water requirements of taro in Hanapëpë Valley, cooperative 

study by the Territory of Hawai‘i and McBryde 

Sugar Co.: ‘Ele‘ele, Hawai‘i, 52 p.

Oki, D.S., Wolff, R.H., and Perreault, J.A., 2006, 

Effects of surface-water diversion and groundwater withdrawal on streamflow and habitat, 

Punalu‘u Stream, O‘ahu, Hawai‘i: U.S. Geological Survey Scientific Investigations Report 2006-

5153, 104 p.

Ooka, J.J., 1994, Taro diseases — A guide for field 

identification: Honolulu, Hawaiÿi, University of 

Hawai‘i at Mänoa, College of Tropical Agricul- ture and Human Resources, Hawai‘i Institute 

of Tropical Agriculture and Human Resources 

Research Extension Series 148, 13 p.

Penn, D. C., 1997, Water and energy flows in 

Hawai‘i taro pondfields: Honolulu, Hawaiÿi, Uni- versity of Hawai‘i at Mänoa, Ph.D. dissertation, 

376 p.

Rantz, S.E., and others, 1982, Measurement and 

computation of streamflow—Volume 1, Measure- ment of stage and discharge: U.S. Geological 

Survey Water-Supply Paper 2175, 284 p.

Reppun v. Board of Water Supply, 1982, 65 Haw. 

531, 656 P.d 57, cert. denied, 471 U.S. 014, 105 

S. Ct 2016, 85 L Ed 2d 298 (1985), variously 

paged.

State of Hawaiÿi, 2000, In re Water Use Applications, Petitions for Interim Instream Flow 

Standard Amendments, and Petitions for Water 

Reservations for the Waiähole Ditch Combined 

Contested Case Hearing, 94 Hawai‘i 97, 9 P.3d 

409.

Watson, L.J., ed., 1964, Observations made with 

respect to irrigation and growth of taro at certain 

patches at Waiähole and Kahaluu: Honolulu, 

Hawaiÿi, City & County of Honolulu Board of 

Water Supply Water Resources Division in Reppun v. Board of Water Supply, variously paged.

U.S. Geological Survey, 1997 to present, National 

field manual for the collection of water-quality data: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 9, chaps. 

A1–A9, 2 v., variously paged. [Also available 

online at URL:http://pubs.water.usgs.gov/twri9A]. 

Chapters originally were published from 1997 to 

1999; updates and revisions are ongoing and are 

summarized at http://water.usgs.gov/owq/FieldManual/mastererrata.html.

60
Table 9. Water-temperature statistics based on measurements collected at 15-minute intervals for lo‘i complexes on the Island of Haw

[ ̊C, degrees Celsius; na, not applicable]Geographicdesignation Area Station Period of record

Temperature ( ̊C) Range of times daily 

peak temperatures 

occurred

 Temperatur

greate

Mean Range Mean daily range Percent Earlie

of 

Windward Waipi‘o (A) Ha07A-CI 6/11/2006 – 8/8/2006 21.4 19.3 – 24.8 1.6 1000 – 2200 0.0 n

Ha07A-LI 6/11/2006 – 8/8/2006 21.8 19.4 – 28.6 3.0 0900 – 2015 0.4 12

Ha07A-LO 6/11/2006 – 8/8/2006 23.8 20.8 – 29.8 3.9 1030 – 1800 5.3 11

Windward Waipi‘o (B) Ha07B-CI 6/11/2006 – 8/2/2006 23.4 19.8 – 31.2 5.4 1030 – 1715 7.7 10

Ha07B-LI 6/11/2006 – 8/2/2006 24.3 20.3 – 36.2 7.1 1000 – 1700 15.7 10

Ha07B-LO 6/11/2006 – 8/2/2006 25.6 21.1 – 38.1 8.6 1030 – 1630 21.7 09

61
Figure 38. Waipi‘o (A) lo‘i complex, Island of Hawai‘i.

Wailoa Stream

Waipi‘o (A) complex (7.66 acres)

CI

Selected lo‘i (0.34 acres)

‘Auwai

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ha and 07

 Abbreviations

Ha - Hawai‘i C - Complex I - Inflow07 - Waipi‘o L - Lo‘i O - Outflow

CI

LO

LI

155°36'29"W 155°36'20"W

0 150 300 Fee

0 40 80 Meters

a

aaWaipi‘o

Hawai‘i

62
Figure 39. Waipi‘o (B) lo‘i complex, Island of Hawai‘i.

Wailoa Stream

155°36'2"W 155°35'52"W

0 310 620 Feet

Waipi‘o (B) complex (5.47 acres) 0 100 200 Mete

CI

CI

LI

LO

Selected lo‘i (0.52 acres)

‘Auwai

STATION AND ABBREVIATED ID--Complete ID ispreceeded by island and area codes, Ha and 07

 Abbreviations

Ha - Hawai‘i C - Complex I - Inflow07 - Waipi‘o L - Lo‘i O - Outflow 

a

aaWaipi‘o

Hawai‘i

63
Figure 40. Water temperature in Waipi‘o (A) lo‘i complex, Island of Hawai‘i.

X Data

 

18

20

22

24

26

28

30

32

X Data

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

DATE

1 6 11 16 21 26 1 6 11 16 21 26 31 5 10 15 

18

20

22

24

26

28

30

32

270C

270

C

270

C

JUNE 2006 JULY 2006 AUGUST 2006

A complex, complex inflow (Ha07A-CI), Waipi‘o, Island of Hawai‘i

A complex, lo‘i inflow (Ha07A-LI), Waipi‘o, Island of Hawai‘i

A complex, lo‘i outflow (Ha07A-LO), Waipi‘o, Island of Hawai‘i

64
Figure 41. Daily pattern of water temperature in Waipi‘o (A) lo‘i complex, Island of Hawai‘i. Plot shows 

all temperature data plotted against the time of day that each measurement was recorded. TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

18

20

22

24

26

28

30

32

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

270C

270

C

270

C

A complex, complex inflow (Ha07A-CI), Waipi‘o, Island of Hawai‘i

A complex, lo‘i inflow (Ha07A-LI), Waipi‘o, Island of Hawai‘i

A complex, lo‘i outflow (Ha07A-LO), Waipi‘o, Island of Hawai‘i

65
Figure 42. Water temperature in Waipi‘o (B) lo‘i complex, Island of Hawai‘i.

X Data

 

18

20

22

24

26

28

30

32

34

36

38

40

X Data

 

TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

DATE

1 6 11 16 21 26 1 6 11 16 21 26 31 5 10 15 

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

JUNE 2006 JULY 2006 AUGUST 2006

B complex, complex inflow (Ha07B-CI), Waipi‘o, Island of Hawai‘i

B complex, lo‘i inflow (Ha07B-LI), Waipi‘o, Island of Hawai‘i

B complex, lo‘i outflow (Ha07B-LO), Waipi‘o, Island of Hawai‘i

66
Figure 43. Daily pattern of water temperature in Waipi‘o (B) lo‘i complex, Island of Hawai‘i. Plot shows 

all temperature data plotted against the time of day that each measurement was recorded. TEMPERATURE, IN DEGREES CELSIUS

18

20

22

24

26

28

30

32

34

36

38

40

18

20

22

24

26

28

30

32

34

36

38

40

TIME OF DAY

 0000 0400 0800 1200 1600 2000 0000

18

20

22

24

26

28

30

32

34

36

38

40

270C

270

C

270

C

B complex, complex inflow (Ha07B-CI), Waipi‘o, Island of Hawai‘i

B complex, lo‘i inflow (Ha07B-LI), Waipi‘o, Island of Hawai‘i

B complex, lo‘i outflow (Ha07B-LO), Waipi‘o, Island of Hawai‘i

67
Table 10. Summary of water use calculated for loÿi and loÿi complexes by island, State of Hawaiÿi.

[gad, gallons per acre day; na, not available]

Complex Lo‘i

Island Number

Average

water use

(gad)

Average

windward

water use

(gad)

Average

leeward

water use

(gad)

Number

Average

water use

(gad)

Average

windward 

water use

(gad)

Average 

leeward

water use

(gad)

Kaua‘i 6 120,000 97,000 260,000 2 220,000 220,000 na

O‘ahu 5 310,000 380,000 44,000 4 400,000 460,000 210,000

Maui 6 230,000 230,000 na na na na na

Hawai‘i 2 710,000 710,000 na na na na na

Average of all 

measurements 260,000 270,000 150,000 350,000 370,000 210,000

Median of all 

measurements 150,000 150,000 150,000 270,000 320,000 210,000

68
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Gingerich and others—Water Use in Wetland Kalo Cultivation in Hawaiÿi—Open-File Report 2007–1157