U.S. Department of the Interior

Ground-Water Occurrence and Contribution to

Streamflow, Northeast Maui, Hawaii

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 99-4090

Prepared in cooperation with the

COUNTY OF MAUI DEPARTMENT OF WATER SUPPLY

STATE OF HAWAII COMMISSION ON WATER RESOURCE MANAGEMENT
Ground-Water Occurrence and Contribution to

Streamflow, Northeast Maui, Hawaii

By Stephen B. Gingerich

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 99-4090

Prepared in cooperation with the

COUNTY OF MAUI DEPARTMENT OF WATER SUPPLY

STATE OF HAWAII COMMISSION ON WATER RESOURCE MANAGEMENT

Honolulu, Hawaii

1999
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes

only and does not constitute endorsement by the U.S. Geological Survey.

For additional information write to: Copies of this report can be purchased

from:

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

677 Ala Moana Blvd., Suite 415 Box 25286

Honolulu, HI 96813 Denver, CO 80225-0286

U. S. DEPARTMENT OF THE INTERIO

R

MARCH 3, 1849
CONTENTS

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

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Numbering System for Surface-Water Gaging Stations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Description of Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

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

Geologic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Extrusive Volcanic Rocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Intrusive Volcanic Rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Hydraulic Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Hydrologic Budget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Rainfall and Fog Drip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Evapotranspiration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Streamflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Surface-Water Diversion Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Ground-Water Recharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Ground-Water Withdrawal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Conceptual Models of Ground-Water Occurrence and Movement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

West of Keanae Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

In and East of Keanae Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Base Flow and Hydrologic Budgets for Individual Stream Subbasins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

West of Keanae Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Honopou Stream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Hoolawa Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Kailua Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Nailiilihaele Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Oopuola Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Kaaiea Stream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Waikamoi Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Puohokamoa Stream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Haipuaena Stream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Honomanu Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

In and East of Keanae Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Waiokamilo Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Wailuanui Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

West and East Wailuaiki Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Kopiliula Stream. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Waiohue Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Paakea and Waiaaka Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Kapaula Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Hanawi Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Makapipi Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Contents iii
FIGURES

1–4. Maps showing:

1. Island of Maui and northeast Maui study area, Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2. Generalized surficial geology, Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3. Selected drainage basins and fog area for windward east Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4. Mean annual rainfall, selected rain gages, and evaporation stations in northeast Maui, Hawaii . . . . . . . . 11

5–7. Graphs showing:

5. Annual rainfall at Haleakala Ranger Station, Honomanu Gulch, Paakea, and Kailua rain gages,

northeast Maui, Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6. Average annual water-budget components for selected gaged drainage basins, northeast Maui,

Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

7. Average annual total diversion-system flow and flow in selected diversion systems for the

period 1910–98, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8–9. Maps showing:

8. Estimated ground-water recharge, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

9. Selected wells in northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

10. Graph of the annual withdrawal of ground water from selected wells, northeast Maui, Hawaii . . . . . . . . . . . . 22

11. Diagram illustrating the variably saturated ground-water system west of Keanae Valley, northeast

Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

12. Map showing generalized water table and altitude of selected springs, northeast Maui, Hawaii . . . . . . . . . . . . 25

13. Diagram illustrating the fully saturated ground-water system east of Keanae Valley, northeast

Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

14–19. Graphs showing:

14. Daily rainfall at Paakea rain gage and daily streamflow at selected gaging stations, northeast

Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

15. Annual rainfall and estimated average annual base flow at selected northeast Maui streams,

Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

16. Relation of estimated base flow and linear regression line for gaging stations on Honopou

Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

17. Flow-duration curves showing the percentage of time a given flow was equalled or exceeded at

gaging stations 5850 and 5860, Hoolawa Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . 44

18. Relation of estimated base flow and linear regression line for gaging stations on Kapaula

Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

19. Relation of estimated base flow and linear regression line for gaging stations on Wailuanui

Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

20. Diagram of the distribution of mean annual ground-water recharge, discharge, and movement

within the Hanawi Stream drainage basin, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

iv Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
Contents v

TABLES

1. Water-budget components for selected gaged stream basins, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . 9

2. Information from gaging stations on streams, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3. Information from gaging stations on surface-water diversion systems, northeast Maui, Hawaii. . . . . . . . . . . . . . . . 15

4. Summary of surface-water diversion influence on selected streams, northeast Maui, Hawaii. . . . . . . . . . . . . . . . . . 16

5. Temperature, specific conductance, and chloride concentration at selected springs, northeast Maui, Hawaii. . . . . . 27

6. Streamflow in Honopou Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7. Streamflow, temperature, specific conductance, and chloride concentration in Hoolawa Stream,

February 5, 1998, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

8. Streamflow in Kailua Stream, November 2, 1932, northeast Maui, Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9. Streamflow in Nailiilihaele Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

10. Streamflow in selected streams, March 16–20, 1928, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

11. Streamflow, temperature, and specific conductance in Waikamoi Stream, northeast Maui, Hawaii . . . . . . . . . . . . . 48

12. Streamflow in Puohokamoa Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

13. Streamflow in Haipuaena Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

14. Streamflow, temperature, and specific conductance in Honomanu Stream, northeast Maui, Hawaii. . . . . . . . . . . . . 52

15. Streamflow, temperature, and specific conductance in Waiokamilo Stream, May 11, 1999, northeast

Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

16. Streamflow in Wailuanui Stream, northeast Maui, Hawaii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

17. Streamflow and temperature in West Wailuaiki Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

18. Streamflow in Kapaula Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

19. Streamflow, temperature, and specific conductance in Hanawi Stream, northeast Maui, Hawaii . . . . . . . . . . . . . . . 60

PLATES

1. Surface-water gaging stations; measurement sites, springs, and dry, gaining, and losing sections of

selected streams, northeast Maui, Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . in pocket
vi Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

Conversion Factors

Multiply By To obtain

foot (ft) 0.3048 meter

foot per mile (ft/mi) 0.1894 meter per kilometer

foot per day (ft/d) 0.3048 meter per day

gallon (gal/min) 0.003785 cubic meter per minute

million gallons (Mgal) 3,785 cubic meter

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

mile (mi) 1.609 kilometer

2 square mile (mi ) 2.590 square kilometer

inch (in.) 25.4 millimeter

inch per day (in/d) 2.54 centimeter per day

inch per year (in/yr) 2.54 centimeter per year

Water temperature is given in degree Celsius (°C), which can be converted to degrees Fahrenheit (°F) by the following

equation:

°F = 1.8 × °C + 32.

Abbreviations used in water quality descriptions: mg/L, milligrams per liter

μS/cm, microsiemen per centimeter at 25° Celsius
Abstract

The study area lies on the northern flank of the

East Maui Volcano (Haleakala) and covers about

129 square miles between the drainage basins of

Maliko Gulch to the west and Makapipi Stream to

the east. About 989 million gallons per day of rainfall and 176 million gallons per day of fog drip

reaches the study area and about 529 million gallons per day enters the ground-water system as

recharge. Average annual ground-water withdrawal from wells totals only about 3 million gallons per day; proposed (as of 1998) additional

withdrawals total about 18 million gallons per day.

Additionally, tunnels and ditches of an extensive

irrigation network directly intercept at least 10 million gallons per day of ground water.

The total amount of average annual streamflow in gaged stream subbasins upstream of 1,300

feet altitude is about 255 million gallons per day

and the total amount of average annual base flow is

about 62 million gallons per day. Six major surface-water diversion systems in the study area have

diverted an average of 163 million gallons per day

of streamflow (including nearly all base flow of

diverted streams) for irrigation and domestic supply in central Maui during 1925–97.

Fresh ground water is found in two main

forms. West of Keanae Valley, ground-water flow

appears to be dominated by a variably saturated

system. A saturated zone in the uppermost rock

unit, the Kula Volcanics, is separated from a freshwater lens near sea level by an unsaturated zone in

the underlying Honomanu Basalt. East of Keanae

Valley, the ground-water system appears to be

fully saturated above sea level to altitudes greater

than 2,000 feet.

The total average annual streamflow of gaged

streams west of Keanae Valley is about 140 million

gallons per day at 1,200 feet to 1,300 feet altitude.

It is not possible to estimate the total average

annual streamflow at the coast. All of the base flow

measured in the study area west of Keanae Valley

represents ground-water discharge from the highelevation saturated zone. Total average daily

ground-water discharge from the high-elevation

saturated zone upstream of 1,200 feet altitude is

greater than 38 million gallons per day, all of which

is eventually removed from the streams by surfacewater diversion systems. Perennial streamflow has

been measured at altitudes greater than 3,000 feet

in several of the streams. Discharge from the highelevation saturated zone is persistent even during

periods of little rainfall.

The total average annual streamflow of the

gaged streams east of Keanae Valley is about 109

million gallons per day at about 1,300 feet altitude.

It is not possible to estimate the total average

annual streamflow at the coast nor at higher altitudes. All of the base flow measured east of Keanae

Valley represents ground-water discharge from the

vertically extensive freshwater-lens system. Total

average daily ground-water discharge to gaged

streams upstream of 1,200 feet altitude is about 27

million gallons per day. About 19 million gallons

per day of ground water discharges through the

Kula and Hana Volcanics between about 500 feet

and 1,300 feet altitude in the gaged stream subbasins. About 13 million gallons per day of this

discharge is in Hanawi Stream. The total groundwater discharge above 500 feet altitude in this part

of the study area is greater than 56 million gallons

per day.

Abstract 1

Ground-Water Occurrence and Contribution to

Streamflow, Northeast Maui, Hawaii

By Stephen B. Gingerich
2 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

INTRODUCTION

A growing population and new agricultural users

have increased demand on the existing water-supply

systems in many areas of the island of Maui. A potential

source of additional water development is ground water

in northeast Maui. The County of Maui Department of

Water Supply has proposed drilling new wells and

using existing wells to ultimately withdraw 16.5 Mgal/d

(million gallons per day) of ground water from the

Haiku area between Maliko and Kakipi Gulches

(County of Maui Department of Water Supply, 1992)

(fig. 1). There is concern that withdrawing ground water

for domestic and agricultural uses could reduce groundwater discharge into streams. The State of Hawaii

Water Resources Protection Plan (State of Hawaii,

1990) emphasizes the importance of instream uses of

water and the natural relations between ground-water

and surface-water resources. Sustained streamflow is

necessary for several endangered and threatened native

animal species. Current knowledge of the relation

between surface and ground water in northeast Maui is

limited and a better understanding of the ground-water

flow system is needed for water-resource management

purposes.

In cooperation with the State of Hawaii Commission on Water Resource Management and the County of

Maui Department of Water Supply, the U.S. Geological

Survey (USGS) investigated the interaction between

ground water and surface water on the north flank of

East Maui Volcano. Historic and new streamflow and

ground-water data were collected and analyzed to determine streamflow gains and losses in selected areas, and

a conceptual model of the ground-water system in the

study area was formulated.

Purpose and Scope

The purpose of this report is to (1) quantify the

ground-water contribution to streams, (2) evaluate the

effects of geologic controls on ground-water/surfacewater interaction, and (3) describe the conceptual model

of ground-water occurrence in northeast Maui. Existing

streamflow data were analyzed to estimate groundwater discharge into streams. Reconnaissance-level

observations of geologic features and their relation to

ground-water discharge were made throughout much of

the study area. Streamflow measurements were made

along selected streams in the study area to characterize

the gains and losses along each stream.

Numbering System for Surface-Water Gaging

Stations

The surface-water gaging stations mentioned in

this report are numbered according to the USGS “downstream order” numbering system. Stations numbers

increase in a downstream direction along the main

stream. All stations on a tributary entering upstream

from a mainstream station have lower station numbers.

A station on a tributary that enters between two mainstream stations is given a number between those two

station numbers. In this report, the complete 8-digit

number for each station has been abbreviated to the

middle four digits, for example 16587000 becomes

5870.

Description of Study Area

The study area lies on the northern flank of the East

Maui Volcano (Haleakala) which forms the eastern part

of the island of Maui, the second-largest island in the

Hawaiian archipelago. The study area, covering about

129 mi2, is bounded to the north by about 19 mi of

coastline and lies between the drainage basins of

Maliko Gulch to the west and Makapipi Stream to the

east (fig. 1). Land-surface altitudes range from sea level

to nearly 9,000 ft at Hanakauhi on the north wall of

Haleakala Crater. The topography is gently sloping

except for the steep sides of gulches and valleys that

have been eroded by the numerous streams. The largest

valley is Keanae Valley, which extends from the coast

to Haleakala Crater where the valley walls are nearly

1,000 ft high.

Most of the study area is made up of forest

reserves; at intermediate altitudes rain forests densely

cover the slopes to about 7,000 ft. Grasses and shrubs

cover the upper slopes to the north wall of Haleakala

Crater. Small towns and farms can be found at low altitudes along the coast. West of Kakipi Gulch (fig. 1),

land use at lower altitudes (below 4,000 ft) changed

from primarily livestock grazing prior to the 1920’s to

pineapple cultivation in the 1920’s and 1930’s and then
Kahului

Bay

La Perouse

Bay

Maalaea 

Bay Hanawi Str

Kakipi Gl

Makapipi Str

Maliko

Gl

Wailuku Kahului

Paia

Nahiku

Keanae Valley

Makena

Wailea

Kihei

Lahaina

Hana

Kaupo

0 5 MILES

0 5 KILOMETERS

156°20'

156°40'

156°

21°

20°40' EAST MAUI VOLCANO

x

x

x

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15". Shaded relief from U.S. Geological Survey 

digital elevation models, 1:250,000

Figure 1. Island of Maui and northeast Maui study area, Hawaii.

Haleakala Crater

Red Hill

10,023 ft

Hanakauhi

8,907 ft

Boundary

of study area 

22°

20°

160° 158° 156°

P a c i f i c O c e a n

Kauai

Niihau

Oahu

Maui

Molokai

Lanai

Kahoolawe

Hawaii

HAWAII

LOCATION MAP

Introduction 3
4 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

to pineapple cultivation mixed with livestock grazing

and some residential areas from the 1940’s to the

present (1999) (Territorial Planning Board, 1939; Economic Planning and Coordination Authority, 1957; Soil

Conservation Service, 1982). At higher altitudes, much

of the land is forested State conservation land or used

for livestock grazing.

Acknowledgments

Garret Hew of East Maui Irrigation Co., Inc. and

many private land owners in the study area provided

cooperation and assistance.

GEOLOGIC SETTING

East Maui Volcano is formed primarily by extrusive shield- and post-shield-stage lavas and secondarily

by rejuvenated-stage volcanic rocks that cover the summit and southern and eastern regions (fig. 2). Intrusive

volcanic rocks in the form of dikes associated with rift

zones and volcanic vents are oriented along three axes.

Extrusive Volcanic Rocks

Extrusive volcanic rocks consist mainly of lava

flows that effused from fissures and vents. Most lava

flows emerge from fissures as pahoehoe, characterized

by smooth, ropy surfaces, and can change to aa as they

advance downslope. Pahoehoe flows generally dominate near the rift zones of volcanoes, whereas aa flows

dominate farther down the flanks. Pahoehoe flows contain numerous ellipsoidal voids (lava tubes) whereas aa

flows contain massive central cores typically sandwiched between rubbly clinker layers.

The East Maui Volcano was built by eruptions

principally from three rift zones and a presumed central

vent (Stearns and Macdonald, 1942). Rocks formed

from the main shield-building stage of the volcano are

known as the Honomanu Basalt (fig. 2) and consist of

tholeiitic basalt found as thick accumulations of thin

lava flows and associated intrusive rocks and rare pyroclastic deposits (Langenheim and Clague, 1987). The

end of the shield-building stage of the volcano has been

estimated to be between 0.93 and 0.97 million years ago

on the basis of potassium-argon age dating (Chen and

others, 1991). The lavas of the Honomanu Basalt have

typical dips of 2 to 22 degrees with the flatter dips near

the isthmus where lava flows approached the West

Maui Volcano. The basalts were laid down as vesicular

pahoehoe and aa flows averaging about 15 ft thick

(Stearns and Macdonald, 1942, p. 61). Contrary to typical observations of shield-stage lava flows in which aa

is found in greater abundance than pahoehoe away from

the volcanic vents, pahoehoe flows are abundant

throughout the Honomanu Basalt, even at the periphery

of the volcano. In the Nahiku area, the Honomanu

Basalt is petrographically more similar in nature to the

Kula Volcanics (Stearns and Macdonald, 1942). Individual lava flows range from 15 to 75 ft thick; few

exceed 40 ft thick and most are less than 30 ft thick.

In the study area, Honomanu Basalt exposures are

found in many of the more deeply incised gulches and

along the coast between the gulches (Stearns and Macdonald, 1942). The most extensive field exposures are

found in Honomanu Stream valley where the type section for this unit is located.

The Kula Volcanics, which overlies the Honomanu Basalt, consists of post-shield-stage lava flows of

hawaiite with some ankaramite and alkalic basalt and

associated intrusive rocks and pyroclastic and sedimentary deposits (Langenheim and Clague, 1987). The Kula

Volcanics is estimated to be 0.36 to 0.93 million years

old with many of the oldest rocks having chemical compositions transitional from the shield- to post-shieldstage lava (Chen and others, 1991). Exposures from this

transitional phase are 50 to 100 ft thick and are commonly difficult to characterize as belonging to either the

Honomanu Basalt or the Kula Volcanics. In some

places the two units are separated by a thin red soil layer

that has been altered by the weight and heat of the overlying flows. The Kula Volcanics almost completely

covers the underlying Honomanu Basalt and exposures

range from 2,500 ft thick near the summit to 50 to 200

ft thick near the coast. Individual lava flows average

about 20 ft in thickness near the summit and 50 ft near

the periphery, but flows as much as 200 ft thick are not

rare (Stearns and Macdonald, 1942, p. 75). The usual

dip of the flows is about 10 degrees. The flows are

thicker and narrower than the Honomanu Basalt and

have more lenticular bedding because they filled swales

and valleys eroded into the underlying Honomanu

Basalt. Flows of the Kula Volcanics are exposed

throughout most of the study area with the exception of

the Keanae Valley floor, along the coast, and the area
    

   

    















 













 Kakipi Gl

Maliko Gl

Kahului

Bay

Uaoa

Bay

Waipio

Bay

Mamalu

Bay

Kaapahu

Bay

La Perouse Bay

Maalaea Bay

Wailuku Kahului

Waikapu

Puunene

Makawao

Pukalani

Pulehu

Keokea

Makena

Kamaole

Kihei

Maalaea

Olowalu

Lahaina

Kaanapali

Honokowai

Waihee

Waiehu

Spreckelsville

Paia

Haiku

Wailua

Nahiku

Hana

Kipahulu

Keanae

0

0

2 4 MILES

2 4 KILOMETERS

156°20'

156°40'

156°

21°

20°40'

Base modified from U.S. Geological Survey

digital data, 1:24,000, 1983, Albers equal area 

projection, standard parallels 20°39'30" and 

20°57'30", central meridian 156°20'15"

Figure 2. Generalized surficial geology, Maui, Hawaii (modified from Langenheim and Clague, 1987).

EXPLANATION

SEDIMENTARY DEPOSITS 

 (Holocene and Pleistocene)

WEST MAUI VOLCANO

 Lahaina Volcanics (Pleistocene)

 Honolua Volcanics (Pleistocene)

 Wailuku Basalt (Pleistocene)

EAST MAUI (HALEAKALA) 

 VOLCANO

 Hana Volcanics (Holocene and Pleistocene?)

 Kipahulu Member (Pleistocene?)

 Kula Volcanics (Pleistocene)

 Honomanu Basalt (Pleistocene)

EAST MAUI

VOLCANO

WEST MAUI

 VOLCANO

CINDER, SPATTER, 

 AND PUMICE CONES

CONTACT

APPROXIMATE 

 CALDERA BOUNDARY

AXIS OF RIFT ZONE--

 Approximately located

BOUNDARY OF

 STUDY AREA

SOUTHWEST

RIFT ZONE

EAST RIFT ZONE

NORTH

RIFT

ZONE

Geologic Setting 5

(Haleakala)

Kopiliula Str

Honomanu Str
6 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

east of Kopiliula Gulch (fig. 2). This latter area is covered with flows of the Hana Volcanics.

The Hana Volcanics is rejuvenated-stage lava

flows of alkalic basalt, basanite, rare occurrences of

ankaramite and hawaiite and associated intrusive rocks

and pyroclastic and sedimentary deposits (Langenheim

and Clague, 1987). The Hana Volcanics is unique

among Hawaiian rejuvenated-stage eruptions because

of the presence of ankaramite and hawaiite, because its

vents are aligned along preexisting rift zones and the

erosional period preceding these eruptions was rather

short. A 300,000-year period of quiescence occurred

between the last Kula Volcanics flows and the onset of

Hana-stage volcanism about 45,000 to 75,000 years ago

(Eric Bergmanis, Univ. of Hawaii, oral commun.,

1998). The most recent eruption of Hana Volcanics was

about 200 years ago on the southwest rift zone of the

East Maui Volcano (fig. 2). No eruptions of Hana Volcanics have been mapped along the north rift zone; the

flows of Hana Volcanics in the study area all appear to

have their source at the summit or along the east rift

zone of the East Maui Volcano.

The Hana Volcanics is mostly aa and ranges from

a few feet thick to several hundred feet thick where it

was confined by valley walls during emplacement

(Stearns and Macdonald, 1942). In a detailed mapping

study of the Hana Volcanics on the southwest rift zone,

90 percent of the flows were found to be aa flows or

flows transitional between aa and pahoehoe. The flows

ranged from 0.05 to 16 mi2

 in area, 0.6 to 8 mi in length,

and 7.2×10-4 to 1×10-1 mi3 in volume (Eric Bergmanis,

Univ. of Hawaii, oral commun., 1998). Flows of the

Hana Volcanics in the study area are expected to exhibit

similar characteristics. Flows of the Kipahulu Member

of the Hana Volcanics are not found in the study area

(fig. 2).

Intrusive Volcanic Rocks

Intrusive volcanic rocks include those rocks, such

as dikes, that formed when magma cooled below the

ground surface. Dikes associated with rift zones are the

dominant intrusive rocks in Hawaiian volcanoes. The

East Maui Volcano has three primary rift zones (Stearns

and Macdonald, 1942; Langenheim and Clague, 1987)

and the study area includes one of these, the north rift

zone (fig. 2). Because of the relative youth of East Maui

Volcano, dike exposures are scarce and limited to the

summit walls and the larger valleys (Stearns and Macdonald, 1942). However, positive gravity anomalies

extending from the summit to the northwest, southwest,

and east, indicate the presence of dense, intrusive dikes

beneath the ground surface (Kinoshita and Okamura,

1965). These gravity anomalies correspond to the locations of typical rift-zone surface features such as cinder,

spatter, and pumice cones.

The dikes and the rocks they intrude are commonly

referred to as dike complexes. In Hawaiian volcanoes,

dike complexes range in width from 1.5 to 3 mi and

average about 1.9 mi (Macdonald and others, 1983).

The north rift zone of East Maui Volcano appears to be

about 3 mi wide near the coast and could be greater than

5 mi wide at 4,000 ft altitude on the basis of the cinder

and spatter cones that are in two parallel and roughly

linear patterns (fig. 2). On Oahu, the rift zones near the

ancient caldera are marked by swarms of closely

spaced, nearly vertical, and nearly parallel dikes

(Takasaki and Mink, 1985). Dikes in a dike complex

average about 100 to 200 per mile of width (Macdonald

and others, 1983) and compose 10 percent or more of

the rock volume (Takasaki and Mink, 1985). The number of dikes in the dike complex is expected to increase

with increasing depth and could average 500 to 600 per

mile of width of the complex (Macdonald and others,

1983). The rift zones are hydrologically important

because dikes have low permeability and tend to

impede the lateral movement of ground water. Groundwater levels in these low-permeability areas can be as

high as several thousand feet above sea level.

Hydraulic Conductivity

Hydraulic conductivity is a measure of the capacity of a rock to transmit water. The main elements of

lava flows contributing to their hydraulic conductivity

are (1) clinker zones associated with aa flows, (2) voids

along the contacts between flows, (3) cooling joints normal to flow surfaces, and (4) lava tubes associated with

pahoehoe flows. Few published estimates of hydraulic

conductivity exist for rocks of the East Maui Volcano.

Stearns and Macdonald (1942) classified the

Honomanu Basalt as extremely permeable and considered it hydrologically similar to dike-free shieldbuilding-stage lavas on Oahu, which have reported

horizontal hydraulic-conductivity values of 500 to

5,000 ft/d (Hunt, 1996). The horizontal hydraulic
Hydrologic Budget 7

conductivity of the Honomanu Basalt in the western end

of the study area was estimated to range from 1,800 to

5,400 ft/d on the basis of aquifer tests and an analytical

solution based on recharge (Gingerich, 1999) even

though the western end of the study area is in a dike

complex. Near the eastern end of the study area near

Nahiku, analysis of a single-well aquifer test made at a

well that is open to the upper lava flows of the Honomanu Basalt, provided a hydraulic conductivity estimate of about 1 ft/d (unpublished data in USGS Hawaii

District aquifer-test files). The rocks of the Honomanu

Basalt in the Nahiku area are described as transitional in

petrology between Honomanu Basalt and Kula Volcanics and are more similar in nature to rocks of the Kula

Volcanics (Stearns and Macdonald, 1942). Therefore,

the hydraulic conductivity of the rocks is probably

closer to the average hydraulic conductivity of Kula

Volcanics.

The specific capacities of wells open to the Honomanu Basalt in or near the Haiku area average about

600 gal/min per ft of drawdown (Gingerich, 1999). The

specific-capacity values decrease toward the east and

range from 1,400 gal/min per ft of drawdown at the

westernmost well to 0.7 gal/min per ft of drawdown at

the easternmost well. The specific capacity of well

4801-48 near Nahiku is about 1.5 gal/min per ft of

drawdown (unpublished data in USGS Hawaii District

aquifer test files).

No estimates of hydraulic conductivity exist from

aquifer tests done in wells in the study area open to the

Kula or Hana Volcanics. Stearns and Macdonald (1942)

classified the Hana Volcanics as very permeable. The

specific capacities of four wells open to the Kula Volcanics in the Haiku area range from 0.01 to 0.09 gal/min

per ft of drawdown (Gingerich, 1999). The average specific capacity of these four wells is about four orders of

magnitude lower than the average specific capacity of

the wells that penetrate into the Honomanu Basalt, indicating that the permeability of the Kula Volcanics is

significantly lower than permeability of the Honomanu

Basalt. This difference in permeability is due to the contrast in thickness of the lava flows and the amount of

interflow void spaces able to transmit water. The Honomanu Basalt is composed of many thin lava flows with

abundant interflow void space. The Kula Volcanics is

composed of thick lava flows with much less interflow

pore space.

In general, the average hydraulic conductivity of a

dike complex decreases as the number of dike intrusions within the dike complex increases. In addition,

hydraulic conductivity is expected to be higher parallel

to the strike of the dikes rather than perpendicular to the

strike. As mentioned above, the hydraulic conductivity

of the rocks in the dike complex along the western end

of the study area below about 1,000 ft altitude, was estimated to be several thousand feet per day (Gingerich,

1999). These relatively high values of hydraulic conductivity indicate that this section of the dike complex

does not contain abundant dikes and that ground-water

flow in the direction parallel to the dikes is relatively

unimpeded. Further upslope, dikes may be more abundant, and the hydraulic conductivity of the dike complex may be similar to dike complexes in other volcanic

aquifers.

On the basis of a numerical model, Meyer and

Souza (1995) estimated that dikes have a hydraulic conductivity of 1×10-5 to 1×10-2 ft/d and that the dikes

reduce the average, effective hydraulic conductivity of

the dike complex to about 1×10-2 to 1×10-1 ft/d. In a

summary of aquifer-test analyses for wells on Oahu,

Hunt (1996) shows that estimates of hydraulic conductivity for dike-intruded shield-building-stage lava flows

are about 10 to 100 times lower than for dike-free,

shield-building-stage lava flows.

HYDROLOGIC BUDGET

The water-budget model used for East Maui is an

accounting procedure that balances moisture inflow of

rainfall and fog drip with moisture outflow of runoff,

evapotranspiration, ground-water recharge, and the

change in soil-moisture storage (Shade, 1999). The relation of the water budget components is expressed by:

G = P + F −R − ET − ∆SS, (1)

where: G = ground-water recharge,

P = rainfall,

F = fog drip,

R = runoff,

ET = evapotranspiration, and

∆SS = change in soil-moisture storage.

The recharge estimates reported by Shade (1999)

represent the average of two different monthly water-
8 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

budget computation methods that differ in the order in

which recharge and evapotranspiration are taken into

account. Each water-budget computation method produced a recharge estimate that differed from the average

value by about 8 percent.

The water-budget model assumes natural vegetation conditions. Compared with natural vegetation,

pineapple cultivation can increase recharge to an area

because evapotranspiration from unirrigated pineapple

fields is less than evapotranspiration from areas of natural vegetation. Potential evapotranspiration from pineapple fields is estimated to be about 20 percent of

measured pan evaporation whereas potential evapotranspiration from sugarcane fields and areas of natural

vegetation is equal to pan evaporation (Giambelluca,

1983). During the 1960’s, part of the study area west of

Kakipi Gulch had as much as 9 mi2 in pineapple cultivation (7 percent of the study area) (University of

Hawaii Land Study Bureau, 1967). Therefore, the

recharge estimate calculated on the basis of natural vegetation conditions is probably slightly underestimated

in this area when the effects of pineapple cultivation are

considered. Also, a significant amount of water probably recharges the aquifer by infiltration from surfacewater diversion ditches and tunnels and from associated

surface-water reservoirs, but this amount has not been

estimated.

Water budgets were estimated for 14 stream subbasins (table 1 and fig. 3) with USGS surface-water

gaging stations upstream of any surface-water diversions. Ground-water discharge is not included in the

water-budget determinations for each subbasin because

a significant volume of ground water discharges downstream of the gaging stations, either to streams or

through springs and diffuse seepage near sea level.

Rainfall and Fog Drip

Rainfall distribution in the area is primarily governed by the orographic effect (fig. 4). Precipitation is

heaviest where the prevailing northeasterly trade winds

encounter the windward flank of East Maui Volcano,

forcing warm, moist air into the cool, higher altitudes.

Mean annual rainfall increases from about 50 in/yr at

the coast on the western end of the study area to more

than 300 in/yr at middle altitudes in the central part of

the study area and then decreases to about 50 in/yr at the

volcano summit (Giambelluca and others, 1986).

Annual rainfall at 7,030 ft altitude (Haleakala

Ranger Station, rain gage 338, fig. 4) ranged from about

18 to 111 in. during 1939–96 (fig. 5). Downslope at

6,150 ft altitude (Honomanu Gulch, rain gage 341, fig.

4), annual rainfall ranged from about 56 to 167 in. during 1935–80 and at 1,280 ft altitude (Paakea, rain gage

350, fig. 4) annual rainfall ranged from about 131 to 287

in. during 1919–81 (fig. 5). Nearer the coast at 700 ft

altitude (Kailua, rain gage 446, fig. 4), rainfall ranged

from about 75 to 162 in. annually during 1919–85.

Mean monthly rainfall maps of Giambelluca and

others (1986) were digitized and used as an input data

set for a water-budget model of East Maui (Shade,

1999). The total average annual rainfall in the study

area is estimated to be 989 Mgal/d, or 160 in/yr based

on data from Shade (1999). Rainfall estimates for individual gaged stream subbasins within the study area

(fig. 3) range from 5.18 to 34.79 Mgal/d (table 1, fig. 6).

Studies on the islands of Hawaii, Lanai, and Oahu

(Juvik and Nullet, 1995; Giambelluca and Nullet, 1991;

Ekern, 1964 and 1983) have shown that, in addition to

measured rainfall, water reaches the ground surface

through cloud-water interception (fog drip). The fog

zone on the windward side of East Maui Volcano

extends from about 1,970 ft to the lower limit of the

most frequent temperature-inversion base height at

about 6,560 ft (fig. 3) (Giambelluca and Nullet, 1991).

Using digitized rainfall maps of this area and fog

drip/rainfall ratios estimated from a study on the windward side of Mauna Loa on the island of Hawaii, the

fog-drip rate in the study area was estimated to be about

176 Mgal/d or an average of 65 in/yr in the fog area

(Shade, 1999). Estimates of fog-drip rates for individual

gaged stream subbasins within the study area range

from 0.45 to 9.28 Mgal/d (table 1, fig. 6).

The total precipitation (rainfall plus fog drip) in

each individual subbasin is linearly related to the size of

the individual stream subbasin because almost all of the

subbasins lie in areas of similar rainfall (table 1). The

exception to this trend is at gaging station 5528 at 4,487

ft altitude on Waikamoi Stream (fig. 3). At this site, the

total precipitation is low in relation to the area of the

stream subbasin when compared with the other gaging

stations. This difference is because this stream subbasin

is in an area of lower rainfall and fog drip.

Evapotranspiration

No published pan-evaporation records exist for

any sites in the study area. The nearest site is about 1 mi
Hydrologic Budget 9

Table 1. Water-budget components for selected gaged stream basins, northeast Maui, Hawaii[mi2, square miles; Mgal/d, million gallons per day; ET, evapotranspiration. The difference of the quantity of rainfall plus fog drip minus runoff, ET and recharge may no

Drainage basins shown in figure 3; gaging-station number is preceded by 16 and ends in 00; drainage-basin areas determined digitally from geographic information syste

Gagingstation

number

Gaging-station

location

Drainagebasin area

(mi2)

Inflow Outflow

Rainfall

(Mgal/d)

Fog drip

(Mgal/d)

Total

(Mgal/d)

Runoff

(Mgal/d)

ET

(Mgal/d)

Recharge

(Mgal/d)

Total

(Mgal/d)

East of Keanae Valley

5080 Hanawi Stream 3.46 32.27 8.91 41.18 12.00 4.63 24.56 41.19 5150 Waiohue Gulch 0.52 7.25 1.49 8.74 3.91 0.87 3.96 8.74 5160 Kopiliula Stream 3.91 31.96 8.69 40.65 13.87 5.50 21.27 40.64 5170 East Wailuaiki Stream 3.11 30.20 8.46 38.66 14.90 4.33 19.43 38.66 5180 West Wailuaiki Stream 3.67 33.11 9.28 42.39 18.75 5.05 18.59 42.39 5190 West Wailuanui Stream 1.92 16.22 4.18 20.40 7.27 2.93 10.20 20.40 5200 East Wailuanui Stream 0.51 7.10 1.29 8.39 4.07 0.85 3.47 8.39 

West of Keanae Valley

5240 Honomanu Stream 2.55 19.63 6.05 25.68 7.05 3.65 14.98 25.68 5528 Waikamoi Stream 2.46 9.19 1.18 10.37 1.29 3.22 5.87 10.38 5700 Nailiilihaele Stream 3.61 34.79 8.81 43.60 17.46 6.30 19.84 43.60 5770 Kailua Stream 2.39 23.92 7.22 31.14 15.17 3.62 12.36 31.15 5850 Hoolawanui Stream 1.34 12.48 3.12 15.60 5.13 2.39 8.09 15.61 5860 Hoolawaliilii Stream 0.57 5.18 0.45 5.63 2.52 1.29 1.82 5.63 5870 Honopou Stream 0.65 5.36 0.58 5.94 1.93 1.30 2.72 5.95 
P a c i f i c O c e a n

0 2 1 3 MILES

0 2 1 3 KILOMETERS

156°20' 156°15' 156°10' 156°05'

20°45'

20°50'

20°55'

Keanae

West side of Maliko

Gulch

drainage basin

East ridge

of Makapipi Stream

basin

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15"

Figure 3. Selected drainage basins and fog area for windward east Maui, Hawaii (modified from Shade, 1999).

EXPLANATION

5850

5080

5150

5200

5160

5180

5240

5528

5770

5870 5860

5700

5850

5170

5190

FOG AREA

DRAINAGE BASIN DIVIDE

TOPOGRAPHIC CONTOUR--Interval 1,000 feet

ABBREVIATED STREAM-GAGING STATION 

 NUMBER (COMPLETE NUMBER IS 16585000)

SURFACE-WATER GAGING STATION

MAUI

P a c i f i c O c e a n

Study area

Area

of map

1000

3000

5000

7000

9000

1000

10 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
156°20' 156°15' 156°10' 156°05'

20°45'

20°50'

20°55'

West side of Maliko

Gulch drainage basin

East ridge

of Makapipi Stream

basin

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15"

Figure 4. Mean annual rainfall, selected rain gages, and evaporation stations in northeast Maui, Hawaii 

(modified from Giambelluca and others, 1986).

LINE OF EQUAL MEAN ANNUAL RAINFALL--

 Interval, in inches, is variable

TOPOGRAPHIC CONTOUR--Interval 1,000 feet

BOUNDARY OF STUDY AREA

RAIN GAGE AND NUMBER

RAIN GAGE AND EVAPORATION STATION AND NUMBER

EXPLANATION

Keanae

0 2 1 3 MILES

0 2 1 3 KILOMETERS

P a c i f i c O c e a n

Makawao

Nahiku

Haiku

40

338

1000

2000

3000

5000

7000

9000

1000

338

341

350

446

485

485

235

275

235

275

200

200

160

160

120

120

100

100

80

80

60

60

50

40

30

20

40

30

Hydrologic Budget 11
0

350

50

00

50

00

50

300 PAAKEA AT 1,280 FT (rain gage 350) Data not available for 1942, 1968-69, 1973, 1977-80, 1982-present

1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

0

50

00

50

200

250

300

KAILUA AT 700 FT (rain gage 446) Data not available for 1974, 1977- 78, 1981-82, 1986-present

0

50

00

50

200

HALEAKALA RANGER STATION AT 7,030 FT (rain gage 338) Data not available for 1991

0

50

00

50

200

250

HONOMANU GULCH AT 6,150 FT (rain gage 341) Data not available for 1949, 1954, 1956, 1962, 1969, 1975, 1980-present

average annual rainfall

average annual rainfall

average annual rainfall

average annual rainfall

Figure 5. Annual rainfall at Haleakala Ranger Station, Honomanu Gulch, Paakea, and Kailua rain gages, northeast Maui, Hawaii.
Hanawi Stream

(5080)

Waiohue Gulch

(5150)

Kopiliula Stream

(5160)

East Wailuaiki Stream

(5170)

West Wailuaiki Stream

(5180)

East Wailuanui Stream

(5200)

West Wailuanui Stream

(5190)

Honomanu Stream

(5240)

Waikamoi Stream

(5528)

Nailiihaele Stream

(5700)

Kailua Stream

(5770)

Hoolawanui Stream

(5850)

Hoolawaliilii Stream

(5860)

Honopou Stream

(5870)

Figure 6. Average annual water-budget components for selected gaged drainage basins, northeast Maui, Hawaii.

MOISTURE INPUTS

MOISTURE OUTPUTS

Fog drip

Rainfall 

Recharge 

Evapotranspiration

Runoff 
14 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

to the west of Maliko Gulch (station 485, fig. 4) where

the station was at 320 ft altitude. During 1963–70, measured pan evaporation at this station ranged from 85.15

to 102.62 in. (Ekern and Chang, 1985). Shade (1999)

estimated a distribution of pan-evaporation values for

the study area as a function of the rainfall distribution

and used a one-to-one relation between pan evaporation

and potential evapotranspiration in the water-budget

model. According to the model, an average of about 19

percent of rainfall and fog drip or 220 Mgal/d is lost to

evapotranspiration in the study area (Shade, 1999). The

amount of potential evapotranspiration could be underestimated because the ratio of pan evaporation to potential evapotranspiration for wet forested areas could be

closer to 1.3 to 1 (Giambelluca, 1983). Estimates of

evapotranspiration rates for the individual gaged stream

subbasins range from 0.85 to 6.30 Mgal/d (table 1, fig.

6).

Streamflow

Streams in the study area drain radially from the

summit of East Maui Volcano northward to the ocean.

Valley development is in a youthful stage as streams are

eroding downward into the volcano slope, forming

steep-sided valleys and leaving nearly uneroded upland

areas (planezes) between the stream valleys. Streamflow consists of runoff, base flow, and in some cases,

flow added to streams from a network of irrigation

ditches that cross the study area. Base flow is groundwater discharge to the stream. Nearly 30 named perennial streams enter the ocean between Maliko Gulch and

Makapipi Stream and there are numerous other minor

intermittent streams. Currently, the USGS operates four

gaging stations (5080, 5180, 5870, and 5950) on

streams in the study area (plate 1). In the past, the USGS

operated gaging stations on 22 streams (table 2, at end

of report) and all the major diversion systems (table 3)

in the study area (Fontaine, 1996).

Streamflow in the study area is flashy because of

the steep sides of the stream valleys and the common

high-intensity rainfall at middle altitudes. The highest

recorded streamflow in the area was greater than 7,000

Mgal/d in Hanawi Stream at gaging station 5090 on

March 21, 1937 (Grover and Carson, 1939). The highest

average annual daily flow (25.85 Mgal/d) in the study

area was also measured at this gaging station (table 2).

The ratio of runoff to rainfall ranges from 14 percent to 63 percent in the 14 stream subbasins included

in the water-budget study (Shade, 1999). For streams on

the highly permeable Hana Volcanics, runoff is

described as low and most of the rain is expected to

enter the ground as recharge (Takasaki and Yamanaga,

1970). But the two stream subbasins in the study area

(Waiohue and Hanawi) having only Hana Volcanics at

the ground surface have about the same average runoffto-rainfall ratio (46 percent) as the 11 stream subbasins

containing mostly Kula Volcanics (45 percent).

Estimates of streamflow and base flow are based

on streamflow records of varying length and from different times. The error associated with comparing these

records is not considered significant because the average annual values used in the comparisons are expected

to be within about 10 percent of the true value in most

cases. A statistical analysis of five streamflow records,

each with more than 60 years of record, shows that the

average annual discharge for any 10-year period within

that record has a standard error of 12 percent when compared with the whole record (Fontaine, 1996). When the

length of the subset is increased to a 50-year period, the

standard error only improves to 5 percent. Thirty nine of

the streamflow records for the study area are equal to or

greater than 10 years long.

For this study, the length of the period of record at

each gaging station was determined to be unimportant

by comparing each record to three reference records

from the study area. The three longest streamflow

records, 5080 (73 years), 5180 (76 years), and 5870 (85

years) were chosen as reference records. For each other

individual record, a time period equal to the length of

that record was chosen. A subset of a reference record

was then selected from this same time period and the

average flow during that time period was compared

with the total reference record to estimate the ratio of

flow during the subset period to the reference period.

This analysis was made for all three reference records

and the result was averaged to obtain a period-of-record

scale factor for each of the other records. The scale factor ranged from 0.88 to 1.13 (table 2). This variability is

consistent with the statistical analysis reported by Fontaine (1996). This range of accuracy is considered sufficient for the type of comparisons made in this study,

and therefore, no corrections were made to any of the

records to account for differences in length or period of

record.
Hydrologic Budget 15

Surface-Water Diversion Systems

Six major surface-water diversion systems carry

water across the study area from east to west in a complex series of ditches, tunnels, flumes, and pipelines

(plate 1, tables 3 and 4). The two highest-altitude systems, the Upper and Lower Kula Pipelines, divert water

for domestic supply and the rest divert water mainly for

irrigation in central Maui. With few exceptions, the

diversion systems capture all of the base flow and an

unknown percentage of total streamflow at each stream

crossing. Records of reported total diversion-system

flow are most complete at Honopou Stream (Neal Fujii,

Commission on Water Resource Management, written

commun., 1998). During 1925–97, total flow for all of

the diversion systems at Honopou Stream averaged

about 163 Mgal/d (fig. 7). The highest average flows

were measured in the Koolau/Wailoa Ditch system

where total flow crossing Honopou Stream (gaging station 5880) averaged 110.35 Mgal/d for 1924–87 (table

3 and fig. 7). Average flows in the other diversion systems were all much lower: Manuel Luis/Center/Lowrie

and New Hamakua Ditch systems each averaged about

23 Mgal/d, Spreckels and Haiku Ditch systems each

averaged about 15 Mgal/d. Total flow in the Upper and

Lower Kula Pipelines is not gaged by the USGS. Watersale records indicate that total flow through these two

systems averaged less than 5 Mgal/d between 1970 and

1983 (Belt, Collins, and Associates, 1984).

Ground-Water Recharge

Ground-water recharge in the study area was estimated to be 529 Mgal/d (Shade, 1999) (fig. 8). Annual

water budgets were estimated for individual stream subbasins with gaging stations upstream of any surfacewater diversions. The recharge estimate represents an

average recharge of about 86 in/yr over the entire 129

mi2

 study area. However, recharge varies areally from a

minimum of less than 10 in/yr in some western areas

near the coast to a maximum greater than 150 in/yr in

Table 3. Information from gaging stations on surface-water diversion systems, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; gaging-station number is preceded by 16 and ends in 00; --, not known]

Station

number Diversion system

Year

completed

Period of record

used in calculation

Years of

complete

record

Station

altitude

(ft)

Average

annual flow

(Mgal/d)

Lowest

average

annual flow

(Mgal/d)

Highest

average

annual flow

(Mgal/d)

5310 Upper Kula Pipeline 1912 1946–85 40 4,320 0.50 0.29 1.24

5060 Koolau/Wailoa Ditch 1905/1923 1949–65 17 1,300 2.87 2.28 3.46

5120 Koolau/Wailoa Ditch 1905/1923 1900; 1920–85 67 1,289 22.01 9.24 36.32

5230 Koolau/Wailoa Ditch 1905/1923 1911–12; 1919–85 69 1,238 65.26 33.80 107.89

5510 Koolau/Wailoa Ditch 1905/1923 1923–29 7 1,260 69.32 49.15 77.77

5410 Koolau/Wailoa Ditch 1905/1923 1933–87 55 1,240 74.24 39.79 120.50

5880 Koolau/Wailoa Ditch 1905/1923 1924–87 64 1,208 110.35 65.19 149.82

5380 Spreckels Ditch 1879 1923–29; 1931–85 62 1,471 15.54 8.34 27.27

5520 Spreckels Ditch 1879 1929–30; 1932–38 9 1,340 8.17 1.91 14.57

5655 Spreckels Ditch 1879 1919–29 11 960 5.77 0.78 17.72

5890 New Hamakua Ditch -- 1919–85 67 1,170 23.25 7.52 61.69

5900 Old Hamakua Ditch -- 1919–21; 1936–64 30 1,117 1.80 0.30 6.07

5415 Manuel Luis/Center/

Lowrie Ditch

1900/1893/1900 1919–24; 1926–85 66 920 5.31 1.38 11.92

5610 Manual Luis/Center/

Lowrie Ditch

1900/1893/1900 1921–24; 1926–29 8 720 13.61 7.82 15.30

5920 Manual Luis/Center/

Lowrie Ditch

1900/1893/1900 1911–26; 1931–85 71 598 23.44 5.73 51.51

5940 Haiku Ditch 1885 1911; 1914; 1916–

28; 1931–85

70 422 15.51 3.32 49.15
16 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

a Adds water to stream

Table 4. Summary of surface-water diversion influence on selected streams, northeast Maui, Hawaii

[ne, no effect; all values represent the approximate altitude where the diversion system intercepts the stream; all diversion systems take water from stream

unless otherwise noted]

Stream

system

Diversion system

Upper Kula

Pipeline

Lower Kula

Pipeline

Koolau/Wailoa

Ditch

Spreckels

Ditch

Manuel Luis/

Center/Lowrie

Ditch

Haiku

Ditch

Makapipi ne ne 1,300 ne ne ne

Hanawi ne ne 1,300 ne ne ne

Kapaula ne ne 1,320 ne ne ne

Paakea ne ne 1,300 ne ne ne

Waiohue ne ne 1,300 ne ne ne

Kopiliula ne ne 1,300 ne ne ne

Wailuaiki ne ne 1,300 ne ne ne

Wailuanui ne ne 1,300 ne ne ne

Honomanu ne 3,043 1,300 1,720 ne ne

Haipuaena 4,320 3,030 1,300 1,460 900 ne

Puohokamoa 4,310 2,984–3,016 1,300 1,290 900 ne

Waikamoi 4,240 2,961–2,985 1,300 1,200 700 ne

Kolea ne ne 1,250 ne 760 ne

Kaaiea ne ne 1,250 920 700 ne

Oopuola ne ne 1,250 ne 700 ne

Nailiilihaele ne 2,880 1,200 660 660 ne

Kailua 4,300 2,970 1,200 660a 640 480

Hoolawa ne ne 1,200 ne 620 460

Honopou ne ne 1,200 ne 580 440
0

1.5

0.5

1.0

0

160

20

40

60

80

100

120

140

AVERAGE DAILY FLOW, IN MILLION GALLONS PER DAY

5060

STATION

STATION

5120

5510

5230

5410

5880

0

30

10

20

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

DATE

5380

5520

5655

UPPER KULA PIPELINE AT STATION 5310

KOOLAU/WAILOA DITCH

SPRECKELS DITCH

Figure 7. Average annual total diversion-system flow and flow in selected diversion systems for the period 1910-98, 

northeast Maui, Hawaii. 

0

300

100

200

TOTAL REPORTED FLOW, 

IN MILLION GALLONS PER DAY

TOTAL REPORTED DITCH FLOW AT HONOPOU GULCH (Data not available for 1927-31, 1938-44, 1946, 1992, 1995)

average

Hydrologic Budget 17
0

60

20

40

0

60

20

40

AVERAGE DAILY FLOW, IN MILLION GALLONS PER DAY

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

MANUEL LUIS/CENTER/LOWRIE DITCH

HAIKU DITCH STATION 5940

Figure 7. Average annual reported total diversion-system flow and flow in selected diversion systems for the 

period 1910-98, northeast Maui, Hawaii -- Continued.

5415

5610

5920

0

80

20

40

60

5890

STATION

STATION

5900

NEW HAMAKUA/OLD HAMAKUA DITCH

DATE

18 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
 

















 

 

 

    





P a c i f i c O c e a n

0 2 1 3 MILES

0 2 1 3 KILOMETERS

156°20' 156°15' 156°10' 156°05'

20°45'

20°50'

20°55'

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15"

Figure 8. Estimated ground-water recharge, northeast Maui, Hawaii (modified from Shade, 1999).

EXPLANATION

ESTIMATED AVERAGE ANNUAL GROUND-WATER 

RECHARGE, IN INCHES PER YEAR

 Less than or equal to 10

 Greater than or equal to 10 and less than 25

 Greater than or equal to 25 and less than 50

 Greater than or equal to 50 and less than 100

 Greater than or equal to 100 and less than 150

 Greater than or equal to 150

BOUNDARY OF STUDY AREA

Makawao

Nahiku

Keanae

Haiku

Hydrologic Budget 19
20 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

the areas of highest rainfall and fog drip between altitudes of 2,000 and 6,000 ft. The estimated recharge of

529 Mgal/d is about 45 percent of precipitation (rainfall

plus fog drip) in the study area. Recharge estimates for

individual gaged stream subbasins range from 1.82 to

24.56 Mgal/d (table 1, fig. 6). These recharge rates

range from 32 to 60 percent of the precipitation rate for

each individual subbasin. The average ratio of recharge

to precipitation for the two streams in the Hana Volcanics is slightly higher than in the other streams for

which water budgets were determined.

Ground-Water Withdrawal

In the study area, ground water is withdrawn from

public and private wells and from the tunnels and

ditches constructed for the irrigation system. Of the

ground water currently withdrawn from wells, most is

from only three, well 5520-01 in Maliko Gulch, well

5108-01 at Keanae, and well 4806-48 near Nahiku (fig.

9). Water from well 5520-01 is pumped to the Haiku

water-diversion system for irrigation. The records of

yearly pumpage at this well show that the annual

ground-water withdrawal averaged 2.8 Mgal/d during

1913–96. This average value includes 1954–61 when

the pumps in the well were not operating (fig. 10).

Monthly pumpage from the well varied seasonally from

zero to as much as 17 Mgal/d. Water from well 5108-

01, drilled in 1984, is used for domestic supply and,

according to records supplied by the Maui County

Department of Water Supply, withdrawals have averaged about 0.04 Mgal/d since 1988 (fig. 10). According

to East Maui Irrigation, Inc. (EMI) records, withdrawals

at well 4806-48 have averaged about 0.28 Mgal/d since

1956 (fig. 10). This water is pumped into the Koolau

Ditch diversion system on a seasonal basis for irrigation

in central Maui. Unreported withdrawals from domestic

wells in the area probably total less than 0.3 Mgal/d on

the basis of well-installation specifications listed on

well-permit applications. A well (5318-01) presently

being constructed (1999) near Kaupakulua (fig. 9) is

proposed to withdraw 1.5 Mgal/d from the Honomanu

Basalt (State of Hawaii Department of Land and Natural Resources application for well-construction permit,

1997). Proposed withdrawal rates for additional wells in

the Haiku area total about 16.5 Mgal/d, an increase in

withdrawal of about 400 percent.

The network of water-diversion systems contains

many tunnels that capture ground water, which is transported to central Maui for irrigation, but records of flow

are incomplete. Stearns and Macdonald (1942) estimated the average tunnel yield to be about 6 Mgal/d for

22 tunnels totaling more than 20,600 ft in length that

were constructed by EMI in the Nahiku area. Attempts

have also been made to enhance discharge from several

small springs in the study area by tunneling for water

but average yields are reported to total less than 0.1

Mgal/d (Stearns and Macdonald, 1942). Ground-water

seepage directly into an unlined part of the Koolau

Ditch has been estimated to be about 3.8 Mgal/d per

mile of ditch between the start of the ditch and gaging

station 5120 (plate 1) (William Meyer, USGS, written

commun., 1998). No other information exists describing what sections of the ditches gain water, so estimating the total effect of ground-water capture by the

ditches crossing the study area is not possible.

CONCEPTUAL MODELS OF GROUNDWATER OCCURRENCE AND MOVEMENT

Fresh ground water in northeast Maui occurs under

two general conditions: (1) as a high-elevation saturated

zone in relatively low-permeability rocks above an

unsaturated zone, and (2) as a freshwater-lens system

underlain by denser saltwater. West of Keanae Valley,

a high-elevation saturated zone in the upper rock unit,

the Kula Volcanics, is separated from a freshwater lens

near sea level by an unsaturated zone in the underlying

Honomanu Basalt as described in the report for the

Haiku area (Gingerich, 1999). East of Keanae Valley,

the ground-water system appears to be a freshwater-lens

system that is fully saturated above sea level to altitudes

greater than 2,000 ft, similar to the system described in

the Nahiku area (Meyer, in press). The freshwater-lens

system is in direct connection with the underlying saltwater.

West of Keanae Valley

Within the study area and west of Keanae Valley,

ground water is found at high elevations in the Kula

Volcanics and as a freshwater lens floating on denser

underlying saltwater in the Honomanu Basalt (fig. 11).

The rocks beneath the contact between the low permeability Kula Volcanics and the underlying Honomanu
P a c i f i c O c e a n

0 2 1 3 MILES

0 2 1 3 KILOMETERS

156°20' 156°15' 156°10' 156°05'

20°45'

20°50'

20°55'

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15"

Figure 9. Selected wells in northeast Maui, Hawaii.

EXPLANATION

WELL OR TEST HOLE AND NUMBER

BOUNDARY OF STUDY AREA

East ridge

of Makapipi Stream

basin

Makawao

Nahiku

Keanae

Haiku

West side

of Maliko Gulch drainage basin

Ditch

5419-01

5319-01

5519-03

5519-02

5620-01 5520-01

5620-02

5519-01

5518-02

5518-03

5518-01

5517-01

5417-01

5318-01

4910-03

4806-48

4813-01

4813-01

5108-01

5616-02

5516-02

5516-01 5515-01

5615-03

5515-02 5515-03

5615-01

5615-02

5513-01

5514-01

5413-01

5413-09 5413-06

5414-01 5413-08

Conceptual Models of Ground-Water Occurrence and Movement 21
0

8246

0

0.20.40.6

ANNUAL GROUND-WATER WITHDRAWAL, IN MILLION GALLONS PER DAY WELL 5520-01 (No withdrawal during 1954-61; data not available for 1898-1912, 1922, 1942- 43, 1989) WELL 4806- 48 (data not available for 1972, 1982- 83, 1992) AVERAGE ANNUAL WITHDRAWAL AVERAGE ANNUAL WITHDRAWAL

Figure 10. Annual withdrawal of ground water from selected wells, northeast Maui, Hawaii.

1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1

0

0.06

0.020.04

WELL 5108-01 (data not available for 1992)

AVERAGE ANNUAL WITHDRA

DATE

22 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
 











  













    

 



      





 



Water table

HIGH-ELEVATION SATURATED ZONE

SALTWATER FRESHWATER LENS

Water table

UNSATURATED ZONE

Figure 11. Diagram illustrating the variably saturated ground-water system west of Keanae Valley, northeast Maui, Hawaii (arrows indicate

general direction of ground-water flow).

Ocean

Coastal

spring

Spring

Spring

Gaining stream

Water table

HIGH-ELEVATION SATURATED ZONE

SALTWATER

Rain

FRESHWATER LENS

UNSATURATED ZONE

Water table

EXPLANATION

GENERAL DIRECTION OF GROUND-WATER FLOW 

KULA VOLCANICS HONOMANU BASALT

Conceptual Models of Ground-Water Occurrence and Movement 23
24 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

Basalt and above the freshwater lens appear to be unsaturated.

In the Haiku area, water levels measured in shallow wells indicate that a water table lies several tens of

feet below the ground surface of the undissected

uplands and represents the top of a saturated zone in the

thick lava flows and interbedded soils of the Kula Volcanics (Gingerich, 1999). This water-table surface

mimics topography but is more subdued and rises away

from the coastline with a slope of about 340 ft/mi (fig.

12) (Gingerich, 1999). Near the coast and in a few of the

gulches, this high-elevation saturated zone is not

present because erosion has removed the low-permeability layers formed by the Kula Volcanics. Groundwater flow is predominantly to the north from high to

low altitudes along the dip of the geologic layers and

vertically downward from the base of the saturated

zone.

Where valleys have been incised into the highelevation water table, ground water discharges at

springs or directly in streambeds. Conversely, streamflow infiltrates into the aquifer where the streambed lies

above the high-elevation water table and is sufficiently

permeable. Where valley floors consist of Kula Volcanics all the way to the ocean, the streams commonly

flow all the way to the ocean.

The rocks beneath the contact between the Kula

Volcanics and the underlying Honomanu Basalt and

above the freshwater lens appear to be unsaturated on

the basis of several observations, some first discussed

for the Haiku area (Gingerich, 1999):

(1) Stream channels incised into the Honomanu

Basalt (Maliko and Kakipi Gulches in the

Haiku area, and Oopuola, Honomanu, and

Haipuaena Streams further to the east) are

dry or lose streamflow during base-flow

conditions. After flowing over the less

permeable Kula Volcanics, streamflow seeps

into the more permeable Honomanu Basalt

downstream.

(2) The hydraulic conductivity of the Honomanu

Basalt, on the basis of aquifer tests, is too high

to support a thick ground-water lens with the

estimated recharge to the study area.

(3) Small springs are commonly found along sea

cliffs in this part of the study area at the base

of the Kula Volcanics but no springs have been

observed lower in the Honomanu Basalt but

above sea level.

(4) Wells that penetrate through the contact have

penetrated cascading water from above the

contact and dry lava tubes in the Honomanu

Basalt.

Water levels from wells penetrating to sea level

indicate that the surface of the freshwater lens in the

Haiku area forms a hydraulic gradient of about 3 ft/mi

inland (Gingerich, 1999). The source of freshwater in

the lens is ground-water recharge from overlying highelevation saturated zones and rainfall infiltration. Fresh

ground water flows from the inland areas to the coast

where it discharges at springs and by diffuse seepage at

and below sea level. In coastal aquifers, a saltwatercirculation system exists beneath the lens (Souza and

Voss, 1987). Saltwater flows landward in the deeper

parts of the aquifer, rises, and then mixes with seawardflowing freshwater. This mixing creates a freshwatersaltwater transition zone. No wells in the study area are

known to penetrate the transition zone or underlying

saltwater.

For hydrostatic conditions, the freshwater-lens

thickness can be estimated by the Ghyben-Herzberg

principle. If the specific gravities of freshwater and saltwater are assumed to be 1.000 and 1.025, respectively,

then the Ghyben-Herzberg principle predicts that every

foot of freshwater above sea level must be balanced by

40 ft of freshwater below sea level. For dynamic conditions, the Ghyben-Herzberg principle tends to overestimate the freshwater-lens thickness in the recharge zone

and underestimate the freshwater-lens thickness near

the discharge zone.

Volcanic dikes, which commonly impede the flow

of water because of their low permeability, appear to be

a factor controlling the shape of both the high-elevation

water table and the freshwater lens within the north rift

zone of East Maui Volcano (Gingerich, 1999). Groundwater flow could be impeded more from east to west in

a direction perpendicular to the preferred dike orientation in the dike complex. But dike impoundments do not

appear to be present seaward of the 2,000-ft topographic

contour in the Haiku area. Because the principal
   

P a c i f i c O c e a n

0 2 1 3 MILES

0 2 1 3 KILOMETERS

156°20' 156°15' 156°10' 156°05'

20°45'

20°50'

20°55'

Base modified from U.S. Geological Survey digital data, 

1:24,000, 1983, Albers equal area projection, standard 

parallels 20°39'30" and 20°57'30", central meridian 

156°20'15"

Figure 12. Generalized water table and altitude of selected springs, northeast Maui, Hawaii.

EXPLANATION

WATER-TABLE CONTOUR--Shows altitude of water

 table. Interval 200 feet. Dashed where approximate.

 Datum is mean sea level

WELL AND FIRST WATER LEVEL REPORTED, 

 IN FEET ABOVE MEAN SEA LEVEL

SPRING AND ALTITUDE, IN FEET ABOVE

 MEAN SEA LEVEL

BOUNDARY OF STUDY AREA

East ridge

of Makapipi Stream

basin

Makawao

Nahiku

Keanae

Haiku

West side

of Maliko Gulch drainage basin



AREA WITH HIGH-ELEVATION WATER

 TABLE PERCHED ABOVE A 

 FRESHWATER LENS--Contours show 

 the top of the perched water body in 

 variably saturated ground-water system 

 (modified from Gingerich, 1999)

AREA WITH VERTICALLY EXTENSIVE 

 FRESHWATER LENS--Contours show the

 top of fully saturated water body in fully 

 saturated ground-water system (modified 

 from Meyer, in press)

400

200

400

600

800

1000

1200

1400

400

200

600 800

1000

1400

1200

4,237

172

6,560

3,200

2,600

1,000

750

230

245

30 240

280

100

1,760

2,160

1,670

1,710

320

2

4,237

1,000

Conceptual Models of Ground-Water Occurrence and Movement 25
26 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

direction of ground-water flow is parallel to the dike

complex, it appears that volcanic dikes are either not

numerous enough or are oriented parallel to each other

so that structures to impound ground water to high levels did not form to a significant extent.

West of Keanae Valley, wells that are open to the

aquifer only at or below sea level will pump ground

water from the freshwater lens. The discharge of freshwater from the lens at the coast will be reduced by the

amount of ground water withdrawn by the pumped

wells. Removal of ground water at these wells should

not affect the upper high-elevation water table because

the thick unsaturated zone will prevent the vertical

ground-water flow gradient from changing significantly. Ground-water withdrawal from wells open to

the high-elevation water body can reduce streamflow

and reduce the amount of recharge that infiltrates to the

freshwater lens below.

No reliable water-level measurements exist from

wells drilled to sea level between Kakipi Gulch and

Keanae Valley or above 1,200 ft altitude anywhere in

the study area to confirm whether ground water is found

in both a high-elevation saturated zone and a freshwater

lens in these areas as well. Most of the wells drilled near

the coast immediately west of Kakipi Gulch encounter

water in the Kula Volcanics, but do not penetrate to sea

level. A test hole (4813-01) drilled in Kula Volcanics at

about 4,300 ft altitude near Waikamoi Stream (fig. 9)

encountered water 63 ft below the ground surface and

the hole had about 5 ft of water in it when it was 650 ft

deep (unpublished records in USGS Hawaii District

files). The well was reported to be dry by Stearns and

Macdonald (1942, p. 215) because the water was

thought to be drilling fluid and not representative of the

water table.

The existence of a high-elevation water body overlying a freshwater lens is inferred from the presence,

similar to that found in the Haiku area, of losing stream

sections where surface water flows from the Kula Volcanics onto the Honomanu Basalt. Oopuola, Haipuaena,

and Honomanu Streams all have gone dry downstream

of the Kula Volcanics/Honomanu Basalt contact. Other

streams in the area may be losing but do not go dry

because they have not incised below the contact.

At most wells in the study area, only single waterlevel measurements are available, so temporal variations in ground-water levels are difficult to determine.

At three wells drilled into the freshwater lens in the

Haiku area, water-level measurements are available

over several-year periods (Gingerich, 1999). Pumped

water levels in well 5520-01, near the coast, were about

2 ft lower than non-pumped water levels and daily tidal

fluctuations were about 0.2 to 0.4 ft. Occasional measurements made in wells 5519-01 and 5419-01 show

that the water level appears to mimic rainfall variations

(Gingerich, 1999).

Water Chemistry.--The chemical characteristics of

ground water and surface water that have been measured at most sites is limited to chloride concentration,

specific conductance, and temperature. Chloride concentration is commonly used as an indicator of saltwater

intrusion into the ground-water system. Generally,

greater withdrawal from a well in a freshwater lens will

cause an increase in the chloride concentration of the

pumped water as more saline water is induced to flow

towards the well. The only long-term chloride-concentration record available in the study area is for well

5520-01 in Maliko Gulch (Gingerich, 1999). Between

1925 and 1996, measured chloride concentration

ranged from 270 to 1,668 mg/L depending on the

amount of withdrawal from the well. Chloride-concentration values from other wells in or near the Haiku

study area that penetrate the freshwater lens range from

49 to 200 mg/L (Gingerich, 1999). The highest concentrations were in samples from wells nearest the coast

where the freshwater lens is thinnest.

Chloride concentrations from springs west of

Keanae Valley average about 10 mg/L (table 5). All of

these springs are assumed to be discharging from the

high-elevation saturated zone. Ground-water chloride

concentrations in these springs decrease with increasing

altitude and distance from the ocean (Gingerich, 1999).

Chloride ions in seawater aerosols carried by the

tradewinds are deposited on land as salts with decreasing concentrations as the distance from the ocean is

increased. Rainfall dissolves the deposited salts and

recharges the high-elevation saturated zone with water

of varying chloride concentration. Water that recharges

the saturated zone at the highest altitude (farthest from

the ocean) will typically have the lowest chloride concentration.
Conceptual Models of Ground-Water Occurrence and Movement 27

Table 5. Temperature, specific conductance, and chloride concentration at selected springs, northeast Maui, Hawaii

[°C, degrees Celsius; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; --, no data; all altitudes estimated from U.S. Geological

Survey topographic maps, Haiku, Keanae, Kilohana, and Nahiku quadrangles]

Location

Altitude

(feet above

sea level) Date

Water

temperature

(°C)

Water specific

conductance

(μS/cm)

Chloride

concentration

(mg/L) Comments

Akeke Spring 750 9/11/97 18.7 131 8

Big Spring 787 1/12/94

2/24/94

2/22/95

9/13/95

9/9/96

15.5

15.5

15.5

15.7

15.6

227

234

229

225

233

--

--

--

10

4

Hanawi Spring at 1,325 ft 1,325 1/11/94

9/13/95

19.3

19.2

64

63

--

10

West bank near gaging

station 5080

Hanawi Spring 1 770 1/12/94

9/13/95

19.6

20.5

53

55

--

10

Hanawi Spring 2 660 1/11/94

2/24/94

19.1

19.2

51

49

--

--

Honolulunui Spring 1,000 9/10/96 19.9 47 7

Honomanu Spring at shore 2 2/26/96 20.2 366 80 Honomanu 1

Honomanu Spring at 30 ft 30 9/10/95

2/26/96

20.9

21.1

156

158

15

12

Honomanu 3b

Hoolawa Spring at 1,200 ft 1,200 2/5/98 20.0 75 15 Hoolawa 12.2

Hosmer Grove Spring 6,560 10/17/94

9/12/95

2/25/96

9/8/97

13.0

10.9

10.7

13.9

30

46

25

28

--

5

3

3

Waikamoi 74

Kaumahina Spring at 280 ft 280 5/23/95 22.7 136 -- Kaumahina 4

Kaumahina Spring at 240 ft 240 5/23/95 22.8 124 -- Kaumahina 5

Kaumahina Spring at 100 ft 100 5/23/95 22.7 138 -- Kaumahina 7

Mossman Spring 1,020 9/10/96

3/2/97

19.9

19.3

47

49

7

8

Nuaailua Roadcut Seep 240 2/26/96

3/3/97

9/9/96

9/11/97

22.7

21.9

23.8

22.5

111

113

107

105

23

23

21

24

Inland side of highway

from PVC collection

pipe

Ohia Spring 230 2/26/96

9/9/96

3/2/97

9/11/97

17.8

18.3

17.7

18.6

147

132

137

114

6

4

5

6

Tavares Spring 40 9/5/96 22.8 526 121

Waikamoi Spring at 3,200 ft 3,200 9/9/97 18.0 37 6 Spring along old flume
28 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

Specific conductance is related to the type and concentration of ions in solution and can be used for

approximating the dissolved-solids content of the

water. For sample-collection sites at sea level, a high

specific conductance probably means that the sample

has a higher chloride concentration in it (such as at

Honomanu coastal springs in table 5). The specificconductance measurements of the water samples collected above sea level west of Keanae Valley range

between 16 and 521 μS/cm. For water samples collected higher than sea level, the variations in specific

conductance are probably caused by a number a factors

including the abundance of sea-spray deposition, the

residence time of the water in the aquifer, and the aquifer-rock age and petrology. It is not possible given the

data to determine the effects on ground water in the

study area of each of these factors individually.

Water temperature can be an indication of the elevation the water recharged the aquifer or, in the case of

elevated temperature, the effects of geothermal activity.

Because none of the temperatures appear to be elevated,

geothermal activity does not appear to play a significant

role in the ground-water flow system of the study area.

Therefore, ground water with the lowest temperature is

assumed to have originated at the highest elevations.

Measured ground-water temperatures west of Keanae

Valley range from 10.9°C at Hosmer Grove Spring

(6,560 ft altitude) to 24.9°C in Uluini Stream (310 ft

altitude).

In and East of Keanae Valley

In and east of Keanae Valley, the freshwater lens

appears to be vertically extensive, similar to the conditions found in the Nahiku area. In the Nahiku area and

as far west as Waiohue Gulch (plate 1), the rocks are

described as fully saturated from sea level to greater

than 2,000 ft altitude on the basis of water-level information from test holes and streamflow measurements

(Meyer, in press). The saturated zone extends from the

Honomanu Basalt at sea level up through the Kula Volcanics and into the Hana Volcanics (fig. 13). Streams

intersect the vertically extensive freshwater-lens system

and are perennial downstream of about 2,100 ft altitude.

These streams continue to gain water from all three rock

units as they descend in altitude to sea level. Discharge

from high-elevation springs in the area is from this vertically extensive freshwater-lens system. Because the

rocks in this area are fully saturated, withdrawal of

ground water from wells open to any part of the aquifer

will reduce streamflow and ground-water discharge at

the coast. The vertically extensive saturated zone results

directly from the combination of high ground-water

recharge rates, low rock hydraulic conductivity, and the

ground-water flow-system geometry (Meyer, in press).

Recharge to parts of this area is greater than 150 in /yr

(fig. 8).

The relatively low hydraulic conductivity of the

rocks (about 1 ft/d) has been demonstrated by the analysis of a 7-day aquifer test done at well 4806-48 which

is open to the Honomanu Basalt between altitudes of

488 and 134 ft. The hydraulic conductivity of the Honomanu Basalt is related to the characteristics of the lava

flows as they were emplaced and cooled. The nature of

flow emplacement is controlled by both the lava petrology and the features onto which the lava is flowing. As

discussed previously, the exposures of Honomanu

Basalt in the Nahiku area above sea level are transitional in petrology between Honomanu Basalt and Kula

Volcanics and are more similar to rocks of the Kula

Volcanics (Stearns and Macdonald, 1942). Because of

the transitional petrology, the hydraulic conductivity of

the Honomanu Basalt in this area may be lower than

typically expected elsewhere and therefore similar to

the hydraulic conductivity of Kula Volcanics.

Several volcanic features in the area indicate that

the Honomanu Basalt may not have been emplaced as

typical flat-lying flank lava flows and therefore the

hydraulic conductivity of the rocks may not be typical

either. A volcanic dike in the sea cliff west of Kapaula

Gulch (Stearns and Macdonald, 1942, pl. 1, inset B) and

a 2-ft thick layer of lithic-vitric tuff (common near eruptive vents) in the sea cliff west of Hanawi Stream

(Stearns and Macdonald, 1942, pg. 71) indicate that the

area may once have been the site of local eruptions.

Also, Stearns and Macdonald (1942) recognized that

the "Hanawi artesian structure," a permeable layer confined above and below by less permeable layers, is

unique for supposed shield-stage basalts and nothing

similar has been described elsewhere in Hawaii's aquifers.

The primary factor controlling the altitude to

which the water table will reach in a freshwater-lens

system is the hydraulic conductivity of the aquifer at sea
  















 



 

 

    







 

SALTWATER

Water table

FULLY SATURATED 

VERTICALLY EXTENSIVE FRESHWATER LENS

Figure 13. Diagram illustrating the fully saturated ground-water system east of Keanae Valley, northeast Maui, Hawaii (arrows indicate general

direction of ground-water flow).

Ocean

Coastal

spring

Spring

Gaining stream

Unsaturated zone

 between seepage 

 faces

SALTWATER

Rain

FULLY SATURATED 

VERTICALLY EXTENSIVE FRESHWATER LENS

Water table

?

?

EXPLANATION

GENERAL DIRECTION OF GROUND-WATER FLOW 

KULA VOLCANICS HANA VOLCANICS HONOMANU BASALT

Conceptual Models of Ground-Water Occurrence and Movement 29
30 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

level. As seen from equation 1 (p. 7), for a given

recharge rate, an aquifer with lower hydraulic conductivity will have a higher water table than an aquifer with

higher hydraulic conductivity. A numerical model has

shown that the recharge estimated for the Nahiku area

will produce a freshwater-lens system with a water table

hundreds to thousands of feet above sea level given a

hydraulic conductivity of about 1 ft/d (Gingerich,

1998). With hydraulic conductivity values in the range

of 1,000 ft/d, freshwater heads will only be a few feet

above sea level several miles inland. At Nahiku, the

aquifer is Honomanu Basalt from below sea level to a

minimum of 150 ft above sea level at the coast to at least

650 ft above sea level at well 4806-48. Above the Honomanu Basalt, the low-permeability Kula Volcanics is

nearly 500 ft thick. The Hana Volcanics is mainly a

veneer on the surface of the shield- and postshield-stage

lavas and this unit has little control on the regional

ground-water flow system. Therefore, there is a layered

sequence of at least 600 ft of low-permeability rock

above sea level at the coast and a greater extent inland

in which a vertically extensive freshwater-lens system

could develop.

In a vertically extensive freshwater-lens system,

regional ground-water flow above sea level is toward

the coast and downward from areas of recharge to areas

of discharge in streams and at the coast. Ground water

will flow from areas of higher hydraulic head to areas of

lower hydraulic head. Meinzer (1923, p. 41) described

ground water that has greater pressure head than an

underlying body of ground water, from which it is, however, not separated by any unsaturated rock. This

description applies to a vertically extensive freshwaterlens system in a layered aquifer: "... after the water table

is struck in drilling a well, the well contains water at all

depths which it reaches but the water level in the well

sinks below the original water table..." (Meinzer, 1923).

In a layered aquifer, the head gradient may not be

uniform with depth because each layer penetrated may

have a different hydraulic conductivity and a different

degree of connection to a discharge point in a stream or

at the ocean. An abrupt water level drop as a new layer

is penetrated may mean only that a layer of significantly

lower hydraulic head has been encountered. An abrupt

decline in water levels during drilling is not necessarily

an indication that a perched water body has just been

penetrated. Stearns and Macdonald did not consider the

concept of a layered system with a vertical head gradient when analyzing the "Hanawi artesian structure"

leading them to conclude "The structure must be

perched, because when the [test] holes penetrate the

supporting member the water level drops" (Stearns and

Macdonald, 1942, p. 260).

Drilling records of water levels from wells penetrating a perched water body above a thin basal freshwater-lens system would be expected to show abrupt

declines to a few tens of feet above sea level, reflecting

the height of the water table in the basal freshwater lens.

This scenario is apparent in the Haiku area where the

basal freshwater lens in highly permeable Honomanu

Basalt has a water table of a few feet above sea level.

Stearns and Macdonald (1942, p. 255) stated that the

Nahiku area was underlain by permeable Honomanu

Basalt with a thin basal freshwater lens but their

assumption was based on inference from other areas

and not on any field data from the Nahiku area. Six

wells were drilled to depths near to or below sea level in

the Nahiku area and the lowest water level encountered

was 47 ft above sea level in a test hole 300 ft from the

ocean (Meyer, in press). At well 4806-48, (about 2 mi

inland from the ocean) the deepest water level encountered was 969 ft above sea level when the well bottom

was at -9 ft altitude (unpublished records from Doak C.

Cox, geologist, Experiment Station, Hawaiian Sugar

Planters Association in files of U.S. Geological Survey,

Honolulu). In most of the test holes drilled in the area,

the water levels dropped during drilling as would be

expected in a vertically extensive freshwater-lens system but still remained higher than the top of the Honomanu Basalt even when drilled as deep as 259 ft below

sea level (Meyer, in press). The pattern of high water

levels indicates that there are no layers of the Honomanu Basalt with relatively high hydraulic conductivity

or a good connection to a discharge zone even as deep

as several hundred feet below sea level.

The water-level data indicate that the water table of

the vertically extensive freshwater-lens system is as

high as the Hana Volcanics in much of the Nahiku area

(Meyer, in press). This water-table surface mimics

topography and slopes toward the coast at about 800

ft/mi (fig. 12). The thickness of the freshwater lens

below sea level would be unreasonably large if the

depth to the theoretical freshwater-saltwater interface

were based on the assumption that the Ghyben-
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 31

Herzberg principle was applicable. However, in areas

where significant downward movement of ground

water exists, the depth to the freshwater-saltwater interface will be shallower than predicted by the GhybenHerzberg relation (Izuka and Gingerich, 1998). Meyer

(in press, fig. 28) used this finding to estimate the position of the interface on the basis of the water-level information obtained from the test holes penetrating to near

sea level. The interface position was estimated to be

about 400 ft below sea level near the coast and greater

than 1,000 ft below sea level about 2 mi inland.

Between Waiohue Gulch and Keanae Valley, no

water-level information is available, but the existence

of a vertically extensive freshwater-lens system can be

inferred from the presence of continuously gaining

streams all the way to the ocean. Although flow measurements are unavailable, visual observations by the

author along both East and West Wailuaiki Streams

showed streamflow gains from about 1,000 ft altitude

downstream to the coast, including the presence of

many small springs and seeps a few tens of feet above

sea level. Several features along the eastern side of

Keanae Valley indicate the presence of the vertically

extensive freshwater-lens system. Akeke Spring

(Banana Spring in Stearns and Macdonald, 1942) and

Plunkett Spring discharge a total of about 4 Mgal/d

from the Honomanu Basalt at altitudes of 750 ft and

1,000 ft, respectively (fig. 12), and the water level in a

test hole (4910-03; fig. 9) drilled through Hana Volcanics into 30 ft of Honomanu Basalt near Plunkett Spring

was reported to be greater than 900 ft altitude. The configuration of the vertically extensive freshwater-lens

system near the coast in Keanae Valley is unknown and

is probably complicated by the flows of the Hana Volcanics and extensive alluvial deposits, which are found

at sea level in this area.

The nature of the transition from a variably saturated system to the west of Keanae Valley to a fully saturated freshwater-lens system east of Keanae Valley is

unknown. Because recharge immediately on either side

of the valley is similar, the significant difference

between the two areas is probably the hydraulic conductivity of the Honomanu Basalt underlying each area.

West of Keanae Valley at Honomanu Stream, where the

type section for the Honomanu Basalt is located, more

typical Honomanu Basalt flows are found at sea level

and the hydraulic conductivity of these rocks is probably higher. No evidence exists to indicate whether the

change is gradational from higher conductivity rocks at

sea level at Honomanu Stream to low conductivity

rocks at sea level at Nahiku, perhaps because of a

regional dip of the rock units, or abrupt, perhaps

because of a structural feature from the shield stage of

East Maui Volcano or an erosional feature associated

with Keanae Valley.

East of Makapipi Stream streams are intermittent

except at lower altitudes near the coast. These streams

are all less incised than streams in the study area. At 600

ft altitude in the study area east of Keanae Valley,

stream valleys are incised from 200 to 260 ft below the

upland surface. The next ten stream valleys east of the

study area are only incised about 20 to 80 ft below the

upland surface. Apparently, the stream valleys are not

incised deep enough to intercept the water table except

at the coast and therefore, do not contain persistent base

flow at higher altitudes.

Water chemistry.--Water chemistry data are available for two wells and several springs and streams in

and east of Keanae Valley. The chemical characteristics

of ground water and surface water that have been measured at most sites are limited to chloride concentration,

specific conductance, and temperature. The chloride

concentration of water from wells 4806-48 and 5108-01

was 6 mg/L and 16 mg/L, respectively on September 9,

1996 (G.W. Tribble, USGS, written commun., 1998).

Both wells are drilled below sea level. The specific conductance of the well water was 966 and 236 μS/cm,

respectively, indicating that the chemistry of water from

well 4806-48 is unusual. Chloride concentrations from

two springs in Keanae Valley were less than 10 mg/L.

The specific-conductance measurements of the

water samples from springs and streams ranged

between 12 and 234 μS/cm. Water temperatures in or

east of Keanae Valley ranged from 15.5°C at Big Spring

(787 ft altitude) to 21.4°C in Hanawi Stream (3,550 ft

altitude).

BASE FLOW AND HYDROLOGIC

BUDGETS FOR INDIVIDUAL STREAM

SUBBASINS

The base-flow component of streamflow was estimated using a computerized base-flow separation
32 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

method described by Wahl and Wahl (1995). Two variables, N (number of days) and f (turning-point test factor) must be assigned values in the method. The method

divides the daily streamflow record into non-overlapping N-day periods and determines the minimum flow

within each N-day window. If the minimum flow within

a given N-day window is less than f times the adjacent

minimums, then the central window minimum is made

a turning point on the base-flow hydrograph. Wahl and

Wahl (1995) recommend a value of 0.9 for the turningpoint test factor for most applications. The value of N

determined for each stream is shown in table 2.

West of Keanae Valley

All of the streamflow-gaging stations operated by

the USGS in the study area west of Keanae Valley were

at stream sites underlain by the Kula Volcanics. Therefore, all of the base flow measured at each of the sites

represents ground-water discharge from the high-elevation saturated zone. No gaging stations in this part of the

study area measure discharge from the freshwater lens.

Most of the surface-water gaging stations were

upstream of the Koolau/Wailoa diversion system at

1,200 ft to 1,300 ft altitude. Data for estimating streamflow and base flow are therefore scarce below about

1,200 ft altitude.

None of the gaged streams west of Keanae Valley

have gone dry near 1,200 ft altitude during the period

they were gaged. The total average annual streamflow

of these gaged streams is about 140 Mgal/d at 1,200 ft

to 1,300 ft altitude. It is not possible to estimate the total

average annual streamflow at the coast from existing

records because of the scarcity of gaging stations and

the presence of the diversion systems, which divert

nearly all base flow in the area and an unknown percentage of runoff. Perennial streamflow has been measured

at altitudes greater than 3,000 ft in several of the streams

(Kailua, Waikamoi, and Honomanu Streams) during the

entire period each station was operating. Eight stations

have recorded periods of no flow during their respective

periods of record (table 2). All of these eight sites were

at altitudes higher than 2,800 ft (plate 1).

Discharge from the high-elevation saturated zone

is persistent even during periods of little rainfall.

Although rainfall between the altitudes of 2,000 to

6,000 ft averages almost 1 in/d, periods of days or

weeks occur with less than one inch of total rainfall.

During an exceptionally dry period from December 27,

1952 to February 6, 1953 only 1.6 in. of rain fell at

Paakea (rain gage 350, fig. 2); no rainfall was recorded

21 out of 42 days (fig. 14). Streamflow records show

steady declines in discharge to nearly constant rates

toward the end of this dry period, but no gaged streams

went dry. This indicates that a significant ground-water

source exists upstream of the gaging stations. On February 6, the last day of the driest period, the total flow

of the gaged streams west of Keanae Valley was about

6.7 Mgal. All of this flow was measured above about

1,200 ft altitude.

Total average daily ground-water discharge from

the high-elevation saturated zone upstream of 1,200 ft

altitude and west of Keanae Valley is greater than 38

Mgal/d, all of which is eventually removed from the

streams by surface-water diversion systems. This value

was estimated by adding the estimated base flow at each

gaging station upstream of 1,200 ft to 1,300 ft altitude

from Honopou to Honomanu Streams (table 2). Estimates of average annual base flow in gaged subbasins

west of Keanae Valley range from about 0.05 to 6.9

Mgal/d with the lowest estimates corresponding to gaging stations at the highest altitudes (table 2). Base flow

in five subbasins for which a water budget was estimated averages about 39 percent of the recharge to

these same subbasins (Shade, 1999). Therefore, about

60 percent of the recharge follows a deeper flow path

and either discharges from the high-elevation saturated

zone further downstream or infiltrates to the freshwater

lens and discharges at the coast. Not enough streamflow

records nor measurements are available to estimate the

ground-water discharge rate from the Kula Volcanics at

altitudes lower than 1,200 ft. Measurements in 11

streams west of Keanae Valley at 500 ft altitude show

gains totaling about 1.9 Mgal/d downstream of 1,200 ft

altitude (table 2). Four of the streams were dry at 500 ft

altitude.

Honopou Stream

Honopou Stream is headed at about 2,200 ft altitude 5.3 mi inland along the eastern limit of the north

rift zone of East Maui Volcano (plate 1). From sea level,

the stream gradually rises to 600 ft altitude 1.9 mi from

the coast (a gradient of about 320 ft/mi). At this altitude

the stream valley is incised 80 ft below the upland surface. Along most of this length, the valley lies on a late
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 33

flow of the Kula Volcanics (Stearns and Macdonald,

1942, fig. 11). Currently, streamflow is captured by

three of the surface-water diversion systems (table 4).

Honopou Stream has never been dry at any of the

four USGS gaging stations between 1,208 ft and 383 ft

altitude (table 2, plate 1) although three diversions systems capture base flow in this altitude range. Base-flow

estimates from long-term streamflow records indicate

that the average annual gains from ground water are 2.3

Mgal/d upstream of 383 ft altitude (station 5950) with

50 percent originating upstream of 1,208 ft altitude (station 5870) (table 2, fig. 15A).

Plots of the estimated base flow at pairs of adjacent

stations on the stream show a linear relation (fig. 16).

The slope of the line is an indication of the rate the

stream is gaining base flow between the two gaging stations and the y-intercept of the regression line represents the amount of base flow at the downstream station

when the upstream station is dry. The data points used

in these plots were obtained from the daily base-flow

estimates that were calculated from the base-flow separation method. About 100 points (less than 2 percent of

the data) were filtered out manually because they were

results of obvious misfitting of the base-flow curve during high-flow conditions. Because diversion systems

intercept all of the base flow between each gaging station, the base flow measured at any one gaging station

is added to the total base flow measured at all gaging

stations upstream of the gaging station of interest to

obtain the total undiverted base flow at that gaging station. Because the regression lines all have slopes greater

than 1.0, apparently the stream has a net gain of water

between each gaging station, and the gain per unit

length of stream increases with decreasing stream altitude.

The scatter of the data points around the regression

line shows that the base-flow distribution along the

stream on any given day can vary significantly. This

indicates that flow measurements made during 1 day

along a stream will not provide a complete description

of the stream’s base-flow characteristics. For example,

representative streamflow records showing low baseflow conditions on 2 different days show gains in base

flow range 0.4 to 1.0 Mgal/d between the highest and

lowest altitude gaging stations (table 6).

In a water budget of the 0.65-mi2

 area upstream of

the highest-altitude gaging station, 5870, Shade (1999)

estimated that 5.36 Mgal/d of rainfall and 0.58 Mgal/d

of fog drip are apportioned into 1.93 Mgal/d of runoff,

1.30 Mgal/d of evapotranspiration, and 2.72 Mgal/d of

recharge (table 1, fig. 6). The estimated base flow at the

gaging station (1.21 Mgal/d) is about 44 percent of the

recharge to the subbasin.

Hoolawa Stream

Hoolawa Stream splits into two branches at 550 ft

altitude; Hoolawanui Stream to the west, headed at

2,400 ft altitude, and Hoolawaliilii Stream to the east,

headed at 1,800 ft altitude (plate 1). The highest stream

head is 5.5 mi inland along the eastern limit of the north

rift zone of East Maui Volcano. The stream gradually

rises from sea level to 600 ft altitude 1.8 mi from the

coast (a gradient of 330 ft/mi) and the stream valley is

incised 120 ft below the upland surface at this altitude.

Similar to Honopou Stream, Hoolawa Stream lies on

flows of the Kula Volcanics along most of its length

(Stearns and Macdonald, 1942, fig. 11) and streamflow

is currently captured by three of the surface-water

diversion systems (table 4).

Hoolawa Stream has never been dry at the two gaging stations on branches upstream of the Wailoa Ditch

at 1,200 ft altitude (stations 5850 and 5860) (table 2,

plate 1). Base-flow estimates indicate that the average

annual gains from ground water are 2.68 and 2.34

Mgal/d for the west and east branches, respectively

(table 2, fig. 15B). Streamflow measurements made on

February 5, 1998 during low-flow conditions show

gains in flow of 3.59 Mgal/d along the entire stream

length (table 7). On the basis of these measurements,

Hoolawa Stream does not appear to have any sections

that are losing water. Because the stream flows only on

the Kula Volcanics, it gains water continuously from

the high-elevation saturated zone all the way to the

coast.

In the Hoolawanui Stream water budget (Shade,

1999) of the 1.34-mi2

 area upstream of gaging station

5850, 12.48 Mgal/d of rainfall and 3.12 Mgal/d of fog

drip is apportioned into 5.13 Mgal/d of runoff, 2.39

Mgal/d of evapotranspiration, and 8.09 Mgal/d of

recharge (table 1, fig. 6). For Hoolawaliilii Stream, the

area upstream of gaging station 5860 is smaller, only

0.57 mi2, hence rainfall (5.18 Mgal/d), fog drip (0.45

Mgal/d), runoff (2.52 Mgal/d), evapotranspiration (1.29

Mgal/d), and recharge (1.82 Mgal/d) are smaller. But

even though recharge for this subbasin is only about 22

percent of the recharge to Hoolawanui Stream subbasin,
0

312

RAINFALL, IN INCHES

0.2

200

0.5

125

102050

100

5080

STATION

5100

5150

5160

0.2

200

0.5

125

102050

100

5170

STATION

5180

5190

5200

5 10 15 20 25 31 5 10 15 20 25 31 5 10 1

December January Februa

1952 1953

0.1

200

0.2

0.5

125

102050

100

5270

STATION

5360

5450

STREAMFLOW, IN MILLION GALLONS PER DAY

Figure 14. Daily rainfall at Paakea (rain gage 350) and daily streamflow at selected gaging stations, December 1, 1952 to Janunortheast Maui, Hawaii.

Paakea rain gage 

34 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
0.05

100

0.10.20.5

125

102050

5550

STATIONSTATIONSTATION

5570

5650

5660

0.2

200

0.5

125

102050

100

5700

5770

5 10 15 20 25 31 5 10 15 20 25 31 5 10 

December January Fe

1952 1953

0.1

100

0.2

0.5

125

102050

5850

5860

5870

STREAMFLOW, IN MILLION GALLONS PER DAY

Figure 14. Daily rainfall at Paakea (rain gage 350) and daily streamflow at selected gaging stations, December 1, 1952 to Jnortheast Maui, Hawaii -- Continued.

Base Flow and Hydrologic Budgets for Individual Stream Subbasins 35
0

350

50

100150200250300

ANNUAL RAINFALL,

IN INCHES

KAILUA (rain gage 446) Data not available for 1974, 1977- 78, 1981-82, 1986-present

0312 

08246

ESTIMATED AVERAGE ANNUAL BASE FLOW, IN MILLION GALLONS PER DAY 

1910 1920 1930 1940 1950 1960 1970 1980 

08246

DATE

ABC

36 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
Figure 15. Annual rainfall and estimated average annual baseflow at selected east Maui stream gages, Hawaii.

0

15

5

10

STATION 5700

0.20.80.40.6

ESTIMATED AVERAGE ANNUAL BASE FLOW, IN MILLION GALLONS PER DAY STATION 5660

1910 1920 1930 1940 1950 1960 1970 1980 

0.52.01.01.5

STATION 5650

DATE

DE

F

021

G

Base Flow and Hydrologic Budget for Individual Stream Subbasins 37
0

350

50

100150200250300

ANNUAL RAINFALL,

IN INCHES

KAILUA (rain gage 446) Data not available for 1974, 1977- 78, 1981-82, 1986-present

08246

ESTIMATED AVERAGE ANNUAL BASE FLOW, IN MILLION GALLONS PER DAY 

1910 1920 1930 1940 1950 1960 1970 1980 

0

15

5

10 

DATE

HI

0624 

J

38 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
0624

ESTIMATED AVERAGE ANNUAL BASE FLOW, IN MILLION GALLONS PER DAY

1910 1920 1930 1940 1950 1960 1970 1980 

0624 

Figure 15. Annual rainfall and estimated average annual base flow at selected east Maui stream gages, Hawaii -- Continued.

DATE

2

10

468 STATION 5160

N

0

10

5

M 

KL

Base Flow and Hydrologic Budget for Individual Stream Subbasins 39
0

350

50

100150200250300

ANNUAL RAINFALL,

IN INCHES

ESTIMATED AVERAGE ANNUAL BASE FLOW, IN MILLION GALLONS PER DAY

264

STATION 5150

PAAKEA (rain gage 350) Data not available for 1942, 1968-69, 1973, 1977-80, 1982-present

O

0312 

0624 

PQ

1910 1920 1930 1940 1950 1960 1970 1980 

DATE

40 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii
ST

ESTIMATED AVERAGE ANNUAL BASE FLOW, 

IN MILLION GALLONS PER DAY

0

20

10

Figure 15. Annual rainfall and estimated average annual base flow at selected east Maui stream gages, Hawaii -- Continued.

R

1910 1920 1930 1940 1950 1960 1970 1980 

0624 

DATE

S

Base Flow and Hydrologic Budget for Individual Stream Subbasins 41

Base Flow and Hydrologic Budgets for Individual Stream Subbasins 43

Table 6. Streamflow in Honopou Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; 1933 data from Grover and Carson (1936); 1946 data from Paulsen (1950); gaging-station number is

preceded by 16 and ends in 00]

Gagingstation

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion

(Mgal/d) Comments

5950 Honopou 383 10/21/33

7/5/46

0.29

0.67

0.54

1.42

Daily mean

5930 Honopou 441 10/21/33

7/5/46

0.10

0.20

0.25

0.75

Daily mean; upstream of

Haiku Ditch diversion

5910 Honopou 557 10/21/33

7/5/46

0.05

0.10

0.15

0.55

Daily mean; upstream of

Lowrie Ditch diversion

5870 Honopou 1,208 10/21/33

7/5/46

0.10

0.45

0.10

0.45

Daily mean; upstream of

Wailoa Ditch diversion

Table 7. Streamflow, temperature, specific conductance, and chloride concentration in Hoolawa Stream, February 5, 1998,

northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; μS/cm, microsiemens per centimeter; mg/L, milligrams per liter; --, not determined; all

altitudes estimated from U.S. Geological Survey topographic map, Haiku quadrangle; gaging-station number is preceded by 16 and ends in 00]

Station

number Stream name

Altitude

(ft)

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion

(Mgal/d)

Water

temperature

(°C)

Water

specific

conductance

(μS/cm)

Chloride

concentration

(mg/L) Comments

Hoolawa 1 Hoolawa 15 0.19 3.59 18.4 161 34

Hoolawa 2 Hoolawa 315 0.08 3.47 20.9 126 25

Hoolawa 2a Hoolawa 420 0.00 -- -- -- -- Diversion takes all flow

Hoolawa 3 Hoolawa 450 0.25 3.39 19.5 97 19 Upstream of Haiku Ditch

diversion

Hoolawa 5 Hoolawanui 590 0.07 -- -- -- -- Diversion takes most flow

Hoolawa 6 Hoolawanui 600 0.25 1.49 -- -- 16 Upstream of Lowrie Ditch

diversion

Hoolawa 7 Hoolawanui 1,080 0.00 -- -- -- -- Diversion takes all flow

Hoolawa 8 Hoolawanui 1,210 1.24 1.24 16.2 54 9 Near gaging station 5850;

upstream of Wailoa Ditch

diversion

Hoolawa 9 Hoolawaliilii 590 0.03 -- -- -- -- Diversion takes most flow

Hoolawa 10 Hoolawaliilii 620 0.53 1.75 -- -- 15 Upstream of Lowrie Ditch

diversion

Hoolawa 11 Hoolawaliilii 1,190 0.00 -- -- -- -- Diversion takes all flow

Hoolawa 12 Hoolawaliilii 1,220 1.22 1.22 14.9 55 10 Near gaging station 5860;

upstream of Wailoa Ditch

diversion

Hoolawa 12.1 unnamed tributary 1,200 0.01 -- -- -- --
44 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

the average annual base flow is 87 percent of the Hoolawanui Stream base flow. The amount of base flow in

Hoolawanui Stream is about 33 percent of the estimated

recharge to the subbasin while in Hoolawaliilii Stream,

the base flow is about 128 percent of the recharge estimated for its subbasin (table 1). This probably indicates

that the ground-water divides are significantly different

than the topographic divides used in the water-budget

estimation and that part of the recharge attributed to the

Hoolawanui Stream subbasin actually belongs in the

Hoolawaliilii Stream ground-water subbasin. The spatial distribution of the two subbasins also supports this

conclusion because much of the Hoolawanui Stream

subbasin lies directly upslope of the Hoolawaliilii

Stream subbasin (fig. 3). The flow-duration curves of

the base flow at each gaging station show that even

though gaging station 5850 measured a higher average

annual base flow, base flow at gaging station 5860 is

higher about 50 percent of the time (fig. 17) indicating

that base flow in Hoolawaliilii Stream is more persistent

than in Hoolawanui Stream.

Kailua Stream

Kailua Stream is headed at 4,000 ft altitude 11 mi

inland near several cinder cones along the eastern limit

of East Maui Volcano’s north rift zone (plate 1). The

stream rises from sea level to 600 ft altitude 1.4 mi from

the coast (a gradient of 420 ft/mi) and at this altitude the

stream valley is incised 120 ft below the upland surface.

2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9 99.99

0.1

100

0.2

0.3

0.4

0.5

0.7

1

2

3

4

5

7

10

20

30

40

50

70

5850

STATION

5860

PERCENTAGE OF TIME INDICATED VALUE WAS EQUALLED OR EXCEEDED

DISCHARGE, IN CUBIC FEET PER SECOND

Figure 17. Flow-duration curves showing the percentage of time a given 

flow was equalled or exceeded at gaging stations 5850 and 5860 on 

Hoolawa Stream, northeast Maui, Hawaii.
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 45

The stream valley lies on a flow of the Kula Volcanics

along much of its length but Honomanu Basalt outcrops

at the ocean (Stearns and Macdonald, 1942, fig. 11).

Oanui Stream forms a tributary to the west at 1,200 ft

altitude. Streamflow is captured by all six surface-water

diversion systems but the highest systems probably only

capture surface runoff (table 4).

Kailua Stream has never been dry at the five gaging stations upstream of the Wailoa Ditch, which is at

1,200 ft altitude (table 2, plate 1). The average annual

gains from ground water are 4.2 Mgal/d between 3,080

ft (station 5745) and 1,253 ft altitude (station 5770)

(table 2, fig. 15C). Streamflow measurements made at

three sites on November 2, 1932 (Hofmann, 1934) and

concurrently at four gaging stations (Grover and Carson, 1935), show gains in flow of 1.6 Mgal/d between

3,080 ft and 1,250 ft altitude during low-flow conditions (table 8). A stream section on the East Branch at

about 3,000 ft altitude lost 0.03 Mgal/d of water and

went dry, but by 2,420 ft altitude, it had gained all of

this water plus 50 percent more back (Hofmann, 1934).

This apparent loss is most likely because plastering

lavas of the Kula Volcanics have altered the surface of

the previous stream channel, allowing water to flow

beneath some younger lava flows before reemerging

further downstream. No data or observations are available to determine if the stream loses water where it

flows over the Honomanu Basalt near the coast.

The area upstream of gaging station 5770 is 2.39

mi2

 and in the water budget (Shade, 1999), 23.92

Mgal/d of rainfall and 7.22 Mgal/d of fog drip is apportioned into 15.17 Mgal/d of runoff, 3.62 Mgal/d of

evapotranspiration, and 12.36 Mgal/d of recharge (table

1, fig. 6). The estimated base flow at the gaging station

is about 35 percent of the recharge to the subbasin.

Nailiilihaele Stream

Nailiilihaele Stream is headed near an unnamed

cinder cone at 3,400 ft altitude 9 mi inland from the

coast (plate 1). The stream rises from sea level at the

same gradient (420 ft/mi) as adjacent Kailua Stream;

the stream valley is incised to the same depth (120 ft)

and is also floored by a flow of the Kula Volcanics

(Stearns and Macdonald, 1942, fig. 11). Streamflow is

captured by four of the surface-water diversion systems,

the highest of which probably captures only surface

runoff (table 4).

Of the five gaging stations on Nailiilihaele Stream,

only one (station 5700) was a continuous-record station

with a long period of record (Fontaine, 1996). Gaging

stations 5690 and 5710 have records of less than a year

and gaging stations 5691 and 5697 were low-flow partial-record stations where only a few measurements

were made. The stream was never dry at 1,205 ft altitude during 1919–75 (station 5700) (table 2, plate 1).

Base-flow estimates using this long-term record indicate that the average annual gain from ground water

upstream of this gaging station is 6.92 Mgal/d (table 2,

fig. 15D). Most of this gain is likely made downstream

of 2,820 ft altitude because gaging station 5691 measured periods of no flow at that altitude. Representative

streamflow records from 2 days when the three gaging

stations were operating concurrently show that base

flow is variable and total gains in flow ranged from 2.48

to 11.25 Mgal/d during base-flow conditions (U.S. Geological Survey, 1967, and 1969) (table 9).

Table 8. Streamflow in Kailua Stream, November 2, 1932, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; all altitudes estimated from U.S. Geological Survey topographic maps, Haiku and Kilohana quadrangles;

1932 flow data from Hofmann (1934) and daily-discharge data from Grover and Carson (1935); gaging-station number is preceded by 16 and ends

in 00]

Station

number Stream name

Altitude

(ft)

Streamflow

(Mgal/d) Comments

5770 Kailua 1,250 1.70 Daily mean at gaging station; upstream of Wailoa

Ditch diversion

5740 Kailua 3,080 0.04 Daily mean at gaging station

Kailua 30 East Branch Kailua Stream 2,420 0.05

Kailua 40 East Branch Kailua Stream 2,980 0.00

Kailua 41 East Branch Kailua Stream 3,080 0.03

5750 Tenth Branch Kailua Stream 3,100 0.03 Daily mean at gaging station

5760 Ninth Branch Kailua Stream 3,080 0.06 Daily mean at gaging station
46 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

In a water budget of the 3.61 mi2 area upstream of

gaging station 5700, Shade (1999) estimated that 34.79

Mgal/d of rainfall and 8.81 Mgal/d of fog drip is apportioned into 17.46 Mgal/d of runoff, 6.30 Mgal/d of

evapotranspiration, and 19.84 Mgal/d of recharge (table

1, fig. 6). The estimated base flow at the gaging station

is about 37 percent of the recharge estimated for the

subbasin.

Oopuola Stream

Oopuola Stream is headed at 1,900 ft altitude 4 mi

inland from the coast (plate 1). This stream rises from

sea level to 600 ft altitude 1.2 mi from the coast (a gradient of 490 ft/mi) and the stream valley is incised 200

ft below the upland surface at this altitude. For 2,000 ft

inland, the stream valley has eroded into the Honomanu

Basalt, upstream it lies on lava flows of the Kula Volcanics (Stearns and Macdonald, 1942, fig. 11). Streamflow is captured by two of the surface-water diversion

systems (table 4).

During 1930–57, gaging station 5660 was operated

at 1,205 ft altitude and Oopuola Stream was never dry

(table 2, plate 1). The estimated average annual base

flow at this gaging station is 0.39 Mgal/d (table 2, fig.

15E). Gaging station 5670 was operated during 1910–

15 at 960 ft altitude (Grover and Larrison, 1917) but

upstream, the New Hamakua Ditch diverted only part of

the streamflow so it is impossible to estimate what percentage of the recorded flow originated downstream of

the diversion point. This stream was observed to be dry

in March 1928 by EMI personnel at about 500 ft altitude

during a period of low flow (table 10). On May 5, 1998,

the author observed a small flow of water over a 50-ft

Table 10. Streamflow in selected streams, March 16–20,

1928, northeast Maui, Hawaii

[ft3/s, cubic feet per second; Mgal/d, million gallons per day; all data

from unpublished notes in files at U.S. Geological Survey, Honolulu,

Hawaii of H.T. Stearns, January 8, 1942 referencing earlier

measurements made by East Maui Irrigation Co. Inc.; all measurements

were made at about 500 ft altitude]

Site name

(plate 1) Stream name

Streamflow

(ft3/s)

Streamflow

(Mgal/d)

E1 Pa Stream 0.31 0.2

E2 Oopuola Stream 0.00 0.0

E3 Kaaiea Stream 0.15 0.1

E4 Kolea Stream 0.16 0.1

E5 Waikamoi Stream 0.31 0.2

E6 Wahinepee Stream 0.46 0.3

E7 Puohokamoa Stream 0.16 0.1

E8 Haipuaena Stream 0.00 0.0

E9 Punalau Stream 0.00 0.0

E10 Honomanu Stream 0.00 0.0

E11 Nuaailua Stream 0.31 0.2

E12 Piinaau Stream 0.47 0.3

E13 Waiokamilo Stream 3.7 2.4

E14 Wailuanui Stream 0.31 0.2

E15 West Wailuaiki

Stream

0.78 0.5

E16 East Wailuaiki

Stream

0.31 0.2

E17 Kopiliula Stream 0.00 0.0

E18 Puakaa Stream 0.62 0.4

E19 Waiohue Stream 0.62 0.4

E20 Paakea Stream 2.8 1.8

E21 Waiaaka Stream 0.62 0.4

E22 Kapaula Stream 2.3 1.5

E23 Hanawi Stream 20.5 13.2

Table 9. Streamflow in Nailiilihaele Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; --, not determined; 1966 data from U.S. Geological Survey (1967); 1967 data from U.S. Geological Survey (1969);

gaging-station number is preceded by 16 and ends in 00]

Gagingstation

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion

(Mgal/d) Comments

5700 Nailiilihaele 1,205 11/28/66

10/4/67

10.99

2.46

11.25

2.48

Daily mean; upstream of Wailoa Ditch diversion

5691 Nailiilihaele 2,820 11/28/66

10/4/67

0.03

0.00

--

--

Instantaneous measurement; downstream of

Lower Kula Pipeline diversion

5697 West Branch

Nailiilihaele

2,860 11/28/66

10/4/67

0.26

0.03

0.26

0.03

Instantaneous measurement; upstream of Lower

Kula Pipeline diversion
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 47

high waterfall 2,000 ft upstream from the coast at 40 ft

altitude. This flow seeped into the streambed within a

few hundred feet downstream of the waterfall and the

stream was dry at the coast. The waterfall seemed to be

formed by a thick lava flow thought to be part of the

Kula Volcanics and the stream went dry on thin-bedded

lava flows thought to be the Honomanu Basalt. A water

budget was not calculated for this stream subbasin.

Kaaiea Stream

Kaaiea Stream is headed near 3,000 ft altitude

between Nailiilihaele and Waikamoi Streams (plate 1).

The stream rises from sea level at a steep gradient to 600

ft altitude 0.6 mi from the coast (a gradient of 1,000

ft/mi) and the stream valley is incised 200 ft below the

upland surface. The valley lies on the Honomanu Basalt

for 1,000 ft from the coast and the Kula Volcanics from

there to the headwaters (Stearns and Macdonald, 1942).

Streamflow is captured by three of the surface-water

diversion systems (table 4).

Kaaiea Stream was never dry during 1921–62 at

gaging station 5650 at 1,310 ft altitude (table 2, plate 1).

Base-flow estimates from long-term streamflow

records indicate that the average annual gains from

ground water are about 1.13 Mgal/d upstream of this

altitude (table 2, fig. 15F). A measurement made by

EMI personnel during a period of low flow at 500 ft altitude showed a streamflow of 0.1 Mgal/d (table 10). All

of this water was gained downstream of the lowest

diversion system at 700 ft altitude. No water budget was

calculated for this stream subbasin.

Waikamoi Stream

Waikamoi Stream is one of the longer streams in

the study area. The stream is 8.5 mi long from the ocean

to the head of several tributaries near Hosmer Grove

Spring at 6,560 ft altitude (plate 1). Alo Stream, a major

tributary, branches to the east at about 840 ft altitude.

Waikamoi Stream rises from sea level to 600 ft altitude

0.8 mi from the coast (a gradient of 790 ft/mi) and at this

altitude the stream valley is incised 280 ft below the

upland surface. Waikamoi Stream lies on Honomanu

Basalt for 3,000 ft from the coast and then on Kula Volcanics to the stream head where cinder cones of the volcano’s north rift zone are located (Stearns and

Macdonald, 1942). Streamflow is captured by five

surface-water diversion systems (table 4).

Waikamoi Stream has not gone dry at any of the

gaging stations downstream of 3,000 ft altitude during

the periods of record despite the presence of Upper and

Lower Kula diversion systems (table 2, plate 1). The

stream has gone dry upstream of these diversion systems at gaging stations 5530 (4,250 ft altitude), 5528

(4,487 ft altitude), and 5526 (5,750 ft altitude). Base

flow at 3,000 ft altitude in the two stream branches

above gaging stations 5540 and 5545 is 1.7 Mgal/d and

increases to 3.02 Mgal/d at 1,300 ft altitude (station

5550), a gain of 1.3 Mgal/d (table 2, fig. 15G–H). Alo

Stream, headed at about 2,400 ft altitude, also gains an

average of about 1.3 Mgal/d upstream of 1,248 ft altitude (station 5570), but along a shorter stream distance

(plate 1).

Streamflow measurements made on October 18

and 24, 1994 during low-flow conditions show gains in

flow of 1.68 Mgal/d between 3,160 ft and 490 ft altitude

(table 11). The cumulative streamflow data were

obtained by converting the October 24 measurements to

equivalent October 18 measurements using a ratio of

flow measurements made at site Waikamoi 33 on both

days. Measurements were not made downstream of 490

ft altitude because the terrain prevented access. On the

basis of the streamflow measurements, Waikamoi

Stream (1) appears to be perennial upstream of 500 ft

altitude and at the least downstream of 3,000 ft altitude,

and possibly as high as 4,200 ft altitude and (2) does not

have any measured sections that are losing water. No

measurements were made where the stream flows on

the Honomanu Basalt.

In the Waikamoi Stream water budget (Shade,

1999) of the 2.46-mi2

 area upstream of gaging station

5280, 9.19 Mgal/d of rainfall and 1.18 Mgal/d of fog

drip is apportioned into 1.29 Mgal/d of runoff, 3.22

Mgal/d of evapotranspiration, and 5.87 Mgal/d of

recharge (table 1, fig. 6). Because the gaged subbasin

lies at higher altitudes with less precipitation than the

rest of the subbasins included in Shade’s study (fig. 3),

it has a smaller ratio of precipitation to the stream subbasin area (fig. 6). Hence, the water-budget components

are all proportionately smaller. The amount of base flow

estimated from the streamflow record is only about 1

percent of the recharge to the subbasin (table 1). Most

of the recharge is apparently following deeper groundwater flow paths and discharging downgradient of this

gaging station.
48 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

a Estimated flow

Table 11. Streamflow, temperature, and specific conductance in Waikamoi Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; μS/cm, microsiemens per centimeter; --, not determined; all altitudes estimated from U.S.

Geological Survey topographic maps, Haiku, Keanae, and Kilohana quadrangles; measured flow from October 24 was scaled by 0.828 to make flow

equivalent to October 18 flow for cumulative flow calculation; 1931 flow data is from Hofmann (1934); all other data is unpublished in files of U.S.

Geological Survey, Hawaii District office]

Station

number Stream name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion,

October 18,

1994

(Mgal/d)

Water

temperature

(°C)

Water

specific

conductance

(μS/cm) Comments

Waikamoi 7a Waikamoi 490 10/18/94 0.14 1.68 22.0 108

Waikamoi 8 unnamed

tributary

500 10/18/94 -- -- 21.9 87 Tributary from spring on

east bank

Waikamoi 8a Waikamoi 510 10/18/94 0.11 1.65 21.9 153

Waikamoi 9 Waikamoi 515 9/10/95 -- -- 21.9 153 Waikamoi Spring at 515

ft, on west bank at

highway

Waikamoi 9a Waikamoi 520 10/18/94

9/10/95

--

--

--

--

21.2

22.8

119

119

Waikamoi Spring at 520

ft, on east bank

Waikamoi 10 Waikamoi 530 10/18/94 0.02 1.56 23.0 84

Waikamoi 11 Waikamoi 680 10/18/94 0.01 1.54 22.2 74 Most flow diverted

Waikamoi 14 Waikamoi 720 10/18/94 0.37 1.54 22.4 80 Upstream of Manuel

Luis Ditch diversion

Waikamoi 15 Waikamoi 760 10/18/94 0.32 1.50 22.8 78

Waikamoi 16 Waikamoi 820 10/18/94 0.36 1.53 23.3 75 Downstream of confluence with Alo Stream

Waikamoi 17 Waikamoi 860 10/18/94 0.15 1.32 23.2 81 Upstream of confluence

with Alo Stream

Waikamoi 29a Alo 1,210 10/24/94 0.69 -- 20.3 42 Upstream of Wailoa

Ditch diversion

Waikamoi 32 Waikamoi 1,190 10/18/94 0.01 1.19 -- --

Waikamoi 33 Waikamoi 1,250 10/18/94

10/24/94

0.53

0.64

1.19

--

21.8

20.2

42

40

Upstream of Wailoa

Ditch diversion

Waikamoi 40 Waikamoi 1,780 10/24/94 0.55 1.11 20.6 37

Waikamoi 45 Waikamoi 2,360 10/24/94 0.33 0.93 19.4 36 Downstream of confluence with East Branch

Waikamoi

Waikamoi 45a Waikamoi

(east branch)

2,420 10/20/31 0.34 -- -- --

Waikamoi 45b Waikamoi

(east branch)

2,560 10/20/31 0.20 -- -- --

Waikamoi 46 Waikamoi 2,375 10/24/94 0.19 0.82 18.0 36 Upstream of East Branch

Waikamoi

Waikamoi 55a flume inflow 3,135 10/18/94 0.13 -- 18.5 18

Waikamoi 56 Waikamoi 3,160 10/18/94 0.72 0.72 19.0 38 Upstream of flume inflow

Waikamoi 60 Waikamoi 4,270 10/18/94 0.00 0.00 -- -- Downstream of Upper

Kula Pipeline diversion dam

Waikamoi 65 Waikamoi 4,500 10/18/94 0.02 0.02 16.0 16

Waikamoi 72 Waikamoi 6,290 10/17/94 0.00 0.00 -- --

Waikamoi 73 Waikamoi

(west branch)

6,400 10/17/94 0.00 0.00 -- --
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 49

Puohokamoa Stream

Puohokamoa Stream splits into three main

branches at 2,100 ft altitude; the longest is the middle

branch that is headed at 4,400 ft altitude 6.4 mi inland

(plate 1). The stream rises steeply from sea level to 600

ft altitude 0.6 mi from the coast (a gradient of 930 ft/mi)

and at this altitude the stream valley is incised 200 ft

below the upland surface. With the exception of 3,000

ft of Honomanu Basalt at the coast, this stream lies on

lava flows of the Kula Volcanics along most of its

length (Stearns and Macdonald, 1942). Streamflow is

captured by five of the surface-water diversion systems

(table 4).

Puohokamoa Stream was never dry during 1913–

71 at gaging station 5450 at 1,322 ft altitude (table 2,

plate 1). At the gaging stations at about 2,800 ft altitude

on the three stream branches, streamflow was perennial

in the west (station 5440) and middle (station 5430)

branches but went dry in the shorter east (station 5420)

branch during 1919–27 when the gaging stations were

operated concurrently. Base-flow estimates from longterm streamflow records indicate that the average

annual gains from ground water are about 5.46 Mgal/d

upstream of 1,322 ft altitude, 2.8 Mgal/d of this flow is

gained downstream of 2,800 ft altitude (table 2, fig.

15I).

Several sets of streamflow measurements in sections of the stream branches also show continuous

streamflow gains upstream of 1,300 ft altitude (table

12). Measurements were made some time in the 1920’s

between 2,050 and 1,300 ft altitude that show a gain of

about 0.6 Mgal/d (written commun. from J.H. Hofmann

Table 12. Streamflow in Puohokamoa Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; all altitudes estimated from U.S. Geological Survey topographic maps, Haiku, Keanae, Kilohana, and Nahiku

quadrangles; 1920 flow data from Hofmann; written commun. to Foss, 11/17/32, in U.S. Geological Survey Hawaii District files and daily-discharge data from

Grover and Stewart (1924); 1932 and 1933 flow data from Hofmann (1934) and daily-discharge data from Grover and Carson (1935); all 1962 data from U.S.

Geological Survey (undated[a]); 1963 daily-discharge data from U.S. Geological Survey (undated[b]); gaging-station number is preceded by 16 and ends in

00]

Station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d) Comments

5450 Puohokamoa 1,322 1920

2/3/20

10/29/32

10/30/32

6/12/33

4/10/62

4/11/63

1.60

1.60

1.20

1.70

2.60

3.62

2.59

Daily mean at gaging station; upstream of

Spreckels Ditch diversion

Puohokamoa 11 Puohokamoa 1,500 1920 1.53

Puohokamoa 12 Puohokamoa 1,650 1920 1.49

Puohokamoa 13 Puohokamoa 1,900 1920 1.20

Puohokamoa 14 Puohokamoa 2,050 1920 0.96

Puohokamoa 19 West Branch

Puohokamoa

2,440 10/30/32 0.40

5440 West Branch

Puohokamoa

2,800 2/3/20

10/30/32

4/11/63

0.40

0.36

0.21

Daily mean at gaging station

Puohokamoa 21 West Branch

Puohokamoa

2,850 4/10/62 0.28

Puohokamoa 29 Middle Branch

Puohokamoa

2,400 6/12/33 0.26

5430 Middle Branch

Puohokamoa

2,900 2/3/20

6/12/33

4/10/62

4/11/63

0.20

0.31

0.32

0.15

Daily mean at gaging station

Puohokamoa 31 Middle Branch

Puohokamoa

3,080 4/10/62 0.28

Puohokamoa 32 Middle Branch

Puohokamoa

3,200 4/10/62 0.14

Puohokamoa 39 East Branch

Puohokamoa

2,460 10/29/32 0.25

5420 East Branch

Puohokamoa

2,800 2/3/20

10/29/32

4/11/63

0.05

0.14

0.13

Daily mean at gaging station
50 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

to J.H. Foss, November 17, 1932 in USGS Hawaii District files). Streamflow data from February 3, 1920 confirm this pattern (table 12). Measurements were also

made on October 29–30, 1932 and June 12, 1933

between 2,900 ft and 2,400 ft altitude during base-flow

conditions that show gains of about 0.1 Mgal/d in the

east and west branches and a slight loss of about 0.05

Mgal/d in the middle branch (Hofmann, 1934). The latter measurement represents only a 15 percent difference

between the upstream and downstream measurements;

therefore, this value is probably about the same magnitude as the measurement error inherent in the method

used in that particular study. Four measurements were

made on April 10, 1962, three on the middle branch

between 3,200 ft and 2,900 ft altitude and one on the

west branch at 2,850 ft altitude (U.S. Geological Survey, undated [a]). These measurements show a gain of

about 0.2 Mgal/d in the middle branch. A measurement

made in March 1928 by EMI shows a gain of about 0.1

Mgal/d between 900 ft and 500 ft altitude (table 10). No

measurements were made where the stream flows over

the Honomanu Basalt. No water budget was calculated

for the Puohokamoa Stream subbasin.

Haipuaena Stream

Haipuaena Stream is headed near 5,200 ft altitude

between Waikamoi and Honomanu Streams, 6.5 mi

from the coast (plate 1). The Haipuaena Stream valley

is similar in gradient and incision to adjacent Puohokamoa Stream valley at 600 ft altitude but is steeper at the

coast. The contact between the Honomanu Basalt and

the overlying Kula Volcanics is within 1,000 ft of the

shore, which accounts for the steep gradient of

Haipuaena Stream near the coast (Stearns and Macdonald, 1942). Streamflow is captured by five of the

surface-water diversion systems (table 4). In addition,

water was diverted at 1,880 ft altitude into Kolea

Stream to the east from 1938 to 1960 to generate electricity.

Seven gaging stations were operated on Haipuaena

Stream and two of the diversion ditches (Fontaine,

1996) (table 2, plate 1). At the Upper Kula Pipeline near

4,300 ft altitude, gaging station 5310 recorded the

diverted flow and gaging station 5311 recorded streamflow past the diversion. These two records were added

together to obtain the total flow at this altitude (0.97

Mgal/d) and the estimated average annual base flow

(0.14 Mgal/d) for 1947–67 (fig. 15J). Three gaging stations measured flow for less than a year on three stream

branches at about 2,900 ft altitude. Streamflow diverted

into Kolea Stream was measured at gaging station 5350.

This record was added to the streamflow record from

gaging station 5360 (1,512 ft altitude) upstream of

Spreckels Ditch to obtain a record of the total streamflow (table 2) and a base-flow estimate at this altitude

(fig. 15J). The base-flow estimates indicate that the

average annual gains from ground water are 2.5 Mgal/d

between 4,300 ft and 1,500 ft altitude.

Streamflow measurements were also made on two

occasions along several stream sections (table 13, plate

1). Measurements were made some time in the 1920’s

between 2,860 and 1,510 ft altitude that show continuous gains totaling about 0.9 Mgal/d (written commun.

from J.H. Hofmann to J.H. Foss, November 17, 1932 in

USGS Hawaii District files). Streamflow data from

gaging stations 5360 and 5320 on two dates in 1962 and

1965 confirm this pattern (table 13). Measurements

were also made on October 13, 1932 between 2,860 ft

and 2,500 ft altitude during low base-flow conditions

(table 13). These measurements, along with concurrent

records from gaging stations, show a gain of about 0.1

Mgal/d in this short reach of the main branch of

Haipuaena Stream (Hofmann, 1934). Overall,

Haipuaena Stream appears to gain water continuously

upstream of 1,500 ft altitude from at least as high as

4,300 altitude. EMI records from March 1928 show that

the stream was dry at about 500 ft altitude indicating no

gain in flow downstream of the lowest diversion system

at about 900 ft altitude (table 10). A water budget was

not estimated for this subbasin.

Honomanu Stream

Honomanu Stream is one of the longest streams in

the study area (8.7 mi) and headed at one of the highest

altitudes (7,800 ft) (plate 1). The stream also has the

most deeply incised valley in the study area (excluding

Keanae Valley), nearly 1,000 ft below the upland surface at 600 ft altitude. Accordingly, the stream gradient

near the coast is low compared with adjacent streams,

about 470 ft/mi. Honomanu Basalt is well exposed

along the valley walls and floor for 2.5 mi from the

coast but upstream of this point (1,600 ft altitude) only

Kula Volcanics are present (Stearns and Macdonald,

1942). Unconsolidated alluvial deposits are found as far

as 3,000 to 4,000 ft upstream from the coast. Stream-
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 51

flow is captured by three of the surface-water diversion

systems (table 4).

Honomanu Stream has never been dry at gaging

station 5270 immediately upstream of the Spreckels

Ditch at 1,733 ft altitude nor at gaging stations 5240,

5260, and 5250 at 2,900 ft altitude on three stream

branches (table 2, plate 1). Base-flow estimates from

the two long-term streamflow records on the main

branch indicate that the average annual gains from

ground water are about 0.6 Mgal/d between gaging station 5240 at 2,900 ft altitude and gaging station 5270 at

1,733 ft altitude (table 2, fig. 15K). Independent sets of

streamflow measurements were made three times (table

14). Measurements were made some time in the 1920’s

between 3,030 ft and 1,733 ft altitude that show a gain

of about 1.6 Mgal/d (written commun. from J.H. Hofmann to J.H. Foss, November 17, 1932 in USGS Hawaii

District files). Streamflow data from August 19, 1920

confirm this pattern (table 14). A set of measurements

along a 3,000-ft section between 2,900 ft and 2,500 ft

altitude on October 7, 1932 shows gains of about 0.10

Mgal/d (Hofmann, 1934). As part of this study, streamflow measurements were made on June 20, 1995

between 3,050 ft altitude and the coast. These measurements show a total gain of about 1 Mgal/d upstream of

1,733 ft altitude and a minor gain downstream to about

360 ft altitude. EMI records indicate that the stream was

dry in March 1928 at about 500 ft altitude (table 10).

Because several waterfalls make access to the stream at

500 ft altitude difficult, this measurement was likely

made at the base of the falls near 360 ft altitude. Downstream of 360 ft altitude (Honomanu 10a, plate 1, at the

base of a large waterfall), base flow decreased and the

stream was dry between 90 ft and 2 ft altitude. During

low-flow conditions no total gain downstream of about

1,733 ft altitude probably exists until close to sea level.

Near sea level, about 1.4 Mgal/d of flow issues from

several springs in the Honomanu Basalt. These springs

a Instantaneous measurement

Table 13. Streamflow in Haipuaena Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; all altitudes estimated from U.S. Geological Survey topographic maps, Keanae, Kilohana, and Nahiku quadrangles;

1920 flow data from Hofmann; written commun. to Foss, 11/17/32, in U.S. Geological Survey Hawaii District files; 1932 flow data from Hofmann (1934) and

daily-discharge data from Grover and Carson (1935); 1963 daily-discharge data from U.S. Geological Survey (undated[b]); 1965 daily-discharge data from

U.S. Geological Survey (1967); gaging-station number is preceded by 16 and ends in 00]

Station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d) Comments

5360 Haipuaena 1,512 1920

10/13/32

10/18/62

1/12/65

1.10a

0.70

1.00

1.00

Daily mean at gaging station; upstream of

Spreckels Ditch diversion

Haipuaena 20 Haipuaena 1,750 1920 0.83a

Haipuaena 30 Haipuaena 1,850 1920 0.97a

Haipuaena 40 Haipuaena 1,950 1920 0.61a

Haipuaena 41 Third Branch

Haipuaena

2,000 1920 0.11a

Haipuaena 42 Haipuaena 2,000 1920 0.50a

Haipuaena 50 Haipuaena 2,500 1920

10/13/32

0.36a

0.39

Haipuaena 51 Haipuaena 2,580 10/13/32 0.35

Haipuaena 52 Haipuaena 2,680 10/13/32 0.30

Haipuaena 53 Haipuaena 2,800 10/13/32 0.29

5320 Haipuaena 2,860 1920

10/13/32

10/18/62

1/12/65

0.20a

0.26

0.23

0.24

Daily mean at gaging station; upstream of

Lower Kula Pipeline diversion

5340 First Branch

Haipuaena

3,000 10/13/32 0.01 Daily mean at gaging station

5330 Third Branch

Haipuaena

2,950 10/13/32 0.10 Daily mean at gaging station

5310; 5311 Haipuaena 4,320 10/18/62

1/12/65

0.03

0.07

Combined flow at gaging stations; at Upper

Kula Pipeline diversion
52 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

a Assumes negligible unmeasured leakage past diversion structuresb Instantaneous measurementc Estimated using base-flow record from gaging stations 5240 and 5270

Table 14. Streamflow, temperature, and specific conductance in Honomanu Stream, northeast Maui, Hawaii[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; μS/cm, microsiemens per centimeter; --, not determined; altitudes estimated from U.S. Geological SurvKilohana, and Nahiku quadrangles; 1920 flow data from Hofmann; written commun. to Foss, 11/17/32, in U.S. Geological Survey Hawaii District files and daily-disch(1924); 1932 flow data from Hofmann (1934) and daily-discharge data from Grover and Carson (1935); all other data is unpublished in files of U.S. Geological Surveotherwise noted; gaging-station number is preceded by 16 and ends in 00]

Station

number

(plate 1)

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow without

diversion, June 20,

1995a

(Mgal/d)

Water

temperature

(°C)

Water specific

conductance

(μS/cm) 

Honomanu 2 Honomanu

(east branch)

2 6/20/95 0.59 -- 20.6 184

Honomanu 2a Honomanu

(west branch)

2 6/20/95 0.78 -- 20.6 264

Honomanu 4 Honomanu 30 6/20/95 0.0 0.00 -- --Honomanu 5 Honomanu 35 6/20/95 0.0 0.00 -- --Honomanu 6 Honomanu 50 6/20/95 0.0 0.00 -- --Honomanu 7 Honomanu 90 6/20/95 0.0 0.00 -- --Honomanu 8a Honomanu 240 6/20/95 0.06 0.06 24.6 110Honomanu 9 Uluini 310 6/20/95 0.01 -- 24.9 50Honomanu 10a Honomanu 360 6/20/95 0.08 1.01 22.3 36Honomanu 11a Honomanu

(east unnamedtributary)

1,750 6/20/95 0.0 -- -- -- Do

Honomanu 11 Honomanu

(east unnamedtributary)

1,770 6/20/95 0.67 -- 20.6 32.5 Up

Honomanu 12 Spring 1,810 6/20/95 0.01 -- 21.6 675270 Honomanu 1,733 1920

8/19/20

1.90b

1.90

-- -- -- Da

Honomanu 13a Honomanu 1,670 6/20/95 0.0 0.93c -- -- DoHonomanu 14a Honomanu

(west unnamedtributary)

1,720 6/20/95 0.0 -- -- -- Do

Honomanu 18a Honomanu 1,950 1920 1.57 -- -- --Honomanu 18b Honomanu 2,250 1920 1.08 -- -- --Honomanu 18c Honomanu 2,350 1920 0.99 -- -- --Honomanu 18d Honomanu 2,500 1920

10/7/32

0.660.19

-- -- --

Honomanu 18e Honomanu 2,600 10/7/32 0.17 -- -- --Honomanu 18f Honomanu 2,740 10/7/32 0.14 -- -- --5240 Honomanu 2,900 1920

8/19/2010/7/32

0.36b

0.350.10

-- -- -- Da

Honomanu 20 Honomanu 3,030 1920

6/20/95

0.280.20

--

0.34

--

19.2

--

34

Do

Honomanu 23 Honomanu 3,050 6/20/95 0.14 0.14 20.0 27 Up
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 53

are likely issuing from the top of the freshwater lens.

The stream valley downstream of the waterfall is

floored by alluvial deposits all the way to the coast so

the springs could also represent streamflow which had

been lost to interbed flow reemerging near sea level.

A water budget was calculated for the 2.55-mi2

area upstream of gaging station 5240 (Shade, 1999). In

the water budget, 19.63 Mgal/d of rainfall and 6.05

Mgal/d of fog drip is apportioned into 7.05 Mgal/d of

runoff, 3.65 Mgal/d of evapotranspiration, and 14.98

Mgal/d of recharge (table 1, fig. 6). The amount of base

flow in this subbasin is only about 5 percent of the estimated recharge to the subbasin. Therefore, it appears

likely that most of the recharge follows deeper groundwater flow paths and eventually discharges further

downgradient offshore or at the shoreline.

In and East of Keanae Valley

The USGS surface-water gaging stations in the

study area east of Keanae Valley were at stream sites

both in the Kula Volcanics and the Hana Volcanics. No

USGS gaging stations were in Keanae Valley. Because

the rocks east of Keanae Valley are considered to be

fully saturated, all of the base flow measured at each of

the sites represents ground-water discharge from the

vertically extensive freshwater-lens system.

None of the gaged streams east of Keanae Valley

have gone dry near 1,300 ft altitude during the period

they were gaged. The total average annual streamflow

of these gaged streams is 109 Mgal/d at 1,300 ft altitude. It is not possible to estimate the total average

annual streamflow at the coast from existing records

because of the scarcity of gaging stations and the presence of the diversion systems, which intercept nearly all

base flow and an unknown percentage of higher streamflow. No streamflow-gaging stations were operated at

higher altitudes in this part of the study area, so it is not

possible to say at what altitudes these streams become

perennial on the basis of long-term records. Two

streams (West Wailuaiki and Hanawi) were flowing

during low-flow conditions at altitudes greater than

3,000 ft during field visits for this study.

Total average daily ground-water discharge to

gaged streams upstream of 1,200 ft altitude in the Kula

and Hana Volcanics is 27 Mgal/d, most of which is

removed from the streams by surface-water diversion

systems. This number was estimated by adding the estimated base flow at each gaging station from Wailuanui

to Hanawi Streams at about 1,300 ft altitude (table 2).

Base flow in the five gaged subbasins in this area for

which a water budget was estimated averages 27 percent of the recharge to these same subbasins. An additional 10 Mgal/d or more of ground water is estimated

to be captured directly by the tunnels and ditches above

1,300 ft altitude. About 22 Mgal/d of ground water discharges through the Kula and Hana Volcanics at altitudes between about 500 and 1,300 ft in the gaged

stream subbasins. Of this 22 Mgal/d, about 13 Mgal/d is

measured in Hanawi Stream. The total ground-water

discharge above 500 ft altitude in this part of the study

area is greater than 59 Mgal/d. About 10 Mgal/d discharges from four springs in Keanae Valley at or below

1,000 ft altitude (Stearns and Macdonald, 1942, p. 212).

Waiokamilo Stream

Waiokamilo Stream is headed at about 3,500 ft

altitude about 5 mi inland on the upland surface east of

Keanae Valley (plate 1). The stream has a flat gradient

near the coast where it flows on Hana Volcanics that

covered alluvium at the mouth of Keanae Valley

(Stearns and Macdonald, 1942). At about 2.5 mi inland,

at the east wall of Keanae Valley, the stream altitude

abruptly increases from about 800 ft up to 1,200 ft along

the next 2,000 ft of stream length. The stream lies on

Hana Volcanics along its entire length (Stearns and

Macdonald, 1942). All base flow is captured by the

Koolau Ditch diversion system at about 1,300 ft altitude

(table 4). Several other diversions capture water for taro

cultivation in the Wailua area.

Streamflow measurements made on May 11, 1999

during low-flow conditions show that the stream was

dry from the Koolau ditch diversion as far downstream

as Akeke Spring. The stream gained about 3.8 Mgal/d

from the spring which discharges from a ridge of Honomanu Basalt (table 15). Downstream from the spring all

the way to the coast, the stream loses water to the subsurface and to at least three diversions. The stream

flows on Hana Volcanics along the entire section of

stream that is losing water. The vertically extensive

freshwater-lens system appears to exist in the Honomanu Basalt, but below the floor of Waiokamilo Stream
54 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

in the overlying Hana Volcanics. A water budget was

not calculated for this stream basin.

Wailuanui Stream

Wailuanui Stream splits into two branches at 940 ft

altitude; the head of the west branch, at 5,600 ft altitude,

is 7 mi inland and the head of the east branch, at 2,400

ft altitude, is 3.4 mi inland (plate 1). The stream has a

relatively flat gradient near the coast where the valley is

floored on alluvial deposits and on a small section of

Hana Volcanics that flowed from Keanae Valley

(Stearns and Macdonald, 1942). At 3,400 ft inland, the

stream altitude abruptly increases from 200 ft to 800 ft

along the next 1,000 ft of stream length as the stream

valley crosses over Honomanu Basalt into Kula Volcanics. Upstream of 1,200 ft altitude, the West Branch

Wailuanui Stream contains a flow of the Hana Volcanics which originally reached the ocean but has since

been eroded away (Stearns and Macdonald, 1942). All

base flow in both stream branches is captured by the

Koolau Ditch diversion system at 1,300 ft altitude (table

4).

The two branches of Wailuanui Stream have never

been dry at gaging stations 5190 and 5200 at about

1,300 ft altitude nor at gaging station 5210 at 620 ft altitude (table 2, plate 1). Base-flow estimates indicate that

the average annual gains from ground water are 2.24

and 1.65 Mgal/d for the west and east branches

upstream of 1,300 ft altitude, respectively (table 2, fig.

15L). Between 1,300 ft and 620 ft, the stream gains an

average of 0.79 Mgal/d. A regression plot of the estimated base flow, obtained the same way that was discussed earlier for Honopou Stream, also shows a linear

relation (fig. 18). Because the regression line has a slope

greater than 1.0, the stream has a net gain of water

between each gaging station. The scatter of the data

points around the regression line shows that the baseflow distribution along the stream is variable. Concurrent streamflow records on 2 different days show the

expected pattern of gains upstream and between the

three gaging stations but the actual values vary significantly (table 16).

In the West Wailuanui Stream water budget

(Shade, 1999) of the 1.92-mi2

 area upstream of gaging

station 5190, 16.22 Mgal/d of rainfall and 4.18 Mgal/d

of fog drip is apportioned into 7.27 Mgal/d of runoff,

2.93 Mgal/d of evapotranspiration, and 10.20 Mgal/d of

recharge (table 1, fig. 6). For East Wailuanui Stream,

the area upstream of gaging station 5200 is smaller,

only 0.51 mi2

, hence rainfall (7.10 Mgal/d), fog drip

(1.29 Mgal/d), runoff (4.07 Mgal/d), evapotranspiration

(0.85 Mgal/d), and recharge (3.47 Mgal/d) are smaller.

But as with the water-budget components for Hoolawa

Stream, the base flow as a percentage of recharge to

each subbasin is unequal; 22 percent in West Wailuanui

and 48 percent in East Wailuanui (table 1). Again, this

a Measured May 28, 1999

Table 15. Streamflow, temperature, and specific conductance in Waiokamilo Stream, May 11, 1999, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; μS/cm, microsiemens per centimeter; --, not determined; all altitudes estimated from U.S.

Geological Survey topographic map, Keanae and Nahiku quadrangles]

Station

number

Stream

name

Altitude

(ft)

Streamflow

(Mgal/d)

Water

temperature

(°C)

Water specific

conductance

(μS/cm) Comments

Waiokamilo 1 Waiokamilo 80 0.47 -- --

Waiokamilo 2 Waiokamilo 110 0.52 -- -- Includes some return flow from taro patch

Waiokamilo 3.1 Waiokamilo 220 0.36 -- --

Waiokamilo 3.2 diversion 220 0.70 -- -- Taro-patch diversion

Waiokamilo 4.1 Waiokamilo 240 0.23 19.9a 123a Includes flow from unnamed spring

Waiokamilo 4.2 Hamau 250 0.83 20.3a 135a Tributary to Waiokamilo Stream

Waiokamilo 5 Waiokamilo 440 2.40 19.1 139 Diversion takes nearly all flow

Waiokamilo 6 Waiokamilo 560 3.66 19.6 137 Upstream from taro-patch diversion

Waiokamilo 7 diversion 540 0.25 -- -- Diversion to taro patch

Waiokamilo 8 Waiokamilo 720 3.80 18.9 147 Downstream from Akeke Spring

Waiokamilo 9 Waiokamilo 750 0.00 -- -- Upstream from Akeke Spring
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 55

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

ESTIMATED BASE FLOW AT STATION 5210,

IN MILLION GALLONS PER DAY

Figure 18. Relation of estimated base flow and linear regression line for gaging stations on Wailuanui Stream, 

northeast Maui, Hawaii

ESTIMATED COMBINED BASE FLOW AT STATIONS 5190 AND 5200,

IN MILLIONS OF GALLONS PER DAY

Regression equation: B2 = (1.1550)(B1) + 0.1018

B2 = estimated base flow at gaging station 5210, in Mgal/d

B1 = estimated combined base flow at gaging stations 5190 and 5200, in Mgal/d

Correlation coefficient = 0.984

Number of data points = 2,460

Table 16. Streamflow in Wailuanui Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; all data from Paulsen (1950); gaging-station number is preceded by 16 and ends in 00]

Gaging-station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion

(Mgal/d) Comments

5210 Wailuanui 620 7/4/46

2/23/47

0.30

0.17

2.50

1.15

Daily mean

5190 West Wailuanui 1,268 7/4/46

2/23/47

1.11

0.56

1.11

0.56

Daily mean; upstream from Koolau

Ditch diversion

5200 East Wailuanui 1,287 7/4/46

2/23/47

1.09

0.42

1.09

0.42

Daily mean; upstream from Koolau

Ditch diversion
56 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

probably indicates that the ground-water divides are

significantly different than the topographic divides used

in the water-budget estimation. Much of the West

Wailuanui Stream drainage subbasin lies directly upslope of the East Wailuanui Stream drainage subbasin

(fig. 3). The combined base flow in both streams is

about 28 percent of the combined recharge to the two

subbasins.

West and East Wailuaiki Streams

Although these streams do not converge, they are

quite similar and hence will be discussed together in this

section. Both streams are headed 6.6 mi inland at 6,000

ft altitude (plate 1). The streams rise steeply from sea

level to 600 ft altitude 0.5 mi from the coast (a gradient

of 1,130 ft/mi) and at this altitude, the valleys are

incised 240 ft below the upland surface. The stream valleys lie on Kula Volcanics along much of their length

but Honomanu Basalt can be found as far as 2,000 ft

from the ocean (Stearns and Macdonald, 1942). Streamflow is captured by the Koolau Ditch diversion system

at 1,300 ft altitude (table 4).

West Wailuaiki Stream (1921–97) and East

Wailuaiki Stream (1922–58) have never been dry at the

gaging stations (5180, 5170) upstream of the Koolau

Ditch (table 2, plate 1). The average annual gains from

ground water upstream of the gaging stations are about

4.53 and 4.82 Mgal/d, respectively (table 2, fig. 15M).

A streamflow measurement made on June 25, 1962 at

the West Wailuaiki gaging station shows a flow of 0.90

Mgal/d (table 17). About 82 percent of this flow was

gained downstream of 3,000 ft altitude where a set of

measurements were made on two stream branches (U.S.

Geological Survey, 1962). Measurements made March

21, 1984 on a shorter stream section show that 72 percent of the flow at the gaging station was gained downstream of 2,565 ft altitude and the largest gains were

between 2,565 ft and 2,400 ft altitude (Chinn, Tateishi,

and Yee, 1985). Measurements made in March 1928 by

EMI personnel at 500 ft altitude in both West and East

Wailuaiki Streams show gains of 0.5 and 0.2 Mgal/d,

respectively, downstream of 1,300 ft altitude (table 10).

The area upstream of gaging station 5180 is 3.67

mi2

 and in the water budget, 33.11 Mgal/d of rainfall

and 9.28 Mgal/d of fog drip is apportioned into 18.75

Mgal/d of runoff, 5.05 Mgal/d of evapotranspiration,

and 18.59 Mgal/d of recharge (table 1, fig. 6) (Shade,

1999). The estimated base flow at the gaging station is

about 25 percent of the recharge to the subbasin. The

results for the 3.11-mi2 subbasin upstream of gaging

station 5170 are similar; 30.20 Mgal/d of rainfall, 8.46

Mgal/d of fog drip, 14.90 Mgal/d of runoff, 4.33 Mgal/d

of evapotranspiration, and 19.43 Mgal/d of recharge

(table 1, fig. 6). Although this subbasin receives less

total precipitation, it receives slightly more recharge

because less runoff and evapotranspiration occur. The

base flow for the East Wailuaiki Stream subbasin is

about 25 percent of the estimated recharge.

Table 17. Streamflow and temperature in West Wailuaiki Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; --, not determined; all altitudes estimated from U.S. Geological Survey topographic

map, Keanae and Nahiku quadrangles; 1962 data from U.S. Geological Survey (undated[a]); 1984 data from Chinn and others (1985); gagingstation number is preceded by 16 and ends in 00]

Station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Water

temperature

(°C) Comments

5180 West Wailuaiki 1,343 6/25/62

3/21/84

0.90

1.55

--

--

Daily mean; upstream of Koolau

Ditch diversion

West Wailuaiki 12 West Wailuaiki 2,400 3/21/84 0.92 20.5

West Wailuaiki 13 West Wailuaiki 2,565 3/21/84 0.45 19.0

West Wailuaiki 14 West Wailuaiki

(east branch)

2,570 3/21/84 0.10 20.5

West Wailuaiki 15 West Wailuaiki

(west branch)

2,570 3/21/84 0.34 -- By subtraction

West Wailuaiki 16 West Wailuaiki

(east branch)

3,040 6/25/62 0.06 --

West Wailuaiki 17 West Wailuaiki

(west branch)

3,080 6/25/62 0.10 --
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 57

Kopiliula Stream

Kopiliula Stream is headed at 7,800 ft altitude and

7.2 mi inland (plate 1). The stream rises steeply from

sea level to 600 ft altitude 0.6 mi from the coast (a gradient of 930 ft/mi) and at this altitude the stream valley

is incised 200 ft below the upland surface. A tributary,

Puakaa Stream, branches to the east at 60 ft altitude and

the stream lies on Honomanu Basalt for 2,000 ft from

the coast and then on Kula and Hana Volcanics farther

upstream (Stearns and Macdonald, 1942). Streamflow

is captured by the Koolau Ditch at 1,300 ft altitude

(table 4).

The minimum flow measured in Kopiliula Stream

was 0.58 Mgal/d for 1921–58 at gaging station 5160

which is upstream of the Koolau Ditch (table 2, plate 1).

Estimates of base flow indicate that the average annual

gains from ground water upstream of the diversion are

4.18 Mgal/d (table 2, fig. 15N). EMI records indicate

that the stream was dry at 500 ft altitude in March 1928

(table 10). Streamflow on the same day in Puakaa

Stream was 0.4 Mgal/d. Apparently the water table had

dropped below the base of Kopiliula Stream at the time

of this measurement or else flow was within sediments

on the stream bottom.

The 3.91-mi2 area upstream of gaging station 5160

is the largest drainage subbasin for which a water budget was estimated (Shade, 1999). Shade estimated that

31.96 Mgal/d of rainfall and 8.69 Mgal/d of fog drip is

apportioned into 13.87 Mgal/d of runoff, 5.50 Mgal/d of

evapotranspiration, and 21.27 Mgal/d of recharge (table

1, fig. 6). The estimated base flow at the gaging station

is about 20 percent of the recharge to the subbasin.

Waiohue Stream

Waiohue Stream is a relatively short stream

headed 2.5 mi inland at 2,400 ft altitude (plate 1). The

stream rises steeply from sea level to 600 ft altitude 0.5

mi from the coast (a gradient of 1,320 ft/mi) and at this

altitude the stream valley is incised 260 ft below the

upland surface. The stream lies on Honomanu Basalt at

the coast and Kula Volcanics farther upstream, but it

appears that lava flows of the Hana Volcanics came

down the valley and reached the ocean (Stearns and

Macdonald, 1942). The Waiohue Stream valley is near

the western boundary of the extensive area of Hana Volcanics that cover most of the volcano surface for many

miles to the east (fig. 6). Streamflow is diverted by the

Koolau Ditch at 1,300 ft altitude (table 4).

The lowest daily streamflow measured during

1921–63 at gaging station 5150, at 1,316 ft altitude, was

1.36 Mgal/d (table 2, plate 1). The estimated average

annual base flow for the 40-year period of record is

about 3.57 Mgal/d (table 2, fig. 15O). EMI records indicate that the flow at about 500 ft altitude was 0.4 Mgal/d

in March 1928 (table 10). This value represents the gain

in flow downstream of the diversion system which is at

1,300 ft altitude.

The drainage subbasin of Waiohue Stream

upstream of the gaging station is the smallest used in the

water-budget estimates, 0.52 mi2 (Shade, 1999). In this

area, 7.25 Mgal/d of rainfall and 1.49 Mgal/d of fog drip

is apportioned into 3.91 Mgal/d of runoff, 0.87 Mgal/d

of evapotranspiration, and 3.96 Mgal/d of recharge

(table 1, fig. 6). The estimated base flow at the gaging

station is about 90 percent of the recharge to the subbasin. This subbasin is another example where the

surface-drainage divides probably do not coincide with

the ground-water divides. If the base flow and recharge

for Waiohue Stream subbasin are combined with the

base flow and recharge for Kopiliula Stream subbasin

which lies directly upstream (fig. 3), the ratio of base

flow to recharge becomes 31 percent. This value is

much more consistent with values for the adjacent

Wailuaiki and Wailuanui Stream subbasins.

Paakea and Waiaaka Streams

Paakea Stream is headed at 1,800 ft altitude 1.7 mi

inland from the coast (plate 1). Waiaaka Stream is short,

0.9 mi long, and heads at 1,400 ft altitude. Both streams

rise from sea level to 600 ft altitude 0.5 mi from the

coast (a gradient of 1,320 ft/mi) and both valleys are

incised 260 ft below the upland surface at this altitude.

Both stream valleys lie on lava flows of the Hana Volcanics along their entire lengths except for a small exposure of Honomanu Basalt near the coast in Waiaaka

Stream valley (Stearns and Macdonald, 1942). Numerous springs have been mapped along both streams (plate

1). All base flow in both streams is captured by the

Koolau Ditch at 1,300 ft (table 4).

During 1932–47, these streams and Kapaula and

Hanawi Streams to the east were gaged at altitudes

ranging from 500 to 650 ft to determine the feasibility

of extending one of the lower altitude ditches from the
58 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

west to capture water gained downstream from the

Koolau Ditch (Takasaki and Yamanaga, 1970). On

Paakea Stream, gaging station 5140, at 650 ft altitude,

measured a minimum daily flow of about 1.29 Mgal/d

(table 2, plate 1). The estimated average annual base

flow at this gaging station is about 2.53 Mgal/d (table 2,

fig. 15P). The minimum daily flow measured at gaging

station 5130 on Waiaaka Stream was about 0.29 Mgal/d

and the estimated average annual base flow is 0.53

Mgal/d (table 2, fig. 15P). No water budgets were calculated for either stream subbasin.

Kapaula Stream

Kapaula Stream is headed at 2,400 ft altitude 1.7

mi inland from the coast (plate 1). This stream has a

similar gradient (1,320 ft/mi) and stream-valley incision depth (260 ft) as Paakea and Waiaaka Streams to

the west and lies entirely on lava flows of the Hana Volcanics (Stearns and Macdonald, 1942). Streamflow is

diverted by the Koolau Ditch at about 1,300 ft altitude

(table 4).

Two gaging stations were operated on Kapaula

Stream, gaging station 5100 upstream of the Koolau

Ditch and gaging station 5110 downstream at 540 ft altitude (plate 1). The estimated average annual base flow

at the upstream gaging station is 2.34 Mgal/d and the

lowest daily flow measured was 0.19 Mgal/d (table 2,

fig. 15Q). At the downstream gaging station, the average annual base flow is estimated to be 1.68 Mgal/d and

the lowest daily flow measured was 1.10 Mgal/d. All of

this flow is gained in the 4,000 ft downstream of the

Koolau Ditch. A regression plot of the estimated base

flow, obtained the same way that was discussed earlier

for Honopou Stream, also shows a linear relation (fig.

19). Because the regression line has a slope greater than

1.0 the stream has a net gain of water between each gaging station. The scatter of the data points around the

regression line shows that the base-flow distribution

along the stream is variable. Concurrent streamflow

records on two different days show the expected pattern

of gains between the two gaging stations but the actual

values vary somewhat (table 18). A water budget was

not calculated for this stream subbasin.

Hanawi Stream

The Hanawi Stream basin has been evaluated more

thoroughly than any of the other subbasins in the study

area (Meyer, in press). The stream is headed at 7,400 ft

altitude 6.8 mi inland (plate 1). The stream rises steeply

from sea level to 600 ft altitude 0.8 mi from the coast (a

gradient of 770 ft/mi) and at this altitude the stream valley is incised 240 ft below the upland surface. The

stream has eroded into the Honomanu Basalt for 2,000

ft from the coast and in Kula Volcanics to 5,000 ft from

the coast (Stearns and Macdonald, 1942) The contact

between the two geologic units has been arbitrarily

located because in the Nahiku area, the exposed rocks

of the Honomanu Basalt are petrographically transitional to the overlying Kula Volcanics and are more like

the Kula Volcanics than the typical rocks of the Honomanu Basalt (Stearns and Macdonald, 1942). Hana Volcanics are found further upstream. Base flow is diverted

by the Koolau Ditch at about 1,300 ft altitude (table 4).

Two surface-water gaging stations have been operated on Hanawi Stream by the USGS (table 2, plate 1).

The upstream gaging station (5080), that records flow

upstream of the Koolau Ditch, had a minimum flow of

0.58 Mgal/d and an average annual base flow of 3.66

Mgal/d (table 2, fig. 15R). The downstream gaging station (5090) records streamflow at 500 ft altitude.

Streamflow at this altitude includes water discharging at

Big Springs, and Hanawi Springs 1 and 2 (plate 1). The

lowest recorded streamflow during the 17 years that the

gaging station was operated was 8.21 Mgal/d (table 2).

The estimate of average annual base flow is by far the

largest in the study area, about 12.99 Mgal/d. All of this

base flow is gained between the Koolau Ditch at 1,300

ft altitude and the gaging station at 500 ft altitude.

Independent sets of streamflow measurements

were made five times, twice as part of this study (table

19). The measurements show flow during extended dry

periods as high as 2,120 ft altitude in the stream channel. On the days of measurement, flow at the upstream

gaging station ranged from about 1 to 6 Mgal/d.

Between 1,300 ft and 1,000 ft altitude, the stream had

small gains (1 Mgal/d) and then gained substantially (6

to 7 Mgal/d) downstream to 620 ft altitude. Between

620 ft and 550 ft altitude, additional gains of 4 to 8

Mgal/d were measured. Downstream to about 50 ft altitude, an additional 1 to 2 Mgal/d of flow was gained, but

two sections that lost flow were measured in this reach.

Between 420 ft and 190 ft altitude, the streamflow

decreased by about 6 percent and between 120 ft and 50

ft altitude streamflow decreased by about 2 percent. The

downstream measurement site for each respective

stream section was considered only fair by the USGS

personnel making the measurements because the
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 59

Table 18. Streamflow in Kapaula Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; all data from Paulsen (1950); gaging-station number is preceded by 16 and ends in 00]

Gaging-station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without

diversion

(Mgal/d) Comments

5100 Kapaula 540 9/11/46

2/24/47

1.20

1.20

2.17

1.97

Daily mean

5110 Kapaula 1,346 9/11/46

2/24/47

0.97

0.77

0.97

0.77

Daily mean; upstream of

Koolau Ditch diversion

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

ESTIMATED BASE FLOW AT STATION 5210,

IN MILLION GALLONS PER DAY

Figure 19. Relation of estimated base flow and linear regression line for gaging stations on Kapaula Stream, 

northeast Maui, Hawaii

ESTIMATED COMBINED BASE FLOW AT STATIONS 5190 AND 5200,

IN MILLIONS OF GALLONS PER DAY

Regression equation: B2 = (1.1550)(B1) + 0.1018

B2 = estimated base flow at gaging station 5210, in Mgal/d

B1 = estimated combined base flow at gaging stations 5190 and 5200, in Mgal/d

Correlation coefficient = 0.984

Number of data points = 2,460
60 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

a Estimated on the basis of February 22, 1995 measurements

Table 19. Streamflow, temperature, and specific conductance in Hanawi Stream, northeast Maui, Hawaii

[ft, feet; Mgal/d, million gallons per day; °C, degrees Celsius; μS/cm, microsiemens per centimeter; --, not determined; <, less than; altitudes estimated from

U.S. Geological Survey topographic map, Nahiku quadrangle; 1974 and 1975 data from U.S. Geological Survey (1976); 1985 data from Chinn and others

(1986); 1994 daily-discharge data from Matsuoka and others (1995); 1995 daily-discharge data from Fontaine and others (1997); all other data is unpublished

in files of U.S. Geological Survey, Hawaii District office; gaging-station number is preceded by 16 and ends in 00]

Station

number

Stream

name

Altitude

(ft) Date

Streamflow

(Mgal/d)

Cumulative

streamflow

without diversion,

July 26, 1994

(Mgal/d)

Water

temperature

(°C)

Water

specific

conductance

(μS/cm) Comments

Hanawi 6 Hanawi 50 7/26/94

2/22/95

--

14.61

19.6a

--

--

17.6

--

198

Hanawi 8 Hanawi 120 10/9/74

5/21/75

7/26/94

2/22/95

12.28

14.22

--

14.93

--

--

20.0a

--

--

--

--

18.9

--

--

--

197

Hanawi 10 Hanawi 190 7/26/94

2/22/95

--

12.54

17.6a

--

--

19.2

--

181

Hanawi 13 Hanawi 420 10/9/74

5/22/75

7/26/94

2/22/95

11.63

12.3

--

13.4

--

--

18.4a

--

--

--

--

--

--

--

--

--

5090 Hanawi 550 10/9/74

5/22/75

11/2/84

7/26/94

2/22/95

9.0

10.3

11.6

12.7

12.8

--

--

--

17.8

--

--

--

--

--

--

--

--

--

--

--

Daily mean at gaging

station

Hanawi 23 Hanawi 620 11/2/84

7/26/94

2/22/95

9.7

7.5

7.4

--

12.7

--

--

--

--

--

--

--

Hanawi 27a Hanawi 920 5/21/75 0.36 -- -- --

Hanawi 27 Hanawi 1,020 7/26/94

2/22/95

1.2

0.52

6.3

--

21.0

19.4

40.0

48.7

Hanawi 29 Hanawi 1,130 7/26/94 0.78 5.9 21.3 40.0

5080 Hanawi 1,318 10/9/74

5/21/75

11/2/84

7/26/94

7/28/94

2/22/95

0.97

3.0

0.71

5.2

5.8

1.5

--

--

--

5.2

--

--

--

--

--

--

--

--

--

--

--

--

--

--

Daily mean at gaging

station; upstream of

Koolau Ditch diversion

Hanawi 38 Hanawi 2,240 7/28/94 1.8 1.8 -- -- Downstream of confluence with tributary

Hanawi 40 Hanawi

(east

unnamed

tributary)

2,280 7/28/94 0.56 0.56 -- --

Hanawi 45 Hanawi

(west branch)

3,500 7/28/94 0.02 0.02 20.9 16

Hanawi 46 Hanawi

(west branch)

3,580 7/28/94 < 0.01 < 0.01 19.5 15

Hanawi 48 Hanawi

(east branch)

3,550 7/28/94 0.06 0.06 21.4 17

Hanawi 51 Hanawi

(west branch)

4,100 7/28/94 0.01 0.01 18.5 12
Base Flow and Hydrologic Budgets for Individual Stream Subbasins 61

streambed consisted of cobbly alluvium that probably

allowed a part of the streamflow to bypass the measurement site (R.A. Fontaine, USGS, oral commun., 1998).

Therefore, the apparent loss of streamflow in these sections is probably not related to actual ground-water/

surface-water interaction but may instead be attributed

to the difficulty in measuring all of the water flowing in

the stream channel.The total flow in Hanawi Stream on

July 26, 1994 was estimated to be 19.6 Mgal/d, all of

which is assumed to be base flow (table 19).

A water budget for the entire Hanawi Stream

drainage basin to the coast has been estimated (Shade,

1999). Water-budget estimates for the other stream subbasins in the study area included only the area upstream

of the upstream gaging station on each respective

stream. Total recharge to the basin was estimated to be

38.1 Mgal/d, 61 percent of which discharges into the

stream or the Koolau Ditch crossing the basin (fig. 20);

the remaining 39 percent discharges to the ocean. Sixtytwo percent of the ground-water discharge to the stream

is estimated to be between the altitudes of 1,300 ft and

550 ft where the stream channel is the most deeply

incised.

Makapipi Stream

The Makapipi Stream drainage basin lies on the

eastern end of the study area and is headed at 1,900 ft

altitude 4 mi inland from the coast (plate 1). This stream

rises from sea level to 600 ft 0.9 mi from the coast (a

gradient of 630 ft/mi) and the valley is incised only 50

ft below the upland surface at this altitude. The stream

lies on rocks of the Hana Volcanics along its entire

length (Stearns and Macdonald, 1942). Streamflow is

diverted by the Koolau Ditch at about 1,300 ft altitude

(table 4).

?

30.6

Ground-water

discharge into

Koolau Ditch

2.0

Figure 20. Distribution of mean annual ground-water recharge, discharge, and movement within the Hanawi Stream 

drainage basin, northeast Maui, Hawaii (modified from William Meyer, U.S. Geological Survey, written commun, 1998).

18.7

30.6

14.8

4.5

13.0

13.0

3.7 Ground-water

recharge

1.1

Ocean

Ground-water

recharge

0.6

Ground-water

recharge

36.3 

Koolau Ditch

Hanawi Stream

Note: Values for ground-water discharge below the lower gage are 

based on discharge measurements made in Hanawi Stream in 1975

EXPLANATION

VOLUMETRIC RATE OF WATER 

 MOVEMENT, IN MILLION

 GALLONS PER DAY

GROUND-WATER DISCHARGE 

 INTO STREAM ALONG 

 INDICATED REACH, IN 

 MILLION GALLONS PER DAY

GAGING STATION AND

 NUMBER

5090

5080

5080
62 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

Three gaging stations were operated in the

Makapipi Stream drainage basin, one at 1,300 ft altitude

(5060, table 3) measuring water flowing from water

development tunnels into the Koolau Ditch, one for

Makapipi Spring at 1,150 ft altitude (5065), and one at

920 ft altitude (5070) downstream of the Koolau Ditch

(table 2, plate 1). The average annual flow at gaging station 5060 during 1949–65 was 2.87 Mgal/d, all of which

is assumed to be ground-water discharge. Ground-water

discharge at gaging station 5065 averaged about 0.67

Mgal/d during 1932–45 but the spring occasionally

went dry during dry weather. The estimated base flow

at gaging station 5070 is about 1.96 Mgal/d and the

stream has gone dry at this altitude during 1932–45

indicating that the stream is not perennial between the

Koolau Ditch and this gaging station (table 2, fig. 15S).

A water budget was not calculated for this stream basin.

SUMMARY AND CONCLUSIONS

The study area lies on the northern flank of the East

Maui Volcano (Haleakala) and covers about 129 square

miles between the drainage basins of Maliko Gulch to

the west and Makapipi Stream to the east. The topography is gently sloping except for the steep sides of

gulches and valleys that have been eroded by the

numerous streams. Most of the study area is made up of

forest reserves; rain forests densely cover the intermediate-altitude slopes to about 7,000 ft and small towns and

farms can be found at low altitudes along the coast.

Three geologic units are found in the study area:

the main shield-building-stage Honomanu Basalt,

formed mainly by thick accumulations of thin lava

flows, the post-shield-stage Kula Volcanics, which consist mainly of lava flows that are many tens to hundreds

of feet thick, and the rejuvenated-stage Hana Volcanics,

which consist mainly of aa flows of several feet thick to

several hundred feet thick where the flows were contained within the walls of previously eroded valleys.

The hydraulic conductivity of the Honomanu

Basalt is estimated to be several thousand feet per day

in the western part of the study area and less than one

foot per day in the eastern part. No hydraulic conductivity estimates are available for the Kula or Hana Volcanics but the specific capacity estimates for wells in the

Kula Volcanics are about four orders of magnitude less

than average of specific capacity estimates for wells

open to the Honomanu Basalt.

About 989 Mgal/d of rainfall and 176 Mgal/d of

fog drip enters the study area with the highest rates

between 2,000 and 6,000 ft altitude. Of the total precipitation, about 529 Mgal/d enters the ground-water system as recharge. Average annual ground-water

withdrawal from wells is only about 3 Mgal/d; proposed

additional withdrawals in the Haiku area total about 18

Mgal/d. Tunnels and ditches in the eastern part of the

study area remove at least 10 Mgal/d from the groundwater system.

The drainage pattern of the stream valleys on east

Maui is radial and the streams in the study area drain to

the north. Streamflow consists of runoff, base flow, and

in some cases, flow added to streams from the network

of irrigation ditches that cross the study area. Only five

streams where flow is recorded by USGS surface-water

gaging stations have gone dry during the respective

period of records for each site. Three of these five sites

are at altitudes higher than 2,800 ft and the other two are

on the most western stream of the study area. Streams

continue to flow during periods of very low rainfall

indicating that a significant ground-water source exists

upstream of the gaging stations.

The total amount of average annual streamflow in

the gaged stream subbasins upstream of 1,300 ft altitude

is about 255 Mgal/d and the total amount of average

annual base flow is about 62 Mgal/d. Six major surfacewater diversion systems in the study area have diverted

an average of 163 Mgal/d of streamflow (most of which

is base flow) for irrigation and domestic supply in central Maui during 1925–97.

Fresh ground water is found in two main forms: (1)

as a high-elevation saturated zone in relatively low-permeability geologic layers above an unsaturated zone,

and (2) as a freshwater-lens system underlain by denser

saltwater. West of Keanae Valley, ground-water flow

appears to be dominated by a variably saturated system.

A saturated zone in the upper rock unit, the Kula Volcanics, is separated from a freshwater lens near sea level

by an unsaturated zone in the underlying Honomanu

Basalt. East of Keanae Valley, the ground-water system

appears to be a freshwater-lens system that is fully saturated above sea level to altitudes greater than 2,000 ft.
Summary and Conclusions 63

The freshwater-lens system is in direct connection with

the underlying saltwater.

West of Keanae Valley, water levels measured in

shallow wells indicate that a water table lies several tens

of feet below the ground surface and represents the top

of a saturated zone in the thick lava flows and interbedded soils of the Kula Volcanics. This water-table surface mimics a subdued version of topography. Ground

water discharges where streams have incised into the

high-elevation water table. The streams commonly are

flowing all the way to the ocean where stream valleys

lie on Kula Volcanics all the way to the ocean.

West of Keanae Valley, the rocks beneath the contact between the Kula Volcanics and the underlying

Honomanu Basalt, and above the freshwater lens appear

to be unsaturated because (1) stream channels incised

into the Honomanu Basalt are dry or lose streamflow

during base-flow conditions, (2) the hydraulic conductivity of the Honomanu Basalt is too high to support a

thick ground-water lens with the estimated recharge to

the study area, (3) small springs are commonly found

along sea cliffs at the base of the Kula Volcanics but no

springs have been observed lower in the Honomanu

Basalt, and (4) wells that penetrate through the contact

have encountered conditions of cascading water from

above the contact and dry lava tubes in the Honomanu

Basalt.

The surface of the freshwater lens in the Haiku area

forms a hydraulic gradient of about 3 ft/mi inland. The

source of freshwater in the lens is ground-water

recharge from overlying high-elevation saturated zones

and rainfall infiltration. Fresh ground water flows from

the inland areas to the coast where it discharges at

springs and by diffuse seepage at and below sea level.

No wells in the study area are known to penetrate the

transition zone or underlying saltwater. The existence

of a freshwater lens in the entire study area west of

Keanae Valley is inferred from the pattern of losing

stream sections where surface water flows from the

Kula Volcanics onto the Honomanu Basalt.

All of the base flow measured in the study area

west of Keanae Valley was at stream sites in the Kula

Volcanics and therefore represents ground-water discharge from the high-elevation saturated zone. The total

average annual streamflow of these gaged streams is

about 140 Mgal/d at 1,200 ft to 1,300 ft altitude. It is not

possible to estimate the total average annual streamflow

at the coast. Perennial streamflow has been measured at

altitudes greater than 3,000 ft in several of the streams

(Kailua, Waikamoi, and Honomanu Streams). Discharge from the high-elevation saturated zone is persistent even during periods of little rainfall. The total flow

of the gaged streams west of Keanae Valley was about

6.7 Mgal after the driest period on record in the area. All

of this flow was measured above about 1,200 ft altitude.

Total average daily ground-water discharge from

the high-elevation saturated zone upstream of 1,200 ft

altitude is greater than 38 Mgal/d, all of which is eventually removed from the streams by surface-water

diversion systems. Estimates of average annual base

flow in gaged subbasins west of Keanae Valley range

from about 0.05 to 6.9 Mgal/d. Base flow in five subbasins for which a water budget was estimated averages

about 39 percent of the recharge to these same subbasins.

In and east of Keanae Valley, the rocks are fully

saturated from sea level to greater than 2,000 ft altitude.

The saturated zone extends from the Honomanu Basalt

at sea level up through the Kula Volcanics and into the

Hana Volcanics. Streams intersect the vertically extensive freshwater-lens system and are perennial downstream of about 2,100 ft altitude. These streams

continue to gain water from all three rock units as they

descend in altitude to sea level. The water-table surface

mimics topography and slopes away from the coast at

about 800 ft/mi. The nature of the transition from a variably saturated system to the west of Keanae Valley to a

fully saturated freshwater-lens system east of Keanae

Valley is unknown. Stream valleys west of Makapipi

Spring are not incised deeply enough to intercept the

water table and therefore, they do not contain persistent

base flow.

The total average annual streamflow of the gaged

streams is about 109 Mgal/d at about 1,300 ft altitude. It

is not possible to estimate the total average annual

streamflow at the coast and no streamflow-gaging stations were operated at higher altitudes. Two streams

(West Wailuaiki and Hanawi) were flowing during lowflow conditions at altitudes greater than 3,000 ft during

field visits. All of the base flow measured east of

Keanae Valley represents ground-water discharge from

the vertically extensive freshwater-lens system. Total

average daily ground-water discharge to gaged streams

upstream of 1,200 ft altitude is about 27 Mgal/d. Base
64 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii

flow in five gaged subbasins averages about 27 percent

of the recharge to these same subbasins. About 19

Mgal/d of ground water discharges through the Kula

and Hana Volcanics between about 500 ft and 1,300 ft

altitude in the gaged stream subbasins. Of this 19

Mgal/d, about 13 Mgal/d is measured in Hanawi

Stream. The total ground-water discharge above 500 ft

altitude in this part of the study area is greater than 56

Mgal/d.

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Table 2 67

Table 2. Information from surface-water gaging stations on streams, northeast Maui, Hawaii[ft, feet; mi2, square miles; BFI, base-flow index parameter (Wahl and Wahl, 1995); BFI parameter f is 0.9 for all locations; <, less than; --, not determined; gaging-statio

ends in 00; na, not applicable]

Station

number Station location

Station

altitude

(ft)

Contributing

drainagebasin area for

base flow

(mi2)

Period of

record used

in analysis

Years of

complete

record

Average

annual

streamflow

(Mgal/d)

Lowest daily

streamflow

(Mgal/d)

BFI

parameter

(N)

5065 West Makapipi Spring 1,150 na 1932–45 10 0.67 0.00 1 5070 Makapipi Stream 920 1.93 1932–45 12 6.58 0.00 4 5080 Hanawi Streama 1,318 3.46 1921–95 73 15.54 0.58 4 

5090 Hanawi Stream 500 na 1932–47

1992–95

17 25.85 8.21 3 

5100 Kapaula Gulch 1,346 0.69 1921–63 40 10.71 0.19 4 5110 Kapaula Gulch 540 na 1932–47 14 7.47 1.10 4 5130 Waiaaka Stream 650 0.10 1932–47 14 0.80 0.29 3 5140 Paakea Gulch 650 0.34 1932–47 14 4.17 1.29 3 5150 Waiohue Gulch 1,316 0.52 1921–63 40 7.43 1.36 4 5160 Kopiliula Stream 1,292 3.91 1914–17

1921–58

36 17.93 0.58 4 

5170 East Wailuaiki Stream 1,329 3.11 1914–17

1922–58

37 19.75 0.84 4 

5180 West Wailuaiki Streama 1,343 3.67 1913–17

1921–97

76 22.75 0.32 4 

5190 West Wailuanui Stream 1,268 1.92 1913–17

1922–58

37 9.35 0.19 4 

5200 East Wailuanui Stream 1,287 0.51 1914–17

1922–58

38 5.59 0.13 4 

5210 Wailuanui Stream 620 na 1932–36

1938–47

10 8.70 0.11 3 

5240 Honomanu Stream 2,900 2.55 1919–27

1932–341962–68

14 8.22 0.06 4 

5250 Seventh Branch Honomanu Stream 2,900 0.30 1932-33 <1 1.40 0.06 -- 5260 Fourth Branch Honomanu Stream 2,900 0.10 1932-33 <1 0.62 0.01 -- 5270 Honomanu Stream 1,733 3.17 1913–64 49 14.72 0.06 4 53105311

Haipuaena Stream 4,320 0.27 1947–67 21 0.97 0.01 4 

5320 Haipuaena Stream 2,860 na 1919–26

1932–34

7 3.63 0.13 4 

5330 Third Branch Haipuaena Stream 2,950 0.06 1932-33 <1 0.34 0.00 -- 
68 Ground-Water Occurrence and Contribution to Streamflow, Northeast Maui, Hawaii 5340 First Branch Haipuaena Stream 3,000 na 1932-33 <1 0.20 0.00 -- 

5350 Haipuaena Stream 1,866 na 1939–59 21 1.97 0.02 4 5360 Haipuaena Stream 1,512 na 1913–67 52 9.65 0.13 5 5350 5360 Haipuaena Stream -- na 1913–67 52 10.50 0.20 5 5420 East Branch Puohokamoa Stream 2,800 0.14 1919–27 1932–33 7 1.24 0.00 4 

5430 Middle Branch Puohokamoa Stream 2,900 0.48 1919–27 1932–34 1962–69 14 2.48 0.04 4 5440 West Branch Puohokamoa Stream 2,800 0.45 1919–28 1932–34 10 3.54 0.08 4 

5450 Puohokamoa Stream 1,322 na 1913–71 58 21.36 0.04 4 5526 Waikamoi Stream 5,750 2.10 1949–66 15 0.36 0.00 4 5528 Waikamoi Stream 4,487 2.46 1953–68 15 1.33 0.00 4 5530 Waikamoi Stream 4,250 na 1945-49 0 -- 0.00 -- 5540 Waikamoi Stream 3,000 na 1918 1919–28 1932–34 10 7.90 0.10 4 

5545 East Branch Waikamoi Stream 3,020 na 1918–28 1932–33 9 2.72 0.07 4 

5550 Waikamoi Stream 1,294 na 1922–57 35 16.37 0.10 4 5560 Waikamoi Stream 1,150 na 1910–22 10 18.24 0.20 5 5570 Alo Stream 1,248 0.47 1910–57 46 4.78 0.19 4 5650 Kaaiea Gulch 1,310 0.58 1921–62 39 4.41 0.22 4 5660 Oopuola Stream 1,205 0.20 1930–57 27 1.74 0.04 5 5670 Oopuola Stream 960 na 1910-15 3 5.90 0.20 5 5690 Second Branch Nailiilihaele Stream 3,130 0.20 1932-33 <1 0.49 0.00 -- 5691 Nailiilihaele Stream 2,820 0.11 1963-68 6 --b 0.00 -- 

5697 West Branch Nailiilihaele Stream 2,860 0.04 1966-68 3 --b -- -- 

5700 Nailiilihaele Stream 1,205 3.61 1910–11

1913–181919–241925–75

55 24.21 0.45 5 

Table 2. Information from surface-water gaging stations on streams, northeast Maui, Hawaii--Continued

[ft, feet; mi2, square miles; BFI, base-flow index parameter (Wahl and Wahl, 1995); BFI parameter f is 0.9 for all locations; <, less than; --, not determined; gaging-statio

ends in 00; na, not applicable]

Station

number Station location

Station

altitude

(ft)

Contributing

drainagebasin area for

base flow

(mi2)

Period of

record used

in analysis

Years of

complete

record

Average

annual

streamflow

(Mgal/d)

Lowest daily

streamflow

(Mgal/d)

BFI

parameter

(N)
Table 2 69

a Active siteb Low-flow partial-record site

5710 Nailiilihaele Stream 1,140 na 1912 <1 -- 0.26 -- 5740 Kailua Stream 3,080 0.8 1918–28

1932–34

10 4.08 0.01 5 

5745 Kailua Stream 2,840 1.10 1963–71 8 4.47 0.02 4 5750 Tenth Branch Kailua Stream 3,100 0.10 1932-33 <1 0.70 0.08 -- 5760 Ninth Branch Kailua Stream 3,080 0.20 1932-33 <1 0.23 0.02 -- 5770 Kailua Stream 1,253 2.39 1910–11

1913–181919–58

40 18.89 0.07 4 

5800 Oanui Stream 1,200 na 1910-11

1913-16

2 7.51 0.4 -- 

5840 Kailua Stream 700 na 1912-13 <1 -- 0.14 -- 5850 Hoolawanui Stream 1,219 1.34 1910–71 60 7.77 0.15 5 5860 Hoolawaliilii Stream 1,245 0.57 1911–57 45 4.88 0.19 5 5870 Honopou Streama 1,208 0.65 1910–97 85 3.12 0.13 5 

5910 Honopou Stream 557 na 1932–47 14 1.27 0.03 4 5930 Honopou Stream 441 na 1932–47 14 1.53 0.08 4 5950 Honopou Stream 383 na 1932–47 14 5.04 0.02 3 

Table 2. Information from surface-water gaging stations on streams, northeast Maui, Hawaii--Continued

[ft, feet; mi2, square miles; BFI, base-flow index parameter (Wahl and Wahl, 1995); BFI parameter f is 0.9 for all locations; <, less than; --, not determined; gaging-statio

ends in 00; na, not applicable]

Station

number Station location

Station

altitude

(ft)

Contributing

drainagebasin area for

base flow

(mi2)

Period of

record used

in analysis

Years of

complete

record

Average

annual

streamflow

(Mgal/d)

Lowest daily

streamflow

(Mgal/d)

BFI

parameter

(N)
1000

3000

4000

5000

6000

7000

8000

9000

2000

1000

3000

4000

5000

6000

7000

8000

2000

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Keanae

Valley

Wa hinepee

Haleakala Highway

Koolau

Ditch

Hanawi

Stream

Piinaau

Stream

Nailiilihaele

Str

Honopou

Stream

Heleleikeoha

Stream

Kuhiwa

Gl

Makapipi

East Branch

West Branch

Puakaa

Str

Kopiliula

Stream

East

Wailuaiki

Stream

West

Wailuaiki

Str

East

Wailuanui

Str

West Wailuanui Str

Waiokamilo

Stream

Kano

Str

Palauhulu

Stream

Nuaailua

Str

Kolea Str

Punalau

Str

Alo

Str

Kolea

Str

Oopuola

Str

Kailua

St ream

Hoalua

Str

Hanehoi

St

H

r

uelo

Str

Waipio

Str

Hoolawa Str

Hoolawaliilii

Str Hoolawanui Str

Puniawa

Str

Papalua

Str

Wailuanui

Str

Honomanu

Stream

W aikamoi

Str

Puohokamoa

Stream

Haipuaena

Stream

Waikamoi

Stream

Kailua

Stream

Oanui

Str

East Branch

West

Branch

West

East Branch

Middle

Branch

Hauoli

Wahine

Gl

Kapaula

Gl

Paakea

Gl

Waiohue Gl

Kale p

alehua

Gl

Waihole

Gl

Pohakuokala Gulch

Mokupapa

Gl

Honokala

Gl

Opana

Gulch

Halehaku

Gulch

Waiohiwi

Gulch

Kaaiea

Gl

Pa

Str

Waiaaka

New

Hamakua

Ditch

Spreckels

Ditch

Ko

o

al u

Ditch

Haiku

Ditch

Lowrie

Ditch

Center

Ditch

Wailoa

Ditch

Lower Kula Pipeline

Upper

Kula Pipeline

Hana

Highway

Hana

Highway

Hana

Highway

MAP SHOWING SURFACE-WATER GAGING STATIONS, MEASUREMENT SITES, SPRINGS, AND

 DRY, LOSING, AND GAINING SECTIONS OF STREAMS, NORTHEAST MAUI, HAWAII

by

Stephen B. Gingerich

PREPARED IN COOPERATION WITH THE

COUNTY OF MAUI DEPARTMENT OF WATER SUPPLY

STATE OF HAWAII COMMISSION ON WATER RESOURCE MANAGEMENT

DEPARTMENT OF LAND AND NATURAL RESOURCES

WATER-RESOURCES INVESTIGATIONS REPORT 99-4090

Measurement sites and stream sections, northeast Maui–PLATE 1

Gingerich, S.B., 1999, Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii

MARSH

STREAM SECTION

DRY (dashed where uncertain)

GAINING (dashed where uncertain)

LOSING (dashed where uncertain)

BOUNDARY OF STUDY AREA

MEASUREMENT SITE AND NAME

SPRING LOCATION AND NAME

EAST MAUI IRRIGATION, CO., INC. MEASUREMENT SITE

AND MAP DESIGNATION--March, 1928

GAGING STATION AND ABBREVIATED NUMBER--Complete 

number is preceded by 16 and ends in 00

CONTINUOUS-RECORD--Active

CONTINUOUS-RECORD--Inactive

LOW-FLOW--Inactive

ABBREVIATIONS

Kl Kailua

H Hoolawa

W Waikamoi

P Puohokamoa

Ha Haipuaena

K Kaumahina

Hn Honomanu

Wo Waiokamilo

WW West Wailuaiki

Hw Hanawi

EXPLANATION

Waipio

Bay

Wailua

Keanae

Nahiku

156°15' 156°12'30'' 156°10'

20°52'30''

20°50'

156°7'30'' 156°05'

P a c i f i c O c e a n

22 ̊

20 ̊

160 ̊ 158 ̊ 156 ̊

Kauai

Niihau

Oahu

Maui

Molokai

Lanai

Kahoolawe

Hawaii

HAWAII

Base modified from U.S. Geological Survey

digital data, 1:24,000, 1983, Albers equal area 

projection, standard parallels 20°35' and 21°, 

central meridian 156°20'

20°55'

20°47'30''

20°45'

P a c i f i c O c e a n

0

0

1 1 2 MILES

1 1 2 KILOMETERS Map

Area

5840

5415

5691

5691

5270

5440

5430

5330

5340

5250

5680

5675

5620

5610

5660

5600

5525

5290

5280

5730

5570

5350

5760

5740

5745

5750

5690

5540

5545

5762

5697

5420

5320

5240

5260

5650

5560

5550

5580

5522

5370

5410

5450

5390

5300

5360

5380

5510

5460

5520

5470

5655

5670

5675

5795

5830

5770

5790

5820

5800

5780 5710

5720

5700

5950

5526

5940

5920

5910

5930

5210

5070

5180

5180

5120

5090

5110

5100

5080

5130

5140

5200

5190

5160 5170 5150

5065

5060

5900

5860

5990

5220

5530

5528

5310

5311

5962

5890

5870

5880

5230

5850

Waikamoi

Spring at

3,200 ft

Hosmer Grove

Spring

W 9a

W 8a

W 8

K 5

K 7 Hn 1

K 4

W 9

Plunkett

Spring

 Akeke

Spring

Nuaailua

Roadcut

Store

Spring

Ohia

Spring

Pali

Spring

Big Spring

Hanawi Spring 1

Hanawi Spring 2

Tavares

Spring

Hoolawa

Spring at

1,200 ft

Hn 3b

Pali Spring

E 3

E 1

E 2

E 4

E 5 E 6

E 7

E 8

E 9

E 10

E 11

E 12 E 13

E 14

E 15

Wo 3.1 Wo 4.1

Wo 4.2

Wo 5

Wo 7

Wo 6

Wo 8

Wo 9

Wo 2

Wo 1 Wo 3.2

E 16 E 17

E 18

E 19

E 20

E 21 E 22

E 23

E 3

H 1

H 2

H 2a

H 3

H 5

H 6

H 9

H 7 H 12.1

H 8

H 11

H 12

H 10

W 33

W 32

W 40

W 17

Hn 2a Hn 2

Hn 4

Hn 5

Hn 6

Hn 7

Hn 8a

Hn 9

Hn 10a

Hn 11a

Hn 11

Hn 13a

Hn 14a

Hn 12

Hn 18a

Hn 18b

Hn 18c

Hn 18d

Hn 18e

Hn18f

Hn 20

Hn 23

Hp 53

Hp 52

Hp 51

Hp 50

Hp 41

Hp 42

Hp 40

Hp 30

Hp 20

W 16

W 15

W 14

W 11

W 10

W 7a

P 11

P 12

P 13

P 14

P 19

P 29

P 39

P 21

P 31

P 32

W 45a

W 45

W 45b

W 46

W 55a

W 56

Kl 41

Kl 40

Kl 30

W 60

W 65

W 72

W 73

W 29a

Hw 6

Hw 8

Hw 10

Hw 13

Hw 23

Hw 27a

Hw 27

Hw 29

Hw 40

Hw 48

WW 16 WW 17

WW 15 WW 14

WW 13

WW 12

Hw 45

Hw 46

Hw 51

Hw 38

H 9