Galleries and Their Use for 

Development of Shallow 

Ground-Water Supplies, with 

Special Reference to Alaska

By ALVIN J. FEULNER

CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES 

GEOLOGICAL SURVEY WATER-SUPPLY?PAPER 1809-E

Prepared on behalf of the 

United States Air Force 

Alaskan Air Command

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

The U.S. Geological Survey Library has cataloged this publication as follows :

Feulner, Alvin John, 1919-

Galleries and their use for development of shallow groundwater supplies, with special reference to Alaska. Washington, U.S. Govt. Print. Off., 1964.

v, 16 p. 4 maps. 24 cm. (U.S. Geological Survey. Watersupply paper 180&-E)

Prepared on behalf of the U.S. Air Force, Alaskan Air Command. 

Bibliography: p. 15-16.

1. Water, Underground. 2. Hydraulic engineering. 3. Waterstorage. I. U.S. Air Force. Alaskan Air Command. II. Title. 

(Series)

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402
CONTENTS

Page

Definition of terms_______________________________________________ in

Abstract___ ____ _ ____________________ ________ El

Introduction_____________-_____-___-___---_-______________________ 1

Types of galleries and their installation_____________________________ 3

French drains___----_---_-_-_-_-_-_---_---_---__--_---___-__-- 3

Lateral galleries________-_________--__-___-___-___-_-_--_____ 5

Vertical galleries____________________________________________ 7

Bedrock galleries.__--_-_-_--__-________________________________ 9

Gallery maintenance.______________________________________________ 9

Cleaning___ _ __ _ _____________________________________________ 10

Prevention of freezing_______________________-___-_____-___-____ 10

Gallery use in Alaska__________-___________________--____-_-_-_--- 11

Areas of continuous and discontinuous permafrost-_________--_-___- 12

Areas of sporadic or no permafrost-___-__---__---_----_---_--_-_- 14

Conclusions.____________-_--___-_______---___-_-_______-___---_--_ 15

References cited.__________________________________________________ 15

ILLUSTEATIONS

Page

FIGURE 1. Sketch map of Alaska showing general distribution of permafrost areas___-_-_______________---_-___--__--__------- E3

2. Sketch map of French drain installation and diagrammatic

section showing material and backfilling._________________ 4

3. Sketch map of lateral gallery installation and diagrammatic

section showing material and backfilling________________ 6

4. Sketch map of vertical gallery installation and diagrammatic

section showing top and front view of the installation_______ 8

DEFINITION OF TEEMS

The following terms used in this report are denned, and the source 

of definition is given, if known.

Aquifer a formation, group of formations, or part of a formation

that is water-bearing. (Meinzer, 1923, p. 30.) 

Drainage system consists of a surface stream or body of impounded

surface water, together with all surface streams and bodies of imITI
IV DEFINITION OF TERMS

pounded surface water that are tributary to it. An artificial 

drainage system is generally understood to include also the conduits 

that have been installed below the surface. (Meinzer, 1923, p. 15.) 

French drain a drain consisting of an underground passage made 

by filling a trench with loose stones and covering with earth called 

also a rubble drain. (G. & C. Merriam's dictionary, 1961, p. 908.) 

Gallery an artificial chamber provided for the collection of groundwater. (G. & C. Merriam's Dictionary, 1961, p. 930.) 

Infiltration gallery an artificial tunnel which extends into the zone 

of saturation and through which water flows by gravity from the 

zone of saturation to the land surface or into a sump or well. 

(Meinzer, 1923, p. 60.)

Permafrost permanently frozen ground; a thickness of soil or other 

superficial deposit or even or bedrock, at variable depth beneath 

the surface of the earth, in which a temperature below freezing 

has existed continually for a long time (from 2 years to tens of 

thousands of years). (Muller, 1947, p. 3.)

Continuous permafrost permafrost at a depth of 30 to 50 feet in 

which temperature is generally below 5° C. (Black, 1954, p. 843.) 

Discontinuous permafrost permafrost at a depth of 30 to 50 feet 

in which temperature is generally l°Cto 5°C. (Black, 1954, 

p. 843.)

Sporadic permafrost permafrost at a depth of 30 to 50 feet in 

which temperature is generally above 1° C. (Black, 1954, p. 843.) 

Well classified with respect to the method of sinking, as:

bored a well that is excavated by means of a hand or power 

auger, the material being brought up, for the most part, by the 

auger. (Meinzer, 1923, p. 63.)

drilled a well that is excavated wholly or in part by means of 

a drill, either percussion or rotary, which operates either by 

cutting or by abrasion, and in which the materials are brought 

up by means of a bailer, sand pump, or hollow drill tool, or by 

a self-cleaning method. (Meinzer, 1923, p. 63-64.) 

driven one constructed by driving a casing at the end of which 

there is a drive point, without the aid of any drilling, boring, 

or jetting device. (Meinzer, 1923, p. 64.)

dug one that is excavated by means of picks, shovels, and 

spades, or by means of a steam shovel or other dredging or 

trenching machinery. (Meinzer, 1923, p. 63.) 

jetted a well constructed by pumping water through a pipe of 

relatively small diameter and forcing the water downward 

through the drill bit against the bottom of the hole. The 

stream of water loosens the material and the finer grained
DEFINITION OF TERMS V

material is carried upward and out of the hole. During drilling, the drill pipe is turned slowly to insure a straight hole. 

Zone of saturation the zone in which the functional permeable 

rocks are saturated with water under hydrostatic pressure. (Meinzer, 1923, p. 21.) In sinking a well it is considered that the zone 

of saturation is reached at the point where water first enters the 

well. This water is ground water. (Meinzer, 1923, p. 22.)

CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

GALLERIES AND THEIR USE FOR DEVELOPMENT OF 

SHALLOW GROUND-WATER SUPPLIES, WITH SPECIAL 

REFERENCE TO ALASKA

By ALVIN J. FEULNER

ABSTRACT

In many areas in Alaska galleries are the only economical or feasible means 

of obtaining an adequate supply of water throughout the year. Galleries used 

in Alaska include French drains, lateral galleries, vertical galleries, and bedrock 

galleries. The type of gallery, method of installation, and amount of maintenance required depend on local geologic and hydrologic conditions: which must 

be examined thoroughly before installation is attempted.

The French drain, a primitive form of the gallery, is merely a drainage trench 

filled with rubble with a sump at one end from which the water may be pumped.

A lateral gallery includes a sump with a lateral pipe, or several pipes which 

extend into the water-bearing zone to increase the flow of water to the sump. 

The design of the lateral galleries may be varied to meet local conditions.

Vertical galleries consist of a group or battery of vertical pipes arranged 

around a central pipe, which is used as a well, and placed in a large-diameter 

dug well. The battery of pipes surrounding the central pipe slows the movement 

of highly turbid water entering the well and allows the fine material to settle 

out before water is pumped.

A bedrock gallery is a tunnel or adit driven into consolidated rock to intercept 

water-bearing zones such as fractures and faults. A shaft in which to collect 

and store the water is generally constructed at the inner end of the tunnel or 

beside it. Offset drilling into seepage zones may be needed to increase the flow 

of water.

Galleries in Alaska have been installed at Air Force installations north of 

the Arctic Circle as well as southward to, and along the length of the Aleutian 

Islands. Such installations, properly maintained and heated, have proven highly 

successful during the past 10 years. For individuals in some rural areas, as 

well as certain villages and towns in Alaska, gallery installations might be the 

best or only means of providing a year-round water supply.

INTRODUCTION

The word "gallery," when used as a hydrologic or engineering term, 

is denned in G. & C. Merriam's dictionary (1961, p. 930) as an "artiEl
E2 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

ficial chamber provided for the collection of groundwater." Watercollection galleries have been used since earliest times as a means of 

developing water supplies. The advent of improved drilling techniques and reduction of the danger of pollution by use of drilled, 

cased wells in recent years, have directed emphasis toward groundwater development by wells. However, under certain geologic and 

hydrologic conditions galleries are superior to wells. For example, 

in areas where water-bearing surficial deposits, underlain by impermeable bedrock or permafrost of great thickness, are thin or discontinuous, a gallery may be the only way of obtaining a water supply. 

Where surficial deposits are absent bedrock galleries may be used to 

tap fault zones or other water-bearing fractures in the bedrock.

Properly constructed galleries have several advantages over surfacewater supplies because the filtering action of material overlying the 

gallery lowers turbidity and lessens the liklihood of contamination, 

and because galleries are not as likely to freeze in winter. Furthermore, the cost of maintaining a gallery may be appreciably less than 

maintaining a surface water intake.

Many gallery designs are used because of differences in local geologic conditions, but three general types are constructed in unconsolidated materials. These include the French drain, the lateral gallery, 

and the vertical gallery. Each of these types, and various combinations of them, can be used to provide water where conventional wells 

are unsuccessful or are too costly to construct and maintain.

Galleries in Alaska have been constructed in regions of continuous 

permafrost, discontinuous permafrost, sporadic permafrost and no 

permafrost. As shown by figure 1, much of Alaska is included in the 

regions of continuous and discontinuous permafrost. Galleries constructed in these regions generally need to be heated to prevent freezing of the installation and piping. In the regions of sporadic or no 

permafrost, galleries generally need not be heated.

About 90 percent of the known galleries in Alaska has been installed 

at Air Force stations and all but two of these galleries are presently 

(1962) in operation. These galleries have provided water to meet 

requirements throughout the entire year for periods ranging from 

1 to 10 years. Some galleries have been inoperable for short periods, 

but in each gallery the trouble was caused by failure of mechanical 

equipment or human error, rather than by failure of the gallery itself.

Because of their rather high cost and limited use, only one bedrock 

gallery is known to have been installed in Alaska. The discussion of 

bedrock galleries is therefore brief.

During the period in which the U.S. Geological Survey has been 

engaged in a program of providing technical assistance regarding 

water supplies at U.S. Air Force installations in Alaska, many changes
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E3

158*

162'

OCEAN

150" 146°

FIGURE 1. Sketch map of Alaska showing general distribution of permafrost 

areas. (Adapted from Hopkins, Karlstrom, and others, 1955.)

have been made in basic gallery design, as well as in the use, construction, and maintenance of galleries. This paper describes use, construction, and maintenance of galleries as an aid in obtaining groundwater supplies in Alaska. The applications and principles in this 

paper, however, apply to many areas and almost any climatic condition. The work on this report was accomplished as a part of the U.S. 

Geological Survey program with the U.S. Air Force, Alaskan Air 

Command.

TYPES OP GALLERIES AND THEIR INSTALLATION

FRENCH DRAINS

The French drain is a rubble-filled trench used to channel the underground flow of water to or away from any specific area. This drain, 

when combined with a sump, is a primitive type of gallery. The

732-761-
E4 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

French drain may be used to channel flows of underground water 

toward a lateral or vertical gallery to increase the amount of water 

available.

French drains may be particularly useful in areas underlain by 

clay, shale, or other impermeable material as a means of channeling 

water from a lake or stream to a point from which it can be pumped 

conveniently. Figure 2 shows an idealized condition in which a 

French drain is used to carry water from a lake, underlain by impermeable clay, to a sump from which the water is taken for use.

Approximate scale

0 50 100 FEET

Contour interval 5 feet 

Cabin

CD

\

Pump 

house

Clay backfill from 

trenching Operation

Sump pipe perforated 

in lower part

FIGUEE 2. Sketch map of French drain installation and diagrammatic section 

showing material and backfilling.
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E5

French drains may provide water of lower turbidity and bacterial 

content than a direct surface-water source. However, as an added 

sanitary precaution, water derived from surface-water sources should 

be chlorinated before use, even though the water may be filtered 

through sand and gravel in the drain prior to being pumped.

Installation of a French drain requires little material besides gravel 

or rubble. Because gravel is widely available, it is commonly used 

for installation of French drains in Alaska. Apart from the cost of 

materials, most of the installation cost of a French drain is for 

trenching and backfilling.

Construction consists of digging a ditch to the zone of saturation, 

filling the lower part of the ditch with graded rock, and filling the 

upper part of the ditch with the excavated material. The ground 

surface is cleared of material excavated from the trench, and the area 

is resodded or reseeded to retard infiltration of silt and to prevent 

surface runoff from entering the drain.

LATERAL GALLERIES

Lateral galleries have many applications and a wide variety of 

designs. A gallery to fit specific geologic and hydrologic requirements 

of a site may, however, require modifications from any type previously 

constructed. Lateral galleries are called infiltration galleries if they 

extend into the zone of saturation. Infiltration galleries may consist 

of a sump with a single small lateral pipe leading from the sump to 

an aquifer below a streambed or they may be elaborate systems with 

two or more banks of laterals radiating from the sump and placed 

at different levels in the aquifer or aquifers.

Lateral galleries are generally less than 40 feet deep because installation of the lateral pipes at greater depths is difficult and costly. 

A method of jacking laterals into place from sumps deeper than 40 

feet has been developed, and although special equipment is required, 

laterals have been successfully placed at depths greater than 200 feet 

(Kazmann, 1948). Because this special type of lateral gallery is 

designed for producing large amounts of water, its greater cost is 

justified.

Figure 3 shows a typical lateral gallery installation under a streambed which has one lateral extending out from the sump. The length 

of laterals in Alaska generally ranges from 25 to 500 feet, depending 

upon the extent of the intake area and the amount of water desired. 

The laterals are constructed of pipe, usually corrugated iron or tile, 

ranging in diameter from 18 inches to 4 feet. Any number of laterals 

may be added in different directions or at different levels to increase 

the volume of water flowing into the lateral. In some areas it may
E6 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

Vertical well or sump

475

Buried perforated 

lateral pipe Approximate scale

Contour interval 5 feet

Clay and rock 

excavated from trench

Graded gravel placed above lateral

ooooooooooo 

o o o4-ft diameter corrugated o o o o

o o o perforated culvert pipe o o o 

ooo ooooo'ooo

Undisturbed ground

FIGTTBE 3. Sketch map of lateral gallery installation and diagrammatic section 

showing material and backfilling.

be desirable to add French drains at several points along a lateral 

to increase the amount of inflow.

Prior to construction of a lateral gallery system consideration should 

be given to the length of time that the system is to be used and to the 

required volume of water. The life of the system is largely controlled 

by the type of materials used for the laterals. Materials which give 

the longest life include vitrified clay, brick, concrete, and cast iron 

(Todd, 1959, p. 146). Materials commonly used in Alaska include
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E7

transite pipe, wood-stave pipe, and corrugated-steel culvert. The 

required rate of waterflow determines the length, diameter, and number of laterals and the size of perforations cut in the pipe.

Where a perennial stream is present, laterals may be laid out parallel 

to the stream to induce infiltration into the gallery from the stream. 

In an area where there is no perennial stream, water may be present 

at shallow depths in water courses which flow only during the summer 

months. Installation of a lateral across such a water course may 

provide water throughout the year. Where several layers of permeable sand or gravel separated by clay are present, laterals might be 

installed into each aquifer to obtain a greater amount of water.

Trenches for lateral galleries are commonly excavated 4 to 6 feet 

below the top of the zone of saturation, or below the level at which 

the top of the zone will be when water levels are lowest. The trench 

is backfilled with about a foot of graded rock and the laterals are 

placed on the fill that slopes slightly toward the sump. Graded rock 

or gravel should cover the laterals completely and should extend upward to or above the point of the highest ground-water level during 

the year in order to take advantage of maximum infiltration. Peasize or slightly coarser gravel, relatively free of fine-grained materials, 

allows water to move rapidly through the fill and prevents plugging 

of the perforations in the lateral. Material excavated from the trench 

is commonly used to complete filling the trench. Excess material 

remaining from the trenching operation should be removed from the 

area, and a cover of grass, tundra, or other native vegetation will 

prevent silt and clay from washing into and plugging the fill.

VERTICAL GALLERIES

A vertical gallery consists of a group, or cluster, of perforated 

vertical pipes surrounding a central pipe placed in a large-diameter 

dug well. The central pipe extends upward to or above the ground 

surface and is used as the well. The additional pipes surrounding 

the central pipe reduce the velocity of water entering the system and 

permit silt and fine sand to settle out of suspension before entering 

the central pipe. Figure 4 shows an idealized vertical gallery installation and the top and side view of the pipe cluster. Vertical 

galleries are best suited for locations along streams where the water is 

turbid and where the zone of saturation is near the ground surface. 

Vertical galleries may be connected to the stream by means of French 

drains.

Vertical galleries are usually installed only where large amounts 

of water are available. The size of the pipe cluster is determined 

by the required amount of water. Generally, however, an excava-
E8 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

tion 20 feet in diameter is large enough for most vertical galleries. 

The depth of excavation depends upon local conditions but is 

generally 20 to 25 feet.

Pipes are arranged in a cluster as shown in figure 4. The pipes 

surrounding the central pipe are cut off and capped both at the top and 

bottom. Usually, the entire cluster is put together before it is placed 

in the excavation; thus, placement can be made with the same equipment used to dig the pit. After placing the pipes vertically in the

Contour interval 5 feet

1-ft diam 

perforated 

pipes

Ground 

surface

/ 4-ft diam sump

2-ft diam 

perforated pipes

TOP VIEW PERSPECTIVE FRONT VIEW

FIGURE 4. Sketch map of vertical gallery installation and diagrammatic section 

showing top and front view of the installation.
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E9

pit, the area surrounding the pipe cluster is backfilled with graded 

rock material to the maximum level at which ground water will 

stand during the year. The upper part of the pit is then refilled 

with the excavated material, and vegetation is replaced around the 

installation.

Installations of the type shown in figure 4 can be very successful 

when located near a perennial stream and in some areas might be used 

as a source for irrigation, mining, or small manufacturing.

BEDROCK GALLERIES

Bedrock galleries are a special type of installation consisting of a 

tunnel or adit driven into bedrock to intercept faults, fractures, or 

other water-yielding zones. For example, the University of Alaska 

at College obtained a water supply by driving a tunnel into bedrock to 

reach water-bearing fractures. At several places along and at the 

end of the tunnel, shafts were sunk to a depth of 30 to 50 feet, and 

the bottoms of these shafts were enlarged to increase the infiltration 

rate and water-storage capacity. In one of the shafts, diamond-drill 

holes were bored into fractures to increase the intake area of the 

fractures.

Bedrock galleries may be installed where permafrost exists. At 

such places, water could be stored in the bedrock shafts which are 

not susceptible to differential thawing as are outside storage tanks 

which require heating.

The method of installation of a bedrock gallery depends on the 

type of rock and its porosity, permeability, and fracture pattern and 

on the position of the water table. To construct a bedrock gallery 

which provides the required amount of water, an adit or tunnel is 

driven into the rock until sufficient fractures or other water-bearing 

zones have been intercepted. Water entering the tunnel may be collected in a sump, usually constructed by driving a shaft vertically 

from the floor or to one side of the tunnel. Several shafts, or sumps, 

may be sunk from one long tunnel to increase the amount of available 

storage. The bottoms of the sumps can be enlarged to increase the 

intake area and to act as storage tanks. In some areas it may be 

desirable to drill holes into the water-bearing zones to increase the 

rate of flow into the storage shafts.

GALLERY MAINTENANCE

Maintenance of galleries is perhaps as important as proper construction if maximum usefulness and gallery life are to be obtained. 

Lateral galleries require more maintenance than either vertical gal-
E10 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

leries or French drains. Bedrock galleries require only a minimum of 

maintenance. Maintenance procedures include periodic cleaning and 

prevention of silting and freezing.

CLEANING

Water entering any kind of gallery generally contains some sediment 

which is deposited in the gallery and which should be removed from 

time to time. In lateral galleries maintenance manholes are usually 

placed every few hundred feet along each lateral. These manholes 

provide a means of washing any accumulated sediment down into 

the sump where it can be easily removed. The manholes also provide 

a means of determining if the pipe has collapsed or been damaged.

French drains and vertical galleries cannot be cleaned. The 

French drains do not usually become plugged with silt except near 

the intake of water at the stream or lake. It is usually more economical to excavate the silt from the drain and to refill the drain with 

clean gravel than to clean the drain. Vertical galleries generally 

have a short operating life which depends upon the turbidity of the 

water entering the gallery. If a vertical gallery becomes plugged 

with silt, it may be more economical to install a new system rather 

than to renovate the old one.

PREVENTION OF FREEZING

Most galleries installed in areas of continuous and discontinuous 

permafrost either are heated by one or more steam lines or by electrical heating cables. The heating system is installed during gallery 

construction and must be adequate to prevent complete freezing of 

the gallery and the immediate surrounding area. The usual procedure in installing steam lines is to place one steam line on the upper 

surface of the gallery lateral and a second about 4 to 6 feet above the 

lateral. In areas of less frost penetration, only the lower line is 

commonly installed. Usually, the pumphouse and sump are also 

heated.

Snow is an excellent insulator and can be used to prevent freezing 

of the gallery during the cold winter months. To insure an adequate 

blanket of snow over the installation, snow fences are placed transverse to the prevailing wind. The fence traps the snow and prevents it from blowing away. A blanket of snow 3 or 4 feet thick 

inhibits freezing of the ground and permits a freer movement of 

ground water into the gallery. In addition to its insulating effect, a 

cover of snow will provide a source of recharge to installations where 

two steam lines are used. In such installations, the upper steam line 

keeps the ground thawed and melts part of the snow cover. The water 

thus formed seeps down through the soil and into the gallery.
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER Ell

To preserve the snow cover in the vicinity of the gallery, the area 

should be kept free of traffic. Vehicle tracks or even footprints 

break the snow cover and allow deep penetration of the seasonal 

frost which could divert ground water away from the gallery. At 

one installation a gallery became dry because an ice dam, formed by 

deep frost penetration where traffic crossed the gallery lateral, diverted the normal movement of water. To eliminate such occurrences, 

the areas surrounding the gallery, particularly those upgradient, may 

be fenced. Fencing not only prohibits traffic from crossing the area, 

but also lessens the possibility of contamination.

In areas of both continuous and discontinuous permafrost, pumping 

of the galleries is controlled in order to maintain a steady flow of water 

to the galleries during the winter months. Because normal daily 

use ranges from 5 to 10 gpm (gallons per minute) and because the 

normal rate of intermittent pumping ranges from 35 to 50 gpm, a 

reduction in the rate of pumpage is necessary to maintain a continuous 

flow through the system. Pumping rates are cut to approximately 

one-half the summer rate at about mid-October and a further reduction to about 5 to 10 gpm usually is made at about mid-December. 

The lowered pumping rate is continued through the following April. 

After April, recharge from melting snow provides sufficient flow to 

prevent the gallery from freezing.

GALLERY USE IN ALASKA

In Alaska galleries have been utilized by the U.S. Air Force at many 

of their remote stations largely because these stations are not located 

near perennial surface-water sources. Gallery construction has proved 

to be a very satisfactory method, and the only method at some sites, 

of providing year-round water supplies. Economics has played a 

major part in stimulating the construction and use of galleries. As 

most remote stations can be reached only by air, transportation of a 

drill rig is both difficult and expensive. In most places a gallery 

can be constructed with local equipment and labor.

Prior to 1950 the city of Anchorage obtained its water supply 

from a lateral gallery extending along Ship Creek, approximately 

1 mile upstream from Cook Inlet. The Alaska Railroad also operated 

a similar gallery on the opposite bank of the stream for its own water 

supply. Each gallery was intended to produce 5 mgd (million gallons per day). Both galleries were placed on a standby basis in 1950 

to be used as emergency supplies for the city of Anchorage until other 

sources were developed, but one has since been abandoned.

In 1950 a power plant in Fairbanks reportedly obtained part of its 

water supply from a gallery driven under the Chena River by the
E12 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

Northern Commercial Co. (Cederstrom, 1950, p. 27). This gallery is 

of interest because, according to C. G. Lincoln (oral commun., 1962) 

formerly of the Northern Commercial Co., it was dug under the river 

by allowing the gravel deposits to freeze prior to excavation. This 

freezing formed a wall of frozen gravel which surrounded the excavation and kept ground water out. Upon completion of the lateral 

tunnel, a charge of explosives was placed at the end of the tunnel under 

the river and the remaining part of the tunnel was filled with coarse 

gravel. The ensuing detonation allowed the gravel-filled tunnel to 

fill with water from the river. The structure thus formed could 

probably be considered as an elaborate type of French drain.

As previously stated, the University of Alaska has utilized a bedrock gallery for many years to obtain a water supply.

Several mining camps in Alaska constructed galleries to obtain 

utility and potable water, but little data are available on the number of 

gallery units or on the amount of water produced. A gallery at the 

Suntrana Mine at Healy has been in operation since 1925, and a gallery 

at the Usibelli Coal Mine has been in operation since 1952 (L. H. 

Saarela, oral commun., 1962).

In 1955 a vertical caisson filled with gravel and a buried lateral 

conduit leading to the river were constructed near the edge of a 

side channel of the Yukon River at Fort Yukon to obtain water for 

a school. Because of stripping of the natural vegetation around 

the area this installation reportedly was partially washed out and 

plugged with silt during floods in 1959 and has therefore been abandoned since that time.

Galleries were installed at 14 military installations in Alaska during 

1951-61, and all except two of these installations are still operating. 

One failure resulted when the electrical heating cable, used to supply 

heat to the gallery, broke during the winter and the gallery froze. 

A second failure was a result of gradual thawing of permafrost under 

the gallery installation, a condition which permitted water to pass 

below the gallery. The water supply was restored by installing a 

second gallery at greater depth.

AREAS OF CONTINUOUS AND DISCONTINUOUS PERMAFROST

Galleries in areas of continuous permafrost, except at sites near 

large lakes or rivers, are the only practical method of obtaining 

year-round water supplies. The thickness of permafrost, which 

ranges from 1 foot to as much as 1,300 feet, and the poor chemical 

quality (generally high iron or chloride content) of water obtained 

from beneath permafrost make the use of wells impossible or uneconomical in most areas of continuous permafrost. "Wells drilled in
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E13

areas of discontinuous permafrost, however, may provide potable 

water if a sufficient thickness of unfrozen saturated material is present 

above, within, or below the frozen zone. In some areas of discontinuous permafrost, where saturated sands and gravels are thin and 

the underlying rock is impermeable, lateral galleries may provide more 

water than drilled, dug, jetted, bored, or driven wells.

In one area in the continuous permafrost zone north of the Arctic 

Circle, a gallery was installed across a stream valley to intercept 

ground water flowing in a thawed zone between permafrost and the 

zone of seasonal frost. A gallery lateral was placed in a trench about 

4 to 6 feet deep in the permafrost underlying the valley. Corrugatedsteel culvert pipe 4 feet in diameter was used as the lateral pipe, and 

a sump, also of culvert pipe 4 feet in diameter} was constructed at 

one end. The gallery and adjacent ground area are heated by two 

steam lines, 2 inches in diameter. One steam line extends along 

the top of the gallery lateral and the other is 6 feet higher. This 

gallery, combined with a heated aboveground storage tank, provides 

a year-round supply of water for the station.

Another gallery, installed across the valley of a small perennial 

stream at a station in the discontinuous permafrost zone slightly 

south of the Arctic Circle, is placed in gravel which is unfrozen 

to a depth greater than 20 feet. The gallery is placed across the 

valley so that both ends are in permafrost, but the area under the 

center of the gallery lateral is free of permafrost. This gallery is 

also constructed of perforated corrugated-steel culvert pipe, 4 feet 

in diameter, and is heated by one electric heating cable placed on the 

upper surface of the gallery lateral. The gallery installation and an 

aboveground storage tank provide a year-round water supply for the 

station.

Gallery installations have also been constructed where no streams 

exist. In one area, in the permafrost zone near the Arctic Circle, a 

perforated corrugated-steel culvert pipe, 2 feet in diameter, was installed to intercept ground water moving along a fault zone. The 

gallery transmits the water from the point of interception to a sump 

from which the water is pumped for use. Installation of the gallery 

required dynamiting more than 300 lineal feet of frozen bedrock and 

removing material to a depth of 10 to 12 feet. The gallery is heated 

along its entire length by means of two steam lines, 1% inches in 

diameter. One steam line is placed on the surface of the gallery 

lateral pipe and the other is buried in the overlying fill about 4 feet 

higher. This installation is successful in providing a year-round 

water supply for the station.

Several Air Force stations in areas of continuous, discontinuous, 

sporadic, and no permafrost have galleries, usually lateral galleries,
E14 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

connected to reservoirs of shallow lakes. Galleries are placed either 

beneath or adjacent to the reservoir or lake. This method of installation serves two purposes: reduces the likelihood of contamination 

and provides a supply of water even when the reservoir or lake is 

completely frozen. Because of the insulating effect of the overlying 

body of ice and its snow cover, the sand and gravel underlying the 

reservoir generally remain unfrozen. Where sand and gravel deposits 

are permeable, adequate supplies of ground water may be obtained. 

Water impounded in reservoirs is sometimes lost by seepage as soon 

as severe winter weather prevents further inflow. Under such conditions a gallery installed in the gravel deposits beneath or slightly 

downgradient from the reservoir may be the best means of salvaging 

the seepage and maintaining a year-round water supply.

AREAS OF SPORADIC OR NO PERMAFROST

Gallery installations in areas of sporadic or no permafrost in Alaska 

are very similar to those installed in areas of continuous or discontinuous permafrost. Generally, however, the installation in areas of 

sporadic or no permafrost does not require heating unless the aquifers 

feeding the gallery are within the depth range of seasonal frost.

Even though surface-water supplies are more widely used in regions 

of sporadic or no permafrost than in other permafrost regions, the 

depth of freezing in shallow lakes or reservoirs is great and thus 

prohibits the use of these supplies during the winter months. Under 

such freezing conditions, galleries installed under the lake or reservoir 

can still supply water. Even if the lake or reservoir is frozen to the 

bottom, the underlying aquifers may remain unfrozen and thus supply 

water to the gallery.

Lateral galleries are constructed along and across stream valleys as 

in other permafrost areas, and in some areas galleries are installed 

where there is no flow of surface water throughout much of the year. 

One such installation in the Aleutian Islands consists of four laterals 

extending along the channels of two intermittent streams. The water 

collected by these laterals is piped into a central sump and passes from 

this sump downslope into a second sump from which the water is 

pumped for use. Although no flow of water appears at the ground 

surface, the gallery collects more than 200 gpm.

At another site in western Alaska, a gallery was installed in an area 

where no definite drainage exists. At this site extensive digging of 

test pits and test drilling were required to determine the lowest elevation at which ground water flowed in the underlying impermeable 

material. When such an elevation was determined, a gallery was constructed by excavating 8 to 10 feet of rubble and broken rock material
GALLERIES USED TO DEVELOP SHALLOW GROUND WATER E15

and 6 to 8 feet of impermeable bedrock. The gallery was then placed 

in the trench and was backfilled with graded rock to within 4 feet of 

the ground surface. The remaining 4 feet was filled with excavated 

material from the trench. The trench acts as a sump to collect water 

and to provide a sufficient head for the pump to operate during periods 

when the amount of water flowing over the subjacent bedrock is 1 foot 

or less in depth.

CONCLUSIONS

Galleries have not been fully utilized in Alaska partly because of 

a lack of knowledge of gallery construction, especially under subarctic 

and arctic conditions, and partly because of the belief that shallow 

ground-water supplies usually are contaminated. The lack of knowledge of how to protect galleries from freezing during winter months 

probably has also been a deterent. Observation has shown, however, 

that under certain geologic and hydrologic conditions properly installed and maintained galleries are a relatively reliable means of 

supplying moderate to large amounts of water throughout the year.

Galleries, either alone or supplemented by French drains, have been 

highly successful at Air Force stations in Alaska. They have been 

used to induce infiltration of water from streambeds, to divert water 

from fault zones, to tap water confined between seasonally frozen 

ground and permafrost, and to obtain low-turbidity water reasonably 

constant in chemical quality from beneath streams, lakes, and 

reservoirs.

For the small water user in areas where no heat is required, gallery 

installations may provide a rather low-cost method of obtaining a 

year-round water supply. For larger supplies, a gallery may also 

provide the most economical method of obtaining water.

Most outlying villages and some larger cities in Alaska are along 

rivers where annual flooding and silt-laden waters are serious obstacles to utilization of a surface-water supply. Also, at such areas 

drilled wells may be impractical to construct and maintain because of 

transportation costs. Therefore, vertical or lateral galleries may be 

the best means of obtaining a water supply because local labor and 

equipment can be used to reduce construction costs and to control 

excessive turbidity. The chance of failure by freezing is almost 

eliminated if proper maintenance procedures are followed.

REFERENCES CITED

Black, R. A., 1954, Permafrost a review: Geol. Soc. of America Bull., v. 66,

p. 839-856. 

Cederstrom, D. J., 1952, Summary of ground-water development in Alaska, 1950:

U.S. Geol. Survey Circ. 169, 37 p.
E16 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

G. & C. Merriam Co., 1961, Webster's third new international dictionary of the

English language: Springfield, Mass., 2662 p. 

Hopkins, D. M., Karlstrom, T. N. V., and others, 1955, Permafrost and ground

water in Alaska: U.S. Geol. Survey Prof. Paper 264-F, p. 113-146. 

Kazmann, R. G., 1948, River infiltration as a source of ground water supply:

Am. Soc. Civil Engineers Trans., v. 29, no. 1, p. 85-92. 

Meinzer, O. E., 1923, Outline of ground-water hydrology with definitions: U.S.

Geol. Survey Water-Supply Paper 494, 71 p. 

Muller, S. W., 1947, Permafrost or permanently frozen ground and related

engineering problems: Ann Arbor, Mich., J. W. Edwards, Inc., 230 p. 

Todd, D. K., 1959, Ground water hydrology: New York, John Wiley & Sons,

336 p.