A Review of 

Water Resources of the 

Umiat Area, Northern Alaska 

A Review of 

Water Resources of the 

Umiat Area, Northern Alaska 

By John R. Williams 

GEOLOGICAL SURVEY CIRCULAR 636 

Washington 19 70 
United States Department of the Interior 

WALTER J. HICKEL, Secretary 

Geological Survey 

William T. Pecora, Director 

Free on application to the U.S. Geological Survey, Washington, D.C. 20242 
CONTENTS 

Abstract ______________ --------------------------------- ___ _ 

Introduction __________________________________ _ 

Geography and geology 

Water resources _ 

Surface water _______ _ 

Ground water ___________ _ 

Bedrock aquifers __ 

Alluvial aquifers 

Springs and seeps_ 

Conclusions ---------------------------------- References cited __________________________ _ 

ILLUSTRATIONS 

FIGURE 1. Map of Umiat area showing location of exploratory test wells in 

Page 

1 

1 

2 

4 

4 

5 

5 

6 

7 

7 

7 

Page 

foothills and in Colville River valley__________________________ ___ ___ _____________________ 2 

2. Well location map, Colville River valley at Umiat ____ -------------------------------

TABLE 1. 

2. 

TABLES 

Subsurface data in the Umiat area __________________________________ _ 

Analysis of Colville River water near Umiat 

III 

4 

Page 

3 

4 

A REVIEW OF WATER RESOURCES OF THE UMIAT AREA, 

N,ORTHERN ALASKA 

By JOHN R. WILLIAMS 

ABSTRACT 

Surface-water supplies from the Colville River, small 

tributary creeks, and lakes are abundant in summer but 

limited in winter by low or zero flow in streams and 

thick ice cover on lakes. 

Fresh ground water occurs in unfrozen zones in alluvium and in the upper part of bedrock beneath the 

Colville River and beneath lakes that do not freeze to 

the bottom in winter. These unfrozen zones, forming 

depressions in the upper surface of permafrost, are 

maintained by flow of heat from bodies of surface water 

into subjacent alluvium and bedrock. 

Brackish or saline ground water occurs in bedrock 

beneath as much as 1,055 feet of permafrost in the 

Arctic foothills and beneath 750 to 800 feet of permafrost bene;;tth low terraces of the Colville River valley. 

The foothill area is unfavorable for developing supplies 

of potable ground water because of the great depth to 

water, predominance of brackish or saline water, and 

low potential yield of the bedrock. In the Colville River 

valley, shallow unfrozen alluvium beneath the river and 

deep lakes will yield abundant year-round supplies of 

ground water, but the bedrock below permafrost yields 

less than 10 gpm (gallons per minute) of saline or 

brackish water. 

INTRODUCTION 

The Umiat area is in the Arctic (northern) 

foothills of the Brooks Range at lat 69° 22' 

30" N., long 152° 08' 30" W. (fig. 1). The 

settlement and adjacent airstrip lie on low 

terraces north of the Colville River near the 

mouth of Sea Bee Creek. The camp was established during exploration for petroleum in 

Naval Petroleum Reserve No. 4. Development 

of the Prudhoe Bay field to the northeast and 

exploration for oil and gas in leases bordering 

the Reserve east of the Colville River may lead 

to growth of the settlement and may increase 

demand for a dependable year-round supply of 

potable water. The existing system obtains 

water from surface sources and melted snow 

and ice. 

1 

Locating and developing supplies of water to 

meet future needs at Umiat and at other settlements in northern Alaska is made difficult by 

the presence of saline or brackish water in bedrock, widespread occurrence of permafrost that 

extends to depths of 500 to 1,330 feet, intermittent winter flow of rivers, and deep freezing of 

surface-water bodies. Nevertheless, abundant 

ground water occurs in unfrozen alluvium that 

occupies depressions in the upper surface of 

permafrost beneath deep 1akes and rivers. 

Ground water from such sources generally is 

warmer in winter and less likely to freeze in 

distribution lines than surface water and does 

not contain suspended sediment. Use of ground 

water eliminates problems of icing of surfacewater intakes by frazil or anchor ice in rivers 

and problems of insufficient river flow in winter. Aquifers beneath lakes have a larger storage capacity than a surface-water supp1y limited to water between the lake bottom and ice 

cover. 

The purpose of this report is to describe 

potential sources of surface water and ground 

water in the Umiat area and to point out possibilities for developing year-round supplies of 

ground water in shallow unfrozen alluvia1 aquifers beneath rivers and deep lakes. The principles relating to occurrence of water in the 

Umiat area apply to other parts of the Colville 

River valley and to other large valleys of northern Alaska. 

This report was prepared as part of a compilation of existing data on the occurrence of 

ground water in permafrost regions; it is based 

entirely on office studies of reports by Black 

(1955), Black and Barksdale (1948), Brewer 

(1958a), and Collins (1958). 
69° 

25' 

152° 20' 

0 2 

10' 152° 00' 

Base from Collins (1958) 

3 4M ILES 

.s 

Shut-in oil well 

and number 

EXPLANATION 

~2 

Dry hole and 

number 

I I ! I I I 

Boundary of 

Colville River valley 

INDEX MAP 

OF ALASKA 

FIGURE !.-Location of exploratory test wells in foothills and Colville River valley. 

GEOGRAPHY AND GEOLOGY 

At Umiat the Colville River, the largest in 

northern Alaska, flows N. 80° E. in a braided 

channel within a valley 2 to 4 miles wide (fig. 

1). The valley, 330 to 340 feet above sea level 

near Umiat, consists of riverbed, bars and 

islands of the flood plain, and low lake-dotted 

terraces that separate the flood plain from the 

hills. The hills bordering the valley are part of 

the Arctic foothills of the Brooks Range. Steep 

bluffs border the river where it impinges 

against the hillsides, as at Umiat Mountain, 600 

feet above the valley floor (fig. 1). 

Bedrock in the vicinity of Umiat is of Cretaceous age (Collins, 1958, p. 73) and consists of 

clay-shale and sandstone which, in the upper 

part, is interbedded locally with bentonite, clay 

ironstone, and coal. The rocks are in broad open 

folds that are cut locally by faults. Northeast of 

2 

Umiat the eastward-trending Umiat anticline is 

cut by the river at Umiat Mountain 'Yhere seeps 

of oil led to exploration and drilling. 

Unconsolidated deposits in the Colville River 

valley are of Pleistocene and Holocene age 

(Black and Barksdale, 1948, p. 8; Collins, 1958, 

p. 73) and consist of interbedded alluvial gravel, 

sand, and silt in the flood plain and low terraces. 

The gravel and sand are made up of subrounded 

to rounded grains of yellow, white, and black 

chert and clear quartz. The deposits are as 

much as 71 feet thick (table 1). 

Permafrost, as measured in wells drilled for 

petroleum, extends to a depth of 535 to 1,055 

feet in the foothills north of the Colville River 

and to a depth of 750 to 800 feet beneath low terraces north of the river (figs. 1 and 2; table 1) 

(Brewer, p. 132, 142, 170, and 197, in Collins, 

1958; Collins, 1958, p. 99; Reed, 1958, p. 78). 
TABLE !.-Subsurface data in the Umiat area 

Thickness Depth to Well in Total of base of Occurrence and yield of ground 

figs. N arne and type depth alluvium permafrost water: results of formation Sources of 1 and 2 of well or hole (feet) (feet) (feet) tests information 

Umiat Test Well 1, 6,005 920 Formation test 1,693-1,816 ft Collins, 1958, p. 95-99. 

dry hole. nroduced 9 gpm fresh water. 

2 Umiat Test Well 2, 6,212 71 750 Formation test 103-345 ft Collins, 1958, 

dry hole. when hole cased to 100 ft; p. 99-116; Reed, 

dissolved-solids cencentrations 1958, p. 78. 1,031 mg/1, chloride 173 mgjl. 

Formation test after reaching total depth; water level 730 ft; 

dissolved-solids concentrations 3,188 mgjl; chloride 1,176 mg/1. 

3 Umiat Test Well 3, 572 No water. Collins, 1958, shut-in oil well. p. 116-125. 

4 Umiat Test Well 4, 840 ~97 Unknown. Brewer, p. 131-132 in shut-in oil well. Collins, 191"8 ; Collins, 19f8, p. 125-131. 

5 Umiat Test Well 5, 1,077 28 800 Fresh water in upper 28 ft of Collins, 1958, shut-in oil well. alluvium sealed off by casing ; p. 132-138. salt water at probable base of permafrost. 

6 Umiat Test Well 6, 825 28+ 770 Water first noted at 825 ft; Brewer, p. 142, in shut-in oil well. sample taken from tank during Collins, 19f 8 ; 

pumping test; dissolved-solids Collins, 1958, concentrations 7,928 mgjl; p. 138-142. chloride 1,400 mgjl. 

7 Umiat Test Well 7, 1,384 35+(?) Above 485 ft small amount of Collins, 1958, 

dry hole. fresh water ; below 485 ft p. 143-148. salinity values affected by brine drilling fluid. 

8 Umiat Test Well 8, 1,327 535( ?) ------------------------------------------ Collins, 1958, shut-in oil well. p. 148-155. 

9 Umiat Test Well 9, 1,257 1,055 -------------------------------------------- Brewer, p. 170-171 in shut-in oil well. Collins, 191\8 ; Collins, 1958, p. 158-170. 

10 Umiat Test Well 10, 1,573 -------------------------------------------- Collins, 1958, shut-in oil well. p. 171-178. 

11 Umiat Test Well 11, 3,303 770( ?) Brackish water recovered in Brewer, p. 197 in dry hole. formation tests (see text p. 5). Collins, 1958; 

Collins, 1958, p. 179-198. 

12 Seismic shot hole ---------- 45 23 45+ -------------------------------------------- Black and Barksdale, 

1948, hole 1, p. 14. 

13 ____________________ do ____________________ 45 31 45+ ------------------------------------------- Black and Barksdale, 

1948, hole 2, p. 14. 

14 __ ----------------~do------------------- 45 23 45+ -------------------------------------------- Black and Barksdale, 

1948, hole 3, p. 14. 

15 -------------------~do __ ----------------- 45 29 45+ ------------------------------------------ Black and Ba.rksdale, 

1948, hole 4, p. 20. 

16 -------------------~do ____________________ 42 24 Above 13ft; Water-bearing sand and gravel Black and Barksdale, 18-42+ ft. between 13 and 18 ft. 1948, hole 5, p. 12, 

20, and fig. 2. 

17 -------------------~do ____________________ 44 25 Above 11 ft; Unfrozen zone between 11 and Black and Barksdale, 

18 ____________________ do __________________ 48 41 

19 ____________________ do ____________________ 41 2.5 

20 ___________________ do ___________________ 44 28 

21 ____________________ do ____________________ 47 31 

Although no test wells or shallow borings have 

been drilled in the riverbed, bars, or islands of 

the flood plain, the upper surface of permafrost 

probably is deep beneath the river because of 

the warming effect of the river on subjacent 

alluvium and bedrock. Similar depressions in the 

upper surface of permafrost beneath lakes that 

do not freeze to the bottom in winter probably 

22-~44+ ft. 22 ft. 1948, hole 6, p. 20. 

3 

48+ -------------------------------------------- Black and Barksdale, 

1948, hole 7, p. 20. 

--------------------------------------------

-------------------------------------------- Do. 

------ ----------------------------------- Do. 

are not as deep nor as wide as that h~neath 

the river. 

Locating and delimiting the extent of unfrozen zones beneath rivers and lakes may b~ done 

by test di'illing, geothermal methods, or 

geophysical investigations. Test drilling is of 

limited value because distinguishing between 

frozen and unfrozen fine-grained bedrock is 
69° 

22' 

30" 

0 2000 4000 FEET 

EXPLANATION 

~ D 

Bedrock Alluvium 

Contact 

.14 

Seismic shot hole 

and number 

~ 

~ 

Gravel 

bars 

07 

Exploratory oil test well 

and number 

FIGURE 2.-Well locations in the Colville River valley at 

Umiat. 

based on action of the drill which may be difficult to evaluate. Geothermal methods described 

by Lachenbruch (1957) and Brown (1963) 

require information on the mean annual ground 

surface temperature, mean annual water temperature (or mean annual temperature of the 

lake bottom or riverbed) , regional geothermal 

gradient, and history of changes in size and 

shape of the water body. These data are not 

available in the Umiat area. The seismic refraction method is the most suitable geophysical 

method for determining the position of the 

upper surface of permafrost (Barnes, 1964) 

and could be applied at Umiat to determine the 

thickness of unfrozen zones beneath the river 

and deep lakes. 

WATER RESOURCES 

Surface-water resources of the Umiat area 

include the Colville River, its tributaries, and 

lakes. Ground-water resources consist of brackish or saline water in bedrock below permafrost 

and fresh, potable water in alluvium and shal4 

low bedrock above the permafrm;t beneath the 

river and deep lakes. 

SURF ACE WATER 

Discharge of the Colville River at Umiat, 

measured only in 1953, ranged from zero flow on 

April 2 to 13,000 cfs (cubic feet per second) on 

September 10 (U.S. Geological Survey, 1958, 

p. 208). Freezing forms 6 to 9 feet of ice on 

rivers and lakes by late winter, but deep pools in 

the river channel and the deeper lakes provide 

year-round sources of water. In February 1954 

water temperature, measured b€neath a 5-foot 

ice cover in a channel 17 feet dee'l, ranged from 

ooc (Celsius) at the base of the ice to about 

0.5°C at the bottom of the river (Brewer, 

1958a, fig. 9). The positive botto"ll temperature 

shows that the alluvium beneath the river is 

above the freezing point in winter. The nearly 

uniform temperature suggests that the river 

was flowing at this time. Although the river 

had no flow in April 1953, perennial flow has 

been reported in other years (Black and Barksdale, 1948). Thick masses of frazil ice accumuJate in deep pools and anchor ice probably forms 

along the bottom of the river; during 1953, 

frazil ice 12 feet deep was reporte1. 

Quality of water of the Colville River at a discharge of 6,500 cfs is excellent, on the basis of 

an analysis of a single sample co1lected July 28, 

1953 (table 2). No data are avdlable to show 

changes in composition of the water during 

winter. The river carries suspended sediment 

during the spring runoff and at other peak 

flows, but at low stage the river is free of 

suspended sediment. 

TABLE 2.-Analysis of Colville River 1/1ater near Umiat 

[U.S. Geological Survey, 1958, r. 239] 

Milligrams 

Chemical constituents per liter 

Silica (Si02) _____________________ -------------------------------- 1.9 

Calcium (Ca) ___________ -------------------------------------- 13 

Magnesium (Mg) ___ -------------------------------------------- 4.8 

Sodium (Na) -------------------------------------------------------- 1.5 

Potassium (K) ------------------------------------------------ .5 

Bicarbonate (HCOa) ------------------------------------------ 53 

Sulfate (S04) ------------------- -------------------------------- 10 

Chloride (Cl) -------------------------------------------------------- .5 

Nitrate (NOa) _____________ ---------------------------------------- .3 

Dissolved solids (residue on 

evaporation at 180°C) -------------------------------- 59 

Hardness as CACOa: 

Calcium, magnesium ------------------------------------ 52 

Noncarbonate ------------------------------------------------ 8 

Specific conductance ________ micromhos at 25°C__ 109 

pH -------------------------------------------------------------------------- 6.8 
Sea Bee Creek, the largest of the tributaries 

of the Colville River in the Umiat area, drains 

the foothills and follows abandoned channels of 

the Colville as it crosses the low terraces. The 

creek is reported to freeze to its bed in winter 

(Reed, 1958, p. 60). Although creeks like Sea 

Bee Creek provide a source of w2ter in summer, 

little or no water is available from them in winter. No determinations of flow or quality of the 

water have been made. 

Numerous lakes occupy abandoned channels 

on the low terraces bordering the Colville River. 

The ice cover of 6 to 9 feet eliminates many of 

the shallower lakes and shallow sections of deep 

lakes as sources of water during winter. The 

temperature of Umiat Lake (fig. 2), one of the 

largest and deepest lakes in this part of the Colville Valley, was studied by Brewer (1958a) in 

February 1954. Water temperature ranged 

from ooc beneath a 5-foot ice cover to 4 oc 

at the bottom of the lake, 12 feet below the ice 

surface. In summer, water of lakes near Umiat 

reportedly contains a high concentration of 

organic compounds that make it objectionable 

for drinking (Black and Barksdale, 1948, p. 10). 

Although no analyses are available, the concentration may be increased as volume of the lake 

is decreased by freezing of its surface. Limited 

year-round supplies of poor quality water are 

available from lakes that do not freeze to the 

bottom. Shallower lakes are sources of supply 

only in summer. 

GROUND WATER 

Ground water occurs in porous, permeable 

beds and fractures in bedrock and in alluvial 

sand and gravel. The water in bedrock beneath 

permafrost in the northern Alaska is generally 

saline or brackish. Within the Colville Rive1· 

valley, water in unfrozen zones in the alluvium 

and in the upper part of bedrock beneath the 

river is fresh. Fresh water also occurs in unfrozen alluvium beneath lakes that do not freeze 

to the bottom in winter and in local unfrozen 

zones in terrace alluvium near the lakes and the 

river. 

BEDROCK AQUIFERS 

Bedrock aquifers consist of permeable finegrained sandstone and fractured sandstone and 

clay-shale of Cretaceous age. The lithology, 

stratigraphy, and structure of these rocks is 

given in greater detail in Collins (1958). Yield 

5 

of bedrock aquifers in the Umiat area 2nd elsewhere in the foothills and Arctic coastal plain is 

only rarely as great as 10 gpm (gallons per 

minute). 

In the foothill belt north of the Colville River 

(fig. 1) six exploratory oil wells were drilled in 

bedrock through 535 to 1,055 feet of permafrost. \Vater was reported in only two of these 

wells. In test well 11 brackish water was obtained from formation tests at depths between 

2,094 to 2,850 feet, as follows: 

Depth 

2,094.5-2,145 

2,375 -2,411 

2,44 7 -2,461 

2,814 -2,830 

2,832 -2,850 

Dissolved 

solids 

(mgjl) 

---------------- --- ___________ _4,290 -------- ________ 6,900 

-------------------------6,434 

________________ 6,543 

Chloride 

1,600 

865 

1,950 

In well 1 water entered at a rate of 9 gpm in a 

formation test of rocks between 1,69~ and 1,816 

feet in depth (table 1) (Collins, 1958). On the 

basis of drilling and formation tests at Umiat 

and elsewhere, bedrock of the foothills is not 

regarded as a significant source of water 

because of high salinity, low yield, and great 

depth to water. 

Ground water in bedrock beneath the low terraces north of the Colville River is rep')rted in 

four of five exploratory oil wells. The water 

below the base of permafrost ( 750 to 800 feet) 

has a higher salinity than acceptable standards 

for public supplies. 

Fresh ground water reportedly, was obtained 

from the upper part of bedrock in two wells in 

the Colville River valley. In well 2, ab':lut 250 

feet east of Umiat Lake, water having 1,031 

mg/1 (milligrams per liter) dissolved solids 

was obtained from a formation test of bedrock 

between 103 and 345 feet. The test was made 

after installation of 100 feet of casing, but the 

effectiveness of the casing in sealing off any 

water in the 71 feet of surficial alluviu~ overlying bedrock was not reported. In well 7, located about 700 feet from the Colville River and 

500 feet from Sea Bee Creek (fig, 2), fresh 

water was reported in the upper 485 feeL but no 

analyis was made, nor was the depth of the 

water-bearing zone specified. If these reports 

of fresh water in bedrock in wells near b'1dies of 

surface water are correct, the unfroz~m zone 

beneath Umiat Lake and beneath the Colville 
River may extend laterally beneath the low terraces. The depth to which fresh water was 

reported in well 2 suggests that the unfrozen 

zone beneath Umiat Lake is at least 103 feet 

deep and perhaps 1nore than 345 feet. These 

suggested depths are reasonable 'When compared with the 190-foot depth of the upper surface of permafrost beneath Imikpuk 

Lake, a much s1naller lake near Barrow, where 

the mean annual ground surface temperature is 

comparable to that at Umiat (Brewer, 

1958b). If fresh water reported in well 7 to a 

depth of about 485 feet is derived from a lateral 

extension of the unfrozen zone beneath Colville 

River, the unfrozen zone beneath the river may 

extend to a depth of 485 feet or even deeper, 

perhaps completely perforating the permafrost 

as postulated by Black ( 1955, p. 119; Black and 

Barksdale, 1948). 

ALLUVIAL AQUIFERS 

Porous and pern1eable sand and gravel 23 to 

71 feet thick was penetrated in five exploratory oil wells and 10 seismic shot holes drilled in low terraces north of the Colville River 

(fig. 2). In all but three holes the alluvium is 

frozen from near the surface to its base. Heat 

flow by conduction fron1 the river and lakes 

maintains year-round unfrozen zones in subjacent alluvial deposits. Three holes located near 

Umiat Lake and the Colville River penetrated 

unfrozen zones in the alluvium that are probably lateral extensions to those beneath the 

lake and the river. 

Unfrozen alluvium beneath the Colville River 

is recharged directly by surface water or by 

underflow through the bed of the river from 

points upstream. The alluvium provides a 

greater volun1e of storage and potential recharge than any other source of water in the 

Umiat area. Athough data on yields from alluvial deposits are not available, the thickness 

and character of the deposits suggest that wells 

might yield as much as several hundred gallons 

per minute. During periods of low or zero river 

flow in winter, deep pools in the river and water 

stored in the unfrozen alluvium probably would 

provide ample recharge and storage throughout 

winter. A well or gallery pumping from alluvium beneath the river probably would induce 

infiltration of river water that contains a low 

6 

proportion of dissolved solids and organic 

constituents. No data are available on the depth 

of scour or rate of bank erosion that might 

affect the useful life of galleries beneath the 

river or wells on its bank. 

Unfrozen alluvium beneath lakes has a more 

limited source of recharge and volume of storage than that beneath the river. Winter 

recharge to the alluvial aquifer beneath lakes 

is lin1ited to lake water beneath the ice cover. 

The rate at which lake water wo•lld replenish a 

pumped aquifer would depend on the thickness 

and permeability of organic material and silty 

bottom sedin1ents that separate the lake from 

the underlying alluvial aquifer. Quality of 

ground water beneath lakes probably is similar 

to that of the lake, although no analyses of 

either lake water or ground water are available. 

Three holes, all within 400 feet of either the 

river or a deep lake, were drilled through unfrozen zones in the alluvium that may be lateral 

extensions of the unfrozen zones beneath the 

river or lakes. Test well 5 reportedly produced 

fresh water in the alluvium in the upper 28 feet 

of the hole. Unfrozen gravel was penetrated 

between 13 to 18 feet in shot hole 16 and 

between 11 and 22 feet in shot hole 17. Gravel 

in hole 16 contained water and ir believed to be 

a lateral extension of the unfrozen alluvium 

beneath the Colville River, only 300 feet away 

(Black and Barksdale, 1948). Water from such 

unfrozen zones may be higher in dissolved solids than that indicated by river water sampled 

in summer. The water level may fluctuate with 

the stage of the river. Drilling wells at locations 

on the low terrace adjacent to rivers or lakes is 

n1ore convenient than drilling at an angle to 

intercept aquifers beneath boc1ies of water. 

However, locating productive rnfrozen zones 

in the terrace deposits near the river and lakes 

is more difficult than locating those beneath 

the river and lakes. From experience elsewhere, 

unfrozen zones in low terrace alluvium may be 

more common and larger on tl1e slipoff side 

than along the former cutbanks of the river or 

linear oxbow lakes. Unfrozen zones may be 

more common along the ends of these linear 

lakes but within the abandoned river channels 

than along the sides. 
SPRINGS AND SEEPS 

Springs were noted in 1946 between the airfield and Umiat camp (fig. 2). Black and 

Barksdale (1948, p. 10) report that the water 

temperature was 1.1 oc and the source of the 

springs is from surface thaw and not from 

unfrozen layers within the alluviun1. They report that several unsuccessful attempts were 

made to locate a supply of ground water in the 

alluvium near the camp. However, Reed ( 1958, 

p. 54), without commenting on the source of the 

water, reports that a shallow well dug near the 

spring provided water for the camp. 

No springs or seeps beneath the river are 

known in the Umiat area. The chemical character of the river water, judging from a san1ple 

collected in summer, suggests that it is not fed 

by seepage of brackish or saline ground water 

from bedrock beneath permafrost. However, 

analysis of river water during low winter flow 

should be made to determine the proportion of 

winter flow from bank storage in the alluvium 

and underflow and that from saline or brackish 

ground water. Abnormally high chloride concentration in such analysis would suggest that 

saline or brackish water is discharged to the 

river in winter from the bedrock. 

CONCLUSIONS 

In the Colville River valley, water from the 

river, its small tributaries, and lakes is limited 

or unavailable in winter when streamflow ceases 

or is very low and the lakes are largely covered 

by ice. Year-round supplies of fresh ground 

water occur in unfrozen aquifers beneath the 

Colville River and lakes that do not freeze to 

the bottom in winter, and in local areas of the 

low terraces near lakes and the river. Yields 

from these aquifers probably are several hundred gallons per minute from alluvium but less 

than 10 gpm from bedrock. Quality of water 

probably is best in alluvium imn1ediately 

beneath the river, but dissolved solids appear 

to increase in concentration with depth. Brackish or saline water may be expected in bedrock 

below permafrost. Dissolved organic material 

may be present in ground water beneath lakes. 

Storage and recharge potential are large in alluvium beneath the river and less beneath lakes. 

7 

In the Arctic foothills north of Umiat 

ground water occurs in permeable beds and 

fractures in bedrock below permafrost. However, the great depth to water, low yield, and 

predominance of brackish or saline wate~ indicate that the foothills are unfavorable for developing supplies of potable ground water. 

Principles relating to the development of 

unfrozen zones or depressions in the upper surface of pern1afrost beneath rivers anc1

. deep 

lakes by conductive heat flow fron1 the water to 

subjacent alluvium and bedrock have been 

established by geothermal studies in northern 

Alaska (Brewer, 1958a, b; Lachenbruch, 1957; 

Lachenbruch and others, 1962). These principles have been applied through use of grr.phical 

solutions in the Mackenzie Valley of Canada 

(Brown, 1963), and can be quantitatively 

applied to the search for water-bearing unfrozen zones above permafrost in alluvial deposits 

at Umiat when the requisite basic data become 

available. The principles applied qualitatively to 

the Un1iat area in this report may be r.pplied 

elsewhere in the Colville Valley and in other valleys of the Arctic where geologic and hydrologic 

conditions are comparable. 

REFERENCES CITED 

Barnes, D. F., 1965, Geophysical methods for delineating 

permafrost: Internat. Conf. on Permafrcst, Lafayette, Ind., 1963, Proc., p. 349-355. 

Brewer, M. C., 1958a, Some results of geothei'mal investigations of permafrost in northern Alaska: Am. 

Geophys. Union Trans., v. 39, no. 1, p. 19-2f, 

--- 1958b, The thermal regime of an Arctic lake: 

Am. Geophys. Union Trans., v. 39, no. 2, p. 278-284. 

Black, R. F., 1955, Arctic Slope in Hopkins, D. M., Karlstrom, T. N. V., and others, Permafrost and ground 

water in Alaska: U.S. Geol. Survey Prof. Paper 

264-F, p. 118-119. 

Black, R. F. and Barksdale, W. L., 1948, Terr~.in and 

permafrost, Umiat area, Alaska: U.S. Geol. Survey 

Permafrost Program Progress Rept. 5, 23 p. ; pub. 

by Eng. Intelligence Div., Office, Chief of Engineers, 

U.S. Army. 

Brown, W. G., 1963, Simple graphical methods for estimating the location of permafrost under shallow 

lakes and rivers in Brown, R. J. E., ed., Proceedings 

of the 1st Canadian Conf. on Permafrost, 1962: 

N atl. Research Council Canada, Assoc. Co:'llmittee 

on Snow and Soil Mechanics, Tech. Memo. 76, p. 

226-231. 
Collins, F. R., 1958, Test wells, Umiat area, Alaska, with 

Micropaleontologic study of the Umiat field, northern Alaska, by H. R. Bergquist and sections on 

Temperature measurement studies by M. C. Brewer 

and Core analyses, Umiat test well 9, by G. L. 

Gates: U.S. Geol. Survey Prof. Paper 305-B, p. 

71-206. 

Lachenbruch, A. H., 1957, Three-dimensional heat conduction in permafrost beneath heated buildings: 

U.S. Geol. Survey Bull. 1052-B, p. 51-69. 

Lachenbruch, A. H., Brewer, M. C., Greene, G. W., and 

Marshall, B. V., 1962, Temperatures in permafrost 

in Temperature-its measure:rrent and control in 

science and industry: New Y or]~. Reinhold Publish

ing Corp., v. 3, pt. 1, p. 791-803. 

Reed, J. C., 1958, Exploration of Naval Petroleum Re

serve No. 4 and adjacent areas northern Alaska

1944-1953, Part 1, History of tl~ exploration: U.S

Geol. Survey Prof. Paper 301, 192 p. 

U.S. Geological Survey, 1958, Quartity and quality of 

surface waters of Alaska, October 1950 to Septem

ber 1953: U.S. Geol. Survey vr ater-Supply Paper 

1466, 243 p. 

*U.S. GOVERNMENT PRINTING OFFICE: 1970 0-387-19i 

8