S GEOLOGICAL SURVEY (200) RFSTON, VA 

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no. D.(0,3-.\\--i, Gs SEP 2 0 200 c.• II1131 11118'1118 10RIAIRLI1R11 811:141/151 Avg jp SR 

LIBRARY science for a changing world STATE WAIF II I: TATATiSSIE, 

Climatology, Hydrology, and Simulation 

of an Emergency Outlet, Devils Lake Basin, 

North Dakota 

Abstract 

Devils Lake is a natural lake in 

northeastern North Dakota that is the 

terminus of a nearly 4,000-square-mile 

subbasin in the Red River of the North 

Basin. The lake has not reached its 

natural spill elevation to the Sheyenne 

River (a tributary of the Red River of 

the North) in recorded history. However, geologic evidence indicates a 

spill occurred sometime within the last 

1,800 years. From 1993 to 1999, Devils 

Lake rose 24.5 feet and, at the present 

(August 2000), is about 13 feet below 

the natural spill elevation. The recent 

lake-level rise has caused flood damages 

exceeding $300 million and triggered 

development of future flood-control 

options to prevent ficrther infrastructure 

damage and reduce the risk of a 

potentially catastrophic uncontrolled 

spill. Construction of an emergency 

outlet from the west end of Devils Lake 

to the Sheyenne River is one floodcontrol option being considered. This 

report describes the climatologic and 

hydrologic causes of the recent lakelevel rise, provides information on the 

potential for continued lake-level rises 

during the next 15 years, and describes 

the potential effectiveness of an emergency outlet in reducing future lake 

levels and in reducing the risk of an 

uncontrolled spill. The potential effects 

of an outlet on downstream u'ater 

quantity and quality in the upper 

Sheyenne River also are described. 

Introduction 

The Devils Lake Basin is a 3,810-

square-mile (mi2) subbasin (fig. 1) in 

the Red River of the North Basin. 

About 3,320 mi2 of the total 3,810 mil 

is tributary to Devils Lake; the remainder is tributary to Stump Lake. At an 

elevation of 1,446.5 feet (ft) above sea 

level (asl), Devils Lake begins to spill 

into Stump Lake; and at an elevation of 

about 1,459 ft asl, the combined lakes 

begin to spill through Tolna Coulee 

into the Sheyenne River (fig. 2). 

Since the end of glaciation about 

10,000 years ago, Devils Lake has 

fluctuated from about 1,459 ft asl, the 

current natural spill elevation of the 

lake to the Sheyenne River, to about 

1,400 ft asl. Although no documented 

records of lake levels are available 

before 1867, Upham (1895, p. 595), on 

the basis of tree-ring chronology, indicated the lake level was 1,441 ft asl 

in 1830. Lake levels were recorded 

sporadically from 1867 to 1901 when 

the U.S. Geological Survey (USGS) 

established a gaging station on Devils 

Lake. From 1867 to the present 

(August 2000), the lake level has 

fluctuated between a maximum of 

1,447.1 ft asl in 1999 and a minimum 

of 1,400.9 ft asl in 1940 (fig. 3). The 

lake rose 24.5 ft from February 1993 

to August 1999, and on August 1, 

2000, the lake level was 1,446.1 ft asl. 

The original survey of the Stump 

Lake area was conducted between 

1881 and 1883. At that time, Stump 

Lake was between 1,420 and 1,425 ft 

asl, about 10 to 15 ft higher than its 

August 1, 2000, level of 1,409.8 ft asl. 

When Devils Lake peaked at 1,447.1 ft 

asl in the summer of 1999, water was 

just beginning to trickle into Stump 

Lake. Therefore, considering its small 

drainage area, for Stump Lake to be 

above 1,420 ft asl between 1881 and 

1883, a substantial amount of water 

probably flowed from Devils Lake into 

Stump Lake sometime before 1880. 

Joseph Nicollet, who explored the 

Devils Lake area in 1839, described 

the area between Devils Lake and 

Stump Lake as big deep coulees (Bray 

and Bray, 1976). Nicollet stated 

"These are dry at the moment but in 

time of high water seem to receive 

water from Devil's Lake." This information indicates water flowed from 

Devils Lake to Stump Lake sometime 

between 1820 and 1840. 

Radiocarbon dating of organic 

matter such as wood, bone, or plant 

matter found in buried soils or beaches 

was used to provide an understanding 

of lake-level fluctuations of Devils 

Lake before the early 1800's. In 

1987 and 1997, North Dakota State 

Geological Survey geologists collected 

samples from beaches along Devils 

Lake and from sediments in the 

Jerusalem outlet for radiocarbon 

U.S. Department of the Interior USGS Water-Resources Investigations Report 00-4174 

U.S. Geological Survey August 2000
99° 98°30. 

Chum s•i: Al SAMPLING SITE AND NUMBER 

ake 

Lake 

Atue 

lrrt 4n. 2A 

Webster 

fliut,. h. ( vulee P. ch.lcr 

48°15' 

for) 

'Ike I Ca.anaLigh 

Morrison 

Lake LdR 

1 <Ike 

Suretuoter 

Lake 

8 Nebrun to 

Lake 

Corryorwk 

rembre 11 Lake 

Mainet. Auk.. DEVILS ~ \ 

a No Oltel r 

48" 

Mmilon 

Bay Fon Ea. 

()cols Totten Mark 

Tige r East Lake Bay Slump 

Lake 

47°45' 

0 MILES 

_J 

11_ — 'or 55'111 1C0.1.5,, Pt' 

? 1C:0 1 

Figure 1. Location of the Devils Lake Basin. Devils Lake and Stump Lake. and 

the Sheyenne River. 

dating and interpretation. By dating 

the material, the lake level could be 

determined. For example, a sample of 

material was taken at an elevation of 

1,454 ft asl from a soil profile. The soil 

was overlain by a clean sand beach that 

had a top elevation the same as the 

spill elevation to the Sheyenne River. 

Radiocarbon dating of the material 

provided an age of 1,800 years before 

the present. Therefore, the geologists 

were able to conclude that sometime 

in the past 1,800 years, Devils Lake 

overflowed into the Sheyenne River. 

Research by the North Dakota 

Geological Survey indicates Devils 

Lake has overflowed into the Sheyenne 

River at least twice and probably more 

often during the last 4,000 years and 

has spilled into Stump Lake several 

times (Bluemle, 1991; Murphy and 

others, 1997). The exact number of 

times Devils Lake has spilled into 

Stump Lake or overflowed into the 

Sheyenne River cannot be determined 

because when the lake rises to the 

spill elevation, the action of the water 

destroys dating material left from a 

previous high stand of the lake. 

John Bluemle, North Dakota State 

Geologist, concluded the natural condition for Devils Lake is either rising 

or falling. This conclusion is supported by lake-level data collected during 

the past 135 years (fig. 3). 

The rapid rise in Devils Lake since 

1993 is in response to above-normal 

precipitation from the summer of 1993 

to the fall of 1999. The above-normal 

precipitation has resulted in the flooding of more than 70,000 acres of land 

around the lake and has caused flooding elsewhere in the Devils Lake 

Basin. State and Federal highways 

near Devils Lake have been raised, 

and some roads have been closed 

because of the flooding. According to 

North Dakota State Water Commission 

(NDSWC) estimates, flood damages 

from 1993 to the present have exceeded $300 million. 

In response to the flooding, the 

NDSWC and the U.S. Army Corps of 

Engineers (COE) developed various 

flood-solution plans to reduce the 

flooding in the Devils Lake area. The 

flood-solution plans include options to 

manage and store water in the Devils 

Lake Basin, continue infrastructure 

protection, and provide an emergency 

outlet to the Sheyenne River via the 

West Bay of Devils Lake. However, 

current and accurate climatologic and 

hydrologic data are needed to assess 

the feasibility of the various options to 

reduce flood damages at Devils Lake. 

The purpose of this report, prepared 

in cooperation with the North Dakota 

State Water Commission and the 

Regional Weather Information Center, 

University of North Dakota, is to describe the climatology and hydrology 

of the Devils Lake Basin as related to 

the simulation of an emergency outlet. 

Climatology 

Nature of Climate Variability 

Devils Lake responds directly to 

climate variability across the region. 

This climate variability generally can 

be regarded as the movement of the jet 

stream from season to season and from 
		

1,490 

ELEVATION, IN FEET ABOVE SEA LEVEL 

1,480 -

1,470 

Big Coulee 

455 

130 

Channel A 

480 

154 

480 DISSOLVED-SOLIDS CONCENTRATION. IN MILLIGRAMS PER LITER 

97 DISSOLVED SULFATE CONCENTRATION. IN MILLIGRAMS PER LITER 

Natural overflow to 

1,460 Highway 57 at 

Narrows 

Sheyenne River: 1,459 feet 

Natural overflow to 

1,450 Stump Lake: 1,446.5 feet 

— — 1.446.1 feet 

1,440 (August 1, 2000) 

1,430 

1,420 

1,410 — 

1,400 -

1,390 

DEVILS LAKE 

(West Bay) 

1,140 

480 

DEVILS LAKE 

(Main Bay) 

1,350 

600 

DEVILS LAKE 

(East Bay) 

2.330 

1,060 

East Devils 

Lake 

5.450 

2,780 

West East 

Stump Stump 

Lake Lake 

11,600 

6,100 

— — 1,409.8 feet 

(August 1. 2000) 

Sheyenne 

River 

480 

97 

1,380 0 5 10 MILES 

1.370 

Figure 2. Spill elevations of Devils Lake and Stump Lake; lake levels on August 1, 2000; and relatively recent (see text) 

dissolved-solids and sulfate concentrations for tributary inflows, lake water, and Sheyenne River streamflow. (Natural 

spill is from West Stump Lake.) 

year to year. The jet stream, which is 

a ribbon of high-velocity air located 

about 30,000 ft above the Earth's surface, exists because of temperature 

differences between air masses at the 

Earth's poles and at the equator. The 

movement of weather systems along 

the jet stream determines the distribution of precipitation about the globe. 

Climate variability results from a longterm shift in circulation patterns of the 

accounts for the dramatic variations in 

precipitation patterns along the western 

equatorial regions of South America. 

Across the plains of the northern 

United States and southern Canada, 

El Nino and its cold counterpart--La 

Nina--produce variations in precipita1,450 

tion and temperature patterns primarily 

in the winter months (Montroy, 1997). 

However, long-term variations in 

annual precipitation and temperature 

patterns across the region also occur 

as a result of variations in the tropical 

sea-surface temperatures. These longjet stream. As the circulation patterns WATER LEVEL.IN FEETABOVESEA LEVEL

1.450 

.445 

1..0 

435 

1.430 

1 425 

,420 986 1988 1990 1992 1994 1996 1998 2000 

shift, precipitation and temperature 

patterns also shift. Devils Lake has 

an enhanced sensitivity to long-term 

shifts in global circulation patterns as 

the level of the lake depends on many 

years of antecedent precipitation, 

runoff, and evaporation. If at any time 

precipitation, runoff, or evaporation is 

dominant, a corresponding dramatic 

response occurs in the lake level. 

Global atmospheric circulation 

patterns are driven predominantly 

by variations in sea-surface tem-

- RECORDED WATER LEVELS 

1.405 • INFREQUENT WATER-LEVEL MEASUREMENTS 1,400 9 

(Oct 1940) 

peratures. The most noticeable of 1.400 

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 

these variations, known as El Nino, 

occurs in the equatorial Pacific and Figure 3. Historic water level for Devils Lake, 1867-2000. 

WATER LEVEL, IN FEET ABOVE SEA LEVEL1.445 

1.440 • 1.438 4 

(1867) 

1.435 • 

1,430 

1.425 • 

1,420 

1,415 

1,410 
term variations often span decades and 

are instrumental in the occurrence of 

flood and drought conditions across the 

Devils Lake Basin and elsewhere. 

When the position of the jet stream 

across the western United States 

shifts to the southwest, strong storm 

systems move predominantly from 

the southwest at upper levels. These 

storm systems, typically referred to as 

Colorado Lows (fig. 4), cause unstable 

conditions across the Devils Lake 

Basin because warm, moist air from 

the Gulf Coast interacts with cool, dry 

air from Canada. The net result is a 

higher frequency of both warmer and 

wetter conditions across the Devils 

Lake Basin than during more stable 

periods. When the position of the jet 

stream shifts to the northwest, the 

Devils Lake Basin experiences a high 

frequency of Alberta Clippers, which 

are associated with cold, dry conditions in the basin. When the position 

of the jet stream shifts to a more 

westerly flow, referred to as a zonal 

pattern, the Devils Lake Basin 

generally experiences more normal 

precipitation and temperature patterns 

(patterns close to long-term seasonal 

average precipitation and temperature 

patterns). 

Recent Atmospheric Weather 

Patterns 

Before the late 1970's, the relatively subdued activity of El Nino and La 

Nina resulted in a low frequency of 

wet years in the Devils Lake Basin 

(fig. 5). Average seasonal precipitation values from the 1950's into the 

late 1970's varied from year to year, 

but precipitation amounts, particularly 

during July-December, generally were 

less than amounts since the late 1970's. 

This is consistent with a more even 

distribution of storm systems from 

the northwest, west, and southwest. 

Average annual temperatures from 

the 1950's into the late 1970's were 

relatively warm compared to temperatures from the late 1970's to 

the present, and a sharp temperature 

contrast occurred between the winter 

and summer extremes. 

Since the late 1970's, the activity 

of El Nino has been greater than at 

any other time during the 20th century. 

This heightened El Nino activity and 

its interaction with other global circulation patterns has resulted in an 

increased frequency of storms bearing 

Gulf of Mexico moisture across the 

Devils Lake Basin, causing a higher 

frequency of wet years in the basin 

(fig. 5). Since the late 1970's, the 

movement of the mean jet stream 

position over time has resulted in 

warmer late winter and early spring 

temperatures. However, the annual 

average temperature for the region 

has decreased slightly since the mid1980's, associated with greater cloud 

cover and precipitation. Since the 

early 1990's, unusually high precipitation amounts have occurred during 

May and June and again during the 

early fall. 

Future Atmospheric Weather 

Patterns 

The duration of the recent wet 

conditions cannot be determined 

definitely because of the complex 

interactions between global weather 

factors. However, according to 

estimates by the Regional Weather 

Information Center, University of 

North Dakota, the present wet conFigure 4. Extratropical storm tracks. (Blue arrow indicates Alberta Clipper storm ditions are expected to continue

track, green arrow indicates Colorado Low storm track, and pink arrow indicates beyond the first decade of the new 

zonal pattern.) century into 2015 (Osborne, 2000). 
During this period, the recent tendency 

for a high frequency of wet years, 

punctuated by occasional dry years, 

probably will continue. Although La 

Nina conditions through the summer of 

2000 could bring some periodic relief 

from the persistent, high precipitation 

of the past 8 years, long-range climate 

models indicate generally wet conditions during the coming fall and winter. 

Also, because the factors causing the 

recent wet conditions across the northern plains are global in scale, the transition from wet conditions to dry conditions may require years. Therefore, 

climatic conditions in the Devils Lake 

Basin during the next 15 years should 

be well represented by the historic 

conditions from the late 1970's to the 

present. 

Hydrology of the Devils 

Lake Area 

Lake Levels and Streamflow 

As Devils Lake rose to about 1,425 

ft asl in the early 1980's, the focus of 

various State and Federal projects was 

on the construction of a levee to protect 

the city of Devils Lake to a lake level 

of 1,440 ft asl and on completion of a 

feasibility report for flood control. The 

lake-level rise of the 1980's culminated 

when Devils Lake reached 1,428.8 ft 

as1 (the highest level since the 1870's) 

in August 1987 as a result of a large 

snowmelt runoff during the spring of 

that year (fig. 3). A severe drought 

began late in the summer of 1987, and 

the lake level declined to 1,422.6 ft asl 

by February 1993. During the drought, 

the volume of water in Devils Lake 

decreased about 37 percent, from 

884,000 acre-feet (acre-ft) in August 

1987 to 558,400 acre-ft in February 

1993. 

The drought also caused lake-level 

declines on other lakes in the Devils 

Lake Basin, including the chain of 

small lakes north of Devils Lake 

(fig. 1). For example, Dry Lake was 

below the outlet elevation (1,445 ft asl) 

to Channel A during most of 1988-92. 

Crops were planted in the lakebed 

20 

January - June 

15 

Mean 

8 44 inches 

1950-79) 

Mean 

9.26 inches 

(1980-99) 

10 

PRECIPITATION. IN INCHES 

0 

20 

July - December 

Mean 

11.11 inches 15 

(1980-99) 

Mean 

8.04 inches 

(1950-79) 

10 

5 

DI ... 0 

1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 

Figure 5. Devils Lake precipitation. 1950-99. 

of Lake Irvine during part of the 

drought. During 1988-91, streamflow 

in tributaries to the chain of lakes 

ranged from only 3 percent of the longterm average at Mauvais Coulee near 

Cando (site 3, fig. 1) to 21 percent of 

the long-term average at Starkweather 

Coulee near Webster (site 2, fig. 1). 

Much-below-average streamflow into 

the chain of lakes and above-average 

evaporation from the lake surfaces 

during most of the drought resulted in 

little flow out of the chain of lakes into 

Devils Lake. The combined streamflow of Channel A (site 7, fig. 1) and 

Big Coulee (site 8, fig. 1) for 1988-92 

was only 26,000 acre-ft. 

From February 1993 to August 

1999, the lake level of Devils Lake 

rose 24.5 ft. This lake-level rise 

corresponds to a 1,878,000-acre-ft 

increase in storage in Devils Lake. 

The estimated average annual inflow 

to Devils Lake for 1950-92 is 60,100 

acre-ft. The estimated average annual 

inflow for 1993-99 is 328,200 acreft, and inflow for this 7-year period 

accounts for 47 percent of all inflow 

to Devils Lake for 1950-99. 

The Devils Lake Basin contains 

many small lakes and wetlands and is 

typical of the prairie pothole region. 

The water levels in these lakes and 

wetlands have increased during the 

recent wet conditions. Analysis of a 

1992 satellite image of about 3,000 mil 

(80 percent) of the Devils Lake Basin 

indicates 42,629 acres of water, 

excluding Devils Lake, within the 

image area, and analysis of a 1997 
image indicates 151,939 acres of water, 

excluding Devils Lake, within the 

same image area (Glenn Kelly, U.S. 

Geological Survey, written commun., 

1998). The area of Devils Lake was 

43,996 acres in 1992 and 100,655 acres 

in 1997. Therefore, during 1992-97, 

the area of land inundated by water 

in the upper basin increased 109,310 

acres (256 percent), and the area of 

Devils Lake increased 56,659 acres 

(129 percent). By 1997, more than 

10 percent of the entire basin area 

was water. 

Sporadic lake-level measurements 

were made on Stump Lake from 1949 

through 1979 and from 1993 through 

1997. Before 1995, West Stump Lake 

ranged from about 1,394 ft asl in the 

dry years to about 1,400 ft asl in the 

wet years, and East Stump Lake ranged 

from about 1,382 ft as1 in the dry years 

to about 1,385 ft asl in the wet years. 

No sustained, major lake-level changes 

occurred on Stump Lake from 1949 

until 1993. 

Although no streamflow gages 

exist in the Stump Lake drainage 

basin, quarterly lake-level measurements since 1993 and observations 

of local landowners, NDSWC 

personnel, and U.S. Fish and Wildlife 

Service (USFWS) personnel indicate 

West Stump Lake received a relatively 

large amount of tributary runoff late 

in the summer of 1993. By February 

1994, the lake level was 1,395.8 ft asl. 

Runoff filled West Stump Lake and 

flowed into East Stump Lake during 

late 1993 and throughout 1994. By 

January 1995, West and East Stump 

Lakes were joined and the lake level 

was 1,398 ft asl. On July 16, 2000, 

Stump Lake reached 1,409.9 ft asl, 

the highest level in about 75 years 

(Swenson and Colby, 1955). 

The natural outlet for Devils Lake 

is from the east end through the current 

West Stump Lake and Tolna Coulee 

to the Sheyenne River. The options 

presently being considered for constructing a Devils Lake outlet would 

discharge water from the west end of 

the lake to the Sheyenne River near 

Sheyenne. The long-term average 

annual streamflow of the Sheyenne 

River near Warwick (site 9, fig. 1) is 

65.9 cubic feet per second (ft3/s). 

Daily streamflows for 1990 and 1997 

indicate the large variability between 

a dry year (1990) and a wet year 

(1997). During 1990, streamflow was 

less than 50 ft3/s almost the entire year. 

However, in 1997, streamflow was 

greater than 500 ft3/s for 39 days (from 

April 1 through May 9) and greater 

than 200 ft3/s for 57 days. 

Surface-Water Quality 

Surface-water quality, especially 

dissolved-solids concentrations, in the 

Devils Lake area is affected by many 

factors, including, but not limited to, 

climate, topography, and geology. 

Climate affects surface-water quality 

through variations in precipitation and 

temperature. For example, warm, dry 

periods increase lake evaporation and, 

therefore, generally increase dissolvedsolids concentrations. Wet periods 

generally increase streamflow and lake 

levels and, therefore, dilute dissolvedsolids concentrations. Topography and 

geology affect surface-water quality 

by influencing the amount and rate of 

runoff and the degree of soil-water 

interaction (Lent and Zainhofsky, 

1995). 

Dissolved-solids concentrations in 

Morrison Lake, Sweetwater Lake, Dry 

Lake, Lake Alice, and Lake Irvine are 

similar. During 1960-99, average 

dissolved-solids concentrations ranged 

from 619 milligrams per liter (mg/L) in 

Sweetwater Lake (site 4; fig. 1) to 747 

mg/L in Lake Alice (site 5; fig. 1). 

Sulfate concentrations averaged about 

205 mg/L in all lakes in the chain of 

lakes. 

Dissolved-solids concentrations in 

Channel A averaged 480 mg/L during 

1993-99, and concentrations in Big 

Coulee averaged 455 mg/L. Sulfate 

concentrations in Channel A averaged 

154 mg/L, and concentrations in Big 

Coulee averaged 130 mg/L. Before 

1993, too few samples were collected 

to compute water-quality statistics for 

Big Coulee and Channel A. 

Devils Lake consists of several 

bays that are, to some extent, isolated 

from each other at low lake levels and 

is characterized by large fluctuations in 

lake level and in concentrations of 

dissolved solids. Dissolved-solids 

concentrations vary both in space and 

time but generally increase from west 

to east in Devils Lake and East Devils 

Lake (fig. 2) as water enters the 

western part of the lake and becomes 

progressively more concentrated by 

evaporation as it moves eastward. 

Average concentrations during 1988-

90 ranged from about 3,400 mg/L west 

of Highway 57 (fig. 1) to about 10,000 

mg/L in East Devils Lake. Muchabove-normal runoff into Devils Lake 

during 1993-99 caused decreases in 

both dissolved-solids and sulfate concentrations. In 1999, dissolved-solids 

concentrations in the western part of 

the lake ranged from 1,140 mg/L in 

West Bay to 1,350 mg/L in Main Bay, 

and sulfate concentrations ranged 

from about 480 mg/L in West Bay to 

600 mg/L in Main Bay (fig. 2) (North 

Dakota Department of Health, written 

commun., 1999). 

Dissolved-solids concentrations 

in Devils Lake generally fluctuate 

inversely with lake level. Concentrations decrease in the spring when 

water is diluted because of icemelt, 

surface-water inflow, and precipitation. 

Concentrations generally increase in 

the summer and fall when evaporation 

exceeds surface-water inflow and 

precipitation and in the winter when 

ions are concentrated because of ice 

formation. 

Water-quality samples were 

collected from West and East Stump 

Lakes sporadically from 1949 through 

1979 and from 1993 through 1999. 

In June 1949, the dissolved-solids 

concentration in West Stump Lake 

was 6,090 mg/L. During 1949-95, 

concentrations ranged from 2,430 

mg/L in May 1995 to 108,000 mg/L 
in September 1963 during a drought. 

In comparison, the dissolved-solids 

concentration in seawater is about 

35,000 mg/L. On February 16, 2000, 

the dissolved-solids concentration in 

West Stump Lake was 11,600 mg/L, 

and the sulfate concentration was 

6,100 mg/L. 

Dissolved-solids concentrations in 

East Stump Lake ranged from 10,300 

mg/L in October 1999 to 241,000 

mg/L in July 1961. On February 16, 

2000, the dissolved-solids concentration in East Stump Lake was 11,600 

mg/L, and the sulfate concentration 

was 6,100 mg/L. During 1993-94, 

the dissolved-solids concentrations in 

West and East Stump Lakes decreased 

dramatically because of dilution from 

the large amount of relatively fresh 

surface-water runoff. From 1995 

through 1999, the dissolved-solids 

concentrations in East Stump Lake 

generally continued to decrease, but 

the concentrations in West Stump Lake 

began to increase. The increase started 

when the two lakes reached the same 

water level and the more-concentrated 

water from East Stump Lake started to 

mix with the less-concentrated water in 

West Stunip Lake. 

Average dissolved-solids concentrations for water samples collected 

from the Sheyenne River near 

Warwick are about the same as those 

for Big Coulee and Channel A, but 

the variability is less in the Sheyenne 

River. Dissolved-solids concentrations for 526 samples collected from 

1951 through 1999 from the Sheyenne 

River near Warwick ranged from 150 

to 1,010 mg/L and averaged 480 mg/L. 

For the same period, sulfate concentrations ranged from 28 to 230 mg/L 

and averaged 97 mg/L. 

Outlet Simulation Model 

Purpose and Description of Model 

Devils Lake currently is a terminal 

lake, and the lake levels in any year are 

affected by the storage and, therefore, 

the lake levels in the previous year. In 

contrast, the elevation of a river in 

any year is not affected by the elevation in the previous year. Because 

of this difference, standard statistical 

tools used to calculate values such 

as the "one hundred year flood" for 

rivers cannot be used for Devils Lake, 

and a tool that accounts for previous 

conditions was needed to evaluate 

the effects of an outlet on Devils 

Lake. As a result, the USGS developed a simulation model for Devils 

Lake. This model, which is a modified version of the model described 

in Wiche and Vecchia (1996), uses 

historical climate conditions and the 

storage available in Devils Lake to 

generate 10,000 possible futures, 

called traces. 

The simulation model for the 

Devils Lake outlet consists of three 

parts: (1) A statistical time-series 

model for generating future precipitation, evaporation, and inflow values 

for Devils Lake and Stump Lake and 

future discharges for the Sheyenne 

River; (2) a water and sulfate massbalance model for generating future 

volumes and sulfate concentrations 

in Devils Lake and Stump Lake in 

response to future precipitation, 

evaporation, and inflow; and (3) a 

model for generating daily pumping 

volumes from Devils Lake to the 

Sheyenne River to meet downstream 

water-quantity and water-quality 

constraints. The water and sulfate 

mass-balance model is used to 

compute the change in volume and 

sulfate concentration in each of five 

major storage compartments--West 

Bay, Main Bay, East Bay, East Devils 

Lake, and Stump Lake (fig. 1)--in 

response to precipitation, evaporation. 

inflow, and outflow from each compartment. In addition to computing the 

flow-induced flux of sulfate into or out 

of each compartment, the model also 

computes the benthic flux of sulfate 

into or out of bottom sediments. The 

benthic flux of sulfate is an important 

component of the sulfate mass balance 

for Devils Lake. The sulfate concentrations of inflows to Devils Lake and 

Stump Lake and the sulfate concentrations of ambient (without an outlet) 

discharges for the Sheyenne River are 

computed on the basis of historical 

relations between flow and sulfate concentration for Big Coulee, Channel A, 

and the Sheyenne River near Warwick. 

Assumptions Regarding 

Climatology 

In the simulation model used by 

Wiche and Vecchia (1996), the timeseries model for generating precipitation, evaporation, and inflow values 

was calibrated using data for 1950-93. 

The entire period of record was used 

because no statistical evidence was 

available at that time to indicate 

climatic conditions were not stationary. 

The simulation model was updated 

in 1999 after 6 more years of data were 

recorded (1994-99). The record now 

available indicates a shift toward wet 

conditions occurred in the late 1970's 

(fig. 5), particularly in the fall. The 

change appears to be rather abrupt, and 

the recent wet conditions do not appear 

to be statistically different than conditions during 1980-92. To better reflect 

the wet conditions, the time-series 

model for generating precipitation, 

evaporation, and inflow values for 

Devils Lake and future Sheyenne River 

discharges was recalibrated using 

data for 1980-99 (data for the late 

1970's were not included to avoid any 

possible transition period between the 

dry and wet conditions). As indicated 

previously, climatic conditions during 

2000-15 are expected to be similar to 

conditions during 1980-99. 

Assumptions Regarding LakeLevel Simulations 

The simulation model was used to 

generate 10,000 traces that begin with 

the same initial conditions that existed 

on January 1, 2000 (a starting lake 

level for Devils Lake of 1,446.2 ft asl), 

and extend through 2015. For each 

trace, future precipitation, evaporation, and inflow values were generated 

at random from the time-series model 

using data for 1980-99 and given initial 
conditions in the basin. Each of the 

10,000 traces was generated using the 

assumption that no west-end outlet is 

constructed. The model was run using 

a base elevation of 1,447 ft asl for the 

spill point between Devils Lake and 

Stump Lake. Since the model was run, 

6 inches (in.) of sediment has been 

removed from the channel at that point, 

lowering the base elevation to about 

1,446.5 ft asl. However, initial calculations indicate this change should 

have little effect on simulated lake 

levels for Devils Lake, especially for 

traces above 1,449 ft asl. Each of the 

10,000 traces represents a realization 

of future lake levels that could happen 

if climate and basin characteristics 

during 2000-15 are the same as those 

during 1980-99. Statistics computed 

from the entire set of 10,000 traces can 

be used to determine the probability 

of future events. For example, 182 of 

the 10,000 traces exceed the natural 

(without a constructed outlet) spill 

elevation (1,459 ft asl) to the Sheyenne 

River between 2000 and 2015. Therefore, the estimated probability of a spill 

occurring sometime during the next 16 

years is 182 divided by 10,000, or 1.8 

percent. 

Water Balance Associated with 

Traces that Exceed Spill Elevation 

to the Sheyenne River 

An analysis of the water balance 

associated with the 182 traces that 

exceed the natural spill elevation 

during 2000-15 provides a reference 

for comparison with the water balance 

for the Devils Lake Basin since 1993. 

The hydrologic characteristics of the 

182 traces are summarized in table 1, 

and two of the traces are shown in 

figures 6 and 7. Although each trace 

is different, the traces shown in figures 

6 and 7 illustrate typical features of the 

traces that exceed the spill elevation. 

For example, Devils Lake generally 

reaches 1,459 ft asl for the first time 

between 2004 and 2014 and remains 

above the spill elevation 2 to 8 years 

before subsiding (table 1). Trace 22 

(fig. 6) reaches the spill elevation in 

2011 and spills for 3 years, and trace 

Table 1. Hydrologic characteristics of 182 traces that spill to the Sheyenne River without a 

constructed outlet 

Trace 80-percent Characteristic average boundsl 

For entire simulation period (2000-15) 

Mean annual precipitation, in inches'` 

Mean annual evaporation, in inches 2 

Mean annual net evaporation, in inches 2 

Mean annual inflow, in thousand acre-feet 2 

Maximum annual inflow, in thousand acre-feetMaximum 4-year total net evaporation, in inches 3 

First year to reach spill elevation 

Time above spill elevation, in years 

Total Tolna Coulee discharge, in thousand acre-feet 

Maximum annual Tolna Coulee discharge, in 

thousand acre-feet 3 

21.7 20.4 to 22.9 

33.3 32.3 to 34.3 

11.6 9.7 to 13.6 

365 298 to 454 

1,478 945 to 2,185 

62.8 52.1 to 75.6 

2009 2004 to 2014 

5 2 to 8 

610 66 to 1,425 

305 40 to 686 

For 5-year period preceding first spill 

Mean annual precipitation, in inches ` 2 22.4 20.8 to 25.2 

Mean annual evaporation, in inches 2 32.9 31.1 to 33.8 

Mean annual net evaporation, in inches 2 10.6 6.9 to 12.5 

Mean annual inflow, in thousand acre-feet 2 671 464 to 853 

1 80 percent of the traces (145 out of 182) were within the 80-percent hounds. 

2Mean refers to the mean for the given time period. 

;Maximum refers to the maximum single value for the given time period. 

161 (fig. 7) reaches the spill elevation 

in 2006 and spills for 5 years. Maximum annual Tolna Coulee discharges 

resulting from the spills average 

305,000 acre-ft and typically range 

from 40,000 to about 700,000 acre-ft 

(table 1). Annual inflows generally 

are highly variable; periods of normal 

(similar to 1980-99) inflow are 

accompanied by periods of very high 

inflow that last 3 to 6 years. For 

example, inflows for trace 22 are 

comparable to inflows during 1980-99 

except for three extremely high inflows 

during 2009-11, and inflows for trace 

161 are comparable to inflows during 

1980-99 except for five extremely high 

inflows during 2003-09. 

Maximum annual inflows during 

2000-15 for the 182 traces that exceed 

the spill elevation average 1,478,000 

acre-ft (table 1) and generally are 

between 1 and 2 million acre-ft. For 

example, trace 22 (fig. 6) has a maximum annual inflow of about 1,800,000 

acre-ft in 2011, and trace 161 (fig. 7) 

has a maximum annual inflow of about 

1,400,000 acre-ft in 2006. To consider 

these large inflows in a historical 

perspective requires an understanding 

of hydrologic conditions in the Devils 

Lake Basin. The chain of lakes 

upstream of Devils Lake, as well as 

many of the smaller lakes and wetlands 

in the upper Devils Lake Basin, have 

filled as a result of the recent wet 

conditions. Therefore, much of the 

Devils Lake Basin that did not contribute flow to Devils Lake during 

1900-92 now contributes flow. For 

example, if the entire drainage area 

of the Devils Lake Basin (3,810 mi2) 

contributed flow, 10 inches (in.) of 

runoff would produce about 2 million 

acre-ft of inflow to Devils Lake. That 

amount of runoff could be generated 

by a snowmelt runoff of 5 in. (comparable to the runoff per square mile 

during 1997 for eastern North Dakota) 
				

	

	 	

		

							

and a late spring-early summer pre- J 1,470 IT I I I ITT I 1 

cipitation runoff of 5 in. (comparable 

to the runoff per square mile during w 1.460 SPILL ELEVATION TO SFIEYENNE RIVER 

1993 for parts of eastern North 

Dakota). The simulation model 1,450 -

-

HISTORIC LEVEL 

SIMULATED LEVEL 

indicates the chances of at least one R, 1.440 

annual inflow during 2000-15 being 

higher than at any other time in Q 1.430 

recorded history are considerable 

unless the wet climatic conditions of 

the past 2 decades are reversed so 

ANNL

IN 

111111111 1111111.1111111111_1 1.420 

32 that saturated conditions in the basin 

are reduced and flow paths and con- ztributing drainage area from the upper 17- O 28 

basin to the lake revert to those w 24 

existing between 1900 and 1992. For LL 

example, 618 (about 6 percent) of the cc Z 

2 

10,000 traces have at least one annual 

inflow during 2000-15 that exceeds 1 • 16 

million acre-ft (almost twice as high as 

the highest recorded inflow of 528,000 12 

acre-ft during 1997). 

44 

An understanding of the hydrologic z 

O 40

conditions required to cause Devils 

Lake to spill to the Sheyenne River can I 

0 w 36 

be gained from table 1. For example, o_ 

T I ' 

11111111 111111 11111111 

the mean annual precipitation for IN

• 32 

2000-15 averaged 21.7 in. for the 182 

traces that exceed the spill elevation z 28 

and was between 20.4 and 22.9 in. for 

80 percent of those traces. Thus, the 24 

mean annual precipitation for 2000-15 • 2.000 11 1 111 111111111 111 generall is slightly higher than for 

1980-99 (20.4 in.). The mean annual 1.600 

net evaporation (evaporation minus 

precipitation) averaged 11.6 in. for the z- w 1.200 

182 traces that exceed the spill elevation and was between 9.7 and 13.6 in. •_1 800 A IN 

for 80 percent of those traces. Thus, < 400 for most traces, the mean annual net 

evaporation for 2000-15 is lower than 

the mean annual net evaporation (13.2 

in.) for 1980-99. The mean annual • 1.000 11111

inflow averaged 365,000 acre-ft for 

the 182 traces that exceed the spill (-) cn 800 

elevation and was between 298,000 111 

and 454,000 acre-ft for 80 percent of LIJ 600 

those traces. These values are cornparable to the mean annual inflow of • 400 

327,000 acre-ft for 1993-99. • H 200

The previous paragraph indicates 111.1

• 0 

climatic conditions during the next 15 1980 1985 1990 1995 2000 2005 2010 2015 

years need to be slightly wetter, on 

Figure 6. Generated data for trace 22. average, than conditions during 1980-
	

1,470 99 to cause Devils Lake to spill to the _J > w Sheyenne River. However, traces that SPILL ELEVATION TO SHEYENNE RIVER w 1,460 w - exceed the spill elevation generally < 

_J W — HISTORIC LEVEL have short time periods during which 1,450 

D w — SIMULATED LEVEL inflows to Devils Lake greatly exceed 

0 

co 1,440 those recorded during the 1990's. < < 

i— These periods of high inflow generally w 

W 1,430 are accompanied by periods of high 

z Z precipitation and low net evaporation. 11111 • 1,420 For example, as indicated in table 1, 

for the 5-year period preceding the first 

32 year the lake spills, the mean annual 

z precipitation for 80 percent of the O 28 traces was between 20.8 and 25.2 in., 

w 24 and the mean annual net evaporation 

in 0 was between 6.9 and 12.5 in. The 5- • z 

a- Z 20 year periods of high precipitation and _J 

low net evaporation usually result from 

16 above normal (compared to 1980-99) 

fall and winter precipitation and cool, 

12 wet summer conditions, which have a 

dramatic effect on inflows. For 80 

44 1111111 11111111 11111 percent of the traces, the mean annual 

z inflow for the 5-year period preceding O 40 

the first spill was between 464,000 cr 0) O w 36 and 853,000 acre-ft, which is much a_ 

< 0 higher than the average annual inflow > Z 

z 32 (363,000 acre-ft) for the 5-year period 

from 1995-99. 

28 

Another characteristic of most 1111 1 1111111 11111111111111 24 traces that exceed the spill elevation 

during 2000-15 is the lack of a severe o 2,000 111111 111111 

z ' I drought, comparable to the drought 

that occurred during 1987-90. A •1,600 

severe drought reduces high lake levels 

1,200 by increasing evaporative losses from 

the lake surface, increasing the avail- OJ 

u_ 800 able capacity of the lake for holding z Al 

future inflows, and reducing surface 

400 runoff from the basin during and after 

z 

z 

0 

CC 1,000 111111 111111 ' I ' 111111 

C.) 

cn 

0 

w 

-J 

800 

600 

0 

CJ 

• 400 

the drought. Surface runoff from the 

Devils Lake Basin is particularly 

sensitive to drought because increased 

evaporative losses remove water from 

the soil profile, increasing the available 

storage capacity in the profile. Also, 

increased evaporative losses lower 

water levels in small lakes and wetlands, decreasing the number of small 

subbasins that compose the contrib- - 200 IN

uting drainage area. 

1 111111111111111111 I 111 • 0 z 1980 1985 1990 1995 2000 2005 2010 2015 The total net evaporation for Devils 

Lake during the 4-year period from Figure 7. Generated data for trace 161. 1987-90 was 85.2 in. As indicated in 
				

table 1, the maximum 4-year total net 

evaporation during 2000-15 averaged 

62.8 in. for the 182 traces that exceed 

the spill elevation and was between 

52.1 and 75.6 in. for 80 percent of 

those traces. For example, in trace 

22 (fig. 6), the driest 4-year period 

occurred during 2005-08, during which 

total net evaporation was about 66 in. 

The combined surface area of Devils 

Lake and Stump Lake during this 

period was about 160,000 acres. 

Therefore, total net evaporative loss 

during 2005-08 was about 900,000 

acre-ft. However, total inflow during 

this period was about 700,000 acre-ft, 

resulting in a total volume decrease of 

about 200,000 acre-ft. If the drought 

during 2005-08 would have been as 

severe as the drought during 1987-90, 

the evaporative loss would have been 

about 1,100,000 acre-ft and the total 

inflow probably would have been 

reduced to near zero, resulting in a 

total volume decrease of about 

1,100,000 acre-ft. The more severe 

drought also would have increased 

available storage in wetlands, lakes, 

and soils in the upper basin and, thus, 

reduced inflows during 2009-11 as 

well. For example, a 5-in. reduction 

in runoff during 2009-11 would reduce 

inflows by about 1 million acre-ft. 

Therefore, with the severe drought, the 

volume of the lake in 2011 would have 

been 1,900,000 acre-ft lower than the 

Simulation of an Emergency Outlet 

To evaluate the potential effects of 

an outlet, each of the 10,000 model 

traces also was generated using an 

assumed emergency outlet configuration proposed by the NDSWC. In the 

simulation, the outlet is assumed to be 

operational May 1, 2001. The pump 

intake is from the southern part of West 

Bay, and the pumps may operate from 

May 1 to November 30 of each year. 

The downstream channel-capacity 

constraint for the Sheyenne River is 

600 ft3/s, and the downstream sulfate 

standard for the Sheyenne River is 450 

mg/L (North Dakota State Department 

of Health and Consolidated 

Laboratories, 1991). Two options 

were considered for outlet capacity. 

In option 1, the NDSWC plan, outlet 

capacity is 300 ft3/s (six 50-ft3/s 

pumps), and in option 2 (presented for 

comparison with option 1), outlet 

capacity is 450 ft3/s (nine 50-ft3/s 

pumps). Therefore, on any given day 

when the pumps are operating, as 

much as 300 ft3/s (option 1) or 450 

ft3/s (option 2) of water can be discharged to the Sheyenne River provided the combined outlet discharge 

and ambient Sheyenne River stream100 

flow is less than 600 ft3/s and the 

combined sulfate concentration is less 

than 450 mg/L. If' either constraint is 

reached, outlet discharge is reduced 

as required to return to levels below 

the constraints. 

The potential effects of an outlet 

on the probabilities of future lake 

levels for Devils Lake are shown in 

figure 8. Without an outlet, the chance 

(probability) that Devils Lake will 

exceed 1,450 ft asl sometime between 

2001 and 2015 is about 33 percent. If' 

the lake level exceeds 1,450 ft asl, 

major infrastructure damage will 

occur, especially to several major highways, and Devils Lake will overflow 

and till Stump Lake. With the 300-

ft3/s-outlet option, the chance that the 

lake level will exceed 1,450 ft asl by 

2015 is about 20 percent, and with the 

450-113/s-outlet option, the chance 

is about 16 percent. Although the 

reduction in risk from 33 percent to 

either 20 or 16 percent is significant, 

the effectiveness of the outlet in 

preventing the lake from reaching 

1,450 ft asl is limited because many 

of the traces reach that level early in 

the simulation period before the outlet 

can be effective in drawing the lake 

actual volume for trace 22 (900,000 

acre-ft more volume decrease during 

2005-08 and 1 million acre-ft less 

inflow during 2009-11). 

The previous example shows that 

the volume of Devils Lake 2 or 3 years 

after a severe drought may be reduced 

by about 2 million acre-ft compared 

to a moderate drought. The reduction 

in volume could be much larger 

depending on the timing and severity 

of the drought. The large increase in 

EXCEEDANCE PROBABILITY. IN PERCENT

50 

40 

30 

20 

WITHOUT OUTLET 

10 

5 

4 

3 

2 300-CUBIC-FOOT-PER-SECOND OUTLET 

450-CUBIC-FOOT-PER-SECOND OUTLET 

0.5 

0.4 

0.3 

available storage greatly decreases the 

chance of a subsequent spill for many 

years after the drought. Thus, most of 

0.2 

0.1 

1,448 1,450 1.452 1.454 1,456 1.458 1,460 1,462 

MAXIMUM LAKE LEVEL. IN FEET ABOVE SEA LEVEL the traces that include a severe drought 

do not exceed the spill elevation by Figure 8. Estimated exceedance probabilities computed from 10.000 model traces 

2015. for Devils Lake for 2000-15. 
				

down. For example, between 2000 

and 2005, 1,570 traces reach 1,450 ft 

asl without an outlet. The 300-ft3/soutlet option prevents 430 of those 

traces from reaching that level, and 

the 450-ft3/s-outlet option prevents 

536 from reaching that level. However, between 2006 and 2015, 1,760 

traces reach 1,450 ft asl without an 

outlet. The 300-ft3/s-outlet option 

prevents 930 of those traces from 

reaching that level, and the 450-

ft3/s-outlet option prevents 1,130 

from reaching that level. 

As indicated in figure 8, the outlet would be effective in reducing 

extremely high lake levels. For 

example, 1,030 of the traces reach 

1,454 ft asl by 2015 without an outlet, 

but only 372 of those traces reach that 

level with the 300-ft3/s-outlet option 

and 269 reach that level with the 450-

ft3/s-outlet option. Similarly, 182 (1.8 

percent) of the traces reach 1,459 ft asl 

(spill elevation) without an outlet, but 

only 81 of those traces reach that level 

with the 300-113/s-outlet option and 

63 reach that level with the 450-ft3/soutlet option. 

The exceedance probabilities 

cannot be used directly to evaluate the 

effects of the outlet on a trace-by-trace 

basis. The effectiveness of the outlet 

in reducing flood damages on a traceby-trace basis can be measured by 

the reduction in peak lake level. This 

reduction is defined as the difference 

between the maximum lake level 

without an outlet and the maximum 

lake level with an outlet. For example, 

if a trace peaks at 1,456 ft asl in 2010 

without an outlet and the same trace 

peaks at 1,452 ft asl in 2006 with an 

outlet, the reduction in peak lake level 

for that trace is 4 ft. The reductions in 

peak lake levels for the 300- and 450-

.1/s-outlet options are shown in figure 

9. The curves in figure 9 were obtained by averaging the reductions over all 

traces that peak near a given elevation 

(without an outlet). For example, the 

average reduction in peak lake level for 

all traces that reach 1,456 ft asl without 

an outlet is 3.3 ft for the 300-ft3/s5 

z 

J 4 

UJ 

_J 

UJ 

3 

z 

Z 2 0 

H 

0 

111 

• 1 

CC 

Lil 

• < 0

1.448 

450-CUBIC-FOOT-PER-SECOND OUTLET 

300-CUBIC-FOOT-PER-SECOND OUTLET 

1.450 1.452 1.454 1.456 1.458 1.460 1.462 

MAXIMUM LAKE LEVEL WITHOUT OUTLET. IN FEET ABOVE SEA LEVEL 

Figure 9. Average reductions in peak lake levels of Devils Lake for 2000-15 for 300-

and 450-cubic-foot-per-second-outlet options. 

outlet option and 4.2 ft for the 450-

ft3/s-outlet option. Although some 

traces will be above these values and 

some below, the average is a reasonable estimate of the expected reduction 

in peak lake level. 

For both outlet options, the outlet is 

most effective in reducing levels of the 

peaks for those traces that peak 

between 1,454 and 1,459 ft asl. Traces 

in this range generally peak long after 

the outlet is operational, and the lake 

generally remains relatively fresh; 

therefore, the sulfate standard does not 

greatly constrain pump output. The 

effectiveness of the outlet is reduced 

for peak lake levels below 1,454 ft asl 

because many of those traces either 

peak early or have increased sulfate 

concentrations that result in reduced 

pumping. The effectiveness also is 

reduced for peak lake levels above 

1,459 ft asl because of the extremely 

high inflows necessary to raise the 

lake above that level. The high inflows 

often exceed combined pumping volumes and evaporative losses although, 

for many traces, the pumps are operating at full capacity. 

The effectiveness of an outlet on 

a trace-by-trace basis also can be 

measured by drawdown. Drawdown is 

defined in this report as the difference 

between the lake level without an 

outlet and the lake level with an outlet 

in a given year. For example, if the 

lake level in 2015 for a certain trace is 

1,452 ft without an outlet and 1,445 ft 

with an outlet, the drawdown is 7 ft. 

The benefits of drawdown are 

twofold--previously flooded land 

around the lake can be reclaimed 

sooner and subsequent flood damages 

occurring after the simulation period 

can be reduced because of more available storage. 

The average drawdowns for the 

two outlet options are shown in figure 

10. The curves shown were obtained 

by averaging over all traces in a 

manner similar to that used for figure 

9. The outlet is much more effective in 

drawing the lake down in the long term 

(2015) than in the short term (2005). 

The 300- and 450-ft3/s-outlet options 

provide about 2 and 3 ft of drawdown, 

respectively, in 2005 for traces that 

have lake levels between 1,450 and 

1,456 ft asl. However, by 2015, the 

300- and 450-ft3/s-outlet options 
							

AVERAG

EDRAWDOWN. INFEET 

10 

2005 450-CUBIC-FOOT-PER-SECOND OUTLET 

- 2015 

8 

300-CUBIC-FOOT-PER-SECOND OUTLET 

4 

450-CUBIC-FOOT-PER-SECOND OUTLET 

300-CUBIC-FOOT-PER-SECOND OUTLET 

0 

1.444 1,446 1,448 1.450 1,452 1,454 1,456 1,458 1,460 

LAKE LEVEL WITHOUT OUTLET, IN FEET ABOVE SEA LEVEL 

Figure 10. Average drawdown of Devils Lake for 2005 and 2015 for 300- and 

450-cubic-foot-per-second-outlet options. 

provide about 5.5 and 8.0 ft of drawdown, respectively, for traces in that 

range. Drawdown is smaller for lake 

levels below 1,450 ft asl because of the 

sulfate standard for the Sheyenne River 

and for lake levels above 1,456 ft asl 

because much more volume is required 

to draw the lake down at those levels. 

The quantity and quality of water 

discharged from an outlet is an important consideration to downstream 

interests. The sulfate concentration in 

the southern part of West Bay (near 

the proposed outlet intake) was about 

480 mg/L in the fall of 1999 (fig. 2). 

This concentration is greater than the 

450-mg/L standard for the Sheyenne 

River. Therefore, without significant 

dilution from Sheyenne River streamflow, the amount of water discharged 

from the outlet may be less than the 

300- or 450-ft3/s pump capacity. The 

in-lake sulfate concentration of each 

trace generated from the model varies 

depending on future climatic conditions. Wet conditions (and increasing 

lake levels) generally produce low 

sulfate concentrations, and dry conditions (stable or decreasing lake levels) 

generally produce high sulfate concentrations. 

The potential effects of an outlet 

on Sheyenne River streamflow are 

shown in figure 11. The maximum 

mean monthly streamflow occurs in 

April when the outlet is not operating. 

However, the mean monthly streamflow (563 ft3/s) for April for traces 

that have maximum lake levels above 

1,450 ft asl is about twice as large as 

the streamflow (296 ft3/s) for traces 

that have maximum lake levels below 

1,450 ft ash because wet conditions 

in the Devils Lake Basin generally 

correspond to wet conditions in the 

Sheyenne River Basin. Most of the 

streamflow in the Sheyenne River from 

May through November, when the 

outlet is operating, is water discharged 

from the outlet. 

For maximum lake levels below 

1,450 f't asl (fig. 11), the amount of 

water discharged with the 450-ft3/soutlet option is only slightly larger than 

the amount discharged with the 300-

ft3/s-outlet option. For both outlet 

options, the mean monthly outlet 

discharge ranges from about 125 ft3/s 

in May to about 80 ft3/s in October and 

November. However, outlet discharge 

is much higher for lake levels above 

1,450 ft asl than for lake levels below 

1,450 f't as1 because in-lake sulfate 

concentrations generally are lower 

and ambient Sheyenne River streamflow generally is higher for levels 

above 1,450 ft asl. For both outlet 

options, the lowest mean monthly 

outlet discharge occurs in May (about 

200 ft3/s for the 300-ft3/s-outlet option 

and 250 ft3/s for the 450-113/s-outlet 

option) when the channel-capacity 

constraint results in reduced pumping 

for many traces. In June-November, 

mean monthly outlet discharge remains 

nearly constant at about 210 ft3/s for 

the 300-ft3/s-outlet option and 280 

ft3/s for the 450-ft3/s-outlet option. 

The potential effects of an outlet on 

sulfate concentrations in the Sheyenne 

River also are shown in figure 11. For 

maximum lake levels below 1,450 ft 

asl and both outlet options, sulfate 

concentrations in the Sheyenne River 

are about 380 mg/L during MayNovember. The sulfate concentrations 

are less than the 450-mg/L standard 

because the pumps operate in 50-113/s 

increments and, therefore, outlet discharge cannot be altered continuously 

to reach the standard. For maximum 

lake levels above 1,450 ft asl and both 

outlet options, sulfate concentrations 

in the Sheyenne River are about 340 

mg/L during May-November. For 

many traces, especially those that 

reach 1,454 ft asl or higher, the in-lake 

sulfate concentrations are below 450 

mg/L for substantial time intervals. 

The potential for a catastrophic 

spill from the natural outlet to the 

Sheyenne River poses a threat for 

downstream interests. If Devils Lake 

reaches the spill elevation (1,459 ft 

asl), the contributing drainage area of 

the Sheyenne River near Cooperstown 

will quadruple (from 1,270 mil to 

5,070 mil) because the entire Devils 

Lake Basin then would contribute flow 

to the Sheyenne River. Although the 

large size of Devils Lake results in 

substantial evaporative losses of water 

and attenuation of outflows, potential 

still exists for major downstream flooding as a result of a natural spill. The 

water in Stump Lake (which becomes 
		

 

SULFATECONCENTRATION. IN MILLIGRAMSPER LITER STREAMFLOW. IN CUBIC FEET PERSECOND 

600 1111111E1111 I I I IIIIIIII 

500 

400 

300 

200 

100 

0 

400 IIIIIIIII 

300 

200 

100 

0 J FM A MJ J A SOND MJ J A SOND 

MAXIMUM LAKE LEVEL BELOW OR EQUAL MAXIMUM LAKE LEVEL GREATER THAN 

TO 1,450 FEET ABOVE SEA LEVEL 1.450 FEET ABOVE SEA LEVEL 

A B 

EXPLANATION 

III450-cubic-foot-per-second outlet Al 300-cubic-foot-per-second outlet Without outlet 

Figure 11. Modeled mean monthly streamflow and sulfate concentrations for the 

Sheyenne River near Warwick, North Dakota, for 2001-15. (A--Average of all traces 

that have maximum lake levels below or equal to 1,450 feet above sea level; 

B--average of all traces that have maximum lake levels greater than 1,450 feet above 

sea level.) 

part of Devils Lake at an elevation of sulfate concentrations are shown in 

about 1,447 ft asl) also is of much figure 12. The amount of water that 

poorer quality than water in western spills from Devils Lake is controlled 

Devils Lake, and substantial volumes by the geometry of the spill channel. 

of water spilling from the natural outlet Devils Lake can rise to an elevation 

could cause serious downstream water- several feet above 1,459 ft asl, and the 

quality degradation. magnitude of the spill will increase as 

the lake rises. Therefore, the 182 

Modeled discharges of spills from traces that exceed the spill elevation 

Devils Lake through Tolna Coulee to were separated into two groups--the 

the Sheyenne River and the associated 50 highest-elevation traces, for which 

Devils Lake exceeded 1,460.8 ft asl, 

and the remaining 132 traces, for 

which Devils Lake peaked between 

1,459 and 1,460.8 ft asl. 

The top graph in figure 12 shows 

daily discharges and sulfate concentrations averaged over 50 traces that 

exceed 1,460.8 ft asl without an 

outlet. The 2 years shown are the 

year in which the lake peaks and the 

year after the lake peaks. Without an 

outlet, discharge is about 2,100 ft3/s in 

late June, above 2,000 ft3/s for more 

than 1 month, above 1,000 ft3/s for 

more than 4 months, and above 400 

ft3/s for more than 1 year. In terms of 

volume and duration, the spills would 

overwhelm ambient Sheyenne River 

streamflow. For example, in 1997, a 

wet year, discharge for the Sheyenne 

River near Warwick peaked at 3,900 

ft3/s, was above 2,000 ft3/s for 12 

days, above 1,000 ft3/s for 20 days, 

and above 400 ft3/s for 42 days. The 

water quality of the spills also would 

be very poor. Sulfate concentrations 

are several times the 450-mg/L 

standard, and dissolved-solids 

concentrations are more than twice 

as large as sulfate concentrations. 

Although neither outlet option would 

eliminate the effects of the potentially 

catastrophic spills, the spill volumes 

and durations would be reduced 

substantially. 

The bottom graph in figure 12 

shows daily discharges and sulfate 

concentrations averaged over 132 

traces that are between 1,459 and 

1,460.8 ft asl without an outlet. Without an outlet, discharge is about 430 

113/s in July, above 200 ft3/s for more 

than 4 months, and above 100 ft3/s 

for more than 1 year. Although these 

discharges are not large enough to 

cause major flooding of the Sheyenne 

River, the duration and high sulfate 

concentrations (more than 2,000 

mg/L) of the spills would cause substantial water-quality degradation 

downstream. The effects of the spills 

would be reduced greatly (or entirely 

eliminated) with either outlet option. 

The 300-ft3/s-outlet option completely 
eliminated the spills in 98 of the 132 2,500 1 2,600

traces and greatly reduced spill vol- 7, 450-CUBIC-FOOT-PER-SECOND OUTLET 2,400 

umes in the remaining traces. The 2.200 

2,000 450-ft3/s-outlet option completely 300-CUBIC-FOOT-PER-SECOND OUTLET z 2,000 0 eliminated the spills in 111 of the WITHOUT H H

OUTLET \ 1,800 132 traces and greatly reduced spill tr 

1.500 w 1,600 volumes in the remaining traces. WITHOUT OUTLET w

0 1,400 z 2 

z Potential Erosion of Natural 1,200 0 cc 1,000 0 w Outlet Channel H 1,000 -J 

300-CUBIC-FOOT-PER-SECOND OUTLET 

800 z The simulation results presented 500 (/) 

earlier were based on the assumption 600 

that the natural outlet channel con- 400 

450-CUBIC-FOOT-PER-SECOND OUTLET 

necting West Stump Lake and the J FMAMJ JASOND J F MA M J J A SOND 200 Sheyenne River remains unchanged MAXIMUM LAKE LEVEL ABOVE 1,460.8 FEET ABOVE SEA LEVEL throughout the simulation period. 

However, preliminary analyses con- 500 2,600 

ducted by the NDSWC and summa 450-CUBIC-FOOT-PER-SECOND OUTLET - 2,400 rized in this section indicate significant 300-CUBIC-FOOT-PER-SECOND OUTLET erosion of the channel is possible 400 - 2,200 z cc 0 w during the course of a natural spill. If WITHOUT OUTLET ---- 2,000 H H

such erosion occurs, the spill volumes cc cc 

21 

would be larger than indicated in the 300 - 1,800

WITHOUT w model simulations. Further hydraulic OUTLET \ 0 1,600 z 2 

analysis is required to accurately z

0 cc 200 - 1,400 model channel-erosion processes. w

However, this section qualitatively 1,200 

_J 

L 2J - describes potential erosion problems D z (/) 100 - 1.000 

that may arise in the event of a natural 300-CUBIC-FOOT-PER-SECOND OUTLET 

450-CUBIC-FOOT-PER-SECOND OUTLET spill. 800 

0 600 

J FMAMJ JASOND J FMAMJ JASOND Stump Lake is connected to Tolna 

Coulee and, therefore, to the Sheyenne MAXIMUM LAKE LEVEL BETWEEN 1,459 AND 1,460.8 FEET ABOVE SEA LEVEL

River by a channel about 600 feet wide EXPLANATION

and 4,000 feet long. The controlling Discharge Sulfate concentration 

channel-bottom elevation is about Figure 12. Modeled discharges and sulfate concentrations of spills through Tolna 1,459 ft asl. A flat region that has Coulee to the Sheyenne River. (Top--average of 50 traces that peak above 

slightly elevated dike-like soil 1,460.8 feet above sea level; bottom--average of 132 traces that peak between 

structures at each end separates the 1,459 and 1,460.8 feet above sea level.) 

eastward slope into West Stump Lake 

and the westward slope to Tolna 

Coulee. The origin of the structures will increase to about 1,400 ft3/s under this prolonged continuous discharge, at each end of this region is unknown; the eroded condition. At higher eleva- erosion probably will continue below however, the structures likely would tions, erosion of the structures will 1,458 ft asl. be eroded quickly during a discharge increase the flow for a given stage by event because of potentially erosive as much as 2,000 ft3/s. The ultimate development of the velocities. If the structures erode, the erosion channel would depend upon controlling channel-bottom elevation The Devils Lake-Stump Lake the rate of erosion and the supply of will decrease to about 1,458 ft asl, 

which is the elevation of the bottom system contains about 900,000 acre- water. If the rate of erosion is large,

ft of water between 1,458 and 1,461 the shifting of the rating curve could of the long, flat region between the 

structures. The rating curves before ft asl. If 1,400 ft3/s is the maximum be sufficient to maintain high rates of 

and after erosion are shown in figure discharge and 700 ft3/s is the average, flow even if the lake level decreases. 

13. If the lake rises to 1,461 ft asl, the about 21 months are needed to reduce The erosion could continue down to 

structures probably will erode and flow the lake level to 1,458 ft asl. With about 1,446.5 ft asl. At that level, DISCHARGE. INCUBIC FEET PER SECOND DISCHARGE. IN CUBIC FEET PERSECOND 
	 	 	

W

ATER-SURFACE ELEVATION. INFEET 

f 1,465 IT

1.464 jr 

WATER-SURFACE ELEVATION--NATURAL CONDITION 

1 463 

1 462 

1,461 

WATER-SURFACE ELEVATION--ERODED CONDITION 

1,460 

1.459 

1-1 _I __1__1 L1 1 1 1 1 l 1 • 1 I 1.458 

o 1.000 2,000 3.000 4,000 5.000 

DISCHARGE. IN CUBIC FEET PER SECOND 

Figure 13. Discharge rating curves for Tolna Coulee under natural and eroded 

conditions. 

Devils Lake separates from Stump 

Lake. (Corresponding erosion at the 

Devils Lake-Stump Lake connection 

is unlikely because of the much longer 

channel and much flatter slopes in that 

area.) Soil profiles in the Tolna Coulee 

outlet (Murphy and others, 1997) 

indicate no erosion-resistant materials 

within the 20-ft sampling depth,. 

therefore, the down-cutting erosion 

probably would not encounter any 

natural harrier. 

Given that the estimated probability 

of a spill occurring during the next 16 

years is 1.8 percent, NDSWC 

engineers conducted an assessment 

of erosion-prevention measures near 

the Tolna Coulee outlet (Bruce 

Engelhardt, North Dakota State Water 

Commission, oral commun., 2000). 

The engineers concluded measures 

such as armoring the controlling dikes 

or paving would not be sufficient to 

control erosion. The engineers also 

concluded that construction of a dam 

to prevent a spill through Tolna Coulee 

is not practical. 

—G. J. Wiche and A. V. Vecchia, U.S. 

Geological Survey; Leon Osborne and 

Carrie M. Wood, University of North 

Dakota Regional Weather Information 

Center; and James T. Fay, North Dakota 

State Water Commission 

References and Further 

Reading 

Bluemle, J.P., 1991, Radiocarbon 

dating of beaches and outlets of 

Devils Lake: North Dakota 

Geological Survey Miscellaneous 

Series 75, 10 p. 

Bray, E.C., and Bray, M.C., eds., 1976, 

Joseph N. Nicollet on the plains 

and prairies--The expeditions of 

1838-39 with journals, letters, 

and notes on the Dakota Indians: 

Minnesota Historical Society 

Press, St. Paul, 294 p. 

Lent, R.M., and Zainhofsky, S.D., 

1995, Variations in surface-water 

quality in the chain of lakes and its 

tributaries, Devils Lake Basin, 

North Dakota, 1957-92: U.S. 

Geological Survey WaterResources Investigations Report 

95-4102, 87 p. 

Montroy, D.L., 1997, Linear relation 

of central and eastern North 

American precipitation to tropical 

Pacific sea surface temperature 

anomalies: Journal of Climate, v. 

10, p. 541-558. 

Murphy, E.C., Fritz, A.K., and 

Fleming, R.F., 1997, The 

Jerusalem and Tolna outlets in 

the Devils Lake Basin, North 

Dakota: North Dakota Geological 

Survey Report of Investigation 

No. 100, 36 p. 

North Dakota State Department of 

Health and Consolidated 

Laboratories, 1991, Standards of 

water quality for State of North 

Dakota--Rule 33-16-02: 

Bismarck, North Dakota, 29 p. 

Osborne, L.F., 2000, Impacts of 

regional climate variability in the 

Red River of the North Basin: 

University of North Dakota 

Regional Weather Information 

Center Report No. 2000-1, 12 p. 

Sether, B.A., Vecchia, A.V., and 

Berkas, W.R., 1999, Spatial and 

temporal variability of dissolved 

sulfate in Devils Lake, North 

Dakota, 1998: U.S. Geological 

Survey Fact Sheet FS-096-99, 4 p. 

Swenson, H.A., and Colby, B.R., 1955, 

Chemical quality of surface 

waters in Devils Lake Basin, 

North Dakota: U.S. Geological 

Survey Water-Supply Paper 1295, 

82 p. 

Upham, Warren, 1895, The glacial 

Lake Agassiz: U.S. Geological 

Survey Monograph No. 25, 658 p. 

Wiche, G.J., and Vecchia, A.V., 1996, 

Lake-level frequency analysis for 

Devils Lake, North Dakota: U.S. 

Geological Survey Water-Supply 

Paper 2469, 57 p. 

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