U.S. Department of the Interior

U.S. Geological Survey

The Black Hills Hydrology Study

—By Janet M. Carter, Daniel G. Driscoll, and Joyce E. Williamson

Introduction

The Black Hills area is an important resource center that provides an 

economic base for western South 

Dakota through tourism, agriculture, 

timber, and mineral resources. Water 

originating from the area is used for 

municipal, industrial, agricultural, and 

recreational purposes throughout 

much of western South Dakota. The 

Black Hills area also is an important 

recharge area for aquifers in the northern Great Plains.

Population growth, resource development, and periodic droughts have 

the potential to affect the quantity, 

quality, and availability of water 

within the Black Hills area. Because 

of this concern, the Black Hills 

Hydrology Study was initiated in 

1990 to assess the quantity, quality, 

and distribution of surface water and 

ground water in the Black Hills area 

of South Dakota. This long-term 

study was a cooperative effort 

between the U.S. Geological Survey 

(USGS), the South Dakota Department of Environment and Natural 

Resources, and the West Dakota Water 

Development District, which represented various local and county cooperators. This fact sheet describes the 

Black Hills Hydrology Study and the 

major findings of the study. More 

detailed summaries are provided in 

a lay-reader summary (Carter and 

others, 2002) and in a technical summary (Driscoll and others, 2002).

Overview of Study

The Black Hills Hydrology Study was 

initiated in 1990 as a partnership among 

several local, State, and Federal agencies. 

The study area for the Black Hills 

Hydrology Study includes portions of 

USGS Fact Sheet FS-046–02

June 2002

Prepared in cooperation with the South Dakota Department of Environment and Natural Resources and the West Dakota Water Development District

Figure 1. Area of investigation for the Black Hills Hydrology Study.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

H ot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER RI VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Cold

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Iron Cr

Cottonwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Sylvan

Lake

Cold B rook

Cr Strawberry

Boles

Canyon

Beaver

Spring

C s

reek

Creek Canyon

Canyon

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton

Cheyenne

Crossing

Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Calamity

Peak

x

Iron

Mountain x

Onyx

Cave

Bear

Butte

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

Approximate extent of the Black

 Hills area, represented by

 generalized outer extent of the

 the outcrop of Inyan Kara

 Group

Outcrop of Madison Limestone

Outcrop of Minnelusa Formation

SOUTH DAKOTA

Area

shown

Black

Hills

EXPLANATION

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Missouri River

Oahe

Reservoir

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

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
six counties in the Black Hills area of 

South Dakota (fig. 1). Outcrops of the 

Madison Limestone and Minnelusa 

Formation in South Dakota, which are 

areas where these geologic formations 

occur at the land surface, are shown in 

figure 1. The generalized outer extent of 

the outcrop of the Inyan Kara Group, 

which approximates the outer extent of 

the Black Hills area, also is shown in 

figure 1.

The purpose of the Black Hills 

Hydrology Study was to assess the quantity, quality, and distribution of surface 

water and ground water in the Black 

Hills area of South Dakota. The study 

was designed as a regional assessment of 

the water resources and was not designed 

to address site-specific issues. Because 

the Black Hills area is an important 

recharge area for several regional bedrock aquifers and various local aquifers, 

the study concentrated on describing the 

hydrologic significance of selected bedrock aquifers. The major aquifers in the 

Black Hills area are the Deadwood, 

Madison, Minnelusa, Minnekahta, and 

Inyan Kara aquifers. The highest priority was placed on the Madison and 

Minnelusa aquifers, which are widely 

used and interact extensively with the 

surface-water resources of the area.

The study consisted of two primary 

phases—data collection and interpretation. An extensive network consisting of 

about 71 observation wells, 94 precipitation gages, and 60 streamflow-gaging 

stations was used during the datacollection phase. Critical components 

of this network (primarily observation 

wells and selected streamflow-gaging 

stations) are being maintained for longterm purposes through a cooperative 

program between the USGS and local 

and State cooperators.

A series of 21 reports and 11 maps 

have been published as part of the study. 

Hydrologic data collected during the 

study have been published in various 

data reports. Maps (1:100,000 scale) 

have included a hydrogeologic unit map 

for the study area, structure-contour 

maps for five geologic formations that 

contain major aquifers, and potentiometric maps for these major aquifers. Interpretive reports have addressed water 

quality and hydrologic conditions for 

surface water and ground water. Many 

of the interpretive reports have dealt 

specifically with the Madison and 

Minnelusa aquifers, which were a primary focus of the study. Additional 

information concerning the study and 

study products is available at http://

sd.water.usgs.gov/projects/bhhs/

BHHS.html.

Description of Study Area

The study area for the Black Hills 

Hydrology Study (fig. 1) consists of the 

topographically defined Black Hills and 

adjacent areas located in western South 

Dakota. The Black Hills are situated 

between the Cheyenne and Belle 

Fourche Rivers. The Belle Fourche 

River is the largest tributary to the 

Cheyenne River. The study area includes 

most of the larger communities in western South Dakota and contains about 

one-fifth of the State’s population.

Climate

The overall climate of the Black Hills 

area is continental, which is characterized generally by low precipitation 

amounts, hot summers, cold winters, and 

extreme variations in both precipitation 

and temperatures. Local climatic conditions are affected by topography, with 

generally lower temperatures and higher 

precipitation at the higher altitudes.

Long-term trends in precipitation for 

water years 1931-98 for the study area 

are illustrated in figure 2; a water year is 

the 12-month period, October 1 through 

September 30, and is designated by the 

calendar year in which it ends. Annual 

precipitation for the study area averages 

18.61 inches and has ranged from 

10.22 inches in water year 1936 to 

27.39 inches in water year 1995. The 

middle to late 1990’s stand out as the 

wettest period since 1931, which has 

caused potential for bias towards wet 

conditions in the data collected in the 

Black Hills during this period. This 

potential bias has been addressed in the 

analysis of hydrologic data throughout 

the course of the study, and has been 

balanced to some extent by relatively dry 

conditions during the late 1980’s and 

early 1990’s.

Hydrogeologic Setting

Throughout geologic time, the Black 

Hills area has experienced frequent 

periods of inundation by seas, extended 

erosion, mountain building, and intrusion 

by igneous rocks; thus, the hydrogeology 

of the study area is very complex. The 

Black Hills uplift formed as an elongated 

dome about 60 to 65 million years ago. 

The oldest geologic units in the study 

area are the Precambrian crystalline 

(igneous and metamorphic) rocks (not 

shown in fig. 1), which are exposed in 

the central core of the Black Hills, 

extending from near Lead to south of 

Custer. The Precambrian rocks generally 

have low permeability; however, localized aquifers occur in many locations in 

the crystalline core of the Black Hills 

The precipitation gage Mt. Coolidge near 

Custer was operated from 1990-98.

Photograph by Darwin L. Rahder

Figure 2. Long-term trends in precipitation for 

the Black Hills area, water years 1931-98.

0

30

10

20

ANNUAL PRECIPITATION, IN INCHES

Annual precipitation

Long-term average

 (18.61 inches)

1930 2000 1940 1950 1960 1970 1980 1990

WATER YEAR
where secondary porosity and permeability have resulted from fracturing and 

weathering of the rocks.

Surrounding the Precambrian crystalline core is a layered series of sedimentary rocks including limestones, 

sandstones, and shales that are exposed 

in roughly concentric rings around the 

uplifted flanks of the Black Hills, as 

shown by the outcrops of the Madison 

Limestone and Minnelusa Formation 

(fig. 1). The more permeable of these 

sedimentary rocks—the Deadwood Formation, Madison Limestone, Minnelusa 

Formation, Minnekahta Limestone, and 

Inyan Kara Group—contain major aquifers that are able to store and transmit 

large quantities of water and are used 

extensively for water supplies within and 

beyond the study area. Alluvial deposits 

along streams also commonly are used as 

local aquifers.

The hydrologic setting of the Black 

Hills area is schematically illustrated in 

figure 3. Individually, the major aquifers 

generally are separated by confining layers, which are composed of less permeable rocks, or by relatively impermeable 

layers within the individual units. The 

aquifers and confining units generally 

dip away from the flanks of the Black 

Hills (fig. 3). In general, ground-water 

flow in these aquifers is radially away 

from the central core of the Black Hills. 

The aquifers primarily receive recharge 

from infiltration of precipitation on outcrops, and the Madison and Minnelusa 

aquifers also receive substantial recharge 

from streamflow losses.

Confined (artesian) conditions generally exist within the major aquifers, in 

locations where an upper confining layer 

is present. Under confined conditions, 

water in a well will rise above the top of 

the aquifer in which it is completed. 

Flowing wells will result when drilled in 

areas where the potentiometric surface 

(level to which water will rise) is above 

the land surface. Flowing wells and artesian springs that originate from confined 

aquifers are common around the periphery of the Black Hills.

Surface water in the Black Hills area 

is highly influenced by geologic conditions, and five hydrogeologic settings 

have been identified that have distinctive 

influences on streamflow and surfacewater quality. The five settings, which 

are shown in figure 4, are represented by 

four areas because two of the settings 

(loss zone and artesian spring) are considered to share a common area.

Numerous headwater (water-table) 

springs, originating primarily from the 

Madison and Minnelusa aquifers, occur 

in the limestone headwater setting, 

which is a high-altitude area of generally 

low relief in the western part of the study 

area known as the “Limestone Plateau” 

(fig. 4). Most of the headwater springs 

occur near the eastern edge of the Limestone Plateau and provide base flow for 

many Black Hills streams. These 

streams flow across the Precambrian 

igneous and metamorphic rocks in the 

crystalline core setting. 

The loss zone setting (fig. 4) consists 

of areas that are heavily influenced by 

streamflow losses. Most streams generally lose all or part of their flow as they 

cross the outcrop of the Madison Limestone. Karst features of the Madison 

Limestone, including collapse features, 

sinkholes, and solution features such as 

caves, are responsible for the Madison 

aquifer’s large capacity to accept 

recharge from streamflow. Large 

streamflow losses also occur in many 

locations within the outcrop of the 

Minnelusa Formation, and limited losses 

probably also occur within the outcrop of 

the Minnekahta Limestone (not shown in 

fig. 1).

Large artesian springs originating primarily from the Madison and Minnelusa 

aquifers occur in many locations downgradient from these loss zones. Thus, the 

loss zone and artesian spring settings are 

represented by the same area (fig. 4). 

These artesian springs provide an important source of base flow in many streams 

beyond the periphery of the Black Hills. 

Headwater springflow at the eastern edge of 

the Limestone Plateau provides flow to 

Rhoads Fork.

Photograph by Van A. Lindquist, West Dakota Water

Development District

Figure 3. Schematic showing simplified hydrologic setting of the Black Hills area.

Spring

conduit

Water

table

Cave

Flowing well

LIMESTONE

PLATEAU

Major aquifer

Confining unit

Spring

EXPLANATION

Deadwood

Madison

Inyan Kara

Group

Formation

Limestone

Precambrian igneous and

metamorphic rocks

Dip of sedimentary rocks exaggerated.

Relative thickness NOT to scale.

Limestone

Minnekahta Minnelusa

Madison

Limestone

Formation

Formation

Deadwood

Minnelusa

Formation

Alluvial aquifer

Potentiometric surface

of the Madison aquifer
No artesian springs are known to be 

located beyond the outcrop of the Inyan 

Kara Group; thus, the area beyond this 

outcrop is considered to be the exterior 

setting (fig. 4).

Summary of Major Findings

Numerous findings have been published in various reports produced for the 

Black Hills Hydrology Study, of which 

several are highlighted in this fact sheet. 

For more information, readers are 

referred to two summary reports for the 

study by Carter and others (2002) and 

Driscoll and others (2002).

Water-level records have been collected for 71 observation wells completed in bedrock aquifers and 2 cave 

sites in the Madison Limestone, providing useful information for hydrologic 

analyses and management of water 

resources. Water levels can be affected 

by several factors including pumping of 

nearby wells and climatic conditions. 

Long-term water-level declines could 

have various effects, including changes 

in ground-water flow patterns, reduction 

of springflow, increased pumping costs, 

and dry wells. A large percentage of the 

observation wells completed in the 

Madison and Minnelusa aquifers respond 

quickly to climatic conditions. Nearly 

all of the hydrographs for these aquifers 

show a downward water-level trend prior 

to 1993, as illustrated in the example 

hydrographs for a well pair completed in 

the Madison and Minnelusa aquifers 

(fig. 5). This downward trend can be 

partially attributed to dry climatic conditions in the Black Hills area during this 

period. Precipitation amounts generally 

were above average after 1993, and 

water levels increased rapidly (fig. 5) in 

most wells due to the large recharge 

capacity of the Madison and Minnelusa 

aquifers. In general, there is very little 

indication of declining water levels from 

ground-water withdrawals in any of the 

bedrock aquifers in the Black Hills area.

The hydraulic head in the Madison 

and Minnelusa aquifers is similar at the 

location for the well pair shown in the 

example hydrographs (fig. 5) and at various other locations throughout the Black 

Hills area. However, the hydraulic head 

in the aquifers can be separated by several hundred feet in some locations. 

Hydraulic connection between the 

Madison and Minnelusa aquifers at some 

locations in the Rapid City area has been 

confirmed through aquifer testing and 

dye tracing (Greene, 1993, 1997). In the 

Spearfish area, aquifer testing provided 

no indication of hydraulic connection in 

the vicinity of the tested wells (Greene 

and others, 1999). Hydraulic connection 

is not known at other locations throughout the Black Hills area because aquifer 

testing has not been performed. Hydraulic connection between the Madison and 

Minnelusa aquifers probably occurs at 

many artesian spring locations, and 

minor leakage probably occurs at many 

locations where a hydraulic gradient 

exists between the aquifers. Artesian 

springflow probably accounts for the 

largest percentage of leakage that occurs.

Streamflow variability is highly influenced by the hydrogeologic settings 

shown in figure 4. For the limestone 

headwater and artesian spring settings, 

streamflow variability is small because 

of the dominance by ground-water discharge. The largest headwater springs 

are in the Rapid Creek and Spearfish 

Creek Basins. The largest artesian 

spring discharge areas are located near 

the northern and southern parts of the 

axis of the Black Hills uplift; the single 

largest discharge area is a complex of 

springs in the northern Black Hills that 

includes Cox Lake and Crow Creek. In 

the crystalline core setting, streamflow 

characteristics are influenced by direct 

runoff and by relatively small groundwater discharge, which tends to diminish 

rather quickly during periods of dry 

climatic conditions.

In the loss zone setting, most streams 

provide an important source of recharge 

to the Madison and Minnelusa aquifers 

because most streams generally lose their 

entire flow when crossing outcrops of the Madison Limestone and 

Minnelusa Formation. Unique loss 

thresholds (maximum sustainable loss 

rates) have been determined for individual streams, with measured thresholds 

ranging from negligible losses for several 

streams to as much as 50 cubic feet per 

second (ft3/s) for Boxelder Creek. In the 

exterior setting, streamflow variability is 

large because streams are heavily influenced by direct runoff and generally have 

only minor influence from ground-water 

discharge. Figure 4. Hydrogeologic settings for the 

Black Hills area.

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton

Cheyenne

Crossing

Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peakx

Calamity

Peak

x

Iron

Mountain x

Onyx

Cave

Bear

x Butte

Ellsworth

Air Force

Base

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

Hydrogeologic settings

Limestone headwater

Crystalline core

Loss zone and artesian spring—Bounded by

 inner extent of Madison Limestone and

 outer extent of Inyan Kara Group

Exterior

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

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

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13

Figure 5. Hydrographs illustrating general 

similarities in water levels for a Madison/

Minnelusa well pair near Whitewood. WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

Whitewood Madison

Whitewood Minnelusa

3,380

3,480

3,400

3,420

3,440

3,460
Water-quality characteristics for the 

ground-water and surface-water 

resources in the Black Hills area were 

summarized for the study. Water quality 

of the major aquifers generally is very 

good in and near outcrop areas but deteriorates progressively with distance from 

the outcrops. In the Minnelusa aquifer, 

concentrations of dissolved sulfate vary 

markedly over short distances, where a 

zone of active anhydrite dissolution 

occurs. Most limitations for the use of 

ground water are related to aesthetic 

qualities associated with hardness and 

high concentrations of chloride, sulfate, 

sodium, manganese, and iron. Very few 

health-related limitations exist for 

ground water; most limitations are for 

substances associated with radioactive 

decay, such as radon and uranium. In 

addition, high concentrations of arsenic 

have been detected in a few samples 

from the Minnelusa aquifer.

Surface-water quality is distinctively 

influenced by the hydrogeologic settings 

(fig. 4). For most streams, concentrations of dissolved solids increase as 

streamflow decreases. However, for 

streams in the limestone headwater and 

artesian spring settings, which are dominated by ground-water discharge, concentrations of dissolved solids have little 

variability. Most streams generally meet 

water-quality standards established for 

designated beneficial uses. The primary 

exceptions are streams in the exterior 

setting, which occasionally fail to meet 

standards for temperature and dissolved 

oxygen during low-flow conditions. 

Standards for suspended sediment also 

have been exceeded in some streams 

(South Dakota Department of Environment and Natural Resources, 1998).

Human influences have the potential 

to degrade water quality for both ground 

water and surface water. For ground 

water, the potential for contamination 

can be large because of development on 

and upgradient of aquifer recharge areas, 

large secondary porosity, and relatively 

fast flow velocities. Contamination by 

septic tanks has been documented for 

some wells in the Blackhawk, Piedmont, 

and Sturgis areas (Bartlett and West 

Engineers, Inc., 1998).

For surface water, various land-use 

practices can affect water quality. Degradation of water quality from largescale mining activities has occurred in 

Annie, Bear Butte, Squaw, and Whitewood Creeks. Approximately 900 abandoned or inactive mines occur throughout the Black Hills area (South Dakota 

Department of Environment and Natural 

Resources, 2001). Potential impacts of 

acid-mine drainage include acidic water 

and increased concentrations of metals, 

sulfate, and dissolved solids that can 

cause detrimental aquatic effects. Efforts 

are underway by Federal, State, and 

private individuals and companies to 

remediate problematic sites. Various 

agricultural, urban, and suburban activities also can degrade stream quality.

The total volume of recoverable water 

stored in the major aquifers (including 

aquifers in the Precambrian rocks) within 

the study area is estimated as 256 million 

acre-feet (table 1), which is slightly more 

than 10 times the maximum storage of 

Oahe Reservoir on the Missouri River. 

Although the volume of stored water is 

very large, water quality may not be 

suitable for all uses in some parts of the 

study area, as previously discussed.

Hydrologic budgets provide an 

accounting of inflows to and outflows 

from a specified area, such as an aquifer 

or drainage basin. Hydrologic budgets 

for ground water and surface water in the 

study area were developed for water 

years 1950-98. Of the average annual

Table 1. Estimated volumes of 

recoverable water in storage for major 

aquifers in study area

[From Carter and others, 2002]

Aquifer

Recoverable

storage

(million

acre-feet)

Precambrian 2.6

Deadwood 30.5

Madison 62.7

Minnelusa 70.9

Minnekahta 4.9

Inyan Kara 84.7

Combined storage 

for major aquifers

256.3

precipitation in the study area, about 

91.6 percent is returned to the atmosphere via evapotranspiration, about 

3.5 percent recharges aquifers in the 

study area, and about 4.9 percent 

becomes runoff from the land surface 

(fig. 6).

The Madison and Minnelusa aquifers 

dominate the ground-water budgets for 

the study area. For example, combined 

average recharge to the bedrock aquifers 

in South Dakota for 1950-98 was estimated as 348 ft3

/s, of which 84 percent 

recharges the Madison and Minnelusa 

aquifers. Springflow was estimated as 

219 ft3

/s, of which 94 percent originates 

from the Madison and Minnelusa aquifers. Well withdrawals were estimated as 

40 ft3

/s, of which 70 percent is withdrawn from the Madison and Minnelusa 

aquifers. Ground-water outflow from the 

study area was estimated as 89 ft3

/s, of 

which 65 percent occurs in the Madison 

and Minnelusa aquifers. Artesian 

springflow is the single largest discharge 

component for the Madison and 

Minnelusa aquifers, and accounts for 

38 percent of the total discharge from 

these aquifers.

Large outcrops of the Madison Limestone and Minnelusa Formation occur in 

the Black Hills of Wyoming and were 

included in estimating recharge to the 

Madison and Minnelusa aquifers. 

Recharge to these aquifers for water 

years 1931-98 in South Dakota and 

Figure 6. Evapotranspiration, runoff, and 

precipitation recharge as percentages of 

average annual precipitation.

Precipitation

recharge

3.5 percent

Evapotranspiration

91.6 percent

Runoff

4.9 percent
Wyoming averaged about 344 ft3/s. 

Annual recharge rates were highly variable (fig. 7) and ranged from about 

62 ft3/s in 1936 to about 847 ft3/s in 

1995.

Total consumptive use within the 

study area from both ground-water and 

surface-water resources was estimated as 

218 ft3/s, which includes well withdrawals of 40 ft3/s, reservoir evaporation 

of 38 ft3/s, and consumptive streamflow 

withdrawals of 140 ft3/s. Net tributary 

flows, after consumptive streamflow 

withdrawals, accounted for about 

201 ft3/s in the Cheyenne River drainage 

basin and about 107 ft3/s in the Belle 

Fourche River drainage basin. Thus, 

streamflow contributions from the study 

area to the Missouri River amount to 

about 4 percent of the average flow of 

the Missouri River where it enters South 

Dakota.

In the Madison and Minnelusa aquifers, regional flowpaths from the west 

are largely deflected around the Black 

Hills. The dominant proportion of water 

in these aquifers within the study area is 

recharged within the Black Hills area, 

with ground-water flow generally radially away from the outcrops. In the 

Rapid City area, geochemical analyses 

indicated that flowpaths in the Madison 

aquifer are not restricted by surfacewater drainage basins, whereby water 

recharged in the Boxelder Creek and 

Spring Creek Basins is recovered by 

wells in the Rapid Creek Basin. Agedating analyses indicated that groundwater flow velocities in these aquifers 

are extremely variable.

Artesian springs act as a “relief valve” 

for the Madison and Minnelusa aquifers 

and are an important mechanism in controlling water levels in these aquifers. 

Springflow of many large artesian 

springs changes very slowly in response 

to long-term climatic conditions. Artesian springflow could be diminished by 

large-scale well withdrawals near 

springs, thus impacting surface-water 

resources. Large-scale development of 

the Madison and Minnelusa aquifers has 

the potential to influence the balance of 

the unique and dynamic “plumbing system” in the Black Hills area that controls 

interactions between ground-water levels 

and artesian springflow.

References

Bartlett and West Engineers, Inc., 1998, 

Piedmont Valley water quality assessment study—Final report: Bismarck, 

N. Dak., Bartlett and West Engineers, 

Inc. [variously paged].

Carter, J.M., Driscoll, D.G., Williamson, 

J.E., and Lindquist, V.A., 2002, Atlas 

of water resources in the Black Hills 

area, South Dakota: U.S. Geological 

Survey Hydrologic Investigations 

Atlas HA 747, 120 p.

Driscoll, D.G., Carter, J.M., Williamson, 

J.E., and Putnam, L.D., 2002, Hydrology of the Black Hills area, South 

Dakota: U.S. Geological Survey 

Water-Resources Investigations 

Report 02-4094, 150 p.

Greene, E.A., 1993, Hydraulic properties 

of the Madison aquifer system in the 

western Rapid City area, South 

Dakota: U.S. Geological Survey 

Water-Resources Investigations 

Report 93-4008, 56 p.

———1997, Tracing recharge from 

sinking streams over spatial dimensions of kilometers in a karst aquifer: 

Ground Water, v. 35, no. 5, p. 898-

904.

Greene, E.A., Shapiro, A.M., and Carter, 

J.M., 1999, Hydrogeologic characterization of the Minnelusa and Madison 

aquifers near Spearfish, South 

Dakota: U.S. Geological Survey 

Water-Resources Investigations 

Report 98-4156, 64 p.

South Dakota Department of Environment and Natural Resources, 1998, 

The 1998 South Dakota 303(d) waterbody list: Pierre, S. Dak., South 

Dakota Department of Environment 

and Natural Resources [variously 

paged].

———2001, Inactive and abandoned 

mines in the Black Hills, Minerals 

and Mining Program: South Dakota 

Department of Environment and 

Natural Resources, accessed July 13, 

2001, at URL http://www.state.sd.us/

denr/des/mining/acidmine.htm

For more information, please

contact:

District Chief

U.S. Geological Survey

1608 Mt. View Road

Rapid City, SD 57702

(605) 355-4560

http://sd.water.usgs.gov/projects/

bhhs/BHHS.html

Figure 7. Annual recharge (water years 

1931-98) to the Madison and Minnelusa 

aquifers in the Black Hills of South Dakota and 

Wyoming (from Carter, Driscoll, and Hamade, 

2001). Prolonged periods of below-average 

recharge occurred during the 1930’s and 

1950’s.

1930 2000 1940 1950 1960 1970 1980 1990

WATER YEAR

0

1,000

200

100

300

400

500

600

700

800

900

RECHARGE, IN CUBIC FEET PER SECOND

EXPLANATION

Streamflow recharge

Precipitation recharge

Combined recharge

Average streamflow

 recharge (1931-98)

Average precipitation

 recharge (1931-98)

Average combined

 recharge (1931-98)

Roughlock Falls along Little Spearfish Creek.

Photograph by Terry A. Carter