U.S. Department of the Interior

U.S. Geological Survey

Open File Report 2005-1269

In cooperation with Oakland County, Michigan

Water Resources in a Rapidly Growing Region — Oakland 

County, Michigan
Water Resources in a Rapidly Growing 

Region — Oakland County, Michigan

By Stephen S. Aichele

Prepared in cooperation with Oakland County, Michigan

Open File Report 2005-1269

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2005

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Aichele, S.S., 2005, Water Resources in a Rapidly Growing Region — Oakland County, Michigan: U.S. Geological 

Survey Open File Report 2005-1269 34 p.
iii

Contents

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

Introduction ................................................................................................ 1

Oakland County — Population and Land ............................................................... 3

People ................................................................................................ 4

Physiography and geomorphology ............................................................... 8

Climate ................................................................................................ 8

Land cover .......................................................................................... 11

The Hydrologic Cycle .................................................................................... 11

Water Budgets for Selected Basins ............................................................ 16

How Humans Can Alter the Hydrologic Cycle ................................................... 17

Water and the Land ....................................................................................... 20

Water in the Ground—The Ground-Water Resources of Oakland County .................. 20

The Glacial Aquifer in Oakland County ................................................... 20

Bedrock Aquifers in Oakland County ...................................................... 22

Ground-Water Quality ........................................................................ 23

Surface Water ....................................................................................... 25

Rivers .......................................................................................... 25

Lakes .......................................................................................... 25

Surface-Water Quality .............................................................................. 26

River-Water Quality ........................................................................... 27

Lake-Water Quality ........................................................................... 30

Summary ................................................................................................... 31

Water for the 21st Century – Meeting the Need ...................................................... 32

Acknowledgments ....................................................................................... 33

References Cited .......................................................................................... 33

Figures

1. Map showing USGS water-monitoring stations used in this study ........................ 2

2. Photographs showing water has many uses in Oakland County ........................... 3

3. Map showing Oakland County is a rapidly urbanizing area in southeastern 

 Michigan, near Detroit ........................................................................ 4

4-6. Graphs showing—

4. Population growth in Oakland County has averaged approximately 

100,000 people per decade throughout the 20th century ........................... 5

5. Ground-water levels near Pontiac recovered quickly after pumping ceased 

 in 1963 .................................................................................... 6

6. Ground water has been an important source of water in Oakland County, 

 Michigan and despite the use of surface-water supplies, ground-water 

 use is still increasing ..................................................................... 6
iv

7-10. Maps showing—

7. Public-water supplies, from both surface-water and ground-water 

sources, are available throughout the southern and central parts 

of Oakland County, Michigan ......................................................... 7

8. Public sanitary sewer service is available throughout much of southern 

 Oakland County ........................................................................... 7

9. Physiography and surficial geology of Oakland County, Michigan. ............... 8

10. Oakland County, Michigan is located in the headwaters of 6 

watersheds .............................................................................. 9

11-15. Graphs showing—

11. Normal daily temperature characteristics at Pontiac, Michigan

 1970-2000 ................................................................................. 9

12. Precipitation, measured at Pontiac, Michigan, is seasonally biased, 

with more rainfall in the summer months than during the winter ............... 10

13. Annual precipitation in southeastern Michigan has been increasing 

since 1960 ................................................................................. 10

14. Winter temperatures in Pontiac, Michigan, as measured by base-32 

degree days, have been increasing since 1975 .................................... 10

15. Winter potential evapotranspiration in southeastern Michigan, 

measured at Ann Arbor, has been greater than the long-term mean 

for most of the last 20 years ............................................................ 11

16-17. Maps showing—

16. The southeastern nine townships of Oakland County, Michigan were

largely urbanized between 1938 and 1980 .......................................... 12

17. Urban areas expanded from southeast to northwest across Oakland 

 County, Michigan from 1980 to 2000 ................................................... 13

18. As these aerial (above) and ground-level (below) photographs show, more 

recent suburban development (right), in an area outside of Milford, Michigan 

frequently includes lower housing densities, more green space, and less 

impervious surface per unit area than earlier 1950s and 1960s suburbs (left), 

like the area in Ferndale, Michigan ......................................................... 14

19. Diagram showing water that is constantly circulating through the 

hydrologic cycle .............................................................................. 14

20. Map showing the ability of soil to retain water varies widely across Oakland 

 County, Michigan from almost zero to 24 percent, compared to the soil 

volume .......................................................................................... 15

21-22. Graphs showing—

21. Ground water is recharged, and ground-water levels rise, during the 

spring and early summer, then ground-water levels decline through 

the remainder of the year ............................................................ 16
v

22. Annual low flows (95 percent exceedance) have generally increased in 

the River Rouge from 1960 to 2000 ...................................................... 19

23-26. Maps showing—

23. Glacial deposits in Oakland County, Michigan range in thickness from 

less than 50 feet to more than 250 feet ................................................ 21

24. Ground water is frequently less than 50 feet below the land surface in 

Oakland County, Michigan.. ............................................................ 21

25. Predicted susceptibility of ground water in Oakland County, Michigan 

to contamination by contaminants like nitrate and chloride ..................... 22

26. Predicted probability of encountering a clay layer 10 or more feet 

thick in the glacial aquifer, Oakland County, Michigan .............................. 23

27-28. Graphs showing—

27. Diversion of water for lake augmentation can substantially alter 

stream flows .............................................................................. 26

28. Specific conductance can increase rapidly in urbanized basins during 

snow melt because of contamination by road salt ................................. 27

29. Map showing trophic status of lakes in Oakland County, Michigan varies 

widely .......................................................................................... 30

Tables

1. Average monthly temperature characteristics at Pontiac, Michigan 

1970-2000 ................................................................................. 9

2. Ground-water component of streamflow for selected U.S. Geological 

Survey streamflow-gaging stations in southeastern Michigan ........................ 17

3. Annual water budgets for watersheds in Oakland County, Michigan can 

vary considerably, from year to year and between watersheds ........................ 18

4. U.S. Environmental Protection Agency primary and secondary maximum 

contaminant levels for ground-water contaminants common in Oakland 

County, Michigan .............................................................................. 23

5. Streamflow yields for selected watersheds in Oakland County, Michigan ............ 25

6. Detection rates for common classes of organic compounds analyzed in 

stream-water samples from Oakland County, Michigan, August 2002 

and Sept. 2003 ................................................................................. 28

7. Number of times samples from selected surface-water sampling sites in 

Oakland County exceeded the Michigan Department of Environmental 

Quality full-body or partial-body contact standard for Eschericia coli. ............... 29

8. Lake water-quality data for selected lakes in Oakland County, Michigan, 

1967 and 2002-2003 ........................................................................... 31
vi

Conversion Factors

Inch/Pound to SI

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8 × °C)+32

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).

Multiply By To obtain

Length

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 4,047 square meter (m2)

square foot (ft2) 0.09290 square meter (m2)

square mile (mi2) 2.590 square kilometer (km2) 

Volume

gallon (gal) 3.785 liter (L) 

million gallons (Mgal) 3,785 cubic meter (m3)

cubic foot (ft2 pt) 0.02832 cubic meter (m3) 

Flow rate

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

cubic foot per second per square 

mile [(ft3/s)/mi2]

 0.01093 cubic meter per second per square 

kilometer [(m3/s)/km2]

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d)

gallon per day per square mile 

[(gal/d)/mi2]

 0.001461 cubic meter per day per square 

kilometer [(m3/d)/km2]

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

million gallons per day per square 

mile [(Mgal/d)/mi2]

1,461 cubic meter per day per square 

kilometer [(m3/d)/km2]

Mass

pound, avoirdupois (lb) 0.4536 kilogram (kg) 

ton per year (ton/yr) 0.9072 metric ton per year
Water Resources in a Rapidly Growing Region - Oakland 

County, Michigan

By Stephen S. Aichele

Abstract 

Oakland County is a suburban county in southeast Michigan. Population and demand for water grew 

steadily in the county over the 20th century, and these 

trends are expected to continue in coming decades. 

Roughly 75 percent of current water demand is met by 

imported water from the Detroit Water and Sewerage 

Division (DWSD), but water use from ground-water 

sources within the county still exceeds 43 million gallons per day. Because much of the population growth is 

in areas beyond the DWSD system, an additional 20-25 

million gallons per day of supply may be necessary to 

meet future demands. Managing the wastewater produced while also protecting human and ecosystem health 

also may present challenges.

Despite considerable expansion of urban areas, 

streamflow characteristics at most sites have not been 

affected. However, at several sites in areas of the county 

that are both supplied by ground water and sewered, 

statistically significant downward trends in low-flow 

stream discharges have been noted between 1970 and 

2003. Stream chemistry, compared to a previous study 

of county water resources prepared in 1972, has generally improved, with marked decreases in concentrations 

of nitrogen, phosphorus, and sulfate. Chloride concentrations, however, have increased dramatically in river 

and lake water across the county. Detectable concentrations of personal-care products, flame retardants, and 

petroleum fuel compounds were identified at all river 

sites sampled. 

Introduction

In 1972, the U.S. Geological Survey (USGS) published Water Supply Paper 2000, “Water for a Rapidly 

Growing Urban Community— Oakland County, Michigan” (Twenter and Knutilla, 1972). In 2001, Oakland 

County and the USGS initiated a cooperative project to 

update the 1972 study in light of changes in the county 

as well as advances in the field of hydrology. From 

2001 through 2003, the USGS monitored stream flow 

and water quality, ground-water level, and lake-water 

quality at sites throughout Oakland County (fig. 1). Several recent USGS technical reports document specific 

aspects of the study: a data report (Aichele and others, 

2004), a report describing characteristics of the glacial 

aquifer (Bissell and Aichele, 2004), a report describing the effects of urban land-cover change on water 

resources (Aichele, 2005), and a report describing the 

microbiological quality of rivers and streams in Oakland 

County (Fogarty and others, 2005). 

This report summarizes the results and conclusions 

in the above-mentioned USGS technical reports and 

serves as an overall assessment of the current quantity 

and quality of water resources in Oakland County. It 

also describes changes in the quantity and quality of 

water resources in Oakland County during the past 30 

years.

In 1972, about 850,000 people lived in Oakland 

County, and used about 100 million gallons of water per 

day (Mgal/d). In 2000, about 1.2 million people lived 

in Oakland County an increase of nearly 50 percent. In 
2 Water for a Rapidly Growing Community - Oakland County, Michigan

2000, Oakland County’s water use totaled 168 Mgal/d, 

an increase of 68 percent. About 75 percent of water 

currently used in the county is supplied from the Great 

Lakes and connecting channels by the Detroit Water 

and Sewerage Department (DWSD). In 2000, DWSD 

supplied 785,000 residents with 125 Mgal/d, slightly less 

than 160 gallons per day (gal/d) per person. Community 

ground-water supplies in the county delivered 23 Mgal/d 

to 169,000 Oakland residents, slightly more than 135 

gal/d per person. A further 240,000 residents met their 

water needs with on-site domestic wells, which delivered 

an estimated 21 Mgal/d, or approximately 86 gal/d per 

person. 

In Oakland County, population and demand for 

water continue to grow. Over the next 20 years, population is expected to grow by an additional 200,000, 

requiring an additional 20 Mgal/d. Much of this growth 

is expected to be in the northern and western parts of 

the county, where water needs are currently met from 

ground-water sources. This report, supported by the 

previously published USGS technical reports, is intended 

to provide decision makers, water-resources managers 

and interested citizens in Oakland County with information necessary to meet not only the recreational, esthetic, 

and water-supply needs of residents but also to meet the 

ecological demands of lakes, rivers, and wetlands. In 

addition, this report provides a retrospective look at the 

effects of population growth in Oakland County on water 

quality and water availability. This information will be 

useful in areas with similar hydrogeologic settings that 

are experiencing rapid population growth and its accompanying demands on water resources.

Water has always been an important part of life 

in Oakland County, in obvious and in subtle ways. 

When settlers first began coming to Michigan, Oakland 

County’s many lakes, streams, and wetlands made it a 

good place for hunting and trapping. Later, agriculture 

thrived, supported by abundant water and fertile soils. 

In the early 1900s, many small communities developed 

waterworks around flowing wells (Leverett and others, 

1906). Through the 20th century, water was important 

to industry, and water continues to be vital to the continued health of Oakland County’s residents, environment, and economy (fig. 2). The most obvious and basic 

need is for drinking water. However, water is also vital 

for diluting and removing waste, including wastewater 

and stormwater, from the county. The many lakes and 

streams in Oakland County are important natural fea42 ̊30’

42 ̊45’

83 ̊45 ’ 83 ̊30’ 83 ̊15’ 83 ̊0 ’

0

Political boundaries from Oakland County GIS Utility, 2003.

Hydrographic data from USGS 1:100,000 scale Digital Line Graphs.

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Streamflow-monitoring station

Stream-water-quality

sample locations

Ground-water-level

monitoring sites

Municipal boundary

Watershed boundary

EXPLANATION Flint River

Watershed

Clinton River

Watershed

Shiawassee River

Watershed

Huron River

Watershed

River Rouge

Watershed

04148035

04143830

04143900

04160800

04161540

04161000 04161810

04160900

04170000

04170500 04166300

04166315 04166100

04166200

04161580

0416600

Belle River

Watershed

N

N

W W W W

Figure 1. USGS water-monitoring stations used in this study.
Introduction 3

tures that have esthetic appeal and attract tourists, vacationers, new homeowners, and businesses to the community. In addition, fish, waterfowl, and other wildlife all 

depend on the continued availability of clean water. 

Water in the ground, on the ground, or in the air is 

all part of a single resource (Winter and others, 1998). 

Water used from the environment for one purpose, such 

as drinking water or industrial cooling, may not be available—or may not be of sufficient quality when returned 

to the environment—to be used for other purposes, 

such as sustaining aquatic ecosystems and habitats. For 

example, water pumped from the ground for household 

use and released to a sewer system is no longer available 

for discharge to a local wetland, lake, or river. Resource 

needs commonly compete; for example, increased 

ground-water withdrawal for public consumption can 

compete against the water needed to support aquatic life 

and habitat in a river, or the need to maintain a specific 

lake level for recreational use can compete against 

the quantity of summer streamflow required to dilute 

wastewater discharge downstream in the same watershed. This report, like the Twenter and Knutilla (1972) 

report, is intended to provide county and local officials, 

and interested citizens, with the background information 

needed for informed decision making. 

To manage competing demands on the water 

resources of Oakland County, a comprehensive assessment of the current state of the resource is required. 

Some of the natural factors affecting this resource 

include the climate, physiography, and geology of the 

county. However, much of the water resource in Oakland County have already been affected in various ways 

by human activity. This report includes three major sections intended to address these issues. The first section 

is a summary of data available on the natural and built 

landscape of Oakland County, including climatology, 

soils, land cover, and population. The second section 

is an overview of the hydrologic cycle and how people 

and water interact in Oakland County. The third section of the report is an assessment of the current status 

of water resources in Oakland County, drawn from 

several recently published technical reports. This section describes the current quantity and quality of water 

resources in the county, including comparison to the 

information presented in Twenter and Knutilla’s 1972 

report where appropriate. More detailed information on 

specific topics can be obtained in the referenced technical reports.

Oakland County — Population and 

Land

Oakland County comprises 910 mi2 of land in 

the southeastern part of Michigan’s Lower Peninsula. 

Figure 2. Water has many uses in Oakland County.
4 Water for a Rapidly Growing Community - Oakland County, Michigan

Southeastern parts of the county are just a few miles 

from downtown Detroit, but the northwestern parts are 

approximately 40 miles distant (fig. 3). The county 

includes 63 cities, villages, and townships, and includes 

the headwaters of 6 rivers. Although much of Oakland 

County was either rural or a suburb of Detroit in 1972, 

several communities have since become centers of economic activity in their own right and have spawned their 

own suburban communities.

The distribution of commercial development in 

Oakland County is driven by the transportation network. 

The primary axis of development is along the Interstate 

75 corridor which links Detroit, Pontiac, and Flint. This 

corridor is crossed by the Interstate 96/696 corridor in 

the south and the Michigan Route 59 corridor across the 

central tier of townships. These three corridors have 

formed the basic framework for development in Oakland County. Overlaid on this framework is a similar 

distribution of residential development, with the highest densities generally in the southeast, followed by the 

southwest, the northwest, and the lowest densities in the 

northeast.

People 

The population of Oakland County has grown 

steadily since about 1900 (fig. 4). Growth has averaged approximately 100,000 new residents per decade 

throughout the 20th century. From a base of around 

50,000 residents and a primarily agricultural economy 

in 1900, the rise of manufacturing in the county spurred 

the population to almost 400,000 in 1950. During the 

1950’s and 1960’s, the growth of suburbs in the southern part of the county as well as continued expansion 

in manufacturing attracted over 30,000 new residents 

per year to the county and over 20,000 new residents 

per year in the 1970’s. By 1980 the population stood at 

slightly over one million. Most of these new residents 

located in suburban communities built in the southeastern corner of the county. Following a brief pause 

in growth in the early 1980’s, the county has continued 

to add about 10,000 new residents every year. In each 

wave of growth, expansion has happened in a series of 

roughly concentric circles radiating from Detroit. With 

1.2 million residents, Oakland County has a total populaFigure 3. Oakland County is a rapidly urbanizing area in southeastern Michigan, near Detroit.

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

Watershed boundary

EXPLANATION

Land cover change to urban

1980 - 2000

Highway

Detroit

83  ̊ 30’ W

83  ̊ 15 ’ W

42  ̊ 45 ’ N

42  ̊ 30 ’ N

Political boundaries from Oakland County GIS Utility, 2003.

Hydrographic data from USGS 1:100,000 scale Digital Line Graphs.

Land cover data from Southeast Michigan Council of Governments.

Holly Groveland Brandon Oxford Addison

Rose

Springfield

Independence Orion Oakland

Highland White Lake Waterford Pontiac Avon

Milford Commerce

West 

Bloomfield Bloomfield Troy

Lyon Novi Farmington Southfield Royal Oak

Flint River

Watershed Clinton River

Watershed

Shiawassee River

Watershed

Huron River

Watershed

River Rouge

Watershed

696 75

96

24

1

59 59

75

24
tion greater than 9 of the 50 United States, and is comparable in population to Hawaii or New Hampshire. 

Increases in population bring accompanying 

increases in water demand. Although per-capita water 

use in Michigan, and in the United States, has decreased 

slightly over the past decade, the decrease has not 

occurred as rapidly as the population has increased. In 

the early decades of the 20th century, when the population of Oakland County was about 50,000 people, water 

use was estimated to be approximately three Mgal/d, 

drawn almost entirely from ground-water sources inside 

the county. Wastewater was largely returned through onsite systems such as cesspools, or discharged to surface 

water, –with little or no treatment, –in small communities with sewer systems. As the population of the county 

grew through the century, water continued to be supplied 

primarily from ground water within the county, hitting 

a peak of approximately 85 Mgal/d in the early 1960’s. 

With the drought of the early 1960’s, Oakland County 

began buying water from the DWSD, which provided 

water from Lake Huron, and the St. Clair and Detroit 

Rivers to the communities south and east of Pontiac. 

This relieved much of the stress on the aquifer system 

in the county, as evidenced by the rebound in the hydrograph of a monitoring well near Pontiac (fig. 5)

Residents of Oakland County consumed approximately 167.75 million gallons of water every day in 

2000 (Luukkonnen, written communication, 2004). Of 

that, approximately 42.5 Mgal/d is supplied from the 

ground-water sources in the county (fig.6). The remainder is piped into the county by the DWSD. 

As the population has expanded into the northern 

and western parts of the county, the number of people 

relying on ground water for their domestic water supply has increased. Although some new lines have been 

added to the DWSD supply system in recent years, most 

of the northern two tiers of townships, as well as Highland, White Lake, Waterford, Milford, and other areas 

in the county still rely on ground water for their water 

supply (fig. 7). Public ground-water suppliers delivered 

approximately 22.87 Mgal/d to 169,000 residents in 

2000, and an additional 240,000 residents used private 

domestic-supply wells. 

The installation and expansion of sanitary sewers 

throughout the county, although generally beneficial in 

terms of water quality and public health, has had some 

detrimental effects on water availability. A household 

using a well and a septic system returns approximately 

90 percent of the water pumped from the well back into 

the ground (Horn, 2000). In contrast, because nearly all 

wastewater treatment plants discharge to rivers, water 

pumped from a well and discharged to a sanitary sewer 

is rapidly transported out of the county in the river 

system; this routing represents nearly a 100 percent loss 

of water to the aquifer system. Areas served by sanitary 

sewers are shown in figure 8. Comparison of figure 7 

with figure 8 reveals several areas where community 

water needs are met from ground water sources, but 

where water is not necessarily returned to the aquifer. 

Figure 4. Population growth in Oakland County has averaged approximately 100,000 people per decade throughout the 20th century.

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 2030

POPULATION

?

Oakland County — Population and Land 5
6 Water for a Rapidly Growing Community - Oakland County, Michigan

0

20

40

60

80

100

120

140

160

180

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Ground water

Surface water

WATER USE, IN MILLIONS OF GALLONS PER DAY

Figure 6. Ground water has been an important source of water in Oakland County, Michigan and despite the use of surface-water 

supplies, ground-water use is still increasing. (Data from Twenter and Knutilla, 1972; and C.L. Luukkonen, USGS Lansing, Michigan.) WATER LEVELS, IN FEET BELOW LAND SURFACE

20

40

60

80

100

120

140

1921

19301940

1950

19601967

Figure 5. Ground-water levels near Pontiac recovered quickly after pumping ceased in 1963 (after Twenter and Knutilla, 1972).
83  ̊ 30 ’ W

83  ̊ 15 ’ W

42  ̊ 45 ’ N

42  ̊ 30 ’ N

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Public supply surface water

(Detroit Water and Sewerage Department)

Public supply ground water

Political boundaries from Oakland County GIS Utility, 2003.

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Public sewer service available

83  ̊ 30 ’ W

83  ̊ 15 ’ W

42  ̊ 45 ’ N

42  ̊ 30 ’ N

Political boundaries from Oakland County GIS Utility, 2003.

Oakland County — Population and Land 7

Figure 7. Public-water supplies, from both surface-water and ground-water sources, are available throughout the southern and 

central parts of Oakland County, Michigan.

Figure 8. Public sanitary sewer service is available throughout much of southern Oakland County. (Data from Southeast Michigan 

Council of Governments, 2005)
8 Water for a Rapidly Growing Community - Oakland County, Michigan

Figure 9. Physiography and surficial geology of Oakland County, Michigan.

83  ̊ 30’ W

83  ̊ 15 ’ W

42  ̊ 45 ’ N

42  ̊ 30 ’ N

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Detroit

Watershed boundary

Glacial lake plain sediments

Outwash

Till

Political boundaries from Oakland County GIS Utility, 2003.

Hydrographic data from USGS 1:100,000 scale Digital Line Graphs.

Surficial geology modified from Zawiskie and Misuraca (Wayne State

and Oakland County, respectively, written communication, 2003)

Holly Groveland Brandon Oxford Addison

Rose Springfield Independence Orion Oakland

Highland White Lake Waterford Pontiac Avon

Milford Commerce

West 

Bloomfield Bloomfield Troy

Lyon Novi Farmington Southfield Royal Oak

Flint River

Watershed

Clinton River

Watershed

Shiawassee River

Watershed

Huron River

Watershed

River Rouge

Watershed

Physiography and geomorphology

Oakland County can be divided into three broad 

but physiographically distinct areas, each oriented along 

an axis from southwest to northeast (fig. 9). In the 

southeast, glacial lake-plain sediments form a relatively 

flat landscape with modest relief, generally sloping 

towards the southeast. Soils tend to be clay rich and 

poorly drained, with low infiltration capacity. Through 

the center of the county, a series of till features interspersed among outwash plains forms a landscape of 

modest relief with many shallow lakes, with occasional 

hills formed by till deposits. In the northwest, a landscape dominated by glacial till features forms a rolling 

and irregular surface, characterized by many hills and 

depressions, generally sloping towards the northwest. 

Soil conditions throughout this area are highly variable, 

ranging from very poorly drained lake-clay soils to welldrained soils derived from glacial channel deposits. 

Oakland County contains the major parts of the 

headwaters of five major river systems, and a small part 

of the headwaters of a sixth (fig. 10). The Clinton River 

drains the central and eastern parts of the county, flowing 

eastward toward Lake St. Clair. The Rouge River drains 

the southern part of the county, flowing to the Detroit 

River. The Huron River drains the southwestern part 

of the county to Lake Erie. The Shiawassee and Flint 

Rivers each drain parts of the northwestern corner of 

the county to Saginaw Bay, and the Belle River drains a 

small area of Addison Township to the St. Clair River.

Climate

Oakland County has a climate typical of the upper 

Midwest, with four distinct seasons characterized by differences in temperature, precipitation, and evaporation. 

Mean daily temperatures range from a low of 23oF in 

January to 72.4oF in July. Typical monthly temperature 

characteristics observed at Pontiac over the period 1970-

2000 are listed in table 1 and shown in figure 11 (Peter 

Kurtz, Michigan Climatological Resources Program, 

written communication, 2004). 

Precipitation typically falls in Oakland County 

during each month, but more falls during the summer 

months than during the winter (fig. 12). From 1960 

through 1998, annual precipitation averaged 29.6 in. in 

Pontiac. However, the precipitation could range from 

less than 20 to more than 40 in. in any specific year. 

Throughout much of the last four decades, the amount 

of precipitation in a given year has been increasing (fig. 

13). 

Over the last century, temperatures have also been 

increasing. This trend is particularly noticeable in winter 
42 ̊30’ N

42 ̊45’ N

83 ̊45’ W 83 ̊30’ W 83 ̊15’ W 83 ̊0’ W

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Watershed boundary

Political boundaries from Oakland County GIS Utility, 2003.

Hydrographic data from USGS 1:100,000 scale Digital Line Graphs.

Michigan

Oakland

County

Stream or lake

Holly Groveland Brandon Oxford Addison

Rose Springfield Independence Orion Oakland

Highland White Lake Waterford Pontiac Avon

Milford Commerce West 

Bloomfield

Bloomfield

Troy

Lyon Novi Farmington Southfield Royal Oak

Flint River

Watershed

Clinton River

Watershed

Shiawassee River

Watershed

Huron River

Watershed

River Rouge

Watershed

Belle River

Watershed

BIRMINGHAM

ROCHESTER

SOUTH

LYON

MILFORD

HOLLY

Figure 10. Oakland County, Michigan is located in the headwaters of 6 watersheds.

Temperatures (in degrees Fahrenheit)

Maximum Minimum Daily mean

January 30.0 16.0 23.0

February 33.5 17.4 25.5

March 44.7 25.9 35.3

April 58.0 36.1 47.1

May 70.4 47.4 58.9

June 79.3 56.6 68.0

July 83.4 61.3 72.4

August 81.2 59.9 70.6

September 73.6 52.6 63.1

October 60.6 41.6 51.1

November 46.4 31.8 39.1

December 34.4 21.6 28.0

Table 1. Average monthly temperature characteristics at Pontiac, 

Michigan 1970-2000.

Figure 11. Normal daily temperature characteristics at Pontiac, 

Michigan, 1970-2000. (Data from Peter Kurtz, Michigan Climatological Resources Program, written communication, 2003.)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

Normal high

Normal low

Normal average

TEMPERATURE, IN DEGREES FAHRENHEIT

January

February

March

April

May

June

July

August

September

October

November

December

Oakland County — Population and Land 9

[Source: Peter Kurtz, Michigan Climatological Resources Program, written 

commun., 2004]
10 Water for a Rapidly Growing Community - Oakland County, Michigan

temperatures. One approach to quantifying this trend is 

to show the number of degree days (based on 32oF) accumulated monthly through a period. The freezing/melting point of water (32o

F) is a convenient threshold for 

water resources because the amount of energy required 

to evaporate a fixed quantity of water in liquid form is 

dramatically less than the energy required to evaporate 

the same quantity of water in solid form. An increase 

in the number of days above freezing during the winter 

reduces the amount of water stored in the snow pack. 

The base-32 degree days are calculated as follows. For 

each of the 365 days of the year, 32 is subtracted from 

the high temperature for the day. If the high temperature 

never reaches 32 degrees, the day has zero degree days. 

Thus, if the high for a day is 40oF, it has eight base-32 

degree days. A graph showing the monthly accumulation of these base-32 degree days is presented in figure 

14. Although the accumulations for summer months are 

relatively steady or even decreasing slightly, the accumulations for winter months have increased considerably 

during the past decade. In the figure 14, this pattern is 

shown by relatively consistent summer peaks, but winter 

troughs that are not as low over time.

Figure 13. Annual precipitation in southeastern Michigan has been 

increasing since 1960.

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

PRECIPITATION, IN INCHES

January

February

March

April

May

June

July

August

September

October

November

December

Figure 12. Precipitation, measured at Pontiac, Michigan, is 

seasonally biased, with more rainfall in the summer months than 

during the winter. (Data from 1960-1998; Peter Kurtz, Michigan 

Climatological Resources Program, written communication, 2003.) 

15

20

25

30

35

40

45

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Trend line

ANNUAL PRECIPITATION, IN INCHES

Figure 14. Winter temperatures in Pontiac, Michigan, as measured by base-32 degree days, have been increasing since 1975.

0

10

20

30

40

50

60

70

1975197619771978197919801981198219831984198519861987198819891990199119921993199419951996199719982000

January degree days

BASE 32 DEGREE DAYS
This increase in base-32 degree days is matched by 

a similar increase in the winter season potential evapotranspiration (PET). Cumulative PET for the period 

from December 1 through February 28 based on data 

measured at Milford, Mich., from 1888 to 2002 is shown 

in figure 15. The PET values were estimated using 

Hargreaves’ method, as described in Leavesly and Stannard (1995). Although specific studies have not been 

completed on this subject, increases in winter season 

temperature and winter PET rates would likely result in a 

smaller volume of water stored in snow pack and potentially lower spring ground-water-recharge volumes.

Land cover

Each expansion in population requires an expansion 

in housing, infrastructure, and commercial services such 

as grocery stores and gas stations. These expansions 

can be seen in the patterns of land cover change in the 

county. The growth of urban areas surrounding the city 

of Detroit up until 1980, based on aerial photography 

and historical maps, is shown in figure 16. Land-cover 

change from 1980 to 2000, based on land-cover data 

from the Southeast Michigan Council of Governments 

(SEMCOG), is shown in figure 17. 

Although much of the growth in the period before 

1980 was in the southeast corner of the county between 

Detroit and Pontiac, most of the growth since then has 

occurred in an arc from Novi around the west and north 

sides of Pontiac and across to Rochester (fig. 17). During this period, the type and structure of developments 

have also changed. Whereas most suburban neighborhoods of the 1950’s and 60’s were built at relatively high 

density, with curbs and storm sewers (fig. 18), many 

newer suburban homes are built on larger lots with more 

green space and less impervious surface. Nearly all new 

development also has to meet requirements regarding 

the construction of control structures, such as detention 

and retention basins, to control the amount of stormwater 

that runs off the land. 

The Hydrologic Cycle

The air, the land surface, and the subsurface can 

each be thought of as a reservoir, and a variety of 

processes move water from one reservoir to another. 

The interaction of these reservoirs and the processes 

by which water is moved from one reservoir to another 

are usually described as the hydrologic cycle (fig. 19); 

this figure, and much of the following discussion of 

the hydrologic cycle, is drawn from Winter and others 

(1998). 

Figure 15. Winter potential evapotranspiration in southeastern Michigan, measured at Ann Arbor, has been greater than the long-term 

mean for most of the last 20 years. Mean potential evapotranspiration is shown with a dashed line.

300

400

500

600

700

800

900

1885 1905 1925 1945 1965 1985 2005

Winter ET

Mean

POTENTIAL EVAPOTRANSPIRATION, 

IN TENTHS OF MILLIMETERS

The Hydrologic Cycle 11
12 Water for a Rapidly Growing Community - Oakland County, Michigan

Figure 16. The southeastern nine townships of Oakland County, Michigan were largely urbanized between 1938 and 1980. (Courtesy U.S. 

Geological Survey Urban Dynamics Project.)

1980 1968

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

1938 1952

EXPLANATION

Scale 1:700,000

Municipal boundaries

Urban areas

Political boundaries from Oakland County GIS Utility, 2003.
0

50

100

150

200

250

300

350

400

1980 1985 1990 1995 2000

AREA, IN SQUARE MILES

Commercial

Residential

Michigan

Oakland

County

Residential

Commercial or Transportation

Agriculture

Open land

Forest

Water

Wetland

Barren

Municipal boundaries

Land use/land cover

Scale 1:700,000

Explanation

Land use/land cover, 1990 Land converted to urban use, 1980 to 2000

Land use/land cover, 1980 Land use/land cover, 2000

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

42 ̊45’N

42 ̊30’N

83 ̊30’ W

83 ̊15’ W

Political boundaries from Oakland County GIS Utility, 2003.

Figure 17. Urban areas expanded from southeast to northwest across Oakland County, Michigan from 1980 to 2000.

The Hydrologic Cycle 13
14 Water for a Rapidly Growing Community - Oakland County, Michigan

Transpiration

Transpiration

Precipitation

Surface water

Evaporation

Ground water

Atmospheric water

Soil water

The

Hydrologic 

Cycle

Runoff

Figure 19. Water is constantly circulating through the hydrologic 

cycle.

Although a description of the hydrologic cycle can 

start at any point, it is convenient to begin with precipitation. Oakland County includes the headwaters of six 

major rivers, all of which flow out of the county. As 

a result, the only natural means for water to enter the 

county is through precipitation. Precipitation replenishing streams and lakes is apparent to any observer; what 

is not apparent is that precipitation also replenishes the 

ground water by infiltrating through the soil into the 

underlying aquifer(s).

As mentioned previously, Oakland County receives 

slightly less than 30 inches of precipitation in an average 

year, although the overall average quantity of precipitation in Oakland County has been increasing slightly 

through time. The actual quantity of precipitation in 

any given year, however, can vary by 10 inches or more 

above and below this average. Oakland County usually 

receives precipitation in every month of the year, but 

there is a slight seasonal bias toward more precipitation 

during the summer. 

Once precipitation has fallen, whether as rain or 

snow, that water either infiltrates into the soil, is stored 

Figure 18. As these aerial (above) and groundlevel (below) photographs show, more recent suburban development (right) in an area 

outside of Milford, Michigan frequently includes lower housing densities, more green space, and less impervious surface per unit 

area than earlier 1950’s and 1960’s suburbs (left) like the area in Ferndale, Michigan.
on the surface in closed depressions or as snow and 

ice, or runs off the surface into lakes and rivers. The 

path precipitation follows once on the land surface is 

determined by various factors, with soil characteristics 

playing an important role. The most important soil 

properties are those that affect the infiltration rate; that 

is, the ability of the soil to absorb and transport water 

downwards. Soils with large amounts of clay, such as 

those typical in the southeastern part of Oakland County, 

generally have lower infiltration rates than sandy soils, 

such as those in the middle of the county. Infiltration 

rates of a particular soil can also decrease if the soil is 

frozen, compacted, or already saturated from prior precipitation. In extreme conditions, precipitation or meltwater delivery may exceed the infiltration capacity of the 

soil, resulting in ponding or runoff. If the soil is sealed 

at the surface by pavement or a structure, the infiltration 

capacity of the soil drops to nearly zero. 

Some infiltrated water is also retained in the soil. 

Depending on the soil, the amount retained can range 

from as little as 2 percent to as much as 24 percent of the 

soil volume in mineral soils (Soil Conservation Service, 

1980). The ability of soils in Oakland County to retain 

and hold water is shown in figure 20. Once this holding 

capacity has been exceeded, excess water drains through 

the soil column to the water table. The water table is an 

interface between the unsaturated zone, where water fills 

only a fraction of the pore space in the rocks and soil, 

and the saturated zone, where water fills nearly all the 

pore space. The drainage of water from the soil to the 

water table is frequently referred to as “recharge.”

In humid climates such as that of Oakland County, 

recharged ground water is slowly transported downgradient toward streams, lakes, rivers, and wetlands where 

it is discharged. Thus, just as surface water is flowing 

from high areas to low areas, ground water is flowing— 

much more slowly—from recharge areas to discharge 

areas. In Oakland County, ground water is typically 

recharged and ground-water levels rise during April and 

May, by a combination of melting snow pack and spring 

rains. Ground-water levels are gradually drawn down 

through the summer and fall, with the lowest levels typically during September and October, just before the first 

hard frost. This cycle of seasonal recharge and discharge 

Figure 20. The ability of soil to retain water varies widely across Oakland County, Michigan from almost zero to 24 percent, compared to 

the soil volume.

0.00 0.05

0.06 0.10

0.11 0.14

0.15 0.19

0.20 0.24

83 ̊30 ’ W

83 ̊15’ W

42 ̊45’ N

42 ̊ 30’ N

Soil data from Natural Resources Convervation Service SSURGO database.

http://www.ncgc.rrcs.usgd.gov/products/datasets/ssurgo/ Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Available water holding capacity

(percent of soil volume)

The Hydrologic Cycle 15
16 Water for a Rapidly Growing Community - Oakland County, Michigan

is shown in the ground-water hydrograph in figure 21. 

Alteration of winter-season temperatures— specifically 

the increases in winter evaporation rates observable in 

recent decades—could have measurable effects on the 

amount of recharge delivered to aquifers.

Despite larger quantities of precipitation during the 

summer months, little or no recharge occurs during the 

summer because evaporation of water from the surface 

and transpiration by vegetation consumes nearly all of 

the available water on the surface and in the soil. These 

different processes are difficult to quantify individually 

and are collectively termed “evapotranspiration,” or ET. 

In some watersheds in Oakland County, ET can intercept 

more than 60 percent of the total precipitation. Evaporated water, whether from the land surface or from the 

oceans, makes up the moisture in the atmosphere and 

again becomes precipitation. 

Water Budgets for Selected Basins

The different components of the hydrologic cycle 

can be cast into the form of a water budget, comparable 

to a household budget. Precipitation is analogous to 

income; runoff, ET, and human use can be thought of 

as expenses; and recharge can be thought of as a savings deposit for dry periods, such as late summer. This 

budget can be expressed as an equation:

P = RO + ET + HU + ∆S

where P is precipitation, RO is runoff, ET is the combined loss to evaporation and transpiration, HU is human 

use, and ∆S is the change in storage. Storage is the 

amount of water in transit, primarily as ground water, 

within the system at any point in time. Managing this 

budget is difficult because “income” (precipitation), and 

the largest “expense” (ET) are beyond human control. 

Runoff can be affected to some degree by land-management decisions, and human use can be managed by 

either controlling the number of people using the water 

or by providing alternative sources for water, such as the 

DWSD supply infrastructure in parts of the county.

Precipitation is the principal means of conveying water into Oakland County. Runoff—in this case 

streamflow—is the next most familiar element of the 

equation. Runoff, however, is itself composed of three 

elements: overland flow, storm seepage or interflow, 

and ground-water runoff. Overland flow is the familiar process of rainfall or melting snow running across 

the landscape into streams and rivers. Storm seepage 

or interflow is a relatively minor element that involves 

shallow infiltration and seepage to the stream channel, 

Figure 21. Ground water is recharged, and ground-water levels rise, during the spring and early summer, then ground-water levels 

decline through the remainder of the year. (Data from USGS monitoring well on Fish Lake Rd. in Oakland County, Michigan.)

33.00

33.50

34.00

34.50

35.00

35.50

36.00

RECHARGE

DEPTH BELOW LAND SURFACE,

IN FEET

2002

January

February

March

April

May

June

July

August

September

October

November

December
typically over a period of days. Storm seepage does 

not actually recharge the aquifer. However, particularly 

during the summer, there may be days, weeks, or even 

months with little or no rain, yet the rivers continue to 

flow. River flows, and the aquatic habitats within the 

rivers, are sustained by ground water gradually seeping 

from the aquifer into the stream channel. This groundwater seepage is generally referred to as “base flow.”

Streamflow is measured at various locations around 

the county by the USGS, MDEQ, Oakland County 

Drain Commission, and others. By analyzing daily 

streamflow records, it is possible to estimate the separate 

event-driven overland and interflowflow contributions to 

streamflow from ground-water-derived base flow (Sloto 

and Crouse, 1996; Appleby, 1970). The relative magnitude of these contributions is determined by a combination of the geologic setting of the basin and land cover 

within the basin. Long-term average base-flow values 

for selected basins in southeast Michigan are shown in 

table 2.

Using precipitation data from the SEMCOG raingage network (Peter Kurtz, Michigan Climatological 

Resources Program, written commun., 2004), annual 

water budgets were developed for three representative 

watersheds in Oakland County—Sashabaw Creek, Paint 

Creek, and the River Rouge—for the 2002 water year 

(table 3). It is evident from comparing these results 

to the average values in table 2, that fluctuations from 

year to year are relatively large. The majority of the 

surface runoff occurs during the spring months, primarily April and May, and surface runoff constitutes most 

of the streamflow during that period. In contrast, in 

August and September, more than 90 percent of the total 

streamflow is derived from ground water. Decreases in 

this ground-water contribution would have direct effects 

on the aquatic habitat within the stream. Therefore, the 

continued health of the surface-water resources in Oakland County, such as Paint Creek, relies on the continued 

abundance of ground water to sustain streamflow during 

periods of low precipitation and high ET.

How Humans Can Alter the Hydrologic Cycle

Human alteration of the hydrologic cycle can take a 

variety of forms, but three are most common in Oakland 

County. First, paving and creating other impervious 

areas, such as buildings, prevents water from infiltrating the land surface and therefore reduces the amount 

of water entering the ground-water system. In many 

cases, impervious surfaces also divert the water directly 

to streams and rivers, increasing the amount of overland 

flow in a watershed and increasing the likelihood of 

floods and damage to ecological communities and habitat. To some extent, these effects can be reduced by the 

use of runoff-control structures, such as retention basins.

Second, ground-water withdrawal reduces the 

amount of ground water available to discharge to rivers 

and lakes in the summer. If ground water is pumped 

for domestic use and discharged to a septic system, the 

total loss of water from an area may be relatively small, 

perhaps as little as 10 percent of total pumpage (Horn, 

2000). If ground water is pumped and then discharged 

to a river through a wastewater treatment plant (WWTP), 

the water is lost from the ground-water system. Wastewater discharged in this manner essentially exports water 

USGS

station number Station name

Average 

streamflow 

Average ground-water 

component of streamflow 

Average ground-water component of streamflow (percent)

04144000 Shiawassee River at Byron 251 202 80

04160800 Sashabaw Creek near Drayton Plains 13.3 11.9 90

04160900 Clinton River near Drayton Plains 53.1 48.2 91

04161540 Paint Creek at Rochester 53.6 46.1 86

04161580 Stony Creek near Romeo 17.6 14.9 85

04166000 River Rouge at Birmingham 20.8 14.1 68

04166100 River Rouge at Southfield 68.8 40.0 58

04166200 Evans Ditch at Southfield 8.91 3.56 40

04166300 Upper River Rouge at Farmington 13.8 8.66 63

04170000 Huron River at Milford 102 89.8 88

Table 2. Ground-water component of streamflow for selected U.S. Geological Survey streamflow-gaging stations in southeastern 

Michigan.

The Hydrologic Cycle 17

[Data from Holtschlag and Nicholas, 1998; all streamflows are in cubic feet per second; percentages are rounded to the nearest whole number]
18 Water for a Rapidly Growing Community - Oakland County, Michigan

04160800 04161540 04166100

Sashabaw Creek near Drayton Plains, Mich. Paint Creek near Rochester, Mich. River Rouge at Southfield, Mich. Precipitation Total streamflow Base flow Base flow fraction Precipitation Total streamflow Base flow Base flow fraction Precipitation Total streamflow Base flow Base flow fraction

1975 37.2 15.7 13.8 0.88 36.5 17.4 12.8 0.74 34.2 13.8 6.6 0.48

1976 29.2 11.8 10.8 0.91 29.2 14.6 12.0 0.82 29.7 13.4 7.3 0.55

1977 26.7 5.0 4.5 0.89 26.3 7.5 6.1 0.81 29.4 10.0 4.8 0.48

1978 23.5 5.8 5.3 0.90 23.2 8.1 6.8 0.83 24.5 7.8 4.9 0.64

1979 30.0 7.1 6.2 0.87 29.2 8.2 6.0 0.73 27.5 10.0 5.4 0.54

1980 32.0 8.5 7.6 0.90 32.1 10.1 8.0 0.79 32.0 10.8 6.1 0.57

1981 33.6 10.7 9.5 0.88 32.9 12.3 9.8 0.80 32.1 11.0 5.9 0.53

1982 29.2 9.9 9.0 0.91 29.0 11.6 8.8 0.76 29.7 12.7 7.8 0.61

1983 31.6 7.4 6.6 0.89 32.7 9.5 7.0 0.74 31.8 11.2 6.7 0.59

1984 26.9 6.1 5.2 0.86 28.3 8.1 6.6 0.82 26.6 9.3 5.1 0.55

1985 40.7 14.4 12.8 0.89 41.4 15.2 11.5 0.76 36.8 15.1 8.3 0.55

1986 33.6 12.3 11.0 0.90 34.0 12.9 10.5 0.82 32.6 14.4 8.5 0.59

1987 32.3 7.6 6.7 0.89 32.4 8.6 7.1 0.83 31.9 10.9 6.4 0.59

1988 29.1 7.3 6.4 0.87 28.2 8.0 6.5 0.81 26.9 9.2 5.6 0.60

1989 33.6 9.4 8.1 0.86 33.4 9.9 7.4 0.75 31.8 12.2 6.0 0.49

1990 38.1 13.0 11.3 0.87 37.0 12.6 9.8 0.78 39.3 17.5 8.2 0.47

1991 32.5 8.4 7.5 0.89 31.4 9.8 8.1 0.82 30.7 12.1 6.6 0.54

1992 36.1 11.8 10.6 0.90 35.1 11.9 9.5 0.80 35.3 13.6 7.9 0.58

1993 31.1 10.9 9.9 0.90 30.2 12.6 9.5 0.75 30.6 14.3 7.9 0.55

1994 32.4 8.5 7.4 0.87 32.0 10.1 7.5 0.74 32.3 13.0 6.1 0.47

1995 30.3 7.3 6.5 0.89 30.1 9.0 7.1 0.78 32.3 13.9 7.0 0.50

1996 34.4 9.8 8.6 0.87 34.6 12.1 8.6 0.71 32.6 14.2 7.0 0.49

1997 30.9 10.1 9.1 0.90 30.9 12.7 10.0 0.79 34.9 14.7 7.8 0.53

1998 27.4 7.4 6.6 0.89 27.0 9.5 7.2 0.77 31.0 12.3 6.6 0.53

1999 31.4 5.2 4.5 0.86 31.3 7.0 4.8 0.68 31.4 10.6 5.8 0.55

2000 38.1 10.3 8.8 0.85 38.5 11.4 7.5 0.66 37.3 10.8 4.7 0.44

Table 3. Annual water budgets for watersheds in Oakland County, Michigan can vary considerably, from year to year and between 

watersheds.

[precipitation and flows in inches]
Figure 22. Annual low flows (95 percent exceedance) have generally increased in the River Rouge from 1960 to 2000. Black line 

represents trend. (Data from USGS streamflow gaging station 04166100, River Rouge near Southfield, Michigan.)

0

5

10

15

20

25

30

19601962196419661968197019721974197619781980198219841986198819901992

19941996

1998

YEAR

DISCHARGE, IN CUBIC FEET PER SECON

D

out of the immediate watershed. WWTP discharge may 

also have effects on the receiving water, because the 

quality of the water discharged from the plant may be 

different than that of ground water.

Third, the large-scale transfer of water into the 

county is a human effect on the hydrologic cycle not typically discussed. The DWSD pumps nearly 125 Mgal/d 

of water into the county. Although much of this water is 

used and discharged back to Wayne County for treatment, some is treated and discharged to rivers in Oakland County. In addition, some of the water leaks out of 

water mains and may recharge underlying aquifers. 

In the area from Southfield north to the edge of 

the Rouge watershed, ground water has been replaced 

by DWSD surface water as the source for domestic 

use. Thus, the stress on the aquifer caused by pumping has been removed, and additional water is being 

diverted to the aquifer from DWSD. This effect can be 

seen in the low-flow record for the River Rouge, where 

low flows have increased by almost 400 percent since 

the introduction of DWSD water in the mid-1960s (fig. 

22). In the case of the River Rouge, this is relatively 

clean water seeping through the ground and is probably a net improvement for the system. Some of the 

water imported into the county is discharged to rivers 

through wastewater treatment plants in Pontiac and 

Ferndale. These discharges also increase the low flow 

of the receiving rivers, but in a different way. Although 

the total amount of water in the Clinton and Lower River 

Rouge has increased, the streamflow is supplemented by 

treated wastewater. Although this water has been treated 

and is relatively clean, it has a higher nutrient content 

and a higher temperature than the river typically would 

have. 

The Hydrologic Cycle 19
20 Water for a Rapidly Growing Community - Oakland County, Michigan

Water and the Land 

Water resources and land resources are intimately 

related—the characteristics of the water are linked to the 

characteristics of the land surface, soils, and geologic 

material with which the water interacts. For instance, 

water flowing through a geologic unit rich in carbonate 

minerals will gradually acquire calcium, magnesium, 

and bicarbonate in solution. Similarly, water flowing 

across a roadway will acquire trace quantities of spilled 

antifreeze, fuel, metals, and solvent residues, as well as 

salts and sealants applied to the pavement.

Water in the Ground—The Ground-Water 

Resources of Oakland County 

Ground-water resources are a vital part of Oakland 

County’s present and future. More than 400,000 Oakland County residents, primarily in the northern and 

western parts of the county, rely on ground water for 

their drinking water. Of these, approximately 240,000 

use private domestic-supply wells, and 169,000 are connected to systems using public water-supply wells. An 

additional 1,923 well permits were issued for new wells 

in Oakland County in 2004. 

In addition to this domestic use, which accounts for 

more than 43 Mgal/d of ground water, nearly all of the 

surface-water bodies in Oakland County rely on ground 

water to sustain them during some part of the year. 

These systems in turn support fish, waterfowl, and other 

ecological uses of water. Thus, although ground water is 

seldom seen while below ground, it is a critical component of water management in Oakland County.

Aquifers of Oakland County can be separated into 

two major groups. Near the surface is a fairly continuous glacial aquifer system, where water is stored and 

transported in the pore space between grains of sand or 

silt. Below that system are bedrock units, some of which 

can provide sources of water with sufficient quantity and 

quality for domestic use. In these bedrock units, most of 

the water is stored and transported through fractures or 

cracks rather than through pores. The properties of both 

the glacial and bedrock aquifers can be highly variable. 

Among the bedrock units in the county, only the Marshall Sandstone is an important source of drinking water. 

The Glacial Aquifer in Oakland County

The glacial aquifer in Oakland County consists of 

sediments deposited by the continental glaciers, which 

retreated across the area approximately 12,000 years 

ago. The environment at the time of glacial recession 

was dynamic, with large volumes of water and sediment 

flowing across the landscape. As a result, the glacial 

aquifer is a complex series of overlapping sedimentary 

deposits. In addition to these mixed depositional settings, lakes may have briefly formed on the landscape, 

producing beds of low-permeability clay of varied areal 

extent (Aichele, 2000). 

The glacial aquifer system ranges in thickness from 

about 100 ft in the southeastern part of the county to 

nearly 400 ft in the central part of the county (fig. 23). 

In general, potable water is available from the glacial 

aquifer throughout the county. Yields in excess of 

20 gal/min are common, and the water table is generally 

less than 30 ft below the land surface. In areas of the 

southeast, notably near Birmingham, the glacial aquifer 

may actually be confined beneath tightly layered lakebed 

sediments, and flowing wells can result (Aichele, 2005). 

Very little data are available in this area, however, so it 

is difficult to interpolate a continuous water surface (fig. 

24).

Although treating the glacial aquifer as one unit is 

frequently convenient, this interpretation is seldom correct. The hydraulic characteristics of the glacial material 

can vary dramatically over relatively short horizontal 

and vertical distances. Throughout much of Oakland 

County, and particularly in the north and west where 

till is prevalent, the glacial aquifer system is frequently 

divided by thick confining clay layers into two or more 

relatively distinct units. Localized clay layers do underlie some parts of the county and may provide some 

level of protection to ground-water resources. However, 

understanding or predicting where these confining clay 

units can be found is practically impossible, except 

where wells have already been drilled. Even then, it is 

difficult to say with any degree of certainty whether the 

well intercepts the clay at the middle of a vast unbroken 

layer or whether a given well falls at the edge of the clay 

layer. There do not appear to be any distinguishable 

clay layers of countywide extent, or even townshipwide 

extent. 

Several previous authors (Leverett, 1906; Mozola, 

1954; Twenter and Knutilla, 1972, Aichele, 2000) have 

attempted to characterize the stratigraphy of the glacial 

aquifer using conventional cross-section approaches 

commonly applied to bedrock and well-ordered glacial 

systems. These techniques are of limited value in a complex glacial environment such as that in Oakland County, 

not only because of the natural heterogeneity of the 

glacial aquifer but also because of variations in the way 

glacial lithologies are reported in drillers’ logs. A recent 

report (Bissell and Aichele, 2004) applied geostatistical 

techniques to document several aspects of the glacial 

aquifer system, including the vertical hydraulic conductivity of the upper part and the probability that a clay 

layer 10 or more feet thick might be present. More than 

36,000 drillers’ logs were considered in the analysis. 

Variography was applied as a quality-control procedure 

to evaluate the consistency of each driller’s interpretation 
Figure 23. Glacial deposits in Oakland County, Michigan range in thickness from less than 50 feet to more than 250 feet.

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Michigan

Oakland

County

Glacial thickness (feet)

0 - 100

101 - 150

151 - 200

201 - 250

 > 250

Supplementary thickness contour

(every 25 feet)

Political boundaries from Oakland County GIS Utility, 2003.

83 ̊30 ’ W

83 ̊15’ W

42 ̊45’ N

42 ̊ 30’ N

Figure 24. Ground water is frequently less than 50 feet below the land surface in Oakland County, Michigan.

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Michigan

Oakland

County

Depth to water (feet)

Less than 10

10 - 20

20 - 30

30 - 40

40 - 50

50 - 75

75 - 250

Political boundaries from Oakland County GIS Utility, 2003.

83 ̊30 ’ W

83 ̊15’ W

42 ̊45’ N

42 ̊ 30’ N

Water and the Land 21
22 Water for a Rapidly Growing Community - Oakland County, Michigan

of the geologic environment. Slightly more than 17,000 

logs were considered to be consistent and were used to 

develop predictive maps. In the southeastern part of the 

county, in the area of lacustrine glacial deposits, well-log 

data were insufficient to complete the analysis.

Vertical hydraulic conductivity (the rate at which 

water will move downward through an aquifer) is one 

commonly used indicator of the susceptibility of ground 

water to contamination. Estimates of susceptibility to 

contamination are shown in figure 25. The most susceptible areas are found through the central outwash 

plain region, where the glacial aquifer is predominantly 

composed of sand and gravel. Lower susceptibilities 

are found in the northwestern part of the county, where 

more clay is present. The map showing the predicted 

probability of encountering a clay layer 10 or more feet 

thick (fig. 26) is very similar to figure 25. Relatively low 

probability is typical in the central outwash plain region, 

whereas the probability is higher in the northwestern part 

of the county. 

Even with the quality-control procedures applied, 

however, the results of Bissell and Aichele (2004) were 

not definitive. Neither statistical model described more 

than half of the overall variability in the dataset. There 

are two likely causes for this relatively poor model 

performance. First, the glacial aquifer is highly variable 

and heterogeneous. Second, although more than half of 

the well logs were discarded because they were inconsistent, the remaining logs still may not be entirely accurate 

interpretations of the geologic environment.

Bedrock Aquifers in Oakland County

The primary bedrock aquifer in Oakland County is 

the Marshall Sandstone, a Mississippian sandstone unit 

with inclusions of limestone, dolomite, siltstone, and 

shale (Westjohn and Weaver, 1994). In the northwestern 

part of the county, the Marshall Sandstone can be a very 

productive aquifer, with yields exceeding 100 gal/min. 

The quality of water in the Marshall Sandstone, rather 

Figure 25. Predicted susceptibility of ground water in Oakland County, Michigan to contamination by contaminants like nitrate and 

chloride (modified from Aichele, 2004).

Susceptibility

Least

Most

Unknown

Suseptibility of ground water

to contamination

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Highways

Source data from Bissell and Aichele, 2004

Basemap data from Oakland County GIS Utlity, 2000.

Holly Groveland Brandon Oxford Addison

Rose Springfield Independence Orion Oakland

Highland White Lake Waterford Pontiac Avon

Milford Commerce

West 

Bloomfield

Bloomfield Troy

Lyon Novi Farmington Southfield Royal Oak

83 ̊30’ W

83 ̊15’ W

42 ̊30’N

42 ̊45’N
than the quantity, is usually the limiting factor. The Marshall Sandstone underlies parts of Holly, Groveland, and 

Brandon Townships but is not present in other parts of 

the county. Deeper parts of the Marshall Sandstone can 

contain saline waters unsuitable for drinking or industrial 

purposes. 

The remaining parts of the county generally do not 

have access to high-quality bedrock aquifers. In very 

specific areas, layers of sandstone or fractures in the 

Coldwater Shale can serve as acceptable drinking-water 

sources.

 Ground-Water Quality 

In most areas of Oakland County, the chemical quality of ground water from either the glacial aquifer system 

or bedrock aquifers is suitable for household drinking 

water or for industrial purposes. The U.S. Environmental Protection Agency sets Maximum Contaminant Levels (MCL) and Secondary MCLs (SMCLs) for a variety 

of potential contaminants. The MCLs and SMCLs for 

chemicals commonly found in ground water in Oakland 

County are listed in table 4. 

Contaminant Limit Units Type of Limit

Nitrite, as N 1 mg/L MCL

Nitrate, as N 10 mg/L MCL

Chloride 250 mg/L SMCL

Sulfate, as SO4 250 mg/L SMCL

Flouride 4 mg/L SMCL

Arsenic 10 mg/L MCL

Iron 0.3 mg/L SMCL

Manganese 0.05 mg/L SMCL

Dissolved solids 500 mg/L SMCL

Table 4. U.S. Environmental Protection Agency primary and secondary maximum contaminant levels for ground-water contaminants common in Oakland County, Michigan. Source: http://www.

epa.gov/safewater/mcl.html.

[mg/L, milligrams per liter; mg/L, micrograms per liter; MCL, maximum 

contaminant level; SMCL, secondary maximum contaminant level]

Figure 26. Predicted probability of encountering a clay layer 10 or more feet thick in the glacial aquifer, Oakland County, Michigan (modified from Aichele, 2004).

83 ̊30’ W

83 ̊15’ W

42 ̊30’N

42 ̊45’N

Probability

Low

High

Not modeled

Michigan

Oakland

County

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Highways

Source data from Bissell and Aichele, 2004

Basemap data from Oakland County GIS Utlity, 2000.

Holly Groveland Brandon Oxford Addison

Rose Springfield Independence Orion Oakland

Highland White Lake Waterford Pontiac Avon

Milford Commerce

West 

Bloomfield

Bloomfield Troy

Lyon Novi Farmington Southfield Royal Oak

Water and the Land 23
24 Water for a Rapidly Growing Community - Oakland County, Michigan

The quality of ground water in Oakland County was 

described in a recent USGS report (Aichele, 2000). The 

most common use impairments involve esthetic issues, 

primarily hardness or high concentrations of sulfur or 

iron, as opposed to health concerns. Hardness refers 

to the calcium and magnesium content of water, which 

makes water less suitable for use in a steam boiler. 

However, high concentrations of calcium and magnesium also affect the way soaps dissolve in water and can 

result in clogging or corrosion of plumbing fixtures and 

pipes. Generally, water containing more than 120 mg/L 

as CaCO3 is considered hard, and water containing more 

than 180 mg/L as CaCO3 is considered very hard (Hem, 

1985). On the basis of samples collected by the USGS 

since 1980, most wells in Oakland County produce water 

classified as very hard. Of 109 samples analyzed, 101 

had hardness greater than 180 mg/L as CaCO3, while 

two additional samples had hardness in excess of

120 mg/L as CaCO3. 

Iron, manganese, and sulfur in ground water are 

indications of a chemically reducing environment in the 

aquifer. This chemical environment can occur naturally in Oakland County, because of the large amount of 

carbon debris in the glacial aquifer system. Naturally 

occurring microbes in the subsurface consume carbon 

and release electrons as a byproduct, which results in the 

reduction of iron, manganese, sulfur, and other electron 

acceptors. High concentrations of iron and sulfur in 

ground water can also be indications of human-generated 

carbon sources, such as gasoline, fuel oil, or sewage. 

Consumption of water with iron or manganese concentrations greater than the SMCL is not considered dangerous from a health perspective; however, both materials 

leave deposits in pipes and fixtures, impart taste, and can 

discolor laundry (Shelton, 1997). Elevated concentrations of sulfur in water impart a characteristic “rotten 

egg” smell and can stain laundry and fixtures. Consuming water with sulfate concentrations in excess of

250 mg/L as SO4 can cause diarrhea (Shelton, 1997). 

Softening the water may also help remove iron, although 

using a softener in a situation where the natural ground 

water is not hard may not be as effective.

The most common health-related ground-waterquality impairments are associated with nitrate and 

chloride. Both can occur naturally in ground water; 

however, elevated concentrations within the glacial aquifer system are usually caused by human activities. Common sources of nitrate contamination include household 

septic tanks, animal waste, and fertilizers. The USEPA 

MCL for nitrate in ground water is 10 mg/L as N. This 

threshold is set based on potential health effects; of 

particular note is an impairment of the ability of hemoglobin to carry oxygen, potentially leading to cyanosis or “blue-baby syndrome.” Only 2 of 109 samples 

collected by the USGS in Oakland County since 1980 

have had nitrate concentrations greater than 10 mg/L as 

N, although Aichele and others (1998) identified nitrate 

concentrations exceeding 10 mg/L as N in 84 of 6,197 

samples of public and private drinking water analyzed by 

the MDEQ laboratory between 1988 and 1997. 

Chloride can be present in wastewater, but its presence in ground-water sources is more commonly the 

result of application of road salt for either deicing or 

dust control. Of 109 samples analyzed for chloride by 

the USGS since 1980, 9 have had concentrations greater 

than 250 mg/L. A 1998 USGS study (Aichele, 1998) 

identified chloride concentrations exceeding 250 mg/L 

in 366 of 6,227 samples of public and private drinking 

water analyzed by the MDEQ laboratory between 1992 

and 1998. The 250-mg/L concentration is an SMCL set 

by the USEPA on the basis of esthetic concerns. Water 

with higher concentrations of chloride tastes salty to 

most people. Although several bedrock units in Oakland 

County have naturally high concentrations of chloride, 

concentrations of chloride in lakes and rivers have been 

increasing significantly (Aichele, 2005) and chloride, 

because it has many uses to society, has been identified 

as an indicator of human effect (Thomas, 2000). 

Arsenic has been found in low concentrations in 

ground water throughout the county. Although none 

of the observed concentrations has been high enough 

to cause acute or immediate symptoms, the USEPA 

recognizes arsenic as a carcinogen and has reduced the 

concentrations permissible in drinking water to 10 μg/L. 

Exposure to concentrations above the MCL over a lifetime could increase the risk of certain types of intestinal 

and urinary-tract cancers. A USGS report (Aichele, 

2004) identified arsenic concentrations exceeding 10 μg/

L in 663 of 1,988 samples of public and private drinking 

water analyzed by the MDEQ laboratory. 

Very few chemical differences distinguish the 

water in the Marshall Sandstone from the water in the 

glacial aquifer immediately above it. Throughout both 

the glacial aquifer and the upper parts of the Marshall 

Sandstone, increasing well depth correlates to increasing 

dissolved solids concentration, water that is more chemically reducing, and generally decreasing desirability as 

a drinking-water source because of elevated chloride, 

iron, and sulfur content. The lower parts of the Marshall 

Sandstone contain water that is saline enough to preclude 

it from domestic use.

Concentrations of ground-water contaminants in 

Oakland County are highly variable both across the 

county and with depth across very short distances. Some 

evidence also indicates that concentrations of sulfur, 

iron, arsenic, and other contaminants may vary seasonally. Public water supplies are required to test their 

water several times during the year, at varying frequencies depending on the type of water supply, to ensure the 

water meets health standards. The only way for a private 

well owner to be certain that his or her water meets 

health standards is to have it tested regularly.
Surface Water 

Water in the streams, rivers, and lakes of Oakland 

County is a prime asset to the quality of life and environment in the county. Oakland County’s many lakes and 

rivers provide recreational, esthetic, and utilitarian benefits found in few other places. Although surface water 

includes rivers and lakes, each of these features functions 

in its own way and has unique characteristics that require 

separate discussion.

Rivers

Because Oakland County is in an upland setting 

that includes the headwaters of six major river systems, 

nearly all of the streams and rivers are relatively small 

and are typically wadable. The actual volume of water 

flowing in a given stream is directly dependent on the 

size of the watershed. For comparison of flows and 

streams, it is useful to use a yield per unit area, obtained 

by dividing the streamflow rate by the area of the 

upstream watershed. Average annual streamflow yields 

in Oakland County range from 0.67 to 0.85 (ft3/s)/mi2

(table 5) depending on watershed. This amounts to 

approximately 447 gal/d in runoff countywide when the 

area of the watershed is taken into account. This figure can also be expressed as a fraction of the long-term 

average precipitation. The average annual precipitation 

in Pontiac is 29.6 in/yr for the period from January 1960 

through December 1998. The average annual runoff 

from the basins accounts for 10.4 in/yr, or slightly more 

than one-third of annual precipitation. The remaining 

two-thirds is accounted for by either evapotranspiration, 

ground water discharging to points outside the county, or 

consumptive human uses within the county.

Human actions can have an effect on streamflow 

characteristics. Increased impervious surface (for example, pavement) can increase the amount and speed of 

runoff during a storm and decrease the amount of water 

recharged to ground water. Similarly, ground-water 

withdrawal will decrease the amount of base flow to 

streams and rivers, although the actual effect is difficult 

to predict without site-specific information. A recent 

study (Aichele, 2005) evaluated the effects of land-cover 

change—specifically conversion of forest and agricultural areas to urban covers—in Oakland County from 

1970 to 2003. Although very little effect was observed 

in peak flows or the variability of streamflow, several 

sites exhibited statistically significant trends in low-flow 

characteristics. Two sites in the River Rouge watershed, 

where nearly all water demand is met by DWSD supply, have significant upward trends in low flows, despite 

being nearly entirely urbanized. One site on the Upper 

River Rouge and two sites on the Clinton River had 

significant downward trends in low flows; in substantial 

areas of the watersheds upstream of each of these sites 

ground water is used for household use and wastewater is discharged to a river system. None of these sites 

received WWTP discharges from upstream.

Lakes

Oakland County has more than 1,600 lakes of 

various sizes, and more than 450 of them have surface 

areas greater than 25 acres. These lakes are valuable 

esthetically, ecologically, and financially. In addition to 

Water and the Land 25

Watershed

Measurement 

location

Years of 

record

Drainage area Annual discharge Base flow Runoff Evapotranspiration

(square miles) (ft3/s)/mi2 Inches (ft3/s)/mi2 Inches (ft3/s)/mi2 Inches (ft3/s)/mi2 Inches

Shiawassee River Linden 30 83.7 0.75 10.25 0.57 7.79 0.18 2.46 1.43 19.35

Stony Creek Romeo 40 25.6 0.67 9.07 0.55 7.43 0.12 1.64 1.51 20.53

Paint Creek Rochester 45 70.9 0.76 10.27 0.65 8.81 0.11 1.46 1.42 19.33

Sashabaw Creek Drayton Plains 45 20.9 0.63 8.49 0.57 7.78 0.05 0.71 1.56 21.11

Clinton River Auburn Hills 42 123.0 0.85 11.48 0.72 9.82 0.12 1.66 1.33 18.12

Rouge River Southfield 46 87.9 0.80 10.89 0.47 6.34 0.33 4.55 1.38 18.71

Upper Rouge River Farmington 46 17.5 0.81 11.06 0.51 7.01 0.30 4.05 1.37 18.54

Huron River Milford 56 132.0 0.77 10.46 0.68 9.23 0.09 1.23 1.41 19.14

Table 5. Streamflow yields for selected watersheds in Oakland County, Michigan.

[ft3/s, cubic feet per second; mi2, square miles]
26 Water for a Rapidly Growing Community - Oakland County, Michigan

income generated by recreation and tourism, Oakland 

County has more than 29,000 waterfront parcels, with 

an estimated value of over $10.6 billion (Ryan Runnels, 

Oakland County GIS Utility, written commun., 2004). 

Most lakes in Oakland County receive a large part of 

their water from ground-water seepage. Thus, lake 

levels are sensitive to fluctuations in water-table depth. 

Many lakes in Oakland County have regulated lake 

levels, meaning that the elevation of the surface of the 

lake must be maintained within a certain range by order 

of a court or other regulatory body. Lakes with regulated 

levels use either a system of diversions or controls such 

as dams to retain streamflow within a lake or augmentation wells that pump ground water into the lake. Either 

of these methods can pose problems. The record of 

streamflow in the Clinton River at Drayton Plains when 

flow was being retained at an upstream lake to maintain 

a lake level is shown in figure 27.

The summer 2002 streamflow values shown in 

figure 27 are period-of-record low flows for this site, 

based on daily records since October 1959. Although 

the effects of these low flows on the aquatic ecosystem 

of the stream are unknown, this diversion of water to 

maintain lake levels is not without consequence—that 

is, the water is diverted from somewhere, in this case the 

normal streamflow downstream of the lake. 

Similarly, augmentation wells are used in many 

parts of Oakland County in an attempt to maintain lake 

levels. In many cases, lakes are directly connected to the 

underlying glacial aquifer, and the augmentation well 

eventually ends up recirculating water from the aquifer 

to the lake, then drawing it back through the lake bed to 

the well. In situations where there is truly a separation 

between the lake and the aquifer, augmentation wells 

can be effective at maintaining lake levels. However, 

they remove water from the ground-water system, which 

effectively removes it from nearby streams and wetlands 

that would receive that water as ground-water discharge.

Surface-Water Quality 

Because surface water serves as a drinking-water, 

recreational, esthetic, and ecological resource, and as a 

means for removal of excess stormwater, treated wastewater, and other waste products there is an obvious need 

to strike a balance between these sometimes competing 

functions. For this reason, various standards have been 

Figure 27. Diversion of water for lake augmentation can substantially alter stream flows. (Data from USGS streamflow gaging 

station 04160900 — Clinton River at Drayton Plains, Mich.)

0

20

40

60

80

100

120

140

Long-term average

2002

January

February

March

April

May

June

July

August

September

October

November

December

Diversions

MONTH

DISCHARGE, IN CUBIC FEET PER SECOND
developed by MDEQ to evaluate the quality of surface 

water, on the basis of its use.

River-Water Quality

Because Oakland County is located in the headwaters of its river systems, the relatively small streams 

present have not been developed as a source of drinking 

water. However, all surface-water bodies in the county, 

and throughout Michigan, are required to meet waterquality standards for recreational waters. 

It is possible to compare the current (2001–2003) 

chemical quality of surface water in Oakland County 

(Aichele and others, 2004) to the period from 1966-

1970, when data for Twenter and Knutilla’s report 

(1972) were collected (Aichele, 2005). Based on these 

comparisons, the chemical quality of stream water is 

generally better than in the late 1960s, with concentrations of nutrients such as nitrate, phosphorus, and sulfate 

decreasing. In contrast, specific conductance (a measure of the dissolved-solids concentration of the water) 

and concentrations of chloride and have approximately 

doubled. Chloride is very stable in the environment 

and is seldom consumed or absorbed. Uses of chloride 

vary widely, from food seasoning to water softening 

and from dust control to snow removal. As a result, it 

has become a common indicator of human influence 

(Thomas, 2000). Dietary consumption varies widely, 

but a recent study estimated U.S. salt (sodium chloride) 

consumption at 10,000 milligrams per person per day 

(Intersalt Cooperative Research Group, 1988), which 

equates to approximately 6 grams of chloride per day or 

2.2 kilograms (4.8 lb) of chloride per year. Distributed 

across the 1.2 million residents of Oakland County, that 

totals nearly 2.6 million kilograms per year, or roughly 

2,900 tons/year. Salt use by the Oakland County Road 

Commission for road deicing averages roughly 

77,000 tons/year (Earryl Heid, Oakland County Road 

Commission, oral commun., 2005), and does not include 

state, local, or private use. A recent study in Ohio 

(Kunze and Sroka, 2004) has documented increases 

in chloride concentrations in ground water of as much 

as 100–300 mg/L as a result of road deicing. Records 

of specific conductance at three sites in three separate watersheds (Shiawassee, Clinton, and Rouge) are 

shown in figure 28. Chemical analysis indicates the 

overwhelming component of the spike observable in the 

Clinton and Rouge watersheds is sodium chloride, from 

runoff associated with a midwinter snowmelt.

Water and the Land 27

Figure 28. Specific conductance can increase rapidly in urbanized basins during snow melt because of contamination by road salt. 

The heavily urbanized River Rouge develops a much larger peak than the less urbanized Clinton and Shiawassee Rivers.

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

Shiawassee River

Clinton River

River Rouge

October November December January February March

Snow melt

MONTH

SPECIFIC CONDUCTANCE, IN MICROSIMENS PER CENTIMETER
28 Water for a Rapidly Growing Community - Oakland County, Michigan

Site number Stream Sampling date

Waste stream 

(of 10)

Flame retardants 

(of 5) Fuels (of 8)

2002

04143830 Shiawassee River Aug. 21 3 4 4

04148035 Kearsley Creek Aug. 21 2 1 5

04160800 Sashabaw Creek Aug. 20 3 2 5

04160900 Clinton River Aug. 20 4 1 5

04161000 Clinton River Aug. 28 6 5 0

04161540 Paint Creek Aug. 28 3 1 0

04161810 Clinton River Aug. 21 7 4 5

04166000 Rouge River Aug. 03 4 4 1

04166100 Rouge River Aug. 20 4 3 0

04166315 Upper Rouge River Aug. 21 3 4 4

04170000 Huron River Aug. 20 5 3 5

04170500 Huron River Aug. 28 2 3 0

2003

04143830 Shiawassee River Sept. 09 5 4 1

04148035 Kearsley Creek Sept. 09 1 0 1

04160800 Sashabaw Creek Sept. 09 2 0 0

04160900 Clinton River Sept. 08 2 0 1

04161000 Clinton River Sept. 08 8 5 2

04161540 Paint Creek Sept. 09 2 0 1

04161580 Stony Creek Sept. 09 1 1 0

04161810 Clinton River Sept. 09 7 4 2

04166000 Rouge River Sept. 08 4 2 2

04166100 Rouge River Sept. 08 3 2 3

04166200 Evans Ditch Sept. 08 5 4 3

04166315 Upper Rouge River Sept. 08 1 2 1

04170000 Huron River Sept. 08 5 3 0

04170500 Huron River Sept. 08 1 1 2

Table 6. Detection rates for common classes of organic compounds analyzed in stream-water samples from Oakland County, Michigan, 

August 2002 and Sept. 2003. Site locations shown in figure 1.

A variety of analyses are available now that were 

not available during the period of the previous study 

(Twenter and Knutilla, 1972). The most noteworthy of 

these are improved analyses for bacteria and for a group 

of chemicals collectively known as “emerging contaminants.” 

Within the group of emerging contaminants are 

several common indicators of human influence, such 

as personal-care products, detergents, pharmaceuticals, 

flame retardants, caffeine, and hormones. In addition, 

many of these compounds are relatively persistent in 

the environment and can be detected at very low levels. 

Many of the compounds are also used in multiple applications; for example, a specific compound in a detergent 

may also be an inert ingredient in a pesticide. Therefore, 

interpretation of these emerging contaminants data can 

be difficult, but all of these compounds are generated by 

humans. 

Samples were collected by the USGS from 12 

sites in August 2002 and from 14 sites in September 

2003 under low-flow conditions (table 6). A subset of 

the compounds analyzed have been grouped into three 

categories: household-waste products, likely associated 

with excreta or personal care products referred to as 

“waste stream” in table 6); flame retardants; and compounds found in petroleum products (referred to as fuels 

in table 6).

Among the household waste products, caffeine 

was detected at 6 of 12 sites in 2002 and 7 of 14 sites in 

2003. DEET (N,N-diethyl-meta-toluamide), the insect 
repellent, was detected at all sites in both years. Cholesterol was detected at 6 of 12 sites in 2002 and 3 of 14 

sites in 2003. AHTN (6-acetyl-1,1,2,4,4,7-hexamethyltetraline), a common musk fragrance used in personal 

care products, was observed at 5 of 12 sites in 2002 and 

4 of 14 sites in 2003. The most frequent detections of 

household waste products were observed in the Clinton 

River at Auburn Heights and at Dequindre Road and in 

the Huron River at General Motors Road near Milford. 

The Pontiac and Milford WWTPs are located upstream 

above the Auburn Hills and General Motors Road sites, 

respectively. The Dequindre Road site is approximately 

12 mi. downstream from the Auburn Hills site. Interestingly, samples from many sites with no obvious wastewater source contained one or more indicators of household wastewater. 

Flame retardants are commonly used in clothing, 

building materials, electronics, and a variety of other 

applications, making determination of a source difficult. 

Water samples from every one of the 12 sites sampled in 

2002 contained at least 1 of the 5 fire retardants analyzed 

for. In 2003, water from only 10 of 14 sites contained 

1 or more fire retardants. The most frequent detections 

were again in the Clinton River at Auburn Hills, which 

had five of five analyzed for, but the Shiawassee River 

and Clinton River at Dequindre Road both had four of 

five in both 2002 and 2003. 

Compounds typically found in petroleum products 

were detected in 8 of 12 samples in 2002 and 11 of 14 

samples in 2003. Compounds were detected more frequently in 2002; water from four sites, Kearsley Creek, 

Sashabaw Creek, Clinton River near Drayton Plains, 

Clinton River at Dequindre Road, and Huron River at 

General Motors Road near Milford all had detections 

of each of the five compounds analyzed for. In 2003, 

the most frequent detections were in the River Rouge at 

Southfield and in Evans Ditch. Water samples from both 

sites contained three of the five compounds analyzed for. 

No site was completely free of the compounds 

described above. All of the detections were at very 

low concentrations—much lower than would pose an 

immediate threat to human health. However, the longterm effects of these compounds in the environment are 

poorly understood, either in the context of human health 

or of ecosystem health. A more detailed description of 

these sample results can be found in Aichele and others (2005). Although the presence of these compounds 

in surface water does not pose an immediate threat to 

human life, it indicates that the quality of surface water 

in Oakland County is affected by human activity.

Concentrations of the bacterium Eschericia coli (E. 

Coli) in Oakland County river water frequently exceeded 

standards set by the MDEQ for recreational waters (table 

7). For partial-body contact such as wading, canoeing, 

Water and the Land 29

Number of samples 

analyzed

Number of samples exceeding

Site number Stream 300 CFU/100 ml 1000 CFU/100ml

04143830 Shiawassee River 9 0 0

04148035 Kearsley Creek 4 3 0

04160800 Sashabaw Creek 10 3 1

04160900 Clinton River 6 2 2

04161000 Clinton River 10 4 2

04161540 Paint Creek 10 6 2

04161580 Stony Creek 3 0 0

04161810 Clinton River 9 5 2

04166000 Rouge River 9 7 1

04166100 Rouge River 9 6 4

04166200 Evans Ditch 2 1 1

04166315 Upper Rouge River 10 6 5

04170000 Huron River 8 2 0

04170500 Huron River 7 0 0

Table 7. Number of times samples from selected surface-water sampling sites in Oakland County exceeded the Michigan Department 

of Environmental Quality full-body or partial-body contact standard for Eshericia coli, 2001-2003. Site locations shown on figure 1.

[CFU, colony forming unit; ml, milliliter]
30 Water for a Rapidly Growing Community - Oakland County, Michigan

Figure 29. Trophic status of lakes in Oakland County, Michigan varies widely.

0 3 6

0 3 6

MILES

KILOMETERS

Municipal boundary

EXPLANATION

Michigan

Oakland

County

Trophic Status - August 2003

Oligotrophic

Mesotrophic

Eutrophic

Hypereutrophic

Political boundaries from Oakland County GIS Utility, 2003.

83 ̊30 ’ W

83 ̊15’ W

42 ̊45’ N

42 ̊ 30’ N

and fishing, the MDEQ standard is 1,000 colony forming 

units (CFU) per 100 ml of sample water. The full body 

contact (bathing) standard is 300 CFU per 100 milliliters 

(mL). Of 14 sites sampled, 11 exceeded the full-body 

contact standard at least once, and 9 of the 14 exceeded 

the partial contact standard at least once. The site in the 

county that is most representative of a bathing location 

is the Huron River near New Hudson, just downstream 

from the Kent Lake Dam. All seven samples analyzed 

at this site had E. coli concentrations well below both 

standards. 

During August and September 2003, an effort was 

made to use antibiotic resistance to identify sources of E. 

coli and enterococci bacteria in surface water in Oakland 

County (Fogarty and others, 2005). The results of this 

project were inconclusive, but did indicate the presence 

of E. coli and enterococci that were resistant to clinical 

antibiotics at some sites. Genetic markers for E. coli

O157, a human pathogen, were detected at sites throughout the county in August and September. Pathogens are 

organisms capable of causing illness. Although E. coli

of type O157 are considered human pathogens, it is not 

clear what effect, if any, the presence of these organisms 

in surface water has on either public health or ecosystem function (Fogarty and others, 2005). Samples were 

also collected from two reference sites in Michigan, one 

near Grayling and one on Isle Royale in Lake Superior. Organisms in both of these reference samples also 

were somewhat resistant to clinical antibiotics, although 

resistance was generally at lower concentrations and to 

lower-order antibiotics compared to the resistance in 

samples from Oakland County. Comparable data from 

other developed counties in Michigan are not currently 

available, so it is difficult to state whether the results 

observed in Oakland County might be typical of other 

counties.

Lake-Water Quality

Two methods were used to quantify lake-water quality in Oakland County. First, samples were collected 

from 12 lake basins. These samples were analyzed for 

nutrients, major ions, and other chemical characteristics. 

Second, lake trophic status, a broad indication of overall 

lake-water quality, was estimated for all large lakes in 

Oakland County by means of satellite imagery interpretation techniques developed by Fuller and others (2004). 

These estimates are shown in figure 29. Water-quality 

samples collected during the previous study (Twenter 

and Knutilla, 1972) had only been analyzed for a few 

select chemical characteristics. The more recent study 
(Aichele and others, 2004) sampled for a more extensive suite of chemical characteristics. A comparison of 

selected water-quality characteristics is given in table 8.

Chloride concentrations have more than doubled at 

every site, paralleling the results from stream samples. 

Sulfate concentrations have generally decreased since 

the late 1960s, except in Kent Lake (part of the Huron 

River). Nitrate concentrations have also generally 

decreased since the late 1960s, except at Kent Lake. 

This pattern is similar to what was observed in stream 

water, and is likely caused by wastewater discharge to 

the Huron River upstream of Kent Lake.

1967 (Twenter and Knutilla, 1972) 2002-2003 (this study)

Sulfate Chloride Nitrate Nitrate 

Specific 

conductance Sulfate Chloride Nitrate 

Specific 

conductance

mg/L as SO4 mg/L as Cl mg/L as N mg/L as N μs/cm mg/L as SO4 mg/L as Cl mg/L as N μs/cm

Kent Lake 39 26 0.2 0.045 457 -- 117 0.144 730

Wolverine Lake 22 62 -- -- 485 32.2 263 <0.022 1080

Union Lake SE 24 28 0.0 0.000 397 -- 118 0.084 676

Lower Pettibone 

Lake

22 15 -- -- 370 -- 96 0.353 695

Big Lake 18 10 -- -- 285 -- 32 0.168 329

Tipsico Lake 12 2.5 0.1 0.023 166 5.1 23.3 <0.022 194

Lake Orion 62 16 1.6 0.361 785 32.5 66 <0.022 554

Valley Lake 19 7.2 -- -- 295 15 38.5 <0.022 418

Lakeville Lake 36 12 0.6 0.135 402 25.6 39.9 <0.022 485

Table 8. Lake water-quality data for selected lakes in Oakland County, Michigan, 1967 and 2002-2003.

[mg/L, milligrams per liter; N, nitrogen; SO4, sulfate; Cl, Chloride; NO3, nitrate; μs/cm, microsiemens per centimeter]

Water and the Land 31

Summary

Water has always had an important role in Oakland County’s economy and vitality. In 1972, the U.S. 

Geological Survey (USGS) published Water Supply 

Paper 2000, “Water for a Rapidly Growing Urban 

Community— Oakland County, Michigan” (Twenter 

and Knutilla, 1972). In 2001, Oakland County and 

the USGS initiated a cooperative project to update the 

1972 study in light of changes in the county as well as 

advances in the field of hydrology. Several recent USGS 

technical reports document specific aspects of the study. 

This report summarizes the results and conclusions in 

the above-mentioned USGS technical reports and serves 

as a current overall assessment of the current quantity 

and quality of water resources in Oakland County.

Demand for water in Oakland County grew steadily 

during the first half of the 20th century, reaching nearly 

85 million gallons per day (Mgal/d) in the early 1960’s. 

Although the county typically receives about 30 inches 

per year of precipitation, this quantity can vary annually 

by as much as 10 inches. Not all parts of the county are 

equally suited for water development. The southeastern part of the county is underlain primarily by lakebed 

sediments, which have very low infiltration rates. The 

central part of the county is underlain by sandier outwash deposits, with relatively high infiltration rates but 

also with a relatively high susceptibility to contamination from surface sources like septic tanks and road 

runoff. The northwestern part of the county has a mixed 

geologic setting, with both high- and low-permeability 

sediments. Drillers’ log data available are insufficient 

to accurately characterize the subsurface environment in 

much of the county, because of high variability in both 

the geology itself and the quality of the drillers’ logs. 

During the drought of the early 1960s, stress on 

water sources, primarily ground water within the county, 

became evident. Much of the southern and eastern parts 

of the county connected to supply mains and sanitary 

sewers operated by the Detroit Water and Sewerage 

Department, removing approximately 80 percent of 

the demand load from the county. Further population 
32 Water for a Rapidly Growing Community - Oakland County, Michigan

expansion beyond the geographical extent of this supply network has increased water use from ground-water 

sources within the county to more than 43 Mgal/d in 

2000. These areas in the northern and western parts of 

the county are currently experiencing the highest level of 

ground-water use ever. Demand for water will continue 

to increase as population increases in these parts of the 

county.

The removal of ground water from the hydrologic 

cycle may result in decreased ground-water levels, summer streamflows, and lake levels in the northern and 

western parts of the county. Although little change was 

observed in most streamflow characteristics for most 

sites in the county, three sites exhibited statistically 

significant downward trends in low-flow characteristics. 

At these sites, streamflow is measured from watersheds 

that have sewers but pump ground water for domestic 

use. Thus, this water is discharged as wastewater (downstream from the measurement sites) and is not available 

as base flow to sustain lake and river levels during dry 

summer months.

Relatively little water-quality data are available for 

direct comparison with the recent studies. However, 

data available from Twenter and Knutilla’s study (1972) 

indicate that concentrations of nitrogen, phosphorus, 

and sulfate have generally decreased in surface water. 

Chloride concentrations have increased between twoand ten-fold over the last three decades in all lakes and 

rivers sampled, indicating widespread chloride contamination. Subtler indications of human effects, such as the 

presence of petroleum compounds, flame retardants, and 

personal care products indicative of household wastewater, were observed at every surface-water site sampled. 

Relatively high concentrations of E. coli and enterococci 

bacteria were observed at sites in the Clinton and River 

Rouge watersheds. E. coli and enterococci bacteria 

resistant to multiple clinical antibiotics were detected in 

water samples from all sites, as well as in samples from 

reference sites in relatively unpopulated areas. 

Water for the 21st Century – Meeting 

the Need

An Oakland County population projected to increase 

by as many as 200,000 people in the next 20 years will 

demand as much as 20 Mgal/d of additional water for 

human use. Several areas in the northern and western 

parts of the county are already experiencing decreasing 

streamflows, likely related to increasing ground-water 

use. Human activity also results in water-quality effects, 

specifically effects related to the disposal and treatment 

of wastewater, and the transportation infrastructure. 

Managing the quantity and quality of water available for 

future residents, and the quantity and quality of water 

returned to the environment, in such a way as to maintain the recreational, ecological, and esthetic value of the 

county’s water resources, will be a continuing challenge 

for citizens and decision makers in Oakland County.

Relatively few options will be available to Oakland 

County to meet the increased water demands in coming 

decades. If this demand is to be met by ground-water 

sources within the county, then ground-water withdrawals would have to increase by approximately 50 percent. 

Water consumed by human use is water that is not available to sustain lake levels or summer streamflow, but 

this has always been the case (Alley and others, 1999). 

For example, parts of the Clinton and Rouge River 

watersheds are already experiencing reduced summer 

streamflows. Citizens and decision makers in the county 

will need to define a balance between human use and the 

needs of the ecosystem 

Forecasting the effect of a specific development 

scenario requires detailed, site-specific information. 

However, at the county scale two general options are 

apparent. First, a reduction in either the rate of population growth or per capita consumption, particularly 

in areas served primarily by ground water, would help 

reduce the increase in demand for ground water. Alternatively, similar reduction of stress on water resources in 

the county might be achieved by extending public-watersupply infrastructure to deliver water from the Great 

Lakes into Oakland County. 

Water quality is also of concern. Although the 

concentrations of most inorganic chemical constituents 

in Oakland County water have decreased in the last three 

decades, concentrations of chloride have increased at all 

sites sampled. Similarly, every site sampled contained 

trace concentrations of personal care products, petroleum products, and flame retardants. Most sites also had 

relatively high concentrations of fecal indicator bacteria 

and bacteria resistant to one or more clinical antibiotics. The ramifications of these emerging contaminants 

and antibiotic-resistant fecal indicator bacteria on stream 

ecosystems or public health are not known; however, the 

presence of these contaminants indicates that the treatment and disposal of wastewater may be as important an 

issue as the availability of water for domestic use. 

As discussed previously, the use of on-site septic 

systems can be an effective way of reducing the consumptive use of a household, although septic systems 

require regular maintenance and periodic inspection 

(Dersch, 2002). They will eventually require replacement, and they are not suitable to construct in all parts 

of the county. Wastewater-treatment plants provide 

effective treatment of waste and are more effectively 

regulated than septic systems, but treatment plants route 

treated wastewater into rivers. If this water was with-
drawn from local ground water, it will be lost to the 

aquifer. Even with treatment, wastewater discharges 

may adversely affect stream ecosystems. 

Projected population growth in Oakland County 

will result in increased demand for water for human 

use, and a continuing need to effectively treat wastewater. Regardless of which approach or combination of 

approaches are used to meet the water needs of Oakland 

County in coming decades, these decisions will require 

decision makers balance competing needs for drinking water, lake levels, and aquatic-ecosystem stability 

with the economic benefits of continued development, 

recreation and tourism, and the quality of life afforded 

by “healthy” lakes, streams, and aquifers. Defining 

the balance between competing human and ecological 

demands for water is an inherently political decision of 

resource allocation and community values (Alley and 

others, 1999).

Acknowledgments

The author would like to acknowledge the assistance 

of Dr. Thomas J. Gordon, Director, Oakland County 

Department of Health and Human Services, Kathy Forzley, Administrator, Environmental Health Services, Oakland County Health Division and Anthony Drautz, Unit 

Chief, Environmental Health Services, Oakland County 

Health Division, and Nina Ignaczak, Senior Planner, 

Oakland County Planning and Economic Development 

in the completion of this study and preparation of this 

report.

References Cited

Aichele, S.S., 2000, Ground-water quality atlas of Oakland County, Michigan: U.S. Geological Survey WaterResources Investigations Report 00–4120, 34 p.

Aichele, S.S., 2005, Effects of urban land-use change on 

streamflow and water quality in Oakland County, Michigan 

1970–2003, as inferred from urban gradient and temporal 

analysis: U.S. Geological Survey Scientific Investigation 

Report 2005–5016, 21 p.

Aichele, S.S., Crowley, S.L., Taricska, C.J., and Stopar, Julie, 

2004, Water Resources Data, Oakland County, Michigan 

2001–2004: U.S. Geological Survey Open-File Report 

2004–1417, 75 p.

Aichele, S.S., Hill-Rowley, Richard, and Malone, Matt, 1998, 

Arsenic, nitrate, and chloride in groundwater, Oakland 

County, Michigan: U.S. Geological Survey Fact Sheet 

135–98, 6 p.

Alley, W.M., Rielly, T.E., and O.L. Franke, 1999, Sustainability of ground-water resources: U.S. Geological Survey 

Circular 1186, 75 p.

Appleby, V.C., 1970, Recession and the baseflow problem, 

Water Resoruces Research, v. 6, n. 5, p. 1398-1403.

Bissell, E.G., and Aichele, S.S., 2004, Geostatistical analysis 

of effective vertical hydraulic conductivity and presence of 

confining layers in the shallow glacial drift aquifer, Oakland 

County, Michigan: U.S. Geological Survey Scientific Investigations Report 2004–5167, 19 p.

Dersch, E., and Solomon, D., 1993, What to do if your septic 

system fails: Michigan State University Extension Bulletin 

WQ-14, 4 p.

Fogarty, L.R., Duris, J.W., and Aichele, S.S., 2005, Preliminary survey of antiobiotic resistant fecal indicator bacteria 

and pathogenic E. coli from river water samples collected in 

Oakland County, Michigan: U.S. Geological Survey Scientific Investigations Report 2005–5058, 34 p.

Fuller, L.M., Aichele, S.S., and Minnerick, R.J., 2004, Predicting water quality by relating Secchi-disk transparency and 

chlorophyll a measurements to satellite imagery for Michigan inland lakes, August 2002: U.S. Geological Survey 

Scientific Investigations Report 2004–5086, 44 p.

Hem, J.D., 1985, Study and interpretation of the chemical 

characteristics of natural water (3rd ed.): U.S. Geological 

Survey Water Supply Paper 2254, 249 p.

Horn, M.A., 2000, Method for estimating water use and interbasin transfers of freshwater and wastewater in an urbanized 

basin: U.S. Geological Survey Water-Resources Investigations Report 99–4287, 34 p.

Intersalt Cooperative Research Group, 1998, Intersalt—An 

international study of electrolyte excretion and blood pressure; results from 24 hour urinary sodium and potassium 

excretion: British Medical Journal v. 297, p. 319-328.

Kunze, A.E., and Sroka, B.N., 2004, Effects of highway 

deicing chemicals on shallow unconsolidated aquifers in 

Ohio—Final report: U.S. Geological Survey Scientific 

Investigations Report 2004–5150, 138 p.

Leavesley, G.H and Stannard, L.G., 1995, The precipitation runoff modeling system — PRMS, in Singh, V.P., ed., 

1995, Computer models of watershed hydrology: Highlands 

Ranch, Colo., Water Resources Publications, 1114 p.

Leverrett, F., and others, 1906, Flowing wells and municipal 

water supplies in the southern portion of the southern peninsula of Michigan: U.S. Geological Survey Water-Supply 

Paper 182, 292 p.

Summary and Conclusions 33
34 Water for a Rapidly Growing Community - Oakland County, Michigan

Mozola, A.J., 1954, A survey of groundwater resources in 

Oakland County, Michigan: Michigan Geological Survey 

Publication 48, Part 2, 348 p.

Shelton,T.B., 1997, Interpreting drinking water analyses—

what do the numbers mean? (5th ed.): New Brunswick, N.J., 

Rutgers Cooperative Extension Publication E214, 67 p.

Sloto, R.A., and Crouse, M.Y., 1996, HYSEP—a computer 

program for hydrograph separation and analysis: U.S. 

Geological Survey Water Resources Investigations Report 

96–4040, 46 p.

Soil Conservation Service, 1982, Soil Survey of Oakland 

County, Michigan: U.S. Department of Agriculture, Washington D.C. 162 p.

Thomas, M.A., 2000, The effect of residential development 

on ground-water quality near Detroit, Michigan: Journal of 

the American Water Resources Association, v. 36, no. 5, p. 

1023–1038

Twenter, F.R., and Knutilla, R.L., 1972, Water for a rapidly 

growing urban community, Oakland County, Michigan: 

U.S. Geological Survey Water-Supply Paper 2000, 148 p.

Westjohn, D.B., and Weaver, T.L., 1996, Hydrogeologic 

framework of Mississippian rocks in the central lower 

peninsula of Michigan: U.S. Geological Survey WaterResources Investigations Report 94–4246, 46 p. 

Winter, T.C., Harvey, J.W., Franke, O.L., and Alley, W.M, 

1998, Ground water and surface water — A single resource: 

U.S. Geological Survey Circular 1139, 79 p.
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Aichele, S.S.-- Water Resources in a Rapidly Growing Region — Oakland County, Michigan -- Open File Report 2005-1269