UNIVERSITY OF
ILLINOIS LIBRARY
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HERTZBERG — NEW METHOD, INC. EAST VANDALIA ROAD, JACKSONVILLE, ILL. 62650
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I GEOLOGY AND WATER RESOURCES OFttWXNOvL AGO COUNTY *
WISCONSIN#
13
36
R.15 E.
7 /
Well Wi-19/15/34-213
Winnebago County —
Township
Range
Serial number of well
Section
Figure 2.—Well-numbering system in Wisconsin.
6 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
The second part of the well number, based on the Federal system of
land subdivision, lists the township north of the Wisconsin base line,
the range east of the fourth principal meridian, and the section number
of the well location. The third part of the well number is the serial
number that is generally assigned in the order that the well was sched¬
uled in the field. Numbers assigned to rock outcrops are similar
but have an “R” preceding the serial number.
Because of space limitations, only the serial numbers of wells and
outcrops are shown on the maps in this report.
GEOLOGIC SETTING AND HYDROLOGIC CHARACTER¬
ISTICS OF ROCK UNITS
Sedimentary rocks underlying Winnebago County form the reser¬
voirs, or acquifers, that supply water to industrial, municipal, farm,
and domestic wells and contribute the base flow of streams. The
movement of ground water is controlled by the physical framework of
the rock units. A knowledge of the geologic setting and hydrologic
characteristics of these rock units is necessary to an understanding
of the hydrology of the county. The lithology and water-yielding
characteristics of the rock units in Winnebago County are summarized
in figure 3.
The bedrock geology and the topography of the bedrock surface
were mapped from well-log and outcrop information, and are shown
on plate 1. Ordovician rocks generally are more extensive and have
a slightly different configuration than shown by Bean (1949). Con¬
tours on the bedrock surface in the southern part of the county gener¬
ally agree with those shown by Alden (1918, pi. 2).
The subsurface geology of Winnebago County, as determined from
well logs, is shown by a fence diagram (pi. 2). The diagram is an
isometric projection of a series of intersecting cross sections, based
on information from wells shown in the index map (pi. 2). It shows
the attitude, thickness, and relationship of the geologic units under¬
lying the county and the relationship of the bedrock, land, and
piezometric surfaces.
PRECAMBRIAN ROCKS
The lower boundary of the ground-water reservoir in Winnebago
County is the surface of the crystalline rocks of Precambrian age.
These rocks are composed principally of granite, as reported for the
wells that reach the Precambrian surface, but other igneous and
metamorphic rock types probably exist in the county. Precambrian
rocks prevent the downward movement of ground water from the
overlying sedimentary rocks. They are devoid of water except for
a limited amount that may be found in fractures.
GEOLOGIC SETTING, HYDROLOGY OF ROCK UNITS
7
LITHOLOGY
Upper part, clay, silt, and
sand, red and pink, strat
ified to unstratified
sorted to unsorted; lower
part, clay, silt, sand, and
gravel, gray and brown
stratified to unstratified
sorted to unsorted
Dolomite, gray to brown
massive, fossiliferous;
sandstone at base,
coarse- to fine-grained,
gray, shaly, dolomitic;
chert (a)
Sandstone, very fine to
coarse-grained, white,
gray, and pink, dolomitic
shale, conglomerate, and
siltstone in basal part
sandy, dolomitic; some
chert (■*)
Dolomite, gray to brown
some sand and shale
layers; some chert, white
oolitic (a)
Sandstone in upper part,
very fine to medium
grained; siltstone and
(or) dolomite in lower
part, gray and red, glau
conitic (G)
Sandstone, coarse- to fine
grained; some siltstone
and dolomite layers, red
and gray, dolomitic, glau¬
conitic (G)
Sandstone, coarse- to me¬
dium-grained, some fine
to very fine grained, some
silt and shale layers
especially in middle part;
white to light gray, some
pink and pale red
Predominantly granite
WATER-YIELDING
CHARACTERISTICS
Yield 50 gpm or less from
sand and gravel layers
and lenses depending on
thickness and extent.
Recent alluvium not con¬
sidered an aquifer
Yield small quantities of
water from joints, bed¬
ding planes, and solution
channels
Yields small to large quan¬
tities of water depending
on thickness
Yields small quantities of
water from joints, bed¬
ding planes, and solution
channels
Yield medium to large
quantities of water de¬
pending on permeability
and thickness
Not an aquifer
Figure 3. —Rock units and their water-yielding characteristics in
Winnebago County.
The configuration of the Precambrian surface in Winnebago County
and surrounding area is shown on the structure-contour map (pi. 3),
which was modified from Thwaites (1957). The Precambrian surface
in Winnebago County dips southeastward at about 20 feet per mile
(pis. 2, 3), and existing data indicate that the surface is fairly smooth.
8 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
However, ridges and knobs rising several hundred feet above the
general Precambrian surface have been found in surrounding areas
(pi. 3), and may exist undetected in Winnebago County. The knob
shown in T. 20 N., Rs. 13 and 14 E., was mapped by Bean (1949).
Any ridges and knobs rising above the general level of the Precam¬
brian surface may impede the movement of ground water through the
overlying sedimentary rocks. The ridges and knobs not only would
form a barrier to horizontal flow of water in sedimentary rocks below
the top of these highs, but also would reduce the thickness of over-
lying sedimentary rocks.
CAMBRIAN AND ORDOVICIAN ROCKS—THE SANDSTONE AQUIFER
Cambrian and Ordovician rocks comprise all consolidated sedimen¬
tary strata above the Precambrian surface in Winnebago County.
These rocks are predominately sandstone, but dolomite is also pres¬
ent (fig. 3). Although Cambrian and Ordovician rocks do not have
the same lithology and permeability, all the units below the upper
dolomite unit in Winnebago County are interconnected hydraulically
and form a single aquifer, which in this report is called the sandstone
aquifer. Water levels in wells in the upper dolomite unit (Platte-
ville, Decorah, and Galena Formations undifferentiated) (fig. 3) and
in the underlying rocks indicate, at least locally, a poor hydraulic
connection. Therefore, the dolomite unit is not included in the sand¬
stone aquifer.
Cambrian and Ordovician rocks range in thickness from 0 feet in
the northwest comer of the county, in the area of a Precambrian
mound, to about TOO feet along the margin of Lake Winnebago (pi.
2). Thickness of these rocks at any location can be determined by
subtracting the altitude of the Precambrian surface (pi. 3) from the
altitude of the bedrock surface (pi. 1). The dip of the rocks, which
generally conforms to the dip of the underlying Precambrian surface
(pi. 2), is southeastward and ranges from 20 to 25 feet per mile, in the
northern part of the county, to 10 to 15 feet per mile, in the southern
part.
CAMBRIAN SYSTEM
The Dresbach Group, one of the most productive water-yielding
units of the sandstone aquifer, is a thick sandstone unit, present
throughout Winnebago County. It is composed predominantly of
coarse- and medium-grained dolomitic sandstone but contains some
fine-grained to very fine grained sandstone. Silt and shale layers
are present, especially in the middle and lower parts, and range in
thickness from a few inches to several feet. The Dresbach ranges in
GEOLOGIC SETTING, HYDROLOGY OF ROCK UNITS 9
thickness from 250 to 300 feet, except in areas of Precambrian mounds
or preglacial valleys; it does not crop out in the county.
The Dresbach Group rests unconformably on the Precambrian sur¬
face. In Wisconsin, the Dresbach can be subdivided into the Mount
Simon, Eau Claire, and Galesville Sandstones in ascending order, but
for the purposes of this report it is not differentiated. The Mount
Simon has not been reported in well logs and apparently is missing
in Winnebago County.
Rocks of the Dresbach Group are thoroughly consolidated and do
not cave into wells. Layers that are cemented with silica are hard
and may cause difficulty in drilling.
The Dresbach Group yields medium to large quantities of water
to wells. The upper part probably produces the most water because
silt and shale in the middle and lower parts reduce permeability and
inhibit the movement of water.
The Franconia Sandstone, a productive water-yielding unit of the
sandstone aquifer, is present over most of Winnebago County except
in the northwestern corner where it has been removed by erosion (pi.
2). The Franconia is mostly a coarse- to fine-grained sandstone, but
may contain siltstone and dolomite layers as thick as 10 feet. The
Franconia has a maximum thickness of about 120 feet in the county.
It is easy to drill and does not cave into wells. The Franconia yields
moderate to large amounts of water to wells, depending on the occur¬
rence of siltstone and dolomite layers.
The Trempealeau Formation, a relatively unproductive water-yield¬
ing unit of the sandstone aquifer, is present over most of the county
except in the northwestern corner where it has been removed by erosion
(pi. 2). It consists of medium-grained to very fine grained dolomitic
sandstone in its upper part and dolomitic siltstone and sandy dolomite
in its lower part. Glauconite is common in the formation. The
Trempealeau has a maximum thickness of about 150 feet in the county.
It may be thin where it is overlain by the St. Peter Sandstone because
of an ancient erosional surface on the upper contact. The thick
section of Trempealeau in the area of well Wi-17/15/29-33 (pi. 2) is
attributed to the presence of an ancient channel which cut into the
Franconia Sandstone and which was subsequently filled by the upper
sandstone unit of the Trempealeau (M. E. Ostrom, Wisconsin Univ.
Geol. and Nat. History Survey, oral commun., 1963). The lower dolo¬
mite unit of the Trempealeau (pi. 1) crops out north and west of Win¬
chester in secs. 11 and 16, T. 20, N., R. 15 E. (Wi-20/15/ll-R52,
Wi-20/15/ll-R 53, and Wi-20/15/16-R39).
The upper part of the Trempealeau Formation probably yields only
small quantities of water to wells because of interbedded siltstone and
10 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
very fine grained sandstone. Small quantities of water may be con¬
tributed to wells tapping joints, fractures, and bedding planes in the
dolomite found in the lower part.
ORDOVICIAN SYSTEM
The combined Prairie du Chien Group and St. Peter Sandstone are
about 200 feet thick and are present over about half of the county.
The contact between the Prairie du Chien and St. Peter is an ancient
erosional surface having a relief equal to, or greater than, the total
thickness of the two units. Consequently, both of these units range
in thickness from 0 to 200 feet, either unit locally filling the entire
interval to the exclusion of the other (fig. 3, pi. 2).
The Prairie du Chien Group, a relatively unproductive water-yield¬
ing unit of the sandstone aquifer, is present in a discontinuous belt
extending diagonally across the county in a northeast-southwest di¬
rection (pi. 1) and in several areas in the southeastern half of the
county. The Prairie du Chien is composed of hard algal dolomite and
has irregular and discontinuous beds, which generally range in thick¬
ness from half an inch to 2 feet. Thin sand and green shale layers are
common, and the unit contains white oolitic chert which is unique to
the Prairie du Chien Group.
Water occurs in limited quantities in solutionally enlarged joints,
fractures, and bedding planes in the dolomite of the Prairie du Chien
Group, and generally only small quantities are contributed to wells
tapping these openings. Thin shale layers restrict the vertical move¬
ment of water through the dolomite. Because the Prairie du Chien
Group has a lower permeability than that of the underlying sand¬
stone of Cambrian age, it retards the vertical movement of water and
thus produces artesian conditions in the underlying sandstones.
The St. Peter Sandstone, a productive water-yielding unit in the
sandstone aquifer, is present over most of the southeastern half of the
county (pis. 1,2). Locally, it is thin or missing in this area where
the Prairie du Chien Group is present. The St. Peter is a very fine
grained to coarse-grained dolomitic sandstone; however, in areas where
it is thick, the lower part generally contains dolomitic shale and silt,
conglomerate, and fragments of chert. Generally, the St. Peter is
poorly cemented and easily drilled. It does not cave into wells except
in the basal shale, silt, and conglomerate zone. The St. Peter is ex¬
posed at the land surface in two small quarries southeast of Eureka
(Wi-17/14/3-R14 and Wi-17/14/3-R15) and crops out southwest of
the village of Rush Lake (Wi-l7/14/32-R70).
The St. Peter Sandstone yields small to large amounts of water to
wells, depending on the unit’s thickness and on the content of fine¬
grained sandstone and shale.
GEOLOGIC SETTING, HYDROLOGY OF ROCK UNITS H
The Platteville, Decorah, and Galena Formations are not differen¬
tiated in Winnebago Comity for the purposes of this report. The
three formations will be considered as one unit and referred to as the
Platteville-Galena unit.
The Platteville-Galena unit, a relatively unproductive water-
yielding unit, is present in the eastern and southern part of the county
(pis. 1, 2). The unit is predominantly a massive to thin-bedded
fossiliferous dolomite, but 5 to 10 feet of course- to fine-grained shaly
dolomitic sandstone is present at its base. It contains dolomitic shale
layers, which mostly are very thin but may be as thick as 10 feet.
Chert is present in the upper part of the unit. The Platteville-Galena
unit ranges in thickness from 0 to about 1’70 feet in the county. Be¬
cause it is the uppermost bedrock unit where it is present, and has
been subject to erosion, the full stratigraphic thickness is not present
in the county. The unit crops out at the land surface in many places
along the low escarpment that it forms, especially in the northeastern
part of the county.
The Platteville-Galena unit generally yields small quantities of
water to wells. As in the Prairie du Chien Group, water moves
through joints, fractures, and bedding planes in the rock which may
locally be enlarged by solution. Low t permeability of the Platteville-
Galena unit probably produces artesian conditions in the underlying,
more permeable sandstone aquifer.
DEVELOPMENT OF WATER FROM THE BEDROCK AQUIFER
High-capacity wells in Winnebago County, including industrial and
municipal or public supply wells, tap the sandstone aquifer. The
upper part of the Dresbach Group, the Franconia Sandstone, and the
St. Peter Sandstone are the most productive formations, but small to
moderate amounts of water are obtained from the Prairie du Chien
Group, the Trempealeau Formation, and the middle and lower part
of the Dresbach Group. The Platteville-Galena unit generally con¬
tributes only small quantities of water to wells.
Generally, domestic and farm wells tap the Platteville-Galena unit
or the upper part of the sandstone aquifer except in areas where the
bedrock surface is deeply buried by unconsolidated deposits of Quater¬
nary age. All bedrock units generally yield enough water for domestic
and farm use.
AQUIFER CHARACTERISTICS
Aquifer characteristics express the capacity of an aquifer to transmit
and store water and are a function of the geologic characteristics of the
aquifer. A knowledge of aquifer characteristics is necessary for pre¬
dicting the effects of pumpage on water levels and for determining
780-197 0 — 65——3
12 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
the volume and velocity of water moving through the aquifer—hence
for determining the availability of water.
Aquifer characteristics are expressed quantitatively as the coeffi¬
cients of transmissibility and storage. The coefficient of transmissi-
bility is defined as the rate of flow of water, at the prevailing water
temperature, in gallons per day, through a vertical strip of the aquifer
1 foot wide extending the full saturated height of the aquifer, under
a hydraulic gradient of 1 foot per foot. The coefficient of storage is
defined as the volume of water released from or taken into storage per
unit surface area of the aquifer per unit change in the component of
head normal to that surface.
Aquifer characteristics may be determined by measuring the rate of
drawdown of water level in a pumped well and in nearby observation
wells as water is withdrawn from the aquifer at a uniform rate. These
data are analyzed by the Theis (1935) nonequilibrium formula to
determine the coefficients of transmissibility and storage for the
aquifer. The nonequilibrium formula assumes that the aquifer is (1)
infinite in areal extent, (2) homogeneous and transmits water in all
directions with equal ease, and (3) confined between impermeable
beds. It also assumes that (4) the coefficients of transmissibility and
storage are constant, (5) the discharging well penetrates the entire
thickness of the aquifer, and (6) the discharged water is released from
storage instantaneously with decline in head. Because these conditions
are not fully met in nature, considerable judgment must be used in
establishing the validity of the results.
An aquifer test of the sandstones of Cambrian age was conducted
at the Winnebago State Hospital and the Winnebago County Hos¬
pital, well Wi-19/17/31-39 being the discharge well and wells Wi-
19/17/31-37, Wi-19/16/36-61, and Wi-19/16/36-32 being observa¬
tion wells. These wells are open only in the sandstones of Cambrian
age and tap all or most of the aquifer.
Water-level measurements were made in the four wells while well
Wi-19/17/31-39 was pumped at an average rate of 290 gpm (gallons
per minute) for a period of about 27.5 hours and during a recovery
period of about 12 hours. It was determined that 20,000 gpd per ft
(gallons per day per foot) and 0.0002 are reliable values for the co¬
efficients of transmissibility and storage, respectively, for the sand¬
stones of Cambrian age in the vicinity of the test area.
The coefficient of transmissibility of an aquifer is dependent on
the permeability and thickness of the aquifer. An examination of
logs of wells located throughout Winnebago County indicates that
the permeability of the sandstone aquifer is relatively uniform. How¬
ever, the thickness of the aquifer is highly variable and, in general,
GEOLOGIC SETTING, HYDROLOGY OF ROCK UNITS
13
decreases from east to west (pi. 2). The coefficient of transmissibility
of the sandstone aquifer probably decreases from a maximum of about
20,000 gpd per ft along the eastern edge of the county, where the
aquifer has its maximum thickness (pi. 2), to very low values in the
northwestern part of the county, where preglacial channels have
reduced the aquifer thickness to a minimum (pis. 1,2).
Specific capacity expresses the general relationship of the discharge
from a pumping well to the resultant drawdown of water level in the
well and is generally expressed in gallons per minute per foot of draw¬
down. Although specific capacity is affected by the construction and
development of the well and the rate and length of time of pumping,
it depends on the coefficients of transmissibility and storage of the
aquifer, and it may be used to determine very roughly the productivity
of the aquifer.
The specific capacities of 140 wells in Winnebago County, open in
either the Platteville-Galena unit, the St. Peter Sandstone, the Prairie
du Chien Group, or the sandstones of Cambrian age, were determined
from data on drawdowns and discharges reported by well drillers.
The average and range in specific capacities for wells tapping each
rock unit and the number of wells used in the analyses are shown in
table 1.
It is impossible to predict accurately the specific capacity of a well
drilled at any particular location because of the differences of the
physical characteristics of the rock units and the differences in well
construction and development.
Table 1.— Average specific capacities of wells open in units of the sandstone
aquifer in Winnebago County
Rock unit
Number of
wells
Average
specific
capacity,
in gpm per ft
of drawdown
Range in
specific
capacities
Platteville-Galena unit_.. _ .. _ _ . ..
60
6.3
0.1-44. 0
St. Peter Sandstone _ .. __ .
18
5.7
. 2-20.0
Prairie du Chien Group .. .. .. . . .. _ __
12
4.2
. 7-12.5
S andst.ones of Cambrian age ... ....
50
6.3
.8-22.5
BEDROCK SURFACE
The topography of the bedrock surface is important in Winnebago
County because this surface forms the upper boundary of the bedrock
aquifers as well as the lower surface of the overlying drift aquifer.
The topography of the bedrock surface is often closely related to the
surficial topography, and thus has an indirect control on the drainage
pattern in the county. The thickness of glacial drift, which can be
determined by subtracting the bedrock-surface altitude from the land-
14 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
surface altitude (pi. 1), is useful for indicating the depth to which
a bedrock well should be cased, the thickness of the drift aquifer, and
areas of thin drift where pollution may be a problem.
The bedrock surface in Winnebago County has been dissected by
preglacial and glacial erosion and has a considerable amount of relief
(pis. 1, 2). Altitudes on this surface generally range from 450 feet
in the northwestern part of the county to about 900 feet in the south¬
western part. In general, the lowland areas in the bedrock surface
are underlain by rather easily eroded sandstone of Cambrian age
and St. Peter Sandstone of Ordovician age. The highland areas are
formed by the dolomite of the Prairie du Chien Group and of the
Platteville-Galena unit (pis. 1, 2).
The Platteville-Galena unit, covering most of the eastern and south¬
ern part of the county (pi. 1), forms a broad, flat, southeastward-
sloping plain on the bedrock surface. The slope of this plain ranges
from an average of about 25 feet per mile in the northeastern part of
the county to an average of about 15 feet per mile in the southern part.
The plain terminates in a northwestward-facing escarpment formed
by the edge of the dolomite and an adjacent lowland underlain by the
St. Peter Sandstone. The lowland formed on the St. Peter probably
underlies most of the marshy Rush Lake area in southwestern Winne¬
bago County (pis. 1, 2).
The Prairie du Chien Group is exposed at the bedrock surface in
a broad discontinuous belt extending from the southwestern corner
of the county to the northern border, roughly parallel to the Platte¬
ville-Galena escarpment (pi. 1). The Prairie du Chien has been
deeply dissected and forms a series of hills and ridges, but the unit as
a whole dips to the southeast at about the same slope as the Platteville-
Galena unit. The Prairie du Chien forms a prominent discontinu¬
ous northwestward-facing escarpment.
Sandstones of Cambrian age form the bedrock surface in the north¬
western part of the county and in the Fox and Wolf River valleys.
The deep valley cut in sandstones of Cambrian age in the northwestern
part of the county (pis. 1, 2) is part of a preglacial valley extending
from Waupaca County (Berkstresser, 1964), through Winnebago
County under the Wolf River and Lake Poygan, and into Waushara
County (Summers, 1965). The valley trends .southward in Waushara
County, parallel to the Winnebago County border, and probably
connects with a preglacial channel just west of Berlin (pi. 3; Alden,
1918, pi. 2) which may represent the course of the ancient Wolf River.
The buried valley underlying the present Fox River (pi. 1) from
the western border of the county to Lake Butte Des Morts probably
represents the course of the ancient Fox River. The bedrock valley
GEOLOGIC SETTING, HYDROLOGY OF ROCK UNITS
15
underlying Little Lake Butte Des Morts and extending southward to
Lake Butte Des Morts (pi. 1) also may have been part of the ancient
Fox River valley. If this is true, altitudes on the floor of the valley
indicate that the ancient Fox River flowed south westward and emptied
into the Wolf River in the vicinity of Berlin. The buried valley
underlying Rush Lake is an extension of the ancient channel now
occupied by Green Lake in Green Lake County as shown by Alden
(1918, pi. 2).
QUATERNARY DEPOSITS—THE DRIFT AQUIFER
Quaternary deposits include all glacial and alluvial deposits be¬
tween the bedrock surface and the land surface in Winnebago County.
These unconsolidated deposits consist of clay, silt, sand, gravel,
boulders, peat, and marl and are sorted to unsorted and stratified to
unstratified. Quaternary deposits in the northern part of the county
have been mapped by Thwaites (1943) and in the southern part of
the county by Alden (1918). These maps are adequate for the pur¬
poses of this report.
Glacial deposits were laid down during the Cary and Valders Stades
of the Wisconsin Glaciation (Thwaites, 1943, p. 121). The deposits of
Cary age cover the county and fill the buried valleys in the bedrock
surface. Deposits of Cary age are gray to brown and consist of mo¬
rainal, glaciolacustrine, and some outwash and ice-contact deposits.
Drillers' logs indicate that there is a high percentage of clay and silt
in the deposits of Cary age in Winnebago County. Deposits of
Valders age overlie the Cary and consist predominantly of reddish-
brown clay and silt in the form of ground moraine and glaciolacustrine
deposits. They generally are very thin and cover most of the county
except the southwestern corner (Alden, 1918, pi. 3; Thwaites, 1943).
Alluvium includes Recent deposits of unconsolidated material laid
down along stream channels, and peat and marl formed in marshes
and lakes. Sand dunes in the northwestern part of the county prob¬
ably formed in Recent times (Thwaites, 1943, p. 141).
Quaternary deposits in Winnebago County range in thickness from
0 feet at rock outcrops to a maximum known thickness of 315 feet in
the northwestern corner of the county (well Wi-20/14/16-136). Fig¬
ure 4 is a generalized map showing the approximate thickness of
Quaternary deposits in the county. These deposits are thickest where
deep valleys are cut in the bedrock surface and thinnest where the
bedrock surface is high (pi. 2). The thickness of Quaternary deposits
at any particular site can be determined by subtracting the bedrock-
surface altitude from the land-surface altitude shown on plate 1.
16 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
)Menasha
Base from State Highway
Commission roadmap
EXPLANATION
Thickness, in feet
0-40
1 41-80
Figure 4.— Approximate thickness of Quaternary deposits in Winnebago County.
Drillers’ logs indicate a nearly continuous layer of sand and gravel
along the floor of the buried preglacial valleys, especially in the valleys
underlying the Wolf and upper Fox Rivers (pi. 1). This layer attains
a maximum thickness of about 100 feet in a few places but generally
is less than 20 or 30 feet. Yields of wells penetrating the sand and
81-120
120 +
SURFACE WATER
17
gravel generally are small, probably because of a high clay and silt
content. There are probably no sand and gravel deposits in the county
that are extensive enough to yield large quantities of water to wells.
Water in the sand and gravel layer is under artesian pressure and is
confined by overlying silt and clay; most of the wells penetrating the
sand and gravel flow at the land surface. Water levels in wells indi¬
cate that a good hydraulic connection exists between this unit and the
underlying sandstones of Cambrian age.
Glacial deposits overlying the basal sand and gravel layer in the
buried valleys and throughout the remainder of the county are prin¬
cipally clay, but isolated sand and gravel lenses are present, especially
in the areas of the buried valleys. These sand and gravel lenses are
under artesian pressure. Small water supplies may be obtained from
these lenses. However, the location and extent of the deposits can¬
not be determined from available data.
In areas of the county not underlain by preglacial valleys, the
limited thickness and extent of sand and gravel layers and the high
clay content of the glacial till make the glacial deposits a poor source
for water. However, the glacial drift acts as a confining layer for the
underlying sandstone aquifer.
The limited thickness and extent of recent alluvial deposits make
these deposits a poor source of water. It has been reported that some
sand dunes in the northwestern part of the county have provided
enough water to wells for domestic use. However, the sand dunes
normally are not a dependable or extensive source of water in Winne¬
bago County.
SOURCES OF WATER
The source of all surface and ground water in Winnebago County
is precipitation. Water from rainfall and snowmelt either returns
to the atmosphere by direct evaporation or by transpiration by plants,
remains in the soil zone above the water table as soil moisture, runs
over the land surface to streams and lakes as runoff, or percolates
downward to the zone of saturation as recharge and becomes ground
water. Ground water moves through the aquifer and is discharged
to streams and lakes.
SURFACE WATER
FOX AND WOLF RIVERS
Winnebago County is in the Lake Michigan drainage area and lies
within the drainage basin of the Fox River and its principal tributary,
the Wolf River. Streams and lakes in the county either are tribu¬
taries to, or are part of, these two rivers which flow into Lake Butte
des Morts (pi. 1) in the central part of the county.
18 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
The Fox River rises in Columbia County in south-central Wisconsin
where it flows within about 1 mile of the Wisconsin River at the city
of Portage. There it is connected to the Wisconsin River by a canal.
The river enters Winnebago County near Eureka, flows northeast¬
ward through Lake Butte des Morts and Lake Winnebago, and leaves
the county north of Menasha. It then flows northeastward to Green
Bay where it empties into Lake Michigan.
Lake Winnebago divides the river into two distinct sections, the
upper and lower Fox River. The upper Fox River flows through a
fairly flat, poorly drained area underlain by sandstones of Cambrian
age and drops only about 35 feet in the 107 miles between Portage and
Lake Winnebago (Smith, 1908, p. 26). This section of the river is
characterized by low banks and frequent flooding. The low gradient
of the upper Fox River provides little opportunity for producing
power.
The lower Fox River, underlain by dolomite of the Plattesville-
Galena unit, drops about 167 feet in the 35 miles between Menasha
and Green Bay (Smith, 1908, p. 29), and provides waterpower for
several hydroelectric plants built along this part of the river. The
storage and regulated release of water at dams make the flow of the
lower Fox River very uniform. Navigation is maintained on the
lower Fox by means of 19 locks operated by the U.S. Army Corps of
Engineers.
The Wolf River rises in Forest County near the Wisconsin-Michi-
gan border. In the upper half of its course, north of the city of
Shawano, the river is underlain by crystalline rocks of Precambrian
age and has high banks, a steep gradient, and many falls and rapids.
The river drops 775 feet in the 80 miles between Lenox and Shawano
(Smith, 1908, p. 96). The lower half of the Wolf River, below
Shawano, is underlain by sandstones of Cambrian age and is charac¬
terized by a low gradient, low banks, and frequent flooding. The
river drops only about 42 feet in the 80 miles between Shawano and
Winneconne in Winnebago County (Smith, 1908, p. 96). The low
gradient and broad flood plains of the lower Wolf River make it
unsuitable for dam construction, but private interests have made sev¬
eral waterpower developments on the upper Wolf River.
The Little Wolf River empties into the Wolf River and the Lake
Winnebago Pool near New London (pi. 3). It drains an area under¬
lain by Precambrian crystalline rocks which are covered chiefly by
till.
The Waupaca River empties into the Wolf River and the Lake
Winnebago Pool a few miles north of the Winnebago County line.
The river drains an area overlain principally by thick outwash de-
SURFACE WATER
19
posits of sand and gravel resting on Precambrian crystalline rocks.
Flow characteristics of the upper Fox River and the Wolf River
and its tributaries, which contribute water to the Lake Winnebago
Pool, are dependent chiefly on the geology of their respective basins.
Stream gages on these rivers are listed in table 2 along with drainage
area and average discharge. Flow-duration curves for these gaging
stations, show that, during 80 to 85 percent of the time, the flow of
the upper Fox, Wolf, and Little Wolf Rivers is principally ground
water. In the Waupaca River, the flow is principally ground water
during about 90 percent of the time. The Little Wolf River, draining
an area of ground moraine and crystalline rocks, has the greatest
amount of rapid surface runoff. The Waupaca River, draining an
area of outwash sand and gravel, has the least amount of rapid surface
runoff. Runoff from the upper Fox and Wolf Rivers, draining areas
of outwash, moraine, crystalline rocks, and sandstones, falls between
these two extremes.
In general, drainage in Winnebago County is controlled by the
topography of the bedrock surface. The prominent features of the
bedrock surface are expressed in the surficial topography of the
county which directly controls the drainage pattern. Parts of the Fox
River and most of the small streams flow parallel to the escarpments
of the Platteville-Galena unit and Prairie du Chien Group, and to
the strike of the bedrock formations; they thus drain the valleys
underlain by St. Peter Sandstone and sandstone of Cambrian age
(pi. 1). The Wolf River, including Lakes Winneconne and Butte des
Morts, and the Fox River at Oshkosh have cut through the dolomite
escarpments, their flow being at right angles to the other streams
and down the dip of the bedrock formations (pi. 1).
LAKES, MINOR STREAMS, A NO WETLAND AREAS
Rush Lake, in the southwestern corner of the county, has an area of
about 4.8 square miles and is very shallow, probably averaging less
than 5 feet in depth. The lake is at an altitude of 821 feet and empties
into the Fox River through Rush Creek (pi. 1).
Rush Creek drains Rush Lake and the large wetland area in the
southwestern part of the county (pi. 1). Eightmile Creek has been
partly dredged to connect with Rush Creek to drain the wetland area.
Rush Creek has an average fall of about 11 feet per mile in the 6 miles
between Rush Lake and the Fox River.
The Rat and Arrowhead Rivers also have been partly dredged to
drain wetlands. These rivers drain the lowland areas in the north-
central part of the county and have gradients of only a few inches
per mile.
790-197 O—65-4
20 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
In general, wetlands are concentrated in the low-lying areas in the
western and northwestern parts of the county, especially in the Wolf
and upper Fox River valleys and in the Rush Lake area. Drainage
has reduced the total wetlands area from about 47,360 acres in 1938
to about 32,550 acres in 1961 (Wisconsin Conserv. Dept., 1962).
Little Lake Butte des Morts in the northeastern part of the county
is below the Menasha Dam and is part of the low r er Fox River. The
lake surface is at an altitude of 738 feet and has an area within the
county of about 2 square miles.
Other streams in the county (pi. 1) are intermittent, generally flow¬
ing only in the spring and early summer and after heavy rainstorms.
RESERVOIRS—THE LAKE WINNEBAGO POOL
The Lake Winnebago Pool is the slack-water area behind the
Menasha and Neenah Dams on the two outlets of Lake Winnebago
(pi. 1). The pool has a surface area of about 265 square miles at the
elevation of the crest of the dam (Knowles and others, 1964, p. 22). It
includes Lakes Winnebago, Butte des Morts, Winneconne, and Poy-
gan, the Fox River upstream to about Eureka in Winnebago County,
and the Wolf River upstream nearly to New London in Waupaca
County. The pool, excluding Lake Winnebago, covers about 7 per¬
cent of the total area of the county.
The Corps of Engineers regulates the release of water from the
Lake Winnebago Pool for navigation and waterpower development
on the lower Fox River. The limits of regulation are from 21 ^ inches
above the crest down to the crest of the Menasha Dam during the
navigation season (generally from the first part of May to the end of
October), and down to 18 inches below the crest during the remainder
of the year (U.S. Army Corps of Engineers, 1922, p. 91). True lake
level is determined by a staff gage at the mouth of the upper Fox
River at Oshkosh which has a datum of 745.05 above mean sea level.
The usable capacity of the pool within the limits of regulation is 25
billion cubic feet or about 190 billion gallons (Knowles and others,
1964, p. 19).
Changes in inflow from the Fox and Wolf Rivers and their tribu¬
taries for the 1959 water year affected the storage and outflow of water
of the Lake Winnebago Pool (fig. 5). The inflow, computed from
records of the daily discharge at four gaging stations above the pool,
is shown in table 2. The drainage area upstream from these gaging
stations is about 75 percent of the drainage above Menasha Dam.
The effect of changes in storage in the pool on the flow of the lower
Fox River also is shown in figure 5. The outflow was computed from
records of daily discharge of Rapide Croche Dam (table 2), at which
the drainage area is only about 2 percent larger than at Menasha Dam.
SURFACE WATER
21
o v£> 01 oo ° o o
Csj r-I o o co
o o °
csi ~
CT)
LO
00
in
cr>
3HIIA1 3dVnOS H3d
SN033V9 30 SNOI33IIM Nl ‘30dVH0Sia
1333 Nl '30V1S
Figure 5.—Inflow, outflow, and stage of the Lake Winnebago Pool for 1959 water year. Modified from Knowles, Dreher,
and Whetstone (1964).
22 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
Water was stored in the Lake Winnebago Pool in the late fall, and
then released steadily through the winter to supplement the naturally
decreasing flow in the lower Fox River and to lower the pool in antici¬
pation of high spring runoff. Much of the spring runoff from the
upper part of the basin was then stored in the Lake Winnebago Pool.
The stage of the pool rose about 2 feet from March 30 to April 18.
The flow at Rapide Croche Dam was kept fairly uniform throughout
the summer as the level of Lake Winnebago fluctuated with the run¬
off from the upper part of the basin.
Table 2. —Average discharge of streams flowing into and out of the Lake
Winnebago Pool
Gaging station
Drainage
area (sq mi)
Average dis¬
charge for
period of rec¬
ord (cfs)
Period of
record
Above Lake Winnebago Pool:
Fox River at Berlin____ _ __
1,430
2,240
514
1,101
1,713
399
1898-1962
Wolf River at New London ... . .....
1896-1962
Little Wolf River at Royalton.. . ___
1914- 62
Waupaca River at Waupaca ._ .. . .....
272
237
1916- 62
Below Lake Winnebago Pool:
Fox River at Rapide Croche Dam__
6,150
4,194
1896-1962
QUALITY OF SURFACE WATER
Surface water in Winnebago County is hard, has a considerable an¬
nual range in temperature, is locally polluted, and has a serious algae
problem in the summer months. However, after treatment of the
water, its quality generally is suitable for municipal and most in¬
dustrial purposes. The water generally requires softening before it
is used in high-pressure boilers and also may require treatment to
reduce turbidity, iron, and manganese. Some industrial uses may
require additional treatment.
The average quality of surface water has probably remained nearly
constant over a long period of time. Analysis of water taken from
several places on the Fox River and Lake Winnebago over the period
1896 to 1963 (table 3) show fairly consistent concentrations of dis¬
solved mineral constituents. The variation that does occur probably
is related both to the time of year that the samples were taken and to
the location of the sampling sites.
The quality of surface water fluctuates because of the variable ratio
of ground-water discharge and surface runoff contributed to streams
throughout the year. During periods of base flow, approximately 85
percent of the time, the streamflow is derived almost entirely from
ground water, and the chemical quality is nearly constant. Ground
water generally is more highly mineralized than surface runoff. The
total hardness of water from the Fox River at Omro, sampled monthly,
is shown in figure 6. Total hardness was greatest during the winter
Table 3. —Chemical analyses of water from selected sites on the Fox River and Lake Winnebago in Winnebago County and from
Lake Michigan
SURFACE WATER
23
[Results except for pH, in parts per million. Agency making analysis: Prentiss, G. N. Prentiss, Chicago, Milwaukee and St. Paul Railroad; WSLH, Wisconsin State Laboratory
of Hygiene; Davidson, G. M. Davidson, Chicago and Northwestern Railway; DDCC, Dearborn Drug and Chemical Co., Chicago, Ill.]
a
a
I 1 ill
i co i i i »-< co •*< oo (N
1 00 00 1 00 • I lOOOOt^t^OO
1 1 III
1 1 III
1 1 III
1 1 III
8.0
8.05
Hard¬
ness
(as
CaCOj)
1 III
KOiOQQOOCO i i i lO 00 CO
i^GOOOcOoOO) 1 1 1 ^05 iOCOCy
IHHHHHH 1 1 IrHHrHf-HH
1 ' III
1 III
1 III
1 III
165
132
Total
solids
CO CD O ' 00 © © OJ © 05 © O0CO»-*O5©64»- »©
1
1
1
1
218
168
Fluo¬
ride
(F)
1 1 1 1 1 III'
1 till AO 1 1 1
ICOIOW^^ i i 1 i ^ CO i 1 '
1 O «-H till III
1 1 1 1 1 III
1 till III
1 till III
to
to
©
Chlo¬
ride
(Cl)
HIOIOOOOO^MNOIO *0
ui®u5oided‘0‘doO'-<
4.7
6.5
Sulfate
(S0 4 )
1 1 \
CO iO O © © ®
pressure or piezometric surface is higher than the land surface, the
well will flow. When the piezometric surface is lowered by pumping
or free flow from a well, the aquifer is not dewatered; water removed
from the aquifer is derived from compaction of the aquifer and associ¬
ated beds and from the expansion of the water itself. This compac¬
tion of the aquifer and expansion of the water constitute the storage
factor of an artesian aquifer.
Under natural conditions, an aquifer often is under water-table
conditions at or near its recharge area where the formation is near the
land surface, but may be under artesian conditions where the forma¬
tion is more deeply buried, down dip from the recharge area.
Throughout most of Winnebago County, the sandstone aquifer is
under artesian pressure. Water in the sandstone aquifer is confined
by the less permeable Platteville-Galena unit where it is present, and
by glacial drift throughout the county. The Prairie du Chien Group
is less permeable than the overlying and underlying sandstones and
probably retards the vertical movement of water between the sand¬
stone units. In its area of outcrop (pi. 1), the upper part of the
Prairie dii Chien Group is probably under water-table conditions, the
water occurring in fractures, solution channels, and bedding planes.
The unit confines water in the underlying sandstones in this outcrop
area.
Water occurs in solutionally enlarged fractures, joints, and bedding
planes in the Platteville-Galena unit. Generally the unit occurs under
water-table conditions in areas where the overlying glacial drift is
thin. Water levels in wells indicate a general hydraulic connection
between the Platteville-Galena unit and the underlying sandstone
aquifer; however, locally these units are hydraulically separated.
Quaternary deposits in Winnebago County generally are saturated,
but because of the high silt and clay content of most of the unconsoli¬
dated material, these deposits yield only small quantities of water to
wells. In the buried bedrock valleys, where the drift is thick, small
artesian wells may be developed from lenses or layers of sand and
gravel confined between layers of silt and clay.
GROUND WATER
27
RECHARGE, DISCHARGE, AND MOVEMENT
Ground water moves through an aquifer from areas of recharge to
areas of discharge. The direction of movement is down the hydraulic
gradient of the aquifer, from points of higher altitude to points of
lower altitude on the piezometric surface. Because the piezometric
surface of the aquifer roughly conforms to the topography in Winne¬
bago County, ground-water movement is, in general, from highland
areas to lowland areas. The velocity of ground-water movement de¬
pends on the slope of the hydraulic gradient and the permeability of
the aquifer, and in the county the velocity generally is only a few
inches to a few feet per day. In dolomite, water may travel at much
higher rates through fractures and solution channels.
The configuration of the piezometric surface in Winnebago County
for the period July 29 through August 4, 1963, is shown on plate 4.
Because all the formations in the county in general are hydraulically
connected, the map was constructed from water levels in 304 wells
penetrating various geologic units.
The formations in Winnebago County that contain water under
water-table conditions receive recharge by direct percolation of water
from the land surface to the zone of saturation. These formations in¬
clude glacial drift that has permeable materials at the land surface,
the Platteville-Galena unit where it is overlain by only a thin layer
of drift, and the Prairie du Chien Group in its area of outcrop.
The formations that contain water under artesian conditions re¬
ceive recharge by water moving from areas of outcrop into more
deeply buried parts of the same formation, through overlying glacial
material, or through overlying consolidated units. These forma¬
tions include (1) the permeable layers in the glacial material that
are overlain by material of lower permeability, (2) the St. Peter
Sandstone, (3) the Prairie du Chien Group where it is deeply buried,
and (4) the sandstones of Cambrian age. Recharge can also take
place by leakage between two formations. For example, if the hydro¬
static head in the St. Peter Sandstone is lowered sufficiently by a
pumping well penetrating that unit, water would move upward into
the St. Peter Sandstone from the underlying Prairie du Chien Group
and sandstones of Cambrian age, and downward into the St. Peter
Sandstone from the overlying Platteville-Galena unit and glacial
drift.
Ground water is discharged naturally from an aquifer by seepage
into streams and lakes, by evapotranspiration, and by springs, and is
discharged artificially by pumping and flowing wells. All streams
and lakes in Winnebago Comity are areas of discharge, ground water
generally making up their flow during 85 to 90 percent of the time.
700-197 0—63-5
28 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
A large quantity of water is discharged from the aquifer by pumping
and flowing wells. Evapotranspiration is a quantitatively important
means of discharge in wetland areas where the water table is at or
near the land surface. Little or no evapotranspiration takes place
from the deep water-table and artesian aquifers. Springs are not
common in Winnebago County and they are not a large source of
discharge.
Winnebago County is subdivided by topographic and ground-water
divides that separate the movement of water toward the Fox River,
the Wolf River, or segments of the two rivers. In Winnebago County,
three ground-water drainage areas, associated with the upper Fox
River, the Wolf River, and Lake Winnebago, are separated by the two
ground-water divides shown on plate 4. These ground-water divides
conform closely to the topographic divides, and for the most part
follow the escarpments of the Platteville-Galena unit and the Prairie
du Chien Group (pi. 1). The divides are drawn across Lakes Butte
des Morts and Winneconne on plate 4 only for discussion purposes.
The lakes are a common discharge point for adjacent ground-water
basins, and actual ground-water movement under the lakes is not
affected by divides.
LAKE WINNEBAGO GROUND-WATER DRAINAGE AREA
The Lake Winnebago ground-water drainage area in Winnebago
County includes the eastern one-third of the county east of the north-
south trending ground-water divide (pi. 4). Dolomite of the Platte-
ville-Galena unit forms the bedrock surface over most of the area
(pi. 1) and the dolomite is overlain by a fairly thin layer of glacial
drift (fig. 4). Recharge to the sandstone aquifer in this area perco¬
lates through semipermeable glacial drift and the Platteville-Galena
unit. The ground water then moves roughly perpendicular to the
contours on the piezometric surface (pi. 4) from the ground-water
divide toward Lake Winnebago and part of Lake Butte des Morts,
except in the areas affected by pumping, and is discharged into these
surface-water bodies.
Because the water table in this area is fairly deep and only a small
percentage of the area is in wetlands (Wisconsin Conserv. Dept.,
1962, p. 5), evapotranspiration is not a large factor of ground-water
discharge.
The depressions in the piezometric surface surrounding Neenah-
Menasha, Oshkosh, and the Winnebago State and County Hospitals
north of Oshkosh (pi. 4) are the result of concentrated pumping.
Because discharge of ground water by pumping has been more rapid
than movement of water toward these areas, water has been removed
from storage, and the piezometric head has been lowered. A steep
GROUND WATER
29
hydraulic gradient has been established toward the center of the
cones of depression. This steepening of the hydraulic gradient has
increased the rate of movement of water toward the centers of pump¬
ing, and some of the water that would have been discharged to Lake
Winnebago under natural conditions now moves toward the cones
and becomes available to wells. This intercepted ground-water dis¬
charge reduces streamflow somewhat in the area of the cone of de¬
pression. However, about 90 percent of the ground water pumped is
not removed from the area but is returned to the stream. About 10
percent of the water pumped is used consumptively. In the Neenah-
Menasha area, intercepted ground-water discharge that might have
entered the Lake Winnebago Pool is pumped from wells and is dis¬
charged to Little Lake Butte des Morts.
Recharge to the Neenah-Menasha area is derived over an area of
only about 43 square miles (pi. 4). The recharge area is bounded
approximately by the major ground-water divide about 4 miles west
of the center of pumping, a minor divide about 6 miles south of the
pumping center, a minor divide about 2 miles east of the center, and
a minor divide about 2 miles north of the center. Ground water
moves down the hydraulic gradient, established by the lowered piezo¬
metric surface under the cities, from the divides toward the center of
pumping. Because the area of recharge and the hydraulic gradient are
greatest west of the cities, this area is contributing the greatest
amount of recharge to the area of pumping. Transmissibility is as¬
sumed to be uniform in the area. The cone of depression, therefore,
is most evident south of the area of pumpage, where the hydraulic
gradient toward the cities is very flat (pi. 4). If pumpage were in¬
creased in the Neenah-Menasha area to the extent that the area affected
by pumpage would expand to the ground-water divides, the divides
would move outward and actually increase the size of the recharge
area. Induced recharge or leakage from Lake Winnebago and Little
Lake Butte des Morts probably prevents rapid expansion of the cone
of depression to the north and east.
If average annual recharge is about 3 inches (probably a conserva¬
tive estimate), recharge to the Neenah-Menasha area is about 2.3 bil¬
lion gallons per year. Total pumpage in the area in 1962 was
estimated at about 1.4 billion gallons per year, or 3.8 mgd (million
gallons per day). Because most of the ground water moves toward
the center of pumping, there is little ground-water discharge to
streams in the Neenah-Menasha area.
Recharge to the Oshkosh area, including the Winnebago State and
County Hospitals, is derived from an area of about 49 square miles
(pi. 4). The area is bounded approximately by the major ground-
30 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
water divide about 5 miles west of the center of pumping, a minor
divide about 5 miles north of the pumping center, a divide about 2
miles east of the pumping center and underlying Lake Winnebago,
and a divide about 3 miles south of the center of pumping. If annual
recharge to the aquifer is 3 inches over this area, the recharge amounts
to about 2.6 billion gallons per year. Annual pumpage in the area
is estimated at about 0.5 billion gallons (1.4 mgd).
The depression in the piezometric surface at Oshkosh is much
shallower than in the Neenah-Menasha area because pumpage in Osh¬
kosh is much less than that in the Neenah-Menasha area. Because
the area of recharge and the hydraulic gradient are greatest
west and southwest of Oshkosh (pi. 4), this area is contributing the
greatest amount of recharge to the area of pumping. Some induced
recharge from Lake Winnebago and the Fox River also probably
reaches the aquifer in the Oshkosh area. This induced recharge
reduces streamflow in the Oshkosh area; however, the amount is small
compared to the flow of the Fox River and probably is not measure-
able.
FOX RIVER GROUND-WATER DRAINAGE AREA
The Fox River ground-water drainage area, lying between the two
major ground-water divides, covers the central and southwestern
part of Winnebago County (pi. 4). The sandstones of Cambrian
age, the Prairie du Chien Group, the St. Peter Sandstone, and the
Platteville-Galena unit all are exposed at the bedrock surface in this
area (pi. 1). Generally, the two dolomite units are under water-table
conditions. The bedrock is overlain by glacial material that generally
ranges in thickness from 20 feet in the highland areas to 120 feet in
the lowland areas (pi. 2). Artesian conditions prevail in the thick
section of the drift aquifer along the upper Fox River and surround¬
ing Lake Butte des Morts. Many of the wells in these areas are flow¬
ing, the artesian head being maintained by recharge from the high¬
lands adjacent to the river and Lake Butte des Morts.
Minor divides separate the movement of ground water toward sev¬
eral streams, Rush Lake, the upper Fox River, and Lake Butte des
Morts; however, the general pattern of movement is from the major
ground-water divides toward the upper Fox River and Lake Butte
des Morts. Ground water from Fond du Lac and Green Lake Counties
enters the southwestern part of Winnebago County and contributes
to the ground-water runoff to the upper Fox River and Rush Lake.
This ground-water movement is greatest in areas where the gradient
is steep, such as in the extreme southwestern corner of the county, and
is least where the gradient is flat, such as in the Rush Lake and upper
Fox River areas.
GROUND WATER
31
Ground water is discharged artificially from the Fox River ground-
water drainage area by municipal pumpage at Omro and Winneconne,
by domestic pumpage from private wells, and by flowing wells along
the Fox River and Lake Butte des Morts. Discharge from wells is
very small compared to ground-water discharge to the streams.
Natural ground-water discharge from the basin is to the Fox River,
Lake Butte des Morts, Rush Lake, and the several small streams in the
area. The discharge of ground water by evapotranspiration is quanti¬
tatively important in the extensive wetlands where the water table is
at or very near the land surface.
Wetlands may be either recharge or discharge areas for ground
water. In the spring, when the water table is at or very near the
land surface, ground water is discharged to streams from the wetlands,
and recharge is rejected because of the saturated soil conditions.
Ground water is rapidly discharged from the wetlands by evapotrans¬
piration during the warm summer months. The water table declines
during this period and, because the soil is no longer saturated at the
land surface, recharge can take place.
WOLF RIVER GROUND-WATER DRAINAGE AREA
The Wolf River ground-water drainage area in Winnebago County
extends from the northern and western borders of the county to the
major ground-water divide (pi. 4). The sandstones of Cambrian age
are exposed at the bedrock surface over most of the area but the
Prairie du Chien Group, St. Peter Sandstone, and Platteville-Galena
unit form the bedrock along the divide (pi. 1). The bedrock is over-
lain by glacial deposits generally ranging from 20 feet at the divide
(fig. 4) to 300 feet along the Wolf River and Lake Poygan (Wi-
20/14/16-136).
The sandstones of Cambrian age receive recharge through the dolo¬
mite units, which are generally under water-table conditions along the
ground-water divide. Recharge also probably occurs by leakage
through the thick section of glacial material in the area. However,
about 15 to 20 percent of the land surface is covered by wetlands
(estimate from Wisconsin Conserv. Dept., 1962) where recharge is
rejected for at least part of the year.
Ground water is entering the county as underflow along the northern
and western border of the county. Ground water is moving toward
the Wolf River and Lake Poygan from near the western edge of
Waushara County (Summers, 1965, fig. 8) and from 3 to 4 miles
north of the Winnebago-Outagamie-Waupaca Counties line (Berk-
stresser, 1964, fig. 9; LeRoux, 1957, pi. 5). This underflow moves into
the county along the western border between Pumpkinseed Creek and
32 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
the Waupaca County line (pi. 4) and along the northern border be¬
tween the Wolf River and the Rat River. The rate of underflow was
estimated by the use of Darcy’s law (Ferris and others, 1962, p. 71) to
be 2 to 3 mgd. However, the complexity of the geology and the
scarcity of data in the area make this figure very approximate.
Ground water in the Wolf River basin moves from the recharge
areas toward the Wolf, Arrowhead, and Rat Rivers and Lakes Poygan
and Winneconne, which are the discharge areas of the basin. Evapo-
transpiration is a quantitatively important means of ground-water
discharge because of the extensive wetland areas adjacent to the lakes
and rivers.
The only pumpage in the basin is for domestic and farm use. How¬
ever, numerous uncapped flowing wells throughout most of the area
greatly increase the artificial discharge.
WATER-LEVEL FLUCTUATIONS AND THEIR SIGNIFICANCE
Water-level fluctuations in wells in Winnebago County indicate
changes in storage in the ground-water reservoir. The ground-water
reservoir is similar to a large tank or surface reservoir in that water
levels fluctuate in response to changes in recharge to and discharge
from the reservoir. When recharge exceeds discharge, storage in¬
creases and water levels rise. When discharge exceeds recharge, stor¬
age decreases and water levels fall. However, unlike the water level of
a surface reservoir, ground-water levels may rise in one part as they
fall in another part of the same reservoir.
Variations in the amount of recharge to the aquifer in Winnebago
County are the result of areal and short- and long-term changes in
rainfall, of variable evapotranspiration rates during the year and from
year to year because of changes in air temperature and plant growth,
and of changes in soil conditions including frost in the ground and
moisture content of the soil. Artificial changes, caused by pumping
of wells and draining of wetlands, also may affect recharge.
Major changes in the amount of discharge from the aquifer are
generally the result of pumping, but natural discharge also varies in
direct relation to the amount of recharge that enters the aquifer.
Seasonal changes in recharge generally cause an annual cycle of
water-level fluctuations. Water levels rise in the spring because low
evapotranspiration rates and saturated soil allow a high percentage of
water from spring rains and snowmelt to soak into the ground and
recharge the aquifer. Water levels decline through the summer be¬
cause most of the rain water is returned to the atmosphere by evapo¬
ration and transpiration or is retained in the soil zone and is not
available for recharge. Water levels may rise slightly in the fall be¬
cause of reduced evapotranspiration after the first frost kills plant life.
GROUND WATER
33
Water levels decline through the winter because frost in the ground
prevents recharge. Annual water-level fluctuations in four wells in
Winnebago County (Wi-20/15/19-129, Wi-19/16/19-168, Wi-
18/14/28-235, and Wi-17/16/25-287), unaffected by pumping are
shown in figure 7. The amplitude of the water-level fluctuations was
not the same in the four wells because wells Wi-19/16/19-168 and
Wi-18/14/28-235 (having the greatest fluctuations) are near local
ground-water divides, whereas wells Wi-20/15/19-129 and Wi-17/
16/25-28 i (having the least fluctuations) are near discharge areas.
W ater levels were higher in 1962 than in 1963 because rainfall was
greater in 1962. However, each of the four wells shows an annual
cycle of fluctuations.
Long-term changes in water levels, resulting from changes in rain¬
fall and effects of pumping, are shown by the hydrograph of Wi-20/
17/20-1 from 1946 to 1962 (fig. 8). Total pumpage in the Neenah-
Menasha area and cumulative departure from normal precipitation
at Oshkosh from 1888 to 1962 for the same period also are shown.
Cumulative departure from normal precipitation is the algebraic
sum of the differences between average monthly precipitation deter¬
mined for the total period of record and the actual monthly precipita¬
tion. The trend of the water level in well Wi—20/17/20—1 approxi¬
mates that of precipitation, both declining from 1946 to 1950 and from
1955 to 1959, rising or leveling off from 1959 to 1962, and declining
in 1963. However, water levels rose or leveled off in the period 1950
to 1955 while precipitation continued to decline. This rise in water
levels may have been caused by a decrease in pumping. Pumping
effects can be seen in the period 1956 to 1963, when water levels gen¬
erally declined during periods of increased pumping and rose during
periods of decreased pumping.
Water levels in the Neenali-Menasha and Oshkosh areas have been
lowered by a concentration of industrial pumping (pi. 4). Water
levels in the Neenah-Menasha area in 1915 were reported to be at or
near the, land surface (Weidman and Schultz, 1915, p. 633), but by
1963 they were 110 to 120 feet below the land surface. Pumping has
lowered water levels in the Oshkosh area 25 to 30 feet below the 1915
level. This lowering of water levels by pumping is caused by a reduc¬
tion of the artesian pressure in the area, not by a dewatering of the
aquifer. Inasmuch as the sandstone aquifer is still saturated with
water, present drawdowns are not excessive, and abundant supplies of
water are still available from the 600-foot-thick aquifer.
The hydrograph of well Wi-20/17/15-17 (fig. 7) shows the effects
of pumping in the Neenah-Menasha area during 1962-63. Because a
large percentage of the ground water is used for industrial cooling,
34 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
30VddnS aNV~I M033a 1333 Nl ‘13A33 d31VM
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GROUND WATER
35
o o
o
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^ m 10 oo
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Figure 8. —Well Wi-20/17/20-1, estimated pumpage in the Neenah-Menasha area, and
cumulative departure from normal precipitation, 1946-63.
36 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
pumping is generally greatest in the summer. The water level de¬
clined sharply from May to October when pumping was greatest and
rose during the fall and early winter months as pumping decreased.
Pumping and a decrease in rainfall in 1963 caused a greater decline
in water levels than in the previous year.
The many flowing and pumped domestic wells in the remainder of
the county and the municipal wells at Omro and Winneconne probably
have lowered the water levels only slightly. A well at Omro was re¬
ported in 1915 to have a head of IT feet above the Fox River (Weidman
and Schultz, 1915, p. 629). A head of 4 feet above land surface or
8 to 10 feet above the river was measured in Wi-18/15/17-30 in 1963.
The many flowing wells recently drilled for cottages and houses sur¬
rounding Lake Poygan and the Wolf River have lowered the piezo¬
metric surface slightly in these areas, but older records are not avail¬
able for comparison.
In general, those wells unaffected by pumping that are located in
the highland or recharge areas, near ground-water divides, have water
levels that are deeper and tend to fluctuate more than water levels in
those wells located in the lowland or discharge areas near rivers and
lakes.
Because the piezometric surface in Winnebago County fluctuates
continuously and unequally in different areas, the configuration of the
surface changes continuously. Ground-water divides are not station¬
ary but shift in response to changes in recharge and discharge and
the cones of depression created by pumping become deeper or shal¬
lower in response to changes in pumping (fig. 7). However, over a
long period of time, the average recharge and natural discharge from
the ground-water reservoir remains fairly constant, and the general
configuration of the piezometric surface does not change except in
response to major changes in pumping.
Water-level measurements in wells used to construct the piezometric
map (ph 4) were made between July 29 and August 4,1963. Precipi¬
tation was deficient in the county for about 9 months before the
time of the measurements, and water levels probably were below
normal when the measurements were made. Above-normal temper¬
atures were recorded in June and July 1963; consequently, pumpage
was above normal and the cones of depression at Oshkosh and Neenah-
Menasha were deeper than normal, as indicated by the hydrograph of
Wi-20/17/22-17 (fig. 7).
QUALITY OF GROUND WATER
The quality of ground water in Winnebago County is generally
good; however, it is very hard and locally high in iron, and saline
water occurs in the sandstone aquifer on the eastern edge of the county.
GROUND WATER
37
Dissolved mineral constituents in ground water are derived from
the soil and rocks with which the water comes into contact as it moves
into and through the aquifer. The concentration depends on the
solubility of the rocks, the solvent, and the length of time that the
water is in contact with the rocks. Dissolved mineral constituents
in ground water, therefore, may become highly concentrated in areas
of the aquifer in which the movement of water through the aquifer is
retarded, such as in areas having low permeability or in the area of
impermeable Precambrian mounds.
The source and significance of dissolved mineral constituents and
properties of water are summarized in table 4. Where applicable,
limits recommended for drinking water by the U.S. Public Health
Service (1962) are listed. Water containing dissolved mineral con¬
stituents above the recommended limits is not necessarily harmful or
unusable for all purposes and actually may be suitable for many
purposes.
Partial chemical analysis of water from 49 wells, most of which
penetrate the sandstones of Cambrian and Ordovician ages, are listed
in table 5.
Ground water in Winnebago County ranges from moderately hard
to very hard. In the saline-water area in the eastern part of the
county, hardness ranges from 600 to 2,200 ppm, increasing from west
to east. Ground water in the northwestern corner of the county is
only moderately hard as indicated by samples from three wells that
ranged from 64 to 110 ppm. In the remainder of the county ground
water is very hard, ranging from 200 to 600 ppm.
The concentration of iron in ground water in the sandstones of
Cambrian and Ordovician ages generally is high throughout Winne¬
bago County. Analyses of 49 samples averaged 1.6 ppm of iron and
ranged from 0.02 to 10 ppm. The map showing distribution of iron
in ground water (fig. 9) indicates that concentrations generally are
greatest along the ground-water divide west of Neenah-Menasha in
Winnebago County. High concentrations of iron also are generally
associated with areas of fairly slow moving water and marsh deposits.
The progressive eastward increase of iron in ground water along the
eastern side of the county is associated with the saline-water zone and
is caused by restricted ground-water movement.
Although iron is a problem in the county, it is not detrimental to
health, and it is fairly easy to remove by precipitation, filtration, or
aeration. Staining of plumbing fixtures and reduction of the effi¬
ciency of wells caused by precipitation of iron in well screens, pump
bowls, pipes, and other areas of turbulance cause the greatest prob¬
lems where the ground water has a high concentration of iron.
38 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
Table 4. —Significance of dissolved mineral constituents and properties of water
Constituent or
property
Source or cause
Significance
Iron (Fe)
Dissolved from practically all
rocks and soils. May also
be derived from iron pipes,
pumps, and other equip¬
ment.
Manganese (Mn)..
Calcium (Ca) and
magnesium
(Mg).
Sodium (Na) and
potassium (K).
Dissolved from some rocks
and soils. Not so common
as iron. Large quantities
often associated with high
iron content and with acid
waters.
Dissolved from practically all
soils and rocks, but especially
from limestone, dolomite,
and gypsum. Calcium and
magnesium are found in
large quantities in some
brines. Magnesium is pres¬
ent in large quantities in sea
water.
Dissolved from practically all
rocks and soils. Found also
in sea water, industrial
brines, and sewage.
Bicarbonate
(HC0 3 ) and
carbonate
(CO 3 ).
Action of carbon dioxide in
water on carbonate rocks
such as limestone and
dolomite.
Sulfate (SO 4 )
Dissolved from rocks and soils
containing gypsum, iron
sulfides, and other sulfur
compounds. Usually pres¬
ent in mine waters and in
some industrial wastes.
Chloride (Cl)
Dissolved solids...
Hardness as
CaC O3.
Dissolved from rocks and soils.
Present in sewage; found in
large amounts in sea water
and industrial brines.
Chiefly mineral constituents
dissolved from rocks and
soils. Includes some water
of crystallization.
In most water nearly all the
hardness is due to calcium
and magnesium, dissolved
from soils, dolomite, and
limestone.
Hydrogen-ion con- Acids, acid-generating salts,
centration (pH). and free carbon dioxide
lower the pH. Carbonates,
bicarbonates, hydroxides,
phosphates, silicates, and
borates raise the pH.
Temperature
On exposure to air, iron in ground water oxidizes to
reddish-brown sediment. More than about 0.3
ppm stains laundry and utensils reddish brown.
Objectionable for food processing, beverages, ice
manufacture, brewing, and other processes. Fed¬
eral drinking-water standards state that iron should
not exceed 0.3 ppm. Larger quantities cause un¬
pleasant taste and favor growth of iron bacteria.
Same objectionable features as iron. Causes dark
brown or black stain. Federal drinking-water
standards recommend that manganese should not
exceed 0.05 ppm.
Cause most of the hardness and scale-forming prop¬
erties of water; soap consuming (see “Hardness").
Water low in calcium and magnesium desired in
electroplating, tanning, and dyeing and in textile
manufacturing.
Large amounts, in combination with chloride, give
a salty taste. Moderate quantities have little effect
on the usefulness of water for most purposes.
Sodium salts may cause foaming in steam boilers,
and a high sodium ratio may limit the use of water
for irrigation.
Bicarbonate and carbonate produce alkalinity.
Bicarbonates of calcium and magnesium decompose
in steam boilers and hot-water facilities to form
scale and release corrosive carbon-dioxide gas. In
combination with calcium and magnesium they
cause carbonate hardness.
Sulfate in water containing calcium forms hard scale
in steam boilers. In large amounts, sulfate in com¬
bination with other ions gives bitter taste to water.
Some calcium sulfate is considered beneficial in
the brewing process. Federal drinking-water
standards recommend that the sulfate content
should not exceed 250 ppm.
In large amounts in combination with sodium gives
salty taste to drinking water. In large quantities
increases the corrosiveness of water. Federal
drinking-water standards recommend that the
chloride content should not exceed 250 ppm.
Federal drinking-water standards recommend that
the dissolved solids should not exceed 500 ppm.
Water containing more than 1,000 ppm of dissolved
solids is unsuitable for many purposes.
Consumes soap before a lather will form. Deposits
soap curd on bathtubs. Hard water forms scale in
boilers, water heaters, and pipes. Hardness equiv¬
alent to the bicarbonate and carbonate is called
carbonate hardness. Any hardness in excess of this
is called noncarbonate hardness. Water of hardness
up to 60 ppm is considered soft; 61-120 ppm, moder¬
ately hard; 121-200 ppm, hard; more than 200 ppm,
very hard.
A pH of 7.0 indicates neutrality of a solution. Values
higher than 7.0 denote increasing alkalinity; values
lower than 7.0 indicate increasing acidity. pH is
a measure of the activity of the hydrogen ions.
Corrosiveness of water generally increases with
decreasing pH. However, excessively alkaline
water may also attack metals.
Affects usefulness of water for many purposes. For
most uses, a water of uniformly low temperature is
desired. Shallow wells show some seasonal fluctu¬
ations in water temperature. Ground water from
depths over 60 feet usually is nearly constant in
temperature, which is near the mean annual air
temperature of the area.
GROUND WATER 39
Manganese is present in only minor quantities and is not a problem
in Winnebago County.
Saline water underlies the eastern edge of Winnebago County, in¬
cluding Neenah-Menasha and Oshkosh, and is part of a large saline-
water area, described by Ryling (1961), which includes parts of
Brown, Outagamie, Calumet, Fond du Lac, and Dodge Counties.
Saline water, as defined by Ryling, contains more than 250 ppm
sulfate or chloride, or more than 1,000 ppm total dissolved solids. In
Winnebago County, only sulfate and dissolved solids exceed these
limits, but other dissolved mineral constituents generally are slightly
higher in the saline-water area than in other parts of the county (table
5). The saline-water area is the result of the retardation of ground-
water movement through the aquifer by Precambrian mounds east
and south of Winnebago County.
Dissolved solids in ground water in Winnebago County range be¬
tween 200 and 400 ppm over most of the county, but are as high as
1,700 ppm in the saline-water area (fig. 10). The concentration of dis¬
solved solids in the saline area increases from west to east towards Lake
Winnebago. Dissolved solids in water in Winnebago County are made
up largely of sulfate, calcium, and magnesium, especially in the saline-
water area in the eastern part of the county.
The concentration of sulfate in ground water is very high in the
saline-water area, but generally is low in other parts of the county.
Concentrations range from about 100 to 900 ppm in the saline-water
area and increase from west to east as shown in figure 11. Sulfate
concentration in other parts of the county generally range from about
10 to 100 ppm.
Concentrations of sodium, potassium, and chloride in ground water
are low in Winnebago County. Chloride ranges from about 2 to about
100 ppm, well below the recommended upper limit of 250 ppm.
Sodium and potassium range from about 2 to 64 ppm. These con¬
stituents have only slightly higher concentrations in the saline-water
area than in other parts of the county.
The temperature of ground water generally is nearly constant and
is slightly higher than the mean annual air temperature. Recorded
ground-w r ater temperatures in Winnebago County ranged between
49° and 54°F. The temperature of water from shallow wells may
vary slightly with seasonal changes in air temperature, but water from
deep wells has a more uniform temperature and generally is slightly
warmer than water from shallow wells. The constant low temper¬
ature of ground water makes it an excellent source for cooling water
and for other purposes.
Chemical analyses of ground water from selected wells in Winnebago County
GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
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42 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
R. 14 E.
R. 15 E.
R. 16 E.
R.17 E.
-0.9-
Isogram
Shows concentration of
iron. Line approxi¬
mately located; interval
0.6 ppm
More than 2.1 ppm of iron
# 1.60
Water well
Number is iron, in
parts per million
Figure 9.—Distribution of iron in ground water in the sandstone aquifer,
Winnebago County.
GROUND WATER
43
R.17 E.
Base from State Highway
Commission roadmap
EXPLANATION
-400-
Isogram
Shows total dissolved solids.
Line approximately lo¬
cated; interval 200 ppm
# 370
Water well
Number is dissolved solids,
in parts per million
Figure 10.—Distribution of dissolved solids in ground water in the sandstone
aquifer, Winnebago County.
44 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
R. 14 E. R. 15 E. R 16 E. R. 17 E.
EXPLANATION
- IOO - # 265
Isogram Water well
Shows concentration of sul- Number is sulfate, in parts
fate. Line approximately per million
located; interval 100 ppm
Figure 11.— Distribution of sulfate in ground water in the sandstone aquifer,
Winnebago County.
AVAILABILITY AND USE OF WATER
Winnebago County has abundant and readily available supplies
of ground and surface water for nearly all anticipated uses. The
supplies are not uniformly available in all areas, however, and may
vary with time and man’s use.
The availability of surface water is dependent upon the storage of
water in the Lake Winnebago Pool, the inflow to the pool from the
Wolf and upper Fox Rivers, and the outflow of the pool to the lower
AVAILABILITY AND USE OF WATER
45
Fox River. The greatest inflow to the pool is from the Wolf River;
measured at New London, the inflow is about 1,200 cfs (cubic feet
per second) during 50 percent or more of the time (fig. 12). The
Fox River contributes about 840 cfs (measured at Berlin) during 50
percent or more of the time (fig. 12). The outflow from the pool,
measured at the Rapide Croche Dam on the lower Fox River, is about
3,750 cfs during 50 percent or more of the time (fig. 12). Assuming
that the flow of the Fox River at Rapide Croche Dam for the period
1918—54 is representative of the long-term flow, the flow-duration
curve can be used to estimate the future availability of water from
the Lake Winnebago Pool. For example, discharge from the pool,
measured at Rapide Croche Dam, equaled or exceeded about 1,200
cfs during 95 percent of the time.
Surface water is not readily available in areas distant from the
Lake Winnebago Pool because of the scarcity of lakes and the small
flow of streams.
Estimated quantities of ground water available to wells in Winne¬
bago County range from about 10 gpm to about 1,000 gpm (fig. 13).
In places where the sand and gravel layers in the drift aquifer are
thick, the sand and gravel generally yield as much as 50 gpm to wells.
PERCENT OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED
EXPLANATION
O--O---O o-O-0-o
Outflow from Lake Winnebago Pool Inflow to Lake Winnebago Pool
Figure 12.— Duration curves of daily flow of major streams flowing into and out
of the Lake Winnebago Pool.
46 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
The Platteville-Galena unit also yields as much as 50 gpm, but the
yields may be greater in areas where the dolomite is highly fractured.
The sandstone aquifer probably yields as much as 1,000 gpm to fully-
penetrating wells in places where the aquifer is of sufficient thickness.
The total use of water in Winnebago County from both surface-
and ground-water sources was estimated to be 53.6 mgd in 1962. Sur¬
face water from Lake Winnebago and the Fox River supplied the
domestic needs of about 72 percent of the people in Winnebago County
and provided an estimated 77 percent of the water used for all pur¬
poses. Ground water supplied the remaining 23 percent of the total
water used in the county; however, because of its county wide avail¬
ability, it is the principal source of water to communities other than
Neenah, Menasha, and Oshkosh, to many industries, and for rural
domestic and stock use.
A summary of the estimated use of surface water in 1962 for various
purposes in municipal areas and in the remainder of the county is
shown in table 6. The two largest users are the municipal powerplant
of Menasha, which diverts large quantities of water for cooling pur¬
poses, and the combined pulp and paper industry in Neenah and
Menasha, which uses water for processing, cooling and air condition¬
ing, and sanitary purposes. Municipal supply for Neenah, Menasha,
and Oshkosh, the three principal cities in the county, is the third
largest user of surface water.
The municipal use of water in Neenah, Menasha, and Oshkosh has
increased from about 7.5 mgd in 1950 to 11.3 mgd in 1960 because of
increased population and an increased use of municipal water by in¬
dustries. If municipal pumpage increases at the same rate, it will
amount to about 27 mgd by the year 2000.
Most of the large quantities of water pumped out of Lake Winne¬
bago and the Fox River for municipal and industrial use is returned
to the surface-water bodies, but with some alteration of chemical
quality and an increase in temperature. The temperature of dis¬
charged surface water used for cooling purposes by the powerplant
at Menasha is raised as much as 18 °F, depending on the time of year.
Surface water pumped for municipal use is returned as treated sewage
effluent. Water used by the pulp and paper industry also is returned
to the Fox River as treated effluent.
The average daily use of ground water for all purposes in Winne¬
bago County in 1962 is estimated at about 9 mgd (table 6). Ground
water is used for public supply in the city of Omro, the village of
Winneconne, the Winnebago State and County Hospitals, all rural
schools and churches, and a shopping center. Industrial use of ground
water includes condenser cooling, washing and processing, boiler use,
I
AVAILABILITY AND USE OF WATER
47
R. 14 E. R 15 E. R 16 E. R. 17 E.
Base from State Highway
Commission roadmap 0 1 2 3 4 MILES
I_l_I_l_i
EXPLANATION
Gallons per minute
0-50
Adequate for domestic
and stock use
51-500
Adequate for small
urban development
and light industry
501-1000
Adequate for munici¬
pal use and heavy
industry
Figure 13.—Estimated availability of ground water, Winnebago County.
brewing, and air conditioning. The largest user of ground water in
the county is the pulp and paper industry. Ground water is used for
rural domestic and stock-watering purposes and a small amount is
used for lawn irrigation by several golf courses and cemeteries.
The greatest use of ground water is in Neenah and Menasha with a
total pumpage of nearly 4 mgd in 1962, or about 44 percent of the
total estimated amount used in the county. The use of ground water
in Oshkosh was about 0.9 mgd, or about 10 percent of the total ground
water used in the county.
48 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
Table 6. —Estimated average daily use of water in Winnebago County, 1962
[Excludes power generation]
Amount of use by area (mgd)
Total
Type of use
Neenah
Mena-
sha
Oshkosh
Omro
Winne¬
conne
Other
use
Public supply
Municipal:
Ground water_ _
0.0
0.0
0.0
0.2
0.1
0.0
0.3
Surface water_ _... .. .
3.5
4.6
4.2
.0
.0
.0
12.3
Other:
Ground water__
.0
.0
.0
.0
.0
.4
.4
Surface water.. _
.0
.0
.0
.0
.0
.0
.0
Total public supply_ ..
3.5
4.6
4.2
.2
.1
.4
13.0
Industrial
Pulp and paper manufacture:
Ground water_ .
2.1
1.2
.0
.0
.0
.0
3.3
Surface water__ ... __
9.9
7.8
.0
.0
.0
.0
17.7
Other manufacturing:
Groundwater... .. . __
.0
.0
.5
.0
.0
.3
.8
Surface water.....
.1
.1
.1
.0
.0
.0
.3
Dairy products processing:
Groundwater.. _ .
.4
.0
.1
.1
.2
.3
1.1
Food processing:
Groundwater. __ .
.0
.0
.0
.0
.0
.1
.1
Brewing and malting:
Ground water__
.0
.0
.2
.0
.0
.0
.2
Air conditioning:
Groundwater_ ___
.2
.0
.1
.0
.0
.0
.3
Cooling in electrical power produc¬
tion:
Surface water_... _
.0
14.4
.0
.0
.0
.0
14.4
Total industrial.._ ..
12.7
23.5
1.0
.1
.2
.7
38.2
Rural
Domestic (total nonurban use):
Ground water___
Farm livestock:
Ground water....
Total rural.
Total use...
1.4
1.0
2.4
53.6
Over the period 1953 to 1962, for which some pumpage records are
available, the industrial use of ground water increased only slightly
both in the county and in the Neenah-Menasha and Oshkosh areas.
The muncipal use of ground water by the city of Omro and the village
of Winneconne increased by about 30 percent and 230 percent, respec¬
tively, over the same period. Population figures indicate an increase
of about 19.5 percent in the rural population between 1950 and 1960
(U.S. Dept. Commerce, 1960). Rural use of ground w^ater probably
increased a corresponding amount during this period.
The amount of water lost by consumptive use, principally by evap¬
oration, in Winnebago County is difficult to determine because of the
many contributing factors. However, the following estimates of con¬
sumptive use generally can be applied for planning purposes. About
10 percent of the water pumped for municipal supply is lost by evap-
PRESENT AND ANTICIPATED WATER PROBLEMS
49
oration from steam boilers, lawn irrigation, and other miscellaneous
uses (Wirth, 1959, p. 33). Water withdrawn for all industrial con¬
sumptive uses is about 2 percent (MacKichan and Kammerer, 1961, p.
17). Consumptive use of water by the pulp and paper industry is
estimated at only about 1 percent (Wirth, 1959, p. 33).
The recreational use of the extensive lakes and rivers in Winnebago
County cannot be overlooked because of its importance to local resi¬
dents and to tourists, but a detailed analysis of such use is beyond the
scope of this report. Quantitative data and recommendations for
recreational use of water in Winnebago County are available from
the Wisconsin Department of Resource Development.
PRESENT AND ANTICIPATED WATER PROBLEMS
Water problems in any area generally can be listed under the fol¬
lowing headings: (1) Supply in relation to demand, (2) distribution,
(3) natural quality, (4) manmade pollution, (5) variability, and (6)
floods. Consideration of these problems in Winnebago County is
given in the following discussion.
SUPPLY IN RELATION TO DEMAND
Winnebago County is fortunate in having an abundant supply of
both ground and surface water. Total recharge to the ground-water
reservoirs greatly exceeds local pumpage throughout the county, even
during periods of scanty rainfall. If pumpage increases at a normal
rate in the future, there is little danger of seriously depleting the
ground-water supply for a long period of time. A problem of declin¬
ing water levels in wells may arise in local areas of high demand if
well spacing is inadequate. Interference between closely spaced wells
could seriously reduce the efficiency of individual wells.
Surface water in the county also greatly exceeds the amount pres¬
ently used. Although streamflow may be seriously diminished during
periods of drought, water is retained in the county by storage in the
Lake Winnebago Pool, and part of this water is available for use.
The generally nonconsumptive uses of surface water also permit the
water to be reused for other purposes. If surface-water use increases
at a normal rate, a shortage of supply is not anticipated in the near
future, except possibly during periods of severe drought.
DISTRIBUTION
Ground and surface water are fairly well distributed throughout
Winnebago County, and for most of the area major distribtuion prob¬
lems do not exist and are not expected to arise in the near future.
50 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
Numerous lakes and streams make surface water readily available
over about two-thirds of the county, and extensive aquifers make
ground water available over most of the county. However, surface
water is not readily available from about one-third of the county. The
sandstone aquifer is fairly thin, and only small to moderate quanti¬
ties of water are available in the preglacial buried channels in the
northwestern part of the county and in the upper Fox River valley
(pi-1)-
NATURAL QUALITY
The principal water-quality problems in Winnebago County are
algae and hardness in surface water and iron, hardness, and salinity
in ground water.
Growth of algae in the shallow Lake Winnebago Pool during the
summer creates serious aesthetic and treatment problems. Hardness
is generally only a minor problem, but for some uses the water must
be treated.
Dissolved iron in ground water occurs over a large part of the
county, and saline ground water occurs on the eastern side of the
county. However, the water still is usable for many purposes, and
treatment can make the water usable for almost all purposes. Pump¬
ing at Neenah-Menasha, the Winnebago State and County Hospitals,
and Oshkosh has locally reversed the natural moA^ement of ground
water. This westward movement of water has created the possibility
that highly mineralized water from the saline-water zone may move
toward the areas of pumping and eventually may contaminate the
sandstone aquifer locally.
The sulfate content in ground water apparently has increased grad¬
ually since before 1934 in wells in the city of Neenah, and also has in¬
creased since 1957 in wells at the Winnebago State Hospital (table 7).
This increase may be related to a westward migration of saline water
because of pumping. However, additional analyses are needed over
a period of time to prove this conclusion. Other constituents in ground
water in these pumping areas and at Oshkosh remained constant
during the same period (table 7).
MANMADE POLLUTION
Pollution of surface water in Winnebago County is a minor and lo¬
cal problem at present, but may be expected to increase in the future.
Streamflow generally is sufficient to dilute sewage and industrial
wastes that are discharged into the Fox and Wolf Rivers before they
enter the county, and to dilute wastes that are discharged to the Lake
Winnebago Pool within the county. Sewage and other organic wastes
PRESENT AND ANTICIPATED WATER PROBLEMS
51
Table 7. —Chemical analyses of ground water at Neenah, Oshkosh, and the
Winnebago State Hospital showing changes in chemical quality
[All values in parts per million]
Well
Owner
Date of
collec¬
tion
Iron
(Fe)
Bicar¬
bonate
(HC0 3 )
Sul¬
fate
(S0 4 )
Chlor¬
ide
(Cl)
Dis¬
solved
solids
Hard¬
ness as
CaCC >3
Wi-20/17/27-28_
City of Neenah_ _
Pre-1934
2.2
305
892
11
1,639
940
20/17/28-59_
Galloway Milk Co.,
1963
1.0
277
956
8
lj 380
1,751
Neenah.
Unknown_
Peoples Brewing Co.,
Pre-1934
1.0
331
319
Oshkosh.
Wi-18/16/25-41_
_do.. ... . ..
1955
.02
307
109
19
412
467
Unknown_
Rockwell Standard Corp.,
Pre-1934
2.4
280
254
Oshkosh.
Wi-18/16/14-356
_do_ _ .
1962
.9
176
220
19/17/31-37. .
Winnebago State Hos-
1957
.9
370
268
964
645
pital.
..do_ ...
1958
.9
273
608
.do.
1961
266
330
740
600
19/17/31-39.
.do. . .
1957
.9
236
310
1,002
674
do.
1958
.7
297
540
.do.
1963
1.6
222
375
910
670
discharged to streams consume oxygen and provide nutrients which
promote the growth of algae. Chemical wastes discharged to streams
may locally render the water unsuitable for ordinary uses. Expand¬
ing industries and cities with inadequate and overtaxed sewage and
waste-disposal systems should take care not to pollute surface water in
the Fox and Wolf River basins.
Pollution of ground water is a potential problem in areas of Winne¬
bago County where dolomite of the Platteville-Galena unit or of the
Prairie du Chien Group crops out or is overlain by only a thin layer of
unconsolidated deposits. Because ground water moves through solu-
tionally enlarged joints, fractures, bedding planes, and other large
openings in dolomite, there is very little purification of water in the
formation. Impurities introduced into the formation, may be carried
for long distances and pollute large areas. Flushing of a polluted
aquifer requires a great length of time before the ground water is
usable.
Polluted water from a defective private sewage system in a dolomite
area could enter shallow wells that are open in the formation. Dump¬
ing of rubbish and industrial wastes in dolomite quarries or highly
permeable sand and gravel pits overlying dolomite also is a potential
cause of ground-water pollution in shallow wells.
A potential ground-water pollution problem exists in a large area
of the Lake Winnebago drainage area (p. 28), especially near Neenah-
Menasha. The area is underlain by dolomite of the Platteville-Galena
unit (pi. 1) and the glacial drift is thin over a large part of the area
(fig. 4). The potential for pollution would be increased in this area
by development that did not include proper methods of waste treat¬
ment and disposal. A potential pollution problem also exists along the
UfliyfcRSITY OF HUNCH
L!RPA r)V
52 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
escarpment of the Prairie du Chien Group in the western and central
parts of the county (pi. 1, fig. 4).
Casing off all or a large part of the dolomite and drilling into under¬
lying sandstone is the best method to prevent polluted water from
entering wells in the dolomite areas. Well owners also should have
their well water checked periodically for bacteriological content to
insure that the aquifer has not become polluted.
Sand and gravel layers and lenses in the drift aquifer generally are
not subject to pollution, because in most places they are overlain by
thick deposits of clay and silt. However, if these sand and gravel lay¬
ers occur near, or crop out at, the land surface, they are susceptible
to pollution as a result of improper waste treatment and disposal.
Pollutants introduced into a sand and gravel layer generally travel
only short distances before they are filtered out, but wells close to the
source of pollution may become polluted. Salt used on roads and man¬
made organic compounds, such as gasoline or pesticides, may travel
much greater distances because they do not break down readily and
are not filtered out by the aquifer. This type of pollution has not
been reported, but these pollutants can be carried into the drift aqui¬
fer and make the water unusable for long periods of time.
The presence of detergent or ABS (alkyl benzene sulfonate) in
ground water has not been reported and does not appear to be a cur¬
rent problem in Winnebago County. The source of ABS in ground
water generally is from private sewage systems. It is recommended
that ABS in drinking water should be limited to 0.5 ppm because
higher concentrations may cause undesirable taste and foaming (U.S.
Public Health Service, 1962, p. 24). The presence of ABS in water
from a well indicates that the water may contain other harmful pollut¬
ants from sewage systems. The presence of ABS in water may be in¬
dicated by foaming when a sample of water is shaken in a small bottle.
Pollution of ground water in the sandstones of Cambrian and Ordo¬
vician ages is unlikely because of the filtering properties of sandstone
and the thickness of overlying material through which recharge must
travel to reach the artesian aquifer. Pollutants may enter the sand¬
stone through wells that are inadequately sealed at the surface or
through dolomite that is exposed or near the surface.
VARIABILITY
*
Variability refers to the changes that can occur in the county in the
amount of streamflow and the amount of ground water in storage.
Generally, variability is not a problem in Winnebago County because
of the control on the surface water (Lake Winnebago Pool) and the
large amount of water available from the ground-water reservoirs.
DEVELOPMENT OF WATER RESOURCES
53
FLOODS
Flooding is not a major problem in Winnebago County because of
the reservoir control and storage of the Lake Winnebago Pool. Flood¬
ing of minor streams is not a current problem because of the low
density of population and agricultural use of land.
SUGGESTIONS FOR DEVELOPMENT OF WATER
RESOURCES
In the next several decades an expanding economy will place greater
demands on the water resources of Winnebago County. Because this
expanding economy depends on the availability of large supplies of
good-quality water, the water resources of the county should be devel¬
oped in an orderly and efficient manner. To choose the best possible
method of developing and using water, water managers need to formu¬
late comprehensive plans for use and management of ground and sur¬
face water and to consider the effects of water development on all
aspects of the local economy. The following suggested methods of
development may be useful to water managers in the county for
planning purposes.
GROUND-WATER DEVELOPMENT
Ground-water development in Winnebago County is expanding and
is expected to continue expanding in the future. This development
will be influenced by surface-water use, by distance of water transpor¬
tation, by relative costs, and by water quality.
In developing a ground-water supply, water levels decline around
a center of pumping, and pumping lifts are increased. The greatest
decline in water levels would be in areas where heavily pumped wells
are very closely spaced. A good development plan should have wells
spaced at distances that will minimize increased pumping lifts due to
well interference without overly increasing the costs of connecting or
transmitting lines. Consequently, estimates of well discharged, well
spacing, and pumping lifts should be made when selecting new well
sites. The 'well discharge for a new well generally may be estimated
from the specific-capacty data for other wells in the area. Before a
new well is drilled in an area where little or no information on the
aquifer is available, a test well should be drilled and pumped to
determine yield.
Estimation of the optimum spacing between a new well and existing
well or between wells in a new well field should be based on computa¬
tion of well interference for different well spacings for an assumed pe¬
riod and rate of pumping. Such estimates may be made from the Theis
nonequilibrium formula, the coefficients of transmissibility and storage
54 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
for the aquifer being determined by aquifer tests or other methods.
Such computations for wells tapping the sandstone aquifer in eastern
Winnebago County are shown by figures 14 and 15. These curves
show the amount of interference that will occur in 1 month, 1 year, and
5 years at 100 to 20,000 feet from a well pumping continuously at a rate
of 500 gpm (fig. 14) and the interference that will occur at any time
between 10 and 4,000 days at 1,000,10,000, and 20,000 feet from a well
pumping continuously at rate of 500 gpm (fig. 15). For example,
the drawdown in a well spaced 1,000 feet from another well pumping
at a rate of 500 gpm for 30 days would be about 20 feet, whereas the
drawdown in a well spaced 10,000 feet from the pumping well would
be about 6 feet (fig. 14). After 2,000 days, or about 5!/2 years of
pumping, drawdown in the well spaced at 1,000 feet would be about 33
feet compared to about 18 feet in a well spaced at 10,000 feet from
the pumped well.
Water-level declines for any rate of pumping can be determined
from the curves by the direct proportionality of drawdown to the rate
of pumping. For example, if the rate of pumping is 300 gpm instead
of 500 gpm, water-level decline will be 0.6 of that shown on the curve.
The interference that will occur from more than one pumping well is
the sum of the interference of all wells.
In most places in Winnebago County, the beds confining water in
the sandstone aquifer only impede or retard the vertical movement of
water; water in the confining beds, in the overlying alluvium, and from
surface water moves downward in response to the lowered piezometric
head around a pumping well. Although the rate of movement of this
water, called vertical leakage, is probably small, large quantities of
water may be contributed to the aquifer over a long period of time.
More work is required to determine the amount of water that is con¬
tributed to the aquifer by leakage. The curves in figures 14 and 15
are based on the assumption that all water pumped is withdrawn from
storage and are not adjusted for recharge to the aquifer. The draw¬
downs shown by the curves are greater than those which actually would
occur.
Additional wells in the Neenah-Menasha and Oshkosh areas should
be located as far as feasible from the center of the cones of depression
beneath the cities to reduce interference from other pumping wells.
Because recharge to the cones of depression is greatest from the west at
Neenah-Menasha and from the west and southwest at Oshkosh (pi. 4),
dispersal of wells in these directions would be more effective in reducing
water-level declines than dispersal in any other direction. Locating
wells close to surface-water bodies might induce recharge and reduce
water-level declines.
Periodic water-level measurements in wells tapping the sandstone
DEVELOPMENT OF WATER RESOURCES
55
aquifer, especially in the Neenah-Menasha and Oshkosh areas, are
necessary for determining water-level trends and predicting the decline
of water level that will result from additional development. All
punipage from high-capacity wells should be metered and correlated
with changes in water levels.
Because highly mineralized water may be moving toward the centers
of pumping on the eastern edge of the county, new sandstone-aquifer
wells should be located as far to the west as is practical, to decrease the
possibility of tapping this saline water. The quality of water from
wells in this area should be monitored to detect saline-water migration.
If there is a migration of saline water, the monitoring program would
aid in its control.
SUPPLEMENTAL USE OF GROUND WATER WITH SURFACE WATER
Surface water is used extensively in Winnebago County for
municipal and industrial purposes, and the present supply is far in
excess of demand. Surface water is an excellent source of supply
during most of the year; however, it is not readily available in all parts
of the county, and high water temperatures and the growth of algae
are inherent problems during the summer months. A possible method
of helping to alleviate these problems, especially during the summer
months, is the supplemental use of ground water from a network of
adequately spaced wells. Ground water generally does not need the
expensive treatment required for surface water. The supplemental
use of ground water would reduce the amount of treatment required for
algae and would lower the temperature of water.
Comparison of costs of installation, operation, and maintenance of
a surface-water system with costs of a ground-water system is beyond
the scope of this report, but the various factors should be evaluated
to determine the most economical system to use. Generally, installa¬
tion costs for a ground-water system are considerably less than for
a surface-water system, but other costs may be comparable. Con¬
sidering costs, the year round supplementing of present surface-water
facilities with ground water should be considered as a means of ex¬
panding present municipal water-supply systems.
Emergency supplies of water can be obtained from ground-water
systems in the event of a natural or manmade disaster, whereby surface-
water sources might become unusable. The ground-water supplies
should be safe, at least for the period of time needed for decontamina¬
tion of surface water. Existing high-capacity wells in Winnebago
County, a large percentage of which are shown on plate 1, should pro¬
vide adequate water for emergency use. A ground-water system sup¬
plementing a municipal surface-water supply also would provide an
emergency source of water.
GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
o
CM
00
lO
CM
O
i-H
00
CO
CM
O
O
o o o o
cm co ^ in
LlI
$
Q
LlI
0 .
D
0.
o
a:
Li.
I-
LlI
LlI
U.
CO
Q
2
<
CO
D
O
I
Ui
o
z
<
t-
CO
Q
133d Nl ‘( s )NMOaMVda
Figure 14.—Theoretical distance-drawdown curves for an infinite aquifer, based on coefficients of transmissibility and storage
determined for the sandstone aquifer at the Winnebago State and County Hospitals.
DEVELOPMENT OF WATER RESOURCES
133j n i '(») NMoaMvaa
Figure 15.—Theoretical time-drawdown curves for an infinite aquifer, based on coefficient of transmissibility and storage
determined for the sandstone aquifer at the Winnebago State and County Hospitals.
58 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
LAKE MICHIGAN AS A SOURCE OF SUPPLY
Water from Lake Michigan, about 45 miles east of Neenah-Menasha,
could be transported into Winnebago County by pipeline and would
provide an abundant water supply for many years. Water from Lake
Michigan is colder and less mineralized than water from the Fox River
and algae are not a serious problem. Although developing and trans¬
porting Lake Michigan water to this area would be costly, such a
development might be economical if a sufficient number of communities
and industries were included in the system. Because of the high cost
of development, local sources of surface and ground water should be
carefully evaluated before Lake Michigan is considered as a source
of supply.
CONCLUSIONS AND RECOMMENDATIONS
Winnebago County has generally good quality ground water and
surface water available over most of its area and in quantities that will
not limit forseeable development. Water from the Lake Winnebago
Pool, which has a storage capacity of 25 billion cubic feet and an aver¬
age discharge of about 4,190 cfs, is hard, is locally polluted, contains
algae during the summer months, and requires treatment, but gen¬
erally it is suitable for municipal and most industrial uses. Water
from the pool ranges in temperature from 32° to 80° F annually.
The sandstone aquifer, present throughout the county, is a depend¬
able source of water for municipal, industrial, and domestic uses.
Yields up to 1,000 gpm may be obtained from fully penetrating wells
in the eastern and southern parts of the county where the sandstone
has a maximum thickness of about 600 feet. The aquifer is confined
under artesian pressure by the overlying Platteville-Galena unit and
glacial drift. Water from the sandstone aquifer is hard to very
hard and contains iron in some places. A saline-water zone, containing
dissolved solids in excess of 1,700 ppm and sulfate in excess of 900
ppm, is present on the eastern edge of the county. Mineralization in
this zone increases from west to east. In the remainder of the county,
water from the sandstone aquifer is of good quality, generally contain¬
ing 200 to 400 ppm dissolved solids. Temperature of the water ranges
from 49° to 54° F.
The Platteville-Galena unit, present, in the eastern and southern
parts of the county, yields as much as 50 gpm to wells and is a depend¬
able source of water for domestic and farm uses. The water is hard
to very hard but otherwise is of good quality. Pollution is a potential
problem because of the poor filtration properties of dolomite and be¬
cause the unit crops out at the land surface.
CONCLUSIONS AND RECOMMENDATIONS
59
A drift-filled preglacial bedrock channel, having a maximum depth
of about 300 feet, extends from Waupaca County through the north¬
western corner of Winnebago County and into Waushara County,
and underlies the Wolf River and Lake Poygan. A preglacial chan¬
nel also underlies the upper Fox River in Winnebago County. Uncon¬
solidated layers and lenses of sand and gravel in these preglacial
channels yield as much as 50 gpm to wells and are dependable aquifers
for domestic and farm use. These deposits are confined by clay till
and are not subject to pollution. Water from the sand and gravel
deposits is generally of good quality and is less mineralized than water
from the underlying sandstone aquifer. The quality and temperature
of the water remain nearly constant, the temperature ranging from
49° to 54° F.
The total estimated use of water in the county in 1962 was 53.6
mgd, of which 44.7 mgd was supplied from the Lake Winnebago Pool
and 8.9 mgd from ground-water sources. Although more surface
water than ground water is used in the county, ground water is the
principal source of supply for communities other than Neenah,
Menasha, and Oshkosh, for many industries, and for all rural domestic
and stock use. Industry is the largest user of surface and ground
water in the county.
The area of greatest use of ground water in 1962 was Neenah-
Menasha, having an estimated annual pumpage of 1.4 billion gallons
(3.8 mgd). Pumpage in the Oshkosh area was estimated at 0.5 bil¬
lion gallons per year (1.4 mgd). Only about 10 percent of the water
used for municipal purposes and 1 to 2 percent of the water used for
industrial purposes was used consumptively, the remainder being
returned to the Lake Winnebago Pool and the lower Fox River.
Pumping of water from the sandstone aquifer has lowered water
levels 110 to 120 feet in Neenah-Menasha and 25 to 30 feet in Oshkosh
below the reported levels in 1915. Water levels in the remainder of
the county are at about the same level as those reported in 1915.
The piezometric surface of the sandstone aquifer indicates that ground
water is moving toward the Wolf and Fox Rivers and Lake Winne¬
bago from ground-water divides which generally coincide with topo¬
graphic divides formed by escarpments of the Prairie du Chien Group
and Plateville-Galena unit.
Present water problems in the county include the growth of algae
and local pollution in the Lake Winnebago Pool, iron in water from
the sandstone aquifer over a large part of the county, and saline ground
water along the eastern edge of the county. Potential water problems
include rapid decline of water levels of interference between closely
spaced wells, migration of saline ground water to areas of pumpage
60 GEOLOGY AND WATER, WINNEBAGO COUNTY, WISCONSIN
in the eastern part of the county, surface-water pollution from inade¬
quately treated sewage and industrial wastes, and pollution of ground
water in dolomite aquifers.
Development of the water resources of the county should follow a
comprehensive plan which takes into consideration all aspects of water
use. The use of ground water to supplement present surface-
water supplies would be a fairly inexpensive method to expand water
supply at Neenah-Menasha and Oshkosh and to reduce the algae-
treatment problems during the summer months. Existing wells and
proposed supplementary ground-water supplies would provide ade¬
quate emergency sources of water. In the Neenah-Menasha and Osh¬
kosh areas, dispersal of wells toward the west, which is the direction
of greatest recharge, would be more effective in reducing water-level
declines than dispersal in any other direction and would also decrease
the possibility of tapping saline water in the sandstone aquifer. A
program of monitoring ground-water levels, pumpage, and quality
of water in the Neenah-Menasha area is necessary to insure proper
development of the ground-water resources.
An abundant supply of good quality water could be obtained from
Lake Michigan by pipeline, but the cost of such an installation prob¬
ably would require the cooperative use of the water by a number of
communities and industries.
REFERENCES
«
Alden, W. C., 1918, The Quaternary geology of southeastern Wisconsin, with a
chapter on the older rock formations: U.S. Geol. Survey Prof. Paper 106,
356 p.
Bean, E. F., 1949, Geologic map of Wisconsin: Wisconsin Geol. and Nat. History
Survey.
Berkstresser, C. F., Jr., 1964, Ground-water resources of Waupaca County, Wis¬
consin : U.S. Geol. Survey Water-Supply Paper 1669-U, 38 p.
Birge, E. A., and Juday, C., 1911, The inland lakes of Wisconsin: Wisconsin
Geol. and Nat. History Survey Bull. 22, 259 p.
Drescher, W. J., 1953, Ground-water conditions in artesian aquifers in Brown
County, Wisconsin: U.S. Geol. Survey Water-Supply Paper 1190, 49 p.
Ferris, J. G., Knowles, D. B., Brown, R. H., and Stallman, R. W., 1962, Theory
of aquifer tests: U.S. Geol. Survey Water-Supply Paper 1536-E, 174 p.
Knowles, D. B., 1964, Ground-water conditions in the Green Bay area, Wiscon¬
sin, 1950-60 : U.S. Geol. Survey Water-Supply Paper 1669-J, 37 p.
Knowles, D. B., Dreher, F. C., and Whetstone, G. W., 1964, Water resources of
the Green Bay area, Wisconsin: U.S. Geol. Survey Water-Supply Paper
1499-G, 67 p.
LeRoux, E. F., 1957, Geology and ground-water resources of Outagamie County,
Wisconsin: U.S. Geol. Survey Water-Supply Paper 1421, 57 p.
MacKichan, K. A., and Kammerer, J. C., 1961, Estimated use of water in the
United States : U.S. Geol. Survey Circ. 456, 44 p.
REFERENCES 61
Newport, T. G., 1962, Geology and ground-water resources of Fond du Lac
County, Wisconsin: U.S. Geol. Survey Water-Supply Paper 1604, 52 p.
lyling, R. W., 1961, A preliminary study of the distribution of saline water
in the bedrock aquifers of eastern Wisconsin: Wisconsin Geol. and Nat.
History Survey Inf. Circ. 5, 23 p.
Smith, L. S., 1908, The water powers of Wisconsin: Wisconsin Geol. and Nat.
History Survey Bull. 20, 354 p.
Summers, W. K., 1965, Geology and ground-water resources of Waushara
County, Wisconsin: U.S. Geol. Survey Water-Supply Paper 1809-B, 32 p.
Theis, C. V., 1935, The relation between the lowering of the piezometric surface
and the rate and duration of discharge of a well using ground-water storage:
Am. Geophys. Union Trans., pt. 2, p. 519-524.
Thwaites, F. T., 1943, Pleistocene of part of northeastern Wisconsin: Geol. Soc.
American Bull., v. 54, p. 87-144.
-1957, Buried Precambrian of Wisconsin : Wisconsin Geol. and Nat. History
Survey map.
J.S. Army Corps of Engineers, 1922, Survey of Fox River: U.S. 67th Cong.,
2d sess., House Doc. 146, 170 p.
J.S. Department of Commerce, 1960, 1960 Census of population, Wisconsin:
U.S. Dept. Commerce Bur. Census, Advance Rept, PC(A1)-51, 19 p.
J.S. Public Health Service, 1962, Drinking water standards, 1962: U.S. Public
Health Service Pub. 956, 61 p.
kVeidman, Samuel, and Schultz, H. R., 1915, The underground and surface water
supplies of Wisconsin: Wisconsin Geol. and Nat. History Survey Bull. 35,
664 p.
iVirth, H. E., 1959, Water use in Wisconsin: Wisconsin State Board of Health,
36 p.
Wisconsin Conservation Department, 1962, Winnebago County wetlands: Wis¬
consin Conserv. Dept., Wisconsin Wetland Inventory, 70 p.
Wisconsin Committee on Water Pollution, 1956, Evaluation of stream loading
and purification capacity: Wisconsin Comm, on Water Pollution Bull. 101,
110 p.
o
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