1

Effects of Historical Land-Cover Changes on Flooding and Sedimentation,

North Fish Creek, Wisconsin

U.S. Department of the Interior

U.S. Geological Survey

USGS Water-Resources Investigations Report 99–4083

June 1999

ABSTRACT

North Fish Creek, a Wisconsin tributary to Lake Superior, is an

important recreational fishery that is potentially limited by the loss of

aquatic habitat caused by accelerated flooding and sedimentation. A

study of the historical flooding and sedimentation characteristics of

North Fish Creek was done to determine how North Fish Creek

responded to human-caused changes in land cover since European

settlement of the region in the 1870’s. Geomorphic field evidence

combined with hydrologic and sediment-transport modeling indicate

that historical clear-cut logging, followed by agricultural activity,

significantly altered the hydrologic and geomorphic conditions of

North Fish Creek. The geomorphic responses to land-cover changes

were especially sensitive to the location of reaches along the main stem

and on the timing of large floods.

On the basis of geomorphic evidence in flood-plain deposits and

abandoned channels, the size of floods and sediment loads increased in

North Fish Creek after conversion of forested land to cropland and

pasture. Changes in channel characteristics were particularly noticeable

after record floods in 1941 and 1946. The upper main stem channel bed

eroded downward at least 3 meters and the channel capacity at least

doubled after European settlement. In the lower main stem, the postsettlement sedimentation rate on the flood plain and in the channel is 4

to 6 times pre-settlement rates. The water table also appears to be rising

By Faith A. Fitzpatrick1, James C. Knox2, and Heather E. Whitman1

near the mouth of North Fish Creek, perhaps consistent with (1) elevated

local streambed elevations caused by sedimentation and (2) a slow

relative rise in the local level of Lake Superior due to crustal rebound

from glaciation. Along a transitional reach of the main stem between the

upper and lower main stem, there is evidence of accelerated flood-plain

sedimentation initially following European settlement. Since at least

the 1940’s, however, the channel bed in the transitional reach has eroded

about 1 meter and the channel capacity has at least doubled.

Results from hydrologic and sediment-transport modeling indicate

that modern flood peaks and sediment loads in North Fish Creek may

be double that expected under pre-settlement forest cover. During

maximum agricultural activity in the mid-1920’s to mid-1930’s, flood

peaks probably were about 3 times larger and sediment loads were about

5 times larger than expected under pre-settlement forest cover. These

results indicate that future changes from pasture or cropland to forest

will help reduce flood peaks, thereby reducing erosion and sedimentation. The addition of detention basins (to decrease flood peaks) on

tributaries to North Fish Creek, or bank and instream restoration (to

decrease erosion) in the upper main stem, also may help reduce the

contribution of sediment from the upper main stem to the transitional

section and lower main stem of the creek.

Figure 1. Location and

major land cover

characteristics of North

Fish Creek.

1

U.S. Geological Survey, Water Resources Division; 2University of Wisconsin–Madison, Department of Geography

0 25 MILES

Study area

WISCONSIN

91°15'

46°35'

46°30'

91°

Fish

Creek

North

Lake Superior

Chequamegon Bay

Fish Creek

Slough

Ino

Ashland

Moquah

Fish

Gaging 2 station

2 Climate station C

(Ashland Experimental Farm) reek

North

0 1 2 3 4 KILOMETERS

0 1 2 3 4 MILES

Streams

Cities

Land cover

Agriculture (crops)

Grassland

Forest

Water

Wetlands

Barren and shrub land

Land use data source: WISCLAND Land Cover, 1992–93

(Lillesand and others, 1998)

Base from U.S. Geological Survey 1:100,000 digital data;

modified by Wisconsin Deparment of Natural Resources.

Wisconsin Transverse Mercator projection.

EXPLANATION

Approximate drainagebasin boundary

Urban Roads

Other features

U P P E R M A I N S T E M UPPER MAIN STEM

L O W E R M A I N S T E M LOWER MAIN STEM

TRANSITIONAL

MAIN STEM

TRANSITIONAL

MAIN STEM

FISH CREEK

SLOUGH FISH CREEKSLOUGH
2

Figure 2. Diagram of common landforms

associated with stream and valley

environments in North Fish Creek

(modified from Ludman and Coch, 1982

and Fitzpatrick and others, 1998).

INTRODUCTION

North Fish Creek, a 122-kilometer2 Wisconsin tributary to

Chequamegon Bay, Lake Superior (fig. 1), is an important recreational

fishery that is potentially limited by the loss of aquatic habitat caused

by accelerated erosion and sedimentation (B. Swanson, Wisconsin

Department of Natural Resources, written commun., 1994). Although

most of the land in the drainage basin is forested, large floods in the past

have contributed to severe erosion problems (Johannes and others,

1970). Potential accelerated sedimentation rates near the mouth of

North Fish Creek also may be affecting fish and waterfowl habitats in

Fish Creek Slough.

Flooding and sedimentation are common problems for many southern Lake Superior tributaries, and Wisconsin shorelines and streams

are known to be major contributors of sediment to Lake Superior

(Robertson, 1996; Natural Resources Conservation Service and U.S.

Forest Service, 1998). North Fish Creek was selected as a typical

example of such a tributary as the focus of a cooperative study between

the U.S. Geological Survey and the Wisconsin Department of Natural

Resources to determine how flooding and sedimentation characteristics for similar Lake Superior tributaries may have changed in response

to changes in land cover after European settlement of the region in the

1870’s. Rates of and responses to human-influenced runoff and erosion were compared to those expected from natural changes in climatic

conditions and relative water level of Lake Superior.

North Fish Creek is naturally susceptible to large floods and erosion

problems because of its geologic setting. Surficial deposits in its basin

consist mainly of red clay, with some areas of sandy deposits along the

northern and southwestern edges of the basin. The sandy deposits also

are present beneath the red clay and are exposed in many of the

25-meter-high bluffs along the stream. The bluffs are highly susceptible to erosion where they are undercut by flowing water. Soils

developed in the red clay have a very low infiltration rate—0.25

centimeters per hour (cm/hr) (Krug and others, 1992). The rate of

precipitation and (or) snowmelt, however, commonly exceeds 0.25

cm/hr; therefore, North Fish Creek naturally has the potential to be a

“flashy stream” with frequent, large floods. In contrast, soils developed in the sandy deposits have an infiltration rate of 19 cm/hr and,

hence, they are associated with minimal surface runoff (Krug and

others, 1992). Ground-water recharge in the sandy areas supplies

abundant springs that discharge to North Fish Creek. The flow from

these springs accounts for the exceptionally high base flow in the creek.

This report presents the results from the above-mentioned study of the

ways in which historical land-cover changes have affected flooding and

sedimentation in North Fish Creek, and illustrates how geomorphic field

techniques and hydrologic modeling were used to determine changes in

North Fish Creek after European settlement. The report describes

• major human and natural influences on flooding and sedimentation,

• the major source of sediment to the stream,

• changes in channel characteristics and flood size after European

settlement,

• comparisons between pre- and post-settlement erosion and sedimentation rates and overall channel adjustments,

• a post-settlement sediment budget, and

• implications of study results on land and water management.

Relevant Fluvial Geomorphology Concepts

Simply defined, fluvial geomorphology is the study of landforms and

processes related to streams and flowing water. It is the study of why

specific landforms are present, what surficial processes create them, and

how landforms develop and change over many years. Geomorphic

studies are typically based on field observations supported by empirical

equations and laboratory analysis. The geomorphic terminology and

concepts used in this report are described in the following paragraphs.

A stream channel is just one of many landforms created by flowing

water (fig. 2). Streambanks form the steep or sloping ground that borders

a channel and confines the water to the channel when the water level, or

flow, is normal. The flood plain is generally a flat to gently sloping

depositional surface adjacent to the channel that is occupied by the

modern stream. The elevation of this active flood plain is considered here

to be the same as bankfull stage. The bankfull stage is the point at which

water just begins to overflow the channel and spill out onto the flood

plain. Field indicators used for determining bankfull stage include any

breaks in the slope along streambanks, and the average maximum

elevation of sand deposition on point bars (Wolman and Leopold, 1957).

In general, bankfull flows are expected to occur on average every 1 to 2

years (Leopold and others, 1964), although considerable variability in

the recurrence interval has been found among streams (Williams, 1978).

A terrace is an abandoned flood plain that formed when the stream

flowed at a higher elevation than at present. Terraces are no longer

related to the modern flow regime of the stream.

The course of a stream sometimes changes location during large

floods when water flows over the flood plain. Channels may also be



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Bankfull stage

Channel Bank

Bank

Point bar Low flow

Terrace

Outside of meander bend

Flood plain

Inside of meander bend

Channel deposits

Fluvial deposits

Flood plain

(Oxbow lake) 

abandoned

channel

Filled in

abandoned

channel Levee

Breach in levee

Point bar

Silt & sand & clay

Valley side

Upland

Terrace

Terrace

Terrace Buried

abandoned

channel

Silt &

clay 

Silt & sand & clay Sand Glacial till

  




3

abandoned when curves in the course of the stream, or meanders,

migrate laterally and eventually intersect. The characteristics of these

abandoned channels are preserved in flood-plain deposits. Some abandoned channels may be filled with water (oxbow lakes), whereas other

channels may become buried by sediment deposited on the flood plain

during floods (fig. 2).

Stream networks commonly consist of an erosion zone (where

sediment and runoff are generated), a transfer or transitional zone

(where sediment and water are transferred through with no gain or loss

of material), and a deposition zone (where sediment from upstream

erosion is dropped out of transport) (Schumm, 1977) (fig. 3). The

longitudinal profile of a stream illustrates how the gradient, or slope, of

a stream changes from relatively high in the erosion zone to relatively

low in the depositional zone near the mouth.

Streams are dynamic features that adjust their physical characteristics to prevailing climate, geology, topography, vegetation, and base

level (the level, or elevation, at which a stream enters a major water

body). A change in any of these conditions may cause a stream to alter

the dimensions, elevation, gradient, and location of its channel. Channel

adjustments can occur over periods as brief as individual storms to as

long as thousands of years. The type of channel adjustment resulting

from an environmental disturbance or change depends on the location

of the channel within the stream network.

The ability or power of a stream to erode and transport sediment is

increased if the amount and intensity of runoff resulting from rainfall or

snowmelt are increased (Leopold and Maddock, 1953). If the amount

and intensity of runoff are increased, channels in an erosion zone of a

stream network may become steeper and have unstable, eroding

streambanks and channel beds, whereas channels and flood plains in the

depositional zone of a stream network will become filled with sediment

as the additional sediment from upstream is deposited.

The onset of channel-bed erosion creates a strong positive feedback

that maintains or even intensifies the erosion. Even large streamflows

may be confined within increasingly entrenched channels with increasing water-conveying capacity, and streamwater will not spill out into the

old flood plain as frequently as in the past. This increased capacity

results in little sediment being deposited on the old flood plain in the

erosion zone. Meanwhile, the erosive power of the stream channel is

increased, the channel bed continues to erode, and more water and

sediment are transported downstream. Over time, streambank erosion

may continue as the stream begins to build a new flood plain through

meandering. Channels in the transition zone between the erosional and

depositional zones will be the most sensitive and will respond the most

quickly to changes in runoff and sediment characteristics.

Importance of Geomorphic Studies for

Land and Water Management

Measuring and modeling floods and instantaneous sediment movement and transport are useful for short time periods, but such methods

are not adequate for representing changes in physical characteristics of

channels and flood plains over decades, centuries, or millennia. Alternatively, geomorphic methods provide insight into the long-term history of channel changes and place these changes in the context of related

flood-plain processes and upstream/downstream effects. Geomorphic

field studies are particularly useful for putting human-caused changes

in land cover into perspective with climatic and other natural changes.

Thus, geomorphic studies are useful for determining the goals and for

assessing the effectiveness of water-resources management, protection,

and restoration. Comparison of modern changes in flooding and sedimentation to past natural environmental changes can, in some instances,

provide useful glimpses of future stream changes that might result from

additional land-cover alterations.

Figure 3. Overhead view and longitudinal profile of geomorphic zones

within a stream network (modified from Schumm, 1977).

Figure 4. Coring techniques used for collecting sediment samples from

the flood plain and channels of North Fish Creek.

A) soil probe,

B) piston corer,

C) vibrating corer,

D) examination of a piston core from Fish Creek Slough.

A

▼

▼

B

▼

C

▼

D

Erosion zone Transition zone Deposition zone

Erosion zone Transition zone Deposition zone

Tributaries

Direction of water flow

Mouth

Main stem

Distance upstream from mouth

Elevation

Low gradient

Longitudinal profile

High gradient
4

Methods Used in the North Fish Creek Study

Historical changes in flooding and sedimentation for North Fish

Creek were reconstructed from field and laboratory analyses of sediment cores extracted at various field sites. Hydrologic and sedimenttransport modeling and historical documents were used to supplement

field data. A detailed description of the methodology used in this study

can be found in Fitzpatrick (1998). Relative degree of soil development,

radiocarbon-age dating, and landscape position were used to determine

pre- and post-settlement rates of erosion and sedimentation. About 200

sediment cores were collected from flood-plain, channel, and mouth

areas of North Fish Creek in 1994 and 1995 (fig. 4). Streambank and

bluff exposures also were examined to reconstruct historical and presettlement erosion and sedimentation rates. Selected sediment samples

from cores and exposures were analyzed for sediment particle size and

organic carbon content. Samples of wood and organic material also

were collected for radiocarbon age determinations. For calculating

sedimentation rates and ages of abandoned channels, calendar-calibrated ranges were calculated from conventional radiocarbon ages

using a calibration procedure based on tree-ring data (Stuiver and

Reimer, 1993). The calendar-calibrated radiocarbon age (in A.D. or

B.C. years in this report) is given as a range that includes a possible

statistical error of 2 standard deviations (95-percent probability).

The ages of five abandoned channels (fig. 5) along the upper,

transitional, and lower main stem were determined, and the size,

elevation, gradient, and sediment characteristics of the abandoned

channels were used to estimate bankfull flows and erosion and sedimentation rates. HEC-2 flood-profile software was used to estimate bankfull

flows in the modern and abandoned channels (U.S. Army Corps of

Engineers, 1991). Estimated flow volumes also were determined for

full-channel-capacity flows—defined here as the cross-section capacity

extending to the level of the now relict historical flood plain in areas of

channel downcutting and (or) active bank erosion.

The HEC-1 rainfall/runoff model (U.S. Army Corps of Engineers,

1990) was used to estimate the variability in flood peaks for various

types of land cover in North Fish Creek. Flood peaks were modeled for

a historical summer storm expected to occur on average approximately

every 2 years (Hershfield, 1961). The modeled floods were integrated

with sediment-transport relations derived from streamflow and sediment data collected at a gaging station on North Fish Creek near

Moquah (fig. 1) (Rose and Graczyk, 1996; Fitzpatrick, 1998). The

hydrologic/sediment-transport model was calibrated with gaging-station data. Three land-cover scenarios were modeled: complete forest

(representing pre-settlement conditions), peak agriculture in the mid1920’s to mid-1930’s (as represented by land-use statistics reported in

the Bayfield County 1928 Land Economic Inventory), and current

conditions (from 1992–93 WISCLAND satellite imagery). Seven small

detention basins were added to the watershed model to determine the

extent to which they would sufficiently reduce flood peaks, which, in

turn, might decrease erosion.

The 1855 Government Land Office (GLO) survey notes were used

to compare modern and pre-settlement channel-width and streambedsediment characteristics. In addition to containing detailed descriptions

of the pre-settlement vegetation, the surveys also included locations of

streams at section lines, the width and direction of the stream, characteristics of streambed sediment, water clarity, and flow. Other historical

documents, such as aerial photographs, bridge-construction records,

and newspaper articles, also were used to support field and laboratory

data. (Newspaper articles contained information about recreational

fishing, logging, and flooding on North Fish Creek.)

Figure 6. Photographs of North

Fish Creek at

railroad crossing,

Ashland Junction,

Wis., sec. 2/3, T. 47

N., R. 5 W.,

Ashland Junction,

Wis.

A) circa 1885–88 (J.M. Turner and Co., 1889),

reproduction courtesy of State Historical

Society of Wisconsin, negative no.

WH:(X3)51439,

B) circa 1888–98 (Turner and Turner, 1898), C) 1997 (courtesy of D. Pratt, Wisconsin

Department of Natural Resources, Superior,

Wis.).

Figure 5. Locations of channel

cross-sections and eroding bluffs

along North Fish Creek. For this

study, the main stem of North Fish

Creek was divided into 3 zones

primarily based on changes in

gradient. The upper main stem

has a high gradient and the lower

main stem has a low gradient.

The gradient changes from high

to low gradient in the transitional

main stem.

2

Road

Stream

Abandoned channel section

Eroded bluff

Lake Superior

Chequamegon

Bay

Bayfield/

Ino site

Moore site

Skulan site

Hanson site

WDNR/Ashland site

EXPLANATION

Channel cross section

0 1 4 MILES

0 123 4 KILOMETERS

Base from U.S. Geological Survey 1:100,000 digital data; 2 3

modified by Wisconsin Department of Natural Resources.

Wisconsin Transverse Mercator projection.

Moquah

46°35'

91°

Ashland

North

Fish

Creek

Pine

Creek

UPPER MAIN STEM

LOWER MAIN STEM

TRANSITIONAL

MAIN STEM

FISH CREEK

SLOUGH
5

MAJOR INFLUENCES ON FLOODING AND

SEDIMENTATION

Three major factors influence the flooding and sedimentation characteristics of North Fish Creek—land cover, climate, and base level.

Clearing and burning of forests after European settlement of the region

constituted an extreme disturbance of land cover. Minor climate and

base-level changes also have occurred since European settlement.

Changes in Land Cover

The removal of forest cover may result in an increase in the size and

peaks of floods by increasing surface runoff (Verry, 1987). If forest

vegetation is allowed to return, recovery to pre-logging hydrologic

conditions may take from only a few years to several decades (Reinhart

and others, 1963). However, in areas where the natural vegetation is

permanently converted to agriculture, substantial long-term changes in

flooding and sedimentation occur (Knox, 1977; Jacobson and Primm,

1997).

Before European settlement, the natural vegetation of the North Fish

Creek Basin consisted mainly of balsam fir/white spruce forest (Finley,

1976). Most of the logging and burning of old-growth forests in the

basin took place from 1882 to 1889; more than 47 million board feet of

logs were floated down North Fish Creek to sawmills on the shoreline

of Chequamegon Bay (D. Pratt, Wisconsin Department of Natural

Resources, written commun., 1996). The significant short-term damage

to streambanks caused by log drives can be seen in a series of photographs of North Fish Creek (fig. 6). Approximately 10 years after the log

drives had ended, the streambanks started to stabilize (fig. 6B). A

photograph of the same location in 1997 (fig. 6C) shows that the

streambanks are much more vegetated and the channel more narrow

under modern land cover than they were during the log drives.

 After the decline in logging, major agricultural development in the

region occurred from 1895 to 1920 (Mahaffey and Bassuk, 1978).

Agricultural activity peaked in the mid-1920’s to mid-1930’s, with

much of the upland areas consisting of cropland (forage crops and some

corn) and pasture for dairy cattle (fig. 7). Since the peak agricultural

activity, the relative amount of agricultural land (cropland and pasture/

grassland) and forest has changed little; however, the amount of

cropland was about 22 percent in 1928 compared to 3 percent in 1992–

93 (fig. 7). In 1992, nearly one-third of the basin (31 percent) was

classified as grassland, which is a combination of grazed or abandoned

pastures for dairy or beef cattle (Lillesand and others, 1998). The

average age of forests in the basin was probably less in 1928 than in

1992–93, based on the small size of trees recorded in the 1928 Land

Economic Inventory (Wisconsin Department of Agriculture and Wisconsin Geological and Natural History Survey, 1928).

 Changes in Climate

 In addition to land cover, climate also affects the frequency and

magnitude of floods and sediment loads by affecting the intensity,

frequency, and magnitude of rainfall and snowmelt (Knox, 1983; 1984).

Depending on the position of a stream within a stream network (fig. 3),

the response of a stream to climatic change can be sedimentation,

erosion, meandering variability, or changes in the dimensions of channels. Infrequent, large floods can trigger substantial geomorphic change

(Baker and Costa, 1987). Such floods, although rare, can cause the

formation of stream terraces and new flood plains and can transport

coarse sediment. Small, frequent floods are important in rebuilding

channel shape after large floods (Wolman and Leopold, 1957). Large

storms, when followed by frequent storms of even moderate magnitude,

have been observed to be particularly destructive to channel stability

(Schumm and Lichty, 1963).

No long-term streamflow records are available for North Fish Creek;

therefore, its flood history was reconstructed from the precipitation

record at the Ashland Experimental Farm (fig. 1) and from local

newspaper accounts. Because large floods can destabilize a river

system, rainfalls greater than 7.6 cm (3 inches) were identified for the

period of record (1900 to 1997) at the precipitation station (fig. 8). These

rainfalls are greater than the 2-year, 24-hour rainfall for the area, which

is approximately 6.4 cm (Hershfield, 1961). The precipitation record

shows that the temporal distribution of large storms from 1900 to 1997

was episodic. Multiple rainfalls greater than 7.6 cm occurred in some

years, whereas no rainfalls exceeded 7.6 cm during several 2- to 5-year

periods (fig. 8). The most obvious 5-year periods without major rainfalls were 1932–37, 1965–70, and 1986–91. In contrast, frequent large

rains between 1949 and 1954 followed the exceptionally large rains of

August 1941 and June 1946.

Figure 7. Land-use history in the North Fish Creek Basin (pre-1870, 1855

government land office surveys; circa 1890, historical accounts, and

newspaper articles; 1928, Land Economic Inventory; 1992–93, WISCLAND

satellite data).

Figure 8. Rainfalls greater than 7.6 centimeters (3 inches), Ashland

Experimental Farm, Wis., 1900–97.

The 1946 storm was by far the largest on record. Total precipitation

over the 2-day period was greater than 23 cm. For comparison, the

estimated 100-year, 24-hour rainfall for the Ashland area is 11.4 cm

(Hershfield, 1961). Several roads, buildings, and rail bridges were

washed out along the tributaries and main stem of North Fish Creek and

at the mouth of Fish Creek.

Changes in Base Level

Rising lake levels typically cause tributary mouths to fill with

sediment, whereas falling levels cause channel erosion at tributary

mouths (Larsen, 1985). For North Fish Creek, a change in base level was

caused mainly by changing levels of Lake Superior over the last several

thousand years. The overall level of Lake Superior since 1860 at the

7/21/09 8/30/41

4/23/60

8/23/78 9/3/85

7/2/92

6/24/46

0 0

1

2

3

4

5

6

7

8

9

10

5

10

15

20

25

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990

YEAR

RAINFALL, IN CENTIMETERS

RAINFALL, IN INCHES

Forest (100%)

Pre-1870 Circa 1890

Clearcut

(90%)

Forest (10%)

1928

Pasture/grassland (7%)

Cropland (22%)

Wetland (4%)

Barren (burn) (1%)

Forest (66%)

1992–93

Pasture/grassland

 (31%)

Cropland (3%)

Wetland (5%)

Barren (shrubland) 

 (3%)

Forest (58%)
6

P-10

P-25 P-26

P-24

P-23

P-8, P-9, P-19

P-1

G-7

P-7

P-17, P-18

P-4, P-15, P-16 P-5

P-3 P-6

P-2

P-27

P-28

P-29

P-30

P-11 P-20

P-22

P-21

1906 channel

1906 outlet

P-10

P-25 P-26

P-24

P-23

P-8, P-9, P-19

P-1

G-7

P-7

1906 channel

North Fish Creek

South Fish Creek

Fish Creek Slough

N

P-17, P-18

P-4, P-15, P-16

P-5

P-3 P-6

P-2

P-27

P-28

P-29

P-30

P-11 P-20

P-22

P-21

1906 outlet

Chequamegon Bay

0

0 1 MILE

1 KILOMETER

0.5

0.5

Lake Superior

North Fish Creek

South Fish Creek

Fish Creek Slough

Chequamegon Bay

Figure 9. Effects of differential crustal rebound on

shoreline elevations for Lake Superior.

Figure 10. Photographs of the upper, transitional, and lower main stem of

North Fish Creek.

Figure 11. 1990 aerial photograph of Fish Creek Slough with locations of cores

collected in 1995. The 1906 channel location was interpreted from historical maps.

control gage near its outlet has been fairly constant at about 183 meters

(m) because of human stabilization (International Joint Commission,

1976; U.S. Department of Commerce, 1973); however, the elevation of

the water surface of the Chequamegon Bay area has increased by about

26 cm relative to the land surface since the 1870’s (fig. 9). This increase

is caused by regional differences in crustal rebound after glacial ice

melted from the region about 10,000 to 11,000 years ago (Larsen, 1994).

The land on the eastern half of Lake Superior, which was more

depressed by glacial ice, is rising at a faster rate than land on the western

half (fig. 9).

POST-SETTLEMENT CHANGES IN FLOODING AND

SEDIMENTATION

 In this section, post-settlement flooding and sedimentation changes

in North Fish Creek are described for three reaches along the main stem

and Fish Creek Slough (fig. 5). Example photographs illustrate the

modern differences in channel characteristics along the main stem (fig.

10). The upper main stem is characterized by a cobble/boulder and sand

channel bed, eroding bluffs, and a high gradient (0.0159 m/m). In the

transitional main stem, a shift from high to low gradient is reflected by

a progressive downstream change from cobble/boulder and sand channel bed to a gravel and sand channel bed. The lower main stem is

characterized by a predominantly sandy channel bed, low streambanks,

and a relatively low gradient (0.00127 m/m). The main channel of Fish

Creek through Fish Creek Slough (fig. 11) also contains a sandy channel

bed.

Source of Sediment in North Fish Creek

A study of sediment loadings in North Fish Creek at the gaging

station (fig. 1) indicated that upland erosion is not a major source of

sediment to the creek (Rose and Graczyk, 1996). A comparison of

eroding bluff locations (fig. 5) from 1938 and 1990 aerial photographs

indicate that bluff erosion along the upper main stem can account for

most of the sediment load observed at the gaging station. On the basis

of the aerial photograph comparisons, bluffs retreated at an average rate

of 25 m over 52 years, or about 0.5 m/yr. The combined amount of

sediment lost from all the bluffs over this 52-year period is about 9,800

m3

/yr, or 14,100 tonnes/yr. Photographs of a large bluff along the upper

main stem of North Fish Creek in 1994 and again in 1996 (fig. 12) show

W E Lake Superior Basin

A.D. 1995

 26 cm

Crustal rebound

Fish Creek Outlet

A.D. 1870

A.D. 1870

}

Upper main stem

Transitional main stem

Lower main stem
7

Figure 12. Photographs of eroding bluff along North Fish Creek, upper

main stem, 1994 and 1996.

observable bluff retreat and substantial change in the channel location

over only a 2-year period. The eroding bluffs along North Fish Creek

expose varied sedimentary beds, ranging from clayey tills and boulders

deposited in former glacial ice-contact settings to sand and silt deposited by former glacial-meltwater runoff and ponding. On the whole, the

eroding bluffs are sources for substantial amounts of sand. They

average about 49 percent sand, with individual beds ranging from

nearly all silt to nearly all sand. Rose and Graczyk (1996) estimated an

average annual total sediment load at the gaging station of approximately 13,800 tonnes/yr in 1990–91, and 60 percent of that sediment

load was sand.

Changes in Channel Characteristics and Small,

Frequent Floods

In general, the texture of streambed sediment in North Fish Creek has

not changed since the 1855 GLO survey. For example, the lower main

stem had a sandy bed in 1855 as well as in 1995. One exception was at

the Hanson site (fig. 5), where the 1855 GLO survey recorded a rocky

streambed sediment. No evidence of rocky streambed sediment was

found, however, in cores from the modern channel, in two nearby

abandoned channels, or in the flood plain.

Post-settlement changes in channel width were dependent on the

location along the main stem. Comparisons of 1995 and 1855 channel

widths indicate that the channel narrowed somewhat in the upper main

stem and widened in the lower main stem (fig. 13). The change from

narrowing to widening corresponds with a shift from a high gradient to

a relatively low gradient channel from upstream to downstream.

Figure 13. Longitudinal profile of North Fish Creek with changes in

channel width, 1855–1990 and estimates of bankfull flow capacity.

Stream-width changes calculated from 1855 Government Land Office

surveys and from cross-section surveys done as a part of this study in

1995.

1996

ALTITUDE, IN METERS

DISTANCE FROM MOUTH, IN KILOMETERS

150

200

250

300

350

400

40 35 30 25 20 15 10 5 0

Estimated bankfull discharge,

in cubic meters per second

Distance, in meters

Transitional reach Degradational reach

Aggradational reach

Elevation, in meters

25 m /s

Modern

3

10 m /s

Pre-1946

3

15 m /s

Modern

3

20–25 m /s

Pre-1946

3

55 m /s

Modern

3

5–10 m /s

Pre-1906

3

0 20 40 60

12

10

8

6

4

0 20 40 60

0 20 40 60

10

8

6

4

8

6

4

Longitudinal

profile Eroding bluffs

-1.1

-0.2

-0.3

-4.9-3.4

0.8

-3.3 -3.3

1.0 0 2.6 0 2.6

Changes in stream width

(1995-1855) Transitional

main stem Lower main stem

Fish Creek

Upper main stem Slough

1994

Geomorphic evidence indicates that the modern bankfull flow along

the upper and transitional main stem is as much as 2.5 times greater than

the pre-1946 bankfull flow (fig. 13). The pre-1946 channel cross

sections shown in figure 13 are from channels abandoned during the

1946 flood. Bankfull flows and the sizes of the modern and pre-1906

channels appear to be about the same in the lower main stem.

Rainfall/runoff model simulation results for the gaging station near

Moquah (fig. 1) indicate that under peak agricultural land use in the

basin (about 1928), flood peaks expected to occur on average every 2

years were about 3 times greater than under pre-settlement forest cover.

Flood peaks of this recurrence interval under modern land cover are

about twice as large as their pre-settlement counterparts (fig. 14). An

actual flood peak under complete forested conditions probably was

even smaller than the modeled flood because the model did not account

for potential decreases in the thickness of an organic detritus layer on the

forest floor after logging and burning.

Changes in Erosion and Sedimentation Rates

Geomorphic evidence and model simulation results indicate that

post-settlement changes in land cover in the North Fish Creek Basin

affected erosion and sedimentation rates and sediment loads. Figure 14

shows the storm hydrograph for a 2-year flood under 4 modeled

conditions and under current, observed conditions. During peak agricultural activity in the 1930’s, sediment loads were 2.5 times greater

than under modern land cover and may have been 5 times greater than

under pre-settlement forest cover. Field evidence indicates up to a

ninefold increase in post-settlement erosion and sedimentation rates

over natural pre-settlement rates. These rates are systematically dependent on location along the main stem.

For the upper main stem of North Fish Creek, interpretations from

cores, eroding cut banks, valley transects, abandoned channels, and

historical bridge data indicate that the channel bed eroded a minimum

of 1 to 3.5 m along the upper main stem since the 1870’s. An example

valley cross section from the Moore site (figs. 5 and 15) illustrates how

the modern channel is entrenched compared to a channel abandoned

during the 1946 flood. The valley cross section illustrates the absence

of a modern flood plain, which is typical for streams that are downcutting
8

rapidly. This entrenchment makes the modern channel very efficient at

transporting water and sediment. Most floods are now confined within

the entrenched channel, and the potential for erosion is not dissipated as

it was in the past when even small floods spilled out onto a more

extensive flood plain. The presence of at least five terraces and the

deposits beneath them at the Moore site indicate that the upper main

stem has been subject to many episodes of erosion over the last 10,000

years.

Figure 15. Valley cross section of North Fish Creek at the Moore site,

upper main stem.

Field evidence indicates that postsettlement flood-plain sedimentation rates

have been highest along the transitional

main stem. Field evidence also indicates

post-settlement channel erosion along the

transitional main stem. Approximately

0.5 to 2 m of post-settlement fine sand

covers the pre-settlement flood-plain surface. An example of core and eroding cutbank data from a partial valley cross section from the Skulan site (figs. 5 and 16)

illustrates the relations between pre- and

post-settlement flood-plain surfaces, terraces, and channel-bed elevations. A wood

sample from a buried soil 2 m below the

top of an eroding terrace exposure (fig.

16) has a radiocarbon age of A.D.

1545±405, supporting the identification

of this buried soil as the pre-settlement

flood-plain soil (pre-A.D. 1870). A radiocarbon age of A.D. 1525±115 for wood

buried below the pre-settlement soil in

this same terrace exposure indicates that,

at this location, the post-settlement sedimentation rate of 1.6 cm/yr is 9 times

greater than the pre-settlement sedimentation rate of 0.17 cm/yr. Coarse sand

layers in the uppermost part of the Skulan

terrace cut, in addition to accumulation of organic material and weak

soil development, indicate that only extremely large floods overtop this

terrace surface under modern conditions.

 The channel bed along the transitional main stem also eroded

approximately 1 m since 1946, as evidenced by the elevation difference

between beds of the modern channel and a channel abandoned during

the 1946 flood (fig. 16). The combination of channel-bed erosion and

flood-plain sedimentation resulted in an entrenched channel along the

transitional main stem. This channel, similar to the upper main stem

channel, is efficient at rapidly moving sediment and water downstream.

The transition from high to low gradient makes the transitional main

stem particularly sensitive to changes in runoff and sediment contributions from upstream. The gravel beds along this reach provide spawning

habitat for several Lake Superior fish species. These beds are highly

susceptible to scour and (or) burying by transported sand.

At the same locality, the bed of a buried abandoned channel below

a terrace surface has a calibrated radiocarbon age of 1670 ±20 B.C. (fig.

16). The bed of this approximately 3,700-year-old channel is at an

elevation similar to that of the modern channel bed. The elevation of the

pre-1946 channel bed 1 m above the dated wood indicates that some

sedimentation in this reach occurred during the 3,600-year period prior

to European settlement. A regional climatic shift to somewhat cooler

conditions around 4,000 years ago (Winkler and Sanford, 1997; Winkler,

1996) may have contributed to an episode of sedimentation in the

transitional main stem. As mentioned earlier, changes in climatic

conditions that affect the amount and intensity of runoff can cause

changes in channel characteristics. (Cooler temperatures result in less

evaporation and more runoff.)

In the lower main stem, approximately 1 to 2 m of post-settlement

sediment accumulated on the flood plain and on the channel bed of

North Fish Creek. The WDNR/Ashland site (fig. 5) is at the downstream

end of the North Fish Creek valley proper and at the beginning of Fish

Creek Slough. A valley transect from this site is used as an example to

show the distribution and thickness of post-settlement sediment across

the flood plain (fig. 17). The core data also show that the post-settlement











 

255

256

257

258

259

260

261

262

263

DISTANCE ACROSS VALLEY, IN METERS

0 15 30 45 60 75 90 105 120

Terrace

Terrace

APPROXIMATE ALTITUDE, IN METERS

Modern

channel Terrace

Terrace

277

278

Well-developed soil

Poorly developed

 soil

Pre-1946

channel

Sand

Gravel

Sand

Gravel

Gravel

Gravel

Sand

Sand

Upland

North Fish Creek Valley

Terrace

135 150 165

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30 35 40 45

TIME, IN HOURS

DISHCARGE, IN CUBIC METERS PER SECOND

0

500

1,000

1,500

2,000

2,500

3,000

3,500

1390 1570

600

1080

3030

SEDIMENT YIELD, IN TONNES

Observed at 

gaging station

Modeled current 

conditions

Modeled pre-1870

complete forest

Detention basins

Modeled

Modeled 1928 peak

 agriculture

Modeled 1928 peak agriculture

Observed at gaging station

Modeled detention basins

Modeled current 

conditions

Modeled pre-1870 complete forest

Figure 14. Storm hydrographs and sediment loads for North Fish Creek near Moquah, Wis., for a historical

storm on September 3, 1991, under four land-cover conditions.
9

Figure 16. Partial valley cross section of North Fish Creek at the Skulan site, transitional

main stem.

Figure 17. Stratigraphic descriptions of cores from a valley transect along the lower

main stem at the WDNR/Ashland site.

sediment deposited in the flood plain is much coarser than that

deposited in the flood plain prior to European settlement. Postsettlement deposits consist of medium to fine sand, whereas

pre-settlement deposits were generally dominated by silt or

clay-rich sediment high in organic content. The pre-settlement flood-plain surface is 1.1 to 1.7 m below the modern

flood-plain surface near the modern channel. The main stem

of North Fish Creek branches into multiple channels near this

site, causing sediment (mainly sand) to be distributed throughout the flood plain. For example, near a 1906 channel 300 m

south of the main channel, approximately 0.5 m of postsettlement sediment has been deposited, presumably originating from the nearby distributary channel of North Fish Creek

(fig. 17).

Water-table elevations in cores along the WDNR/Ashland

transect indicate a water-table gradient of approximately 3

cm/m that slopes away from the modern channel and toward

the abandoned 1906 channel (fig. 17). As the modern channel

continues to fill with sediment at an accelerated rate, the

water-table gradient between the modern channel and abandoned or spring-fed channels continues to steepen, which in

turn increases the potential of North Fish Creek to move into

deep, spring-fed channels in Fish Creek Slough.

 Core data collected near the confluence of North and South

Fish Creeks in Fish Creek Slough (fig. 11, G-7) indicate that

approximately 1.8 m of post-settlement sediment, mainly fine

sand, has accumulated on the flood plain surface at a location

20 m from the modern channel (fig. 18). Radiocarbon ages of

wood samples from buried soils below the pre-settlement soil

indicate that the post-settlement sedimentation rate of 1.4 cm/

yr at this site is 5 times greater than the average rate of 0.28 cm/

yr during the 500 years preceding European settlement. Particle-size data (fig. 18) indicate an increase in the sand content

of post-settlement flood-plain deposits compared to silt and

clay-rich pre-settlement deposits. Percentages of organic carbon increase near the modern flood-plain surface, indicating

a relatively recent decrease in flood-plain sedimentation.

(Organic material from flood-plain vegetation is easily diluted

by sediment deposition or removed by flood flows.)

The position of the outlet of Fish Creek into Chequamegon

Bay changed significantly after European settlement (fig. 11).

There are two modern outlets from the slough into

Chequamegon Bay. The western outlet is the primary outlet of

flow from Fish Creek. The eastern outlet of the slough is

approximately 1 km east of the modern outlet of Fish Creek.

Sandy sediment is mainly confined to channels that feed from

Fish Creek in the western part of Fish Creek Slough, whereas

the spring-fed channels and backwater areas in the eastern part

of the slough are mainly characterized by silt and clay. In the

eastern slough, sandy streambed sediment is found only in the

channel of Fish Creek abandoned around 1920. Water depths

in the modern channel of Fish Creek in the slough tend to be

less than 0.5 m, whereas springfed channels flowing into the

eastern slough are more than 1 m deep. Approximately 0.5 to

1.5 m of post-settlement medium to very coarse sand has

accumulated in the modern channel of Fish Creek near the

mouth of Fish Creek in Fish Creek Slough. Dense silt and clay

with variable amounts of organic debris underlie the sand

filling the modern channel. The fine-grained sediment probably represents pre-settlement backwater sediment deposited

when the mouth of Fish Creek was 1.5 km east of its present

location.

yyyy

 





y  



yyyy



y

    







 yy 

Fine-grained sand

Medium- and coarsegrained sand

Loam

Silt

Peat

Glacial till

EXPLANATION

188

187

186

185

184

183

182

181

100 200 300

North South

DISTANCE, IN METERS

APPROXIMATE ALTITUDE, IN METERS

Modern

channel

P-12

C-40

C-42

C-43 C-58

C-59 C-56 C-45 C-44

Pre-1906

channel

Distributary

channel of

North Fish Water table

0

Organic-rich

silty clay

Lacustrinemodified

glacial till

Peat

M./c.

sand

Sand loam

Silt with

organics

Organic-rich

silt loam

M. sand

M. sand

Red silt

F. sand

Organic-rich

silt

M. sand

Peat

Peat

Sand loam

Organic-rich

silty clay

C. sand

M. sand

y

6

5

4

3

2

1

0



yy

Fine-grained sand

Medium- and coarsegrained sand

Loam

Silt {

Organic material

Gravel Soil development

EXPLANATION

yyyy



 yyy 

 yyy  yyy yyy yy

yz{|yz{|





yz

{|



 

 yyy yyy



  yyy@À

(HORIZONTAL DISTANCE NOT TO SCALE)

ELEVATION, IN METERS

Terrace

Pre-1946 

channel Terrace

Modern 

channel

Water

 level

Organic

material

Charcoal and

wood pieces

Buried soil

with wood,

A.D. 1545±405

Large wood pieces,

A.D. 1525±115

C. sand

F. sand

F. sand

F. sand

F. sand

M. sand

M. sand

M. sand

F. sand

M. sand

F. sand

C. sand

M. sand

Organic 

material

Sand loam Silt

Charcoal

F. sand

Silt loam

Sand loam

Wood

1670±20 B.C.

F. sand

F. sand

M. sand

Covered

Medium sand Sand loam

with wood Sand loam
10

Figure 18. Stratigraphic description of core G-7 near the confluence of

North and South Fish Creeks, Fish Creek Slough.

Figure 19. Historical annual sediment budget for North Fish Creek near

Moquah and near Ashland Junction, Wis. (All inputs and outputs are in

tonnes per year).

Figure 20. A comparison of the modern (A.D. 1995) North Fish Creek

longitudinal profile with profiles from A.D. 1870 and approximately 2,000

B.C.

Geomorphic evidence indicates that the elevation of the water table

near the downstream end of the lower main stem and in Fish Creek

Slough has increased. In the lower main stem, the increase is probably

caused by a combination of flood-plain and channel sedimentation; and

in Fish Creek Slough the increase is probably caused by the slight rise

in base level from crustal rebound. Evidence for a rising water table at

the WDNR/Ashland site is provided by a root crown of a large stump,

identified as elm species (Ulmus), which is now at the current water

level in an abandoned channel at this site. In Fish Creek Slough, soils

near the confluence of North and South Fish Creeks are mapped as being

subject to frequent flooding; they have poor potential for cultivated

crops, hay, or pasture, but they are suitable for wetland wildlife habitat

(Pratt, 1981). In contrast, 250 years ago the confluence of North and

South Fish Creeks was the site of “a large and populous Indian village

of the Ottawas, who there raised Indian corn” (Thwaites, 1895, p. 430).

The presence of woody debris (tree trunks and branches) under approximately 30 cm of water in the backwater areas of Fish Creek Slough also

point to an increase in the level of Lake Superior relative to the land

surface. Pratt (1981) indicates that the amount of open marsh in the

slough has increased possibly twofold since the 1855 GLO surveys.

Overall Channel Adjustments

Overall channel adjustments along the main stem of North Fish

Creek are illustrated in two ways: (1) by a post-settlement sediment

budget and (2) by overall changes in the longitudinal profile along the

main stem. The post-settlement annual sediment budget for North Fish

Creek at the mouth (fig. 19) shows the sources and sinks of sediment in

North Fish Creek. Except for upland erosion rates, which were estimated from sediment-load data from Rose and Graczyk (1996), this

budget relies on post-settlement erosion and sedimentation rates derived from geomorphic field data (Fitzpatrick, 1998). Annual variations

in erosion and deposition are highly dependent on the size of floods

during each year. Post-settlement inputs of sediment from erosion in the

upper and transitional main stem (22,000 tonnes) are greater than longterm outputs to Chequamegon Bay (15,900 tonnes) because of longterm sediment deposition in the flood plain and channel along the lower

main stem. The sediment budget again illustrates the overwhelmingly

large contribution of sediment from bluff erosion along the upper main

stem.

Estimated longitudinal profiles for North Fish Creek over the last

4,000 years indicate how the elevation of the main stem has changed in

response to natural changes in climate and base level before European

settlement and to human changes in land cover after European settlement (fig. 20). Near the mouth of Fish Creek, the amount of channel

sedimentation caused by land-cover changes over the 125 years after

European settlement is about equal to that caused mainly by an increase

in base level over 4,000 years before European settlement.

IMPLICATIONS FOR FUTURE MANAGEMENT

ACTIVITIES

Modern inputs of sediment from North Fish Creek to Lake Superior

may be as much as 2.5 times higher than pre-settlement rates because

of the long-term response of channel downcutting in the upper main

stem that was initiated by clearcut logging and burning, accelerated by

agricultural land use, and maintained by accelerated runoff associated

with deforestation. This rate may have been as much as 5 times higher

in the 70 years after European settlement because of logging and more

intense agricultural activity. Depending on the position of the channel

along the main stem, overbank and channel sedimentation rates may

have been 9 times higher than pre-settlement rates, especially within the

sensitive transitional zone between upper (erosional) and lower (depo187

APPROXIMATE ALTITUDE, IN METERS

188

186

185

184

183

182

181

Pre-settlement

surface

A.D. 1360±80

A.D. 1125±135

2015±185 B.C. 0 02 1 3

Organic

carbon

PERCENT

Organic

carbon

100

Sand

Silt

Clay

PERCENT

Particle size Stratigraphic diagram







yz



Chequamegon Bay

15,900

Bluff

15,000

Upland

1,100

Streambank

1,300 Gully

910

Channel

4,100

Floodplain

4,940

Channel

1,570

RIVER KILOMETER ABOVE MOUTH AT CHEQUAMEGON BAY

ALTITUDE IN METERS

160

180

200

220

240

260

280

300

30 25 20 15 10

Transitional

main stem

5 0

Upper main stem Lower main stem Fish Creek

Slough

EXPLANATION

A.D. 1995

A.D. 1870

Approx. 2,000 B.C.
11

sitional) main stems. The exact geomorphic effects of clearcut logging

and log driving on North Fish Creek could not be separated from the

effects of agricultural activity because agriculture immediately followed clearcut logging. A few available photographs, however, indicate that streambanks along the lower main stem stabilized within a few

decades after the log drives.

In general, the texture of streambed sediment in North Fish Creek has

not changed during historical time. The stability of the channel bed,

however, has changed. The accelerated channel sedimentation rates

and shifting sand bottom have resulted in the filling of scour holes, loss

of aquatic-plant beds, and loss of fish habitat. These effects are most

noticeable in the transitional and lower main stem.

The effects of land cover on channel characteristics of North Fish

Creek were especially noticeable after large rainfalls and floods. From

about 1910 to 1940, when agricultural activities in the basin were at

their peak, large rainfalls were few and far between (fig. 8). Two of the

three largest rainfalls on record, however, occurred within 5 years of

each other (1941 and 1946) and were followed by a cluster of large

floods in the early 1950’s. This episode of large floods over about 15

years resulted in the most change in channel conditions in North Fish

Creek on the basis of geomorphic field data and historical accounts.

Thus, there may have been a delayed response in channel conditions of

about 30 years or more between peak agricultural activity and the time

when channel conditions actually reflected peak agricultural activity.

The possibility of a delayed response in channel conditions after a

change in land cover implies that short-term climatic conditions need

to be examined in the context of long-term climatic variability for

proper interpretation of cause and effect relations between land cover

and channel conditions.

Sedimentation rates and flood peaks have potentially decreased

since the 1940’s with a decrease in the extent of agricultural activity;

however, entrenched channels and floods larger than those during presettlement time continue to promote streambank and bluff erosion and

channel instability in the upper and transitional main stems. Minimal

streambank erosion in the lower main stem provides only local sources

of sediment (fig. 19). Thus, management and restoration activities

would be most effective if they focused on drainage-basin practices that

reduce runoff and on channel restorations that reduce bluff and

streambank erosion in the upper and transitional main stems. Channelrestoration or bank-stabilization efforts along the lower main stem

would result in only local benefits at best because they would not affect

the direct causes of the flooding and sedimentation problems.

Returning the vegetation in the drainage basin to its pre-settlement

forested state would reduce the amount of storm runoff, peak flows, and

related bluff erosion. Rainfall/runoff and sediment-load modeling

results indicate that the construction of detention basins in upper

tributaries may also reduce peak flows and related bluff erosion (fig.

14). Another alternative for reducing erosion and sedimentation along

North Fish Creek is to stabilize eroding bluffs along the upper main

stem and thereby potentially reduce the largest source of sediment. The

toe of the bluffs most prone to erosion could be stabilized through bank

protection. Bluff erosion also may be reduced by placement of structures in the channel that would reduce the lateral flow of water against

the toe of a bluff. Alternatively, the modern channel could be relocated

away from the eroding bluff face.

Northern Wisconsin streams such as North Fish Creek are typically

used as baseline reference sites because they are presumed to represent

nearly natural conditions. Although the effects of human activity are

less in the North Fish Creek Basin than in other, more agriculturally

dominated basins elsewhere, the results from this study indicate a

strong human influence on the stream’s geomorphology and hydrology. Nevertheless, geomorphic and modeling data both indicate that the

size of floods and sedimentation rates were markedly reduced as the

intensity of agriculture decreased over the past several decades. As a

result, aquatic habitat has the potential to improve. Long-term monitoring of streamflow, sediment loads, channel conditions, and aquatic

habitat would be useful for determining how channel conditions and

aquatic habitat adjust to future land-cover changes or management

efforts.

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Catastrophic flooding: Proceedings from the 18th Binghamton Symposium,

Boston, Allen and Unwin, p. 1–21.

Finley, R.W., 1976, Original vegetation of Wisconsin: Wisconsin Geological and

Natural History Survey Map, scale 1:500,000, 1 sheet.

Fitzpatrick, F.A., 1998, Geomorphic and hydrologic responses to vegetation, climate, and base level changes, North Fish Creek, Wisconsin: Madison, Wis.,

Geography Dept., University of Wisconsin-Madison, Ph.D. dissertation, 275 p.

Fitzpatrick, F.A., Waite, I.R., D’Arconte, P.J., Meador, M.R., Maupin, M.A., and

Gurtz, M.E., 1998, Revised methods for characterizing stream habitat in the

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Hershfield, D.M., 1961, Rainfall frequency atlas of the United States: U.S. Weather

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Johannes, S.I., Sather, L.M., and Threisen, C.W., 1970, Surface-water resources of

Bayfield County: Wisconsin Department of Natural Resources report, 372 p.

Knox, J.C., 1977, Human impacts on Wisconsin stream channels: Annals of the

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____1983, Responses of river systems to Holocene climates, in Wright, H.E., Jr., ed.,

Late Quaternary environments of the United States, v. 2, The Holocene: Minneapolis, University of Minnesota Press, p. 26–41.

____1984, Fluvial responses to small scale climate change, in Costa, J.E., and

Fleisher, P.J., eds., Developments and applications of geomorphology: Berlin,

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Krug, W.R., Conger, D.H., and Gebert, W.A., 1992, Flood-frequency characteristics

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Leopold, L.B., and Maddock, T., 1953, The hydraulic geometry of stream channels

and some physiographic implications: U.S. Geological Survey Professional

Paper 252, 57 p.

Leopold, L.B., Wolman, M.G., and Miller, J.P., 1964, Fluvial processes in geomorphology: San Francisco, W.H. Freeman and Co., 522 p.

Lillesand, T., Chipman, J., Nagel, D., Reese, H., Bobo, M., and Goldmann, R., 1998,

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25 p.

Ludman, A., and Coch, N.K., 1982, Physical geology: New York, McGraw-Hill

Book Co., 587 p.

Mahaffey, C.G., and Bassuk, F.R., 1978, Images of the cutover—a historical

geography of the resource utilization in the Lake Superior region, 1845–1930:

University of Wisconsin-Madison, Institute for Environmental Studies Report

98, 38 p.

Natural Resources Conservation Service and U.S. Forest Service, 1998, Executive

summary report-erosion and sedimentation in the Nemadji River Basin: Nemadji

River Basin Project, 16 p.
12

Information

For more information on USGS publications and activities in

Wisconsin, please contact:

District Chief

U.S. Geological Survey

8505 Research Way

Middleton, WI 53562

(608) 828-9901

www: http://wi.water.usgs.gov/

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Project Area: Wisconsin Department of Resources, unpublished report [variously paged].

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Acknowledgments

Project development: Bruce Swanson, Dennis Pratt—Wisconsin Department of Natural Resources; William Rose, David

Graczyk—USGS.

Land access: Mr. and Mrs. Fiorio, Betty Hanson, the Johaniks,

the Martinsens, the Mihaleks, the Moores, the Palmers, and

David Skulan.

Data collection and analyses: John Attig, Ross Bagwell, Richard Baker, William Becker, Reid and Robert Bryson, Thomas

Cogger, Brian Dalsing, Suzanne Femmer, William Fitzpatrick,

Steven Gaffield, Michael Gardner, Scott Hulse, Robert Jarrett,

Diann Kiesel, Christopher Kent, Keith Ligler, David McJunkin,

David Mickelson, Richard Mihalek, Kenneth Potter, Bruce

Rapps, Ty Sabin, Todd Stuntebeck, Sam Veda “Fish Creek

Sam”, Marjorie Winkler, and Herbert Wright.

Report layout: Michelle Greenwood—USGS.

Editorial and technical reviews: William Rose—USGS; Barbara Lensch—Natural Resources Conservation Service; Michael

Eberle and Betty Palcsak—USGS.

For more information on this study, please contact:

Faith Fitzpatrick, U.S. Geological Survey, 8505 Research Way,

Middleton, WI 53562 (608) 821-3818.

Professor James Knox, Geography Department, University of

Wisconsin–Madison, 550 N. Park St. Madison, WI 53706

(608) 262-1804.

Chequamegon Bay near the mouth of Fish Creek, Ashland, Wis.

CONVERSION FACTORS AND ABBREVIATIONS

centimeter (cm) 0.3937 inch

meter (m) 3.2808 foot

kilometer (km) 0.6214 mile

square kilometer (km2) 0.3861 square mile

cubic meter per second (cms) 35.314 cubic foot per second

tonne 1.10229 ton

Multiply By To obtain