Field Trip Number One
By: Pat Dryer
Geography 360
Table of Contents
Introduction……. Page 1
Stop One…………... Page 2
Stop Two…………... Page 4
Stop Three…………...
Page 5
Stop Four…………... Page 7
Bibliography…… Page 8
Campus Map
Source: http://www.uwec.edu/home/tour/images/grayscalemap.pdf
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Summary
The purpose of the field trip was to familiarize oneself with many geomorphic features
that are prevalent on campus or near the UWEC campus. The first trip was to introduce the
concept of using field notebooks. There are many features that are located very close to the
campus including cut banks, point bars, and many other features. We also looked at how the
University compensated for some potentially dangers situations because of the location that the
University sits on. The University recently invested a great deal of money into the riverbank
reconstruction pictured below in Figure 1.
Figure 1- The newly reconstructed cut bank on the University of Wisconsin- Eau Claire campus
was completed in the summer of 2006. The goal of this project was to stop the erosion that was
occurring to the south bank of the Chippewa River. Notice the sediment deposit in the bottom
right of the photo (point bar).
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Stop One
Stop one was located on the north side of the Chippewa River near the Haas Fine Arts
Center. Conditions at stop one were partly cloudy skies, with an approximate temperature of 85
degrees F, and a relative humidity of 75%. On the point bar, I primarily faced the cut bank that
has been recently reconstructed near the Putnam Residence Hall on Garfield Avenue. A cut bank
is a geomorphic feature that is typically associated with steep slopes and deep river depths
directly in front of the cut bank. Cut banks are formed when rivers take a bend and the sweeping
current causes erosion to the bank, this is pictured in Figure 1. Stop one is also considered a
point bar (Figure 1). This also is a place where sediments have been deposited by the river. This
particular point bar is a migrating point bar which literally moves over time and can be proven
with aerial photographs from years past. The point bar has migrated down stream over the past
years and is still slowly migrating further downstream. Furthermore, the point bar is protected
by a feature called rock armor. Rock armor is a deposit of larger rock/stone that is protecting the
sand from eroding. This rock keeps the point bar from being easily eroded through flooding and
strong river currents. It is clear which way the stream flow is by looking at the position of the
rocks in the rock armor. The rocks are positioned by currents so that the water easily flows over
the top, otherwise the river would pick up the rock and move it down stream (Figure 2).
Figure 2- The river flow can be noted by the shape of
the rocks pictured. The rocks are shaped from
collisions of rocks and other sediments that bounce
across the bottom carried in the river load.
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I noticed that the deposited rocks are fairly large in size, and approximately five inches in
diameter. The rocks downstream are much smaller and more gravel like. This point bar is
located on the flood plain of the Chippewa River. This can be observed in Figure 3 by the very
minimal vegetation on the point bar and also by the sand deposits 10 yards inland. This shows
that the river deposited the material there at some point in time. It is obvious that the Chippewa
River floods time to time from the high water marks on the bridge pillars. This can also bee seen
in Figure 1 by the brown discoloration of the bridge pillars. It is also important to know that the
Chippewa River is controlled by a dam that minimizes flooding throughout the year. When
flooding does occur, it is visible because the flood waters that are filled with leaves and sediment
washed away by the fast current. This leaves a brownish stain on the white concrete bridge
pillars. As I walked upstream, I noticed that the sediment that was deposited was much smaller
than the depositie at stop one. The deposits are more gravel like and the largest diameter or
rocks are approximately two inches in diameter. I also noted that there was algae growth in the
water just offshore of the point bar. This indicates that there is little movement in the water,
otherwise the algae would not be able to grow. This shows that the current is much slower near
the point bar.
Figure 3- There is minimal vegetation on the point
bar, it isn’t until further inland that trees and small
shrubs are more abundant.
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Stop Two
Stop two is located on the south side of the McIntyre Library, between the library and
Little Niagara Creek. The conditions at stop two were pleasant with overcast skies and
temperatures near 70 degrees F. The purpose of stop two is to observe the location of the
Library with respect to Little Niagara Creek. The McIntyre Library was built on the flood plane
of the creek. This means that if the creek was to flood, the library would become partially
submerged. To compensate for this potential problem the library was built on a series of pillars
so that flood waters will not harm the building. These pillars can be observed in Figure 4.
Vegetation is prominent on the banks of the creek as well as some vegetation growing in the
water as well. The water in the creek is fairly clear and fast moving in certain areas. As I
progressed downstream I noticed that the creek began to widen. Large culverts divert water into
the creek from the marshes and storm drains located on the south side of Phillips Parking Lot.
The grade of the land surrounding the creek slowly descends towards the creek from bank of the
Chippewa River. There is a noticeable cut bank downstream from the culverts that are slowly
creating a point bar just downstream from the location. As I progress downstream further, I
encounter the flood control dam that was created to stop flood waters from the Chippewa River
backing up into the creek.
Figure 4- The McIntyre Library was built on a
series of pillars to protect itself from a flood of the
Little Niagara Creek.
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At this location there are very large pumps that will pump the water over the damn and into the
Chippewa River if flood stage were to be reached. The flood control system is controlled by a
large gate that swings down once the water in the Chippewa River reaches flood stage. When
the gate is closed water is restricted from backing up into the creek. The gate also prevents water
in the creek from flowing into the Chippewa River. The pumps are then activated to pump the
water from the creek over the wall and into the Chippewa River to protect the creek from
backing up and flooding valuable land located upstream. Once I crossed Garfield Avenue the
sand in the river began to decrease. Within a few yards downstream there was little to no sand at
all in the river bed. The river bed was primarily a entrenched meander. An entrenched meander
is created when a river slowly erodes through the bedrock over years and creates a canal for the
water to flow. Because of the erosion there are large areas of bedrock outcropping. This is
where the river banks are steep and the bedrock protrudes from the ground. Figure 4 is a great
example of a entrenched meander and bedrock outcroppings. Downstream the river flows
primarily over bedrock.
Figure 4- A photograph of an
entrenched meander that Little Niagara
Creek has formed near the Chippewa
River.
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Stop Three
Stop three is located at the point where the Little Niagara Creek empties into the
Chippewa River. This point is also known as a nick point. A nick point is where the water is
forced over a particular object, in this case bedrock, and creates a waterfall. The nick point is
slowly eroding away due to the constant steady flow of the stream. Figure 5 illustrates the
various canals and other features that have been worn into the bedrock from years of erosion.
There is an outcropping of bedrock on the Chippewa River near this area. There is a gravel
upstream as well as downstream from location, and a gravel bar is located directly in front of the
nick point in the Chippewa River. This gravel is a result of the erosion of the point bar and the
river depositing the material downstream. There is evidence of back eddies that formed here
near the nick point. A back eddy is a cove where water flows into and circulates. This
circulating water creates potholes in the bedrock which is visible in Figure 6. Water can reach
these areas when flooding occurs.
Figure 5- This is a picture of the nick point
of the Little Niagara River, water has slowly
eroded the bedrock over time.
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Figure 6- This pothole was created
when flood waters were high enough
to flood the nick point and create a
back eddy. The back eddy created a
swirling the water current and eroded
the bedrock in a unique way.
Stop Four
Stop four was located on a portion of the newly reconstructed riverbank on Garfield
Avenue. The goal of this project was to reconstruct the cut bank with the placement of large
rock and cement pillars embedded into the riverbank. The purpose of this reconstruction was to
stop erosion and protect the infrastructure directly behind the river bank. The infrastructure
includes many utility lines, water mains, as well as residence halls located near the riverbank.
Many university buildings are built on the natural levy that has resulted from flooding on the
Chippewa River. This levy protects many of the buildings, but in recent years there has been
fear of erosion to this natural levy. From this location the point bar is directly across the
Chippewa River which was of interest in stop one. The newly re-engineered riverbank project is
pictured in Figure 1.
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Bibliography
University Publications, University of Wisconsin- Eau Claire Campus map,
http://www.uwec.edu/home/tour/images/grayscalemap.pdf, 1sheet.