Primary Use, Relative Abundance of Fish Species, and Hydrology

84 Pages·2017·13.5 MB·English

University of Colorado, Boulder
CU Scholar
Undergraduate Honors Theses Honors Program
Spring 2017
Primary Use, Relative Abundance of Fish Species,
and Hydrology: A Comparison of Select Mountain
and Plains Reservoirs in Colorado USA
Robert Wilson
[email protected]
Follow this and additional works at:https://scholar.colorado.edu/honr_theses
Recommended Citation
Wilson, Robert, "Primary Use, Relative Abundance of Fish Species, and Hydrology: A Comparison of Select Mountain and Plains
Reservoirs in Colorado USA" (2017).Undergraduate Honors Theses. 1473.
https://scholar.colorado.edu/honr_theses/1473
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Primary Use, Relative Abundance of Fish Species, and Hydrology: A Comparison of Select
Mountain and Plains Reservoirs in Colorado USA

By
Baxter Wilson
University of Colorado at Boulder

A thesis submitted to the
University of Colorado at Boulder
in partial fulfillment
of the requirements to receive
Honors designation in
Environmental Studies
April 2017

Thesis Advisors:
Ben Livneh, Civil, Environmental, and Architectural Engineering, Committee Chair
Peter Blanken, Geography
Dale Miller, Environmental Studies

© 2017 by R. Baxter Wilson V
All rights reserved
Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

Abstract

The difference between regional reservoir groups can be evaluated to help
determine useful management strategies for optimizing both the primary uses and
ecosystems of the reservoirs. My thesis is an analysis of selected reservoirs in two regional
groups of Colorado, the plains and mountain regions. Ten reservoirs are included in this
study, with five in the plains region and five in the mountain region of the state. I selected
the reservoirs based on the availability of required data sets and their relative geographic
location within the state. The analysis was done based on data surrounding the reservoirs’
primary uses, abundance of fish species, and hydrology. The primary use analysis
concluded that the plains reservoir group is 80% irrigation, while the mountain reservoir
group is 60% municipal water supply storage. The fish species analysis concluded that the
plains reservoir group’s most common abundant fish species are walleye and gizzard shad,
while the mountain reservoir group’s most common abundant fish species are rainbow
trout, suckers, and brown trout. The hydrologic analysis was a Oneway ANOVA and t-Test
evaluation of the reservoirs’ ratio of mean annual releases to mean annual storage volume,
concluding a statistically significant difference between plains and mountain regional
reservoir groups with a p-value of .04. The overall analysis concludes there is a significant
difference in the primary uses, fish species, and hydrology of this selection of plains and
mountain reservoirs in Colorado. I recommend my research methods be applied to a larger
reservoir comparison at statewide, regional, or even global levels to form a better
understanding of regional reservoirs as systems.
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

Preface

Before you lies the thesis “Primary Use, Relative Abundance of Fish Species, and Hydrology:
A Comparison of Select Mountain and Plains Reservoirs in Colorado USA”, an analysis I
conducted comparing select reservoirs in the main two geographic regions of Colorado. It
has been written to fulfill the Departmental Honors designation requirements for the
Environmental Studies Program at the University of Colorado at Boulder (CU). I was
devoted to researching and writing this thesis from January 2016 to April 2017.

The thesis was embarked upon at the recommendation of Dale Miller, senior instructor at
the CU Environmental Studies program. My research question was formulated with the
help of my primary advisor Ben Livneh, and my committee members Peter Blanken and
Dale Miller. The research and analysis proved challenging, but through careful study I was
able to establish the differences between my two regional selections of reservoirs.
Thankfully my thesis advisors, as well as the CU librarians Leanne Walther and Andrew
Johnson, eagerly answered any questions I had regarding hydrologic data and how to
approach my analysis.

I would like to thank my thesis advisors for their outstanding leadership and assistance
during this undertaking. I also wish to thank my mother Erin Wilson for being the
inspiration of my interest in water, without whose assistance I would not have been able to
retrieve the data to conduct my hydrologic analysis.

I would also like to thank all of my classmates at CU who have been involved alongside me
in the Honors Thesis process. I believe it was always beneficial to learn about other
people’s ideas and the approaches to their own theses, as it helped me apply important
concepts to my own work.

I hope you enjoy your reading.

R. Baxter Wilson V

Boulder, March 30, 2017
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

ABSTRACT...............................................................................................................................................................I
PREFACE.................................................................................................................................................................II
INTRODUCTION....................................................................................................................................................1
BACKGROUND.......................................................................................................................................................3
LITERATURE REVIEW.........................................................................................................................................4
INSTREAM FLOW.......................................................................................................................................................4
OFF-STREAM WATER USES......................................................................................................................................6
FISH IN RESERVOIRS.................................................................................................................................................7
RESERVOIR USES AND IMPACTS...............................................................................................................................7
RESERVOIRS AS ECOSYSTEMS...................................................................................................................................8
METHODS...............................................................................................................................................................9
DATA......................................................................................................................................................................11
COLORADO PLAINS RESERVOIR GROUP................................................................................................................13
PLAINS 1: PREWITT RESERVOIR...............................................................................................................................................13
PLAINS 2: JACKSON RESERVOIR................................................................................................................................................15
PLAINS 3: HORSETOOTH RESERVOIR.......................................................................................................................................17
PLAINS 4: JOHN MARTIN RESERVOIR.......................................................................................................................................19
PLAINS 5: BARR LAKE.................................................................................................................................................................21
COLORADO MOUNTAIN RESERVOIR GROUP..........................................................................................................23
MOUNTAIN 1: TRINIDAD LAKE RESERVOIR............................................................................................................................23
MOUNTAIN 2: SPINNEY MOUNTAIN RESERVOIR...................................................................................................................25
MOUNTAIN 3: RIDGWAY RESERVOIR.......................................................................................................................................27
MOUNTAIN 4: ELEVENMILE CANYON RESERVOIR.................................................................................................................29
MOUNTAIN 5: DILLON RESERVOIR...........................................................................................................................................31
ANALYSIS & DISCUSSION.................................................................................................................................33
PRIMARY USES........................................................................................................................................................34
PLAINS REGIONAL GROUP..........................................................................................................................................................35
MOUNTAIN REGIONAL GROUP...................................................................................................................................................36
DISCUSSION OF PRIMARY USES.................................................................................................................................................37
FISH SPECIES...........................................................................................................................................................39
PLAINS REGIONAL GROUP..........................................................................................................................................................40
MOUNTAIN REGIONAL GROUP...................................................................................................................................................41
DISCUSSION OF FISH SPECIES....................................................................................................................................................42
HYDROLOGY............................................................................................................................................................47
ANALYSIS OF FLOW/STORAGE RATIO......................................................................................................................................48
DISCUSSION OF FLOW/STORAGE RATIO..................................................................................................................................49
RECOMMENDATIONS & CONCLUSIONS.......................................................................................................52
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

APPENDIX.............................................................................................................................................................57
FISH SPECIES RELATIVE ABUNDANCE DATA TABLE.............................................................................................57
FISH SPECIES RELATIVE ABUNDANCE BAR GRAPHS.............................................................................................59
RESERVOIR CONTENT (ACFT) GRAPHS 1999 - 2015.......................................................................................64
REFERENCES........................................................................................................................................................70

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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

Introduction
I investigated whether the hydrologic impacts of mountain reservoirs differ
significantly from plains reservoirs in Colorado. With differing geographic conditions and
uses affecting the reservoirs in these two regions, variables such as primary use, reservoir
storage, mean annual outflows, and relative abundance of fish species are expected to vary,
yet these variables may be common within each region. My thesis evaluates the statistical
difference between two regional groups of Colorado reservoirs, mountain and plains, based
on the reservoirs’ primary uses, relative fish species abundance data from the Colorado
Parks and Wildlife, and an emphasis on the evaluation of the hydrologic flows of the
reservoirs.

Figure 1: A USGS map of the reservoir locations in Colorado. The blue points are plains reservoirs and the green
points are mountain reservoirs. Minimum / Maximum latitude: 36.4 degrees / 41.2 degrees. Minimum /
Maximum longitude: -110.9 degrees / -100.7 degrees.
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

The mountain reservoir group consists of Trinidad Lake, Spinney Mountain
Reservoir, Ridgeway Reservoir, Eleven Mile Reservoir, and Dillon Reservoir. The plains
reservoir group includes Prewitt Reservoir, Jackson Reservoir, Horsetooth Reservoir, John
Martin Reservoir, and Barr Lake. This is only a selection of reservoirs within the state of
Colorado, and I selected these two regional reservoir groups based both on their relative
geographic locations within the State of Colorado, and since all 10 of these reservoirs have
a common 15-year period of available hydrologic data from USGS. The comparison of the
hydrology of two reservoir groups was done using the daily diversions, daily releases, and
reservoir capacity all over the time period beginning November 1 1999 and ending October
31 2015. This specific time period was selected because it is recent and the hydrologic data
were available for all 10 selected reservoirs.
I hypothesize there is a significant difference between my selected mountainous and
plains reservoir groups based on the four following criteria: primary reservoir use, the
ratio of reservoir storage to mean annual outflow for each of the 15 years, the variance and
standard deviation of the monthly reservoir outflows, and the relative percent abundance
of fish species in each body of water. My specific research questions for this thesis include:
Is there a consistent primary use within each of the regional reservoir groups? Is there a
significant difference in the relative abundance of fish species of mountain and plains
reservoirs? Do the two regional groups of reservoirs have statistically different
storage/outflow ratios? Does one regional reservoir group have a higher degree of
seasonality compared to the other regional group?
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

Background
Reservoirs are bodies of water of various size, artificially created by humans for a
water supply intended for many uses, and ecosystems are altered as a result of the large-
scale land-use and hydrologic changes brought about by a reservoir’s construction. When a
reservoir is filled, the health of the previously riparian ecosystem and fish population are
both influenced by the functional uses of the reservoir. The two main geographical regions
of Colorado which I base my reservoir study, mountains and plains, vary greatly in both
elevation and hydrologic flow patterns. One can expect to see variation on both a monthly
and annual basis. The lowest point of elevation in Colorado is found in the plains region of
the state on the Arkansas River at 3,315 feet (1,010 meters) above sea level. By contrast,
the highest point of elevation in Colorado is at the peak of Mt. Elbert at 14,440 feet (4,401
meters) above sea level (USGS, 2015). With such a drastic change in elevation in Colorado
there may be some difference in the primary use, resulting hydrology and fish species
makeup of both plains and mountain reservoirs.
The Great Plains region makes up roughly the eastern 2/5 of Colorado, with quite
flat topography and a mellow elevation that slowly increases from east to west. The Rocky
Mountains of Colorado make up approximately the central 2/5 of the state, stretching
continuously from north to south (NETSTATE, 2016). The headwaters for six major rivers
begin in the mountains of Colorado: The Rio Grande, Arkansas, Republican, North Platte,
and South Platte rivers all begin east of the Continental Divide, and flow toward their deltas
into the Atlantic Ocean while the Colorado River flows from the western side of the
Continental Divide towards the Pacific Ocean. Only 371 square miles (960.886 square
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Daily Flow, Reservoir Content and Fish Ecosystems Baxter Wilson

kilometers) of Colorado are covered by water, while 103,730 square miles (268659.467
square kilometers) of Colorado are land areas. Some major water bodies in Colorado
include Grand Lake, John Martin Reservoir and Blue Mesa Reservoir (NETSTATE, 2016).

Literature Review
In this section of my thesis I will outline the five most important aspects related to
the management of reservoirs. I will begin by discussing instream flow water rights
because this is a useful way to normalize flows for fish ecosystems, and then will provide
an overview of the different off-stream water uses. Next I will outline a summary of the
origin of fish in reservoirs because this is important for thinking about the degree to which
a fish species is native or invasive. Then I will explain the primary uses and environmental
impacts of reservoirs, and finish with a description of how reservoirs function as
ecosystems. Each of the aspects I describe are important to consider when trying to
optimally manage reservoirs for a variety of functions.
Instream Flow
Colorado’s Instream Flow and Natural Lake Level water rights programs are very
important to maintain the fish ecosystems, and are unique within the prior appropriation
system of western US water rights. The prior appropriation system determines water
rights based on the timing of the water claims and the nature of whether the water use is
beneficial (M. Alters, et al. 2006). The purpose of an instream flow water right is to protect
the different environments in Colorado. These environments include critical habitat for
threatened fish species, riparian vegetation, unique hydrologic and geologic features,
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