THESIS
GEOMORPHIC ANALYSIS OF THE MIDDLE RIO GRANDE –
ELEPHANT BUTTE REACH, NEW MEXICO
Submitted by
Tracy Elizabeth Owen
Department of Civil and Environmental Engineering
In partial fulfillment of the requirements
For the Degree of Master of Science
Colorado State University
Fort Collins, Colorado
Spring 2012
Master’s Committee:
Advisor: Pierre Julien
Christopher Thornton
Sara Rathburn
Copyright by Tracy Elizabeth Owen 2012
All Rights Reserved
ABSTRACT
GEOMORPHIC ANALYSIS OF THE MIDDLE RIO GRANDE –
ELEPHANT BUTTE REACH, NEW MEXICO
The Elephant Butte Reach spans about 30 miles, beginning from the South Boundary
of the Bosque del Apache National Wildlife Refuge (River Mile 73.9) to the “narrows” of
the Elephant Butte Reservoir (River Mile 44.65), in central New Mexico. Sediment plugs
occasionally form along the Middle Rio Grande, completely blocking the main channel
of the river. In 1991, 1995, and 2005, the Tiffany Plug was initiated at the upstream end
of the Elephant Butte Reach. In 2008, the Bosque del Apache Plug formed just upstream
of the Elephant Butte Reach. Sediment plugs occur at the location of a constriction or
channel aggradation (Burroughs 2011). As aggradation within the Elephant Butte Reach
is known to contribute to a decrease in channel capacity (Reclamation 2007), it is
important to understand the influences of Elephant Butte Reservoir levels on channel
aggradation/degradation in order to decrease the potential for future sediment plug
formation. Further understanding of the historical and spatial changes within Elephant
Butte Reach, along with a better understanding of the influences of Elephant Butte
Reservoir levels on channel aggradation/degradation, are essential for improvement in
future river management practices along the Middle Rio Grande.
Using aerial
photographs, survey data, reservoir water surface elevation data, and bed material data,
the following objectives are addressed in this study:
1. Quantify temporal changes in channel widths and sinuosity from 1935 to 2010.
ii
2. Quantify change in channel slope temporally.
3. Quantify rate of aggradation/degradation in response to a change in base-level
(i.e., change in reservoir water surface elevation).
4. Quantify aggradation/degradation wave propagation upstream.
5. Quantify spatial and temporal trends in bed material grain size.
From 1935 to 2010, channel widths and sinuosity decrease over time.
The
majority of the Reach’s channel slope decreases from 1935 to 2010; the downstreammost stretch of the channel, closest to Elephant Butte Reservoir, alternates between
increasing and decreasing channel slopes.
As the Elephant Butte Reservoir level (base-level) increases, the channel aggrades
in response. As the base-level decreases, the channel degrades. The rates of aggradation
and degradation vary between different periods of base-level changes, and are quantified
within the report.
When the base-level changes a wave of aggradation/degradation
travels upstream. The rate of wave propagation upstream varies relative to the rate of
base-level
change,
and
is
quantified
within
the
report
for
four
sets
of
aggradation/degradation waves.
Bed material samples obtained from cross-section surveys and at the San Acacia
and San Marcial gauges showed a coarsening at a rate of about 0.03 mm/year. In the
downstream direction, bed material became slightly finer. The median bed material grain
size ranged from 0.11 mm to 0.26 mm.
- iii -
ACKNOWLEDGEMENTS
I would first like to thank the U.S. Bureau of Reclamation in Albuquerque for
providing me with this project and the incredible amount of data. I would especially like
to thank Jonathan Aubuchon, of the Albuquerque office, and Drew Baird, of the Denver
office, for their insights about the river. Dr. Rathburn and Dr. Thornton, thank you for
serving on my committee and providing thoughtful comments to improve my Thesis.
Thanks to my advisor, Dr. Pierre Julien, for his constant guidance and encouragement.
Special thanks to Seema Shah-Fairbank for answering all of my questions and
guiding me through the vast database. Many thanks to Katharine Anderson who helped
me with planform delineations, range line cross-section plots, sinuosity calculations,
etc… Thanks to Ted Bender for reading this report and for gracefully listening to my
frustrations during those challenging times. Thanks also to Kiyoung Park for his insight
and ideas regarding the river’s behavior.
And finally, I would like to thank my family and Ben Mapes for supporting me
every step of the way. Mom, thanks for always being available for a phone call. Dad and
Janet, thanks for your encouragement and belief in me. Will, thanks for being a great
role model, setting the example at every stage in life. Ben, I can’t even begin to express
my thanks for your support and understanding throughout this entire process. Without
you I would have never left my computer and would have missed countless adventures; I
look forward to more adventures with you.
- iv -
TABLE OF CONTENTS
Abstract ............................................................................................................................... ii Acknowledgements ............................................................................................................ iv Table of Contents ................................................................................................................ v List of Figures .................................................................................................................... vi List of Tables ..................................................................................................................... ix List of Appendices .............................................................................................................. x Section 1: Introduction ................................................................................................... 1 1.1 Habitat and Endangered Species .......................................................................... 2 1.2 Sediment Plugs ..................................................................................................... 5 Section 2: Site Description and Background ................................................................. 7 2.1 Elephant Butte Reach ........................................................................................... 7 2.2 Subreach Definition.............................................................................................. 8 2.3 Available Data .................................................................................................... 18 2.3.1 Survey Lines and Dates ...............................................................................18 2.3.2 Discharge Data .............................................................................................21 2.3.3 Bed Material.................................................................................................24 2.3.4 Suspended Sediment Data............................................................................24 Section 3: Reservoir Level Analysis ............................................................................ 26 3.1.1 Reservoir Level Analysis .............................................................................26 Section 4: Channel Analysis ........................................................................................ 30 4.1 Channel Planform Analysis from Aerial Photographs ....................................... 30 4.1.1 Channel Delineation.....................................................................................30 4.1.2 Channel Widths from GIS ...........................................................................37 4.1.3 Sinuosity ......................................................................................................39 4.2 Aggradation and Degradation from Agg/Deg Surveys ...................................... 45 4.2.1 Channel Thalweg Profile from Agg/Deg Surveys .......................................45 4.2.2 Change in Channel Thalweg Elevation from Agg/Deg Surveys .................48 4.3 Aggradation and Degradation from Range Line Surveys .................................. 55 4.3.1 Channel Thalweg Profile from Range Line Surveys ...................................55 4.3.2 Change in Thalweg and Average Bed Elevation from Range Line Surveys66 4.3.3 Rate of Aggradation/Degradation from Range Line Surveys ......................75 4.3.4 Rate of Wave Propagation Upstream from Range Line Surveys ................80 4.4 Bed Material Analysis ........................................................................................ 86 4.4.1 Grain Size Distributions...............................................................................86 4.4.2 Median Grain Size .......................................................................................93 4.5 Suspended Sediment Data .................................................................................. 96 Section 5: Summary and Conclusions ....................................................................... 100 References ....................................................................................................................... 103 Appendices ...................................................................................................................... 105 v
LIST OF FIGURES
Figure 1.1 Map of the Rio Grande Watershed (MRGBI 2009) ......................................... 1 Figure 1.2 Historical Timeline of Middle Rio Grande (Modified After Makar 2011, Pers.
Comm.) ............................................................................................................................... 4 Figure 1.3: Rio Grande Silvery Minnow and Southwestern Flycatcher ............................ 5 Figure 1.4 Aerial View of Tiffany Plug in 2005 ................................................................ 6 Figure 2.1: Location of the Elephant Butte Reach from Google Maps ............................. 7 Figure 2.2 Profile of Elephant Butte Reach Widths and Thalweg at Agg/Deg Lines ....... 9 Figure 2.3 2008 Aerial Photo of Subreach 1.................................................................... 11 Figure 2.4 2008 Aerial Photo of Subreach 2.................................................................... 12 Figure 2.5 2008 Aerial Photo of Subreach 3.................................................................... 13 Figure 2.6 2008 Aerial Photo of Subreach 4.................................................................... 14 Figure 2.7 2008 Aerial Photo of Subreach 5.................................................................... 15 Figure 2.8 2008 Aerial Photo of Subreach 6.................................................................... 16 Figure 2.9 2008 Aerial Photo of Elephant Butte Reservoir ............................................. 17 Figure 2.10 Subreach Definitions and Agg/Deg Line Locations (2008 GIS Elephant
Butte Reach Delineation Shown) ...................................................................................... 19 Figure 2.11 Subreach Definitions and Range Line Locations (2008 GIS Elephant Butte
Reach Delineation Shown) ............................................................................................... 20 Figure 2.12 Location of Gauges....................................................................................... 22 Figure 2.13: Daily Discharge of the Rio Grande in 1999 ................................................. 23 Figure 2.14 Comparison of Annual Peak Flows at San Acacia and San Marcial Gauges24 Figure 2.15: Annual Suspended Sediment Yield at San Acacia and San Marcial Gauges25 Figure 3.1 Elephant Butte Reservoir Level Time Series ................................................. 27 Figure 3.2 Elephant Butte Reservoir Historical Sediment Survey Longitudinal Profile
(Reclamation, 2008) .......................................................................................................... 29 Figure 4.1 Channel Planforms from Aerial Photography ................................................ 31 Figure 4.2 Subreach 1 Channel Planforms from Aerial Photography ............................. 32 Figure 4.3 Subreach 2 Channel Planforms from Aerial Photography ............................. 32 Figure 4.4 Subreach 3 Channel Planforms from Aerial Photography ............................. 33 Figure 4.5 Subreach 4 Channel Planforms from Aerial Photography ............................. 34 Figure 4.6 Subreach 5 Channel Planforms from Aerial Photography ............................. 35 Figure 4.7 Subreach 6 Channel Planforms from Aerial Photography ............................. 36 Figure 4.8 Channel Widths from GIS (1918 - 2010) ....................................................... 38 Figure 4.9 Channel Widths from GIS (1962 - 2010) ....................................................... 39 Figure 4.10 Subreach Lengths and Total Lengths as Measured From GIS Data ............ 40 Figure 4.11 Temporal Sinuosity Trends .......................................................................... 43 Figure 4.12 Thalweg Elevation Profile From Agg/Deg Surveys ..................................... 46 Figure 4.13 Bed Slope from Agg/Deg Surveys ............................................................... 47 Figure 4.14 Change in Channel Thalweg Elevation from Agg/Deg Surveys .................. 49 Figure 4.15 Change in Channel Thalweg Elevation (1962 – 1972) Based on Agg/Deg
Surveys.............................................................................................................................. 50 Figure 4.16 Change in Channel Thalweg Elevation (1972 – 1992) Based on Agg/Deg
Surveys.............................................................................................................................. 50 vi
Figure 4.17 Change in Channel Thalweg Elevation from 1992 – 2002 Based on Agg/Deg
Surveys.............................................................................................................................. 51 Figure 4.18 Change in Channel Thalweg Elevation from 1962 – 2002 Based on Agg/Deg
Surveys.............................................................................................................................. 51 Figure 4.19 Temporal Trend in Thalweg Elevation at Agg/Deg Lines ........................... 54 Figure 4.20 Rate of Channel Aggradation between 1972 and 1992 ................................ 55 Figure 4.21 Thalweg Elevation Profile From Range Line Survey Data .......................... 57 Figure 4.22 Subreach 1 Average Channel Thalweg Slope: Temporal Trend .................. 58 Figure 4.23 Subreach 2 Average Channel Thalweg Slope: Temporal Trend .................. 58 Figure 4.24 Subreach 3 Average Channel Thalweg Slope: Temporal Trend .................. 59 Figure 4.25 Subreach 4 Average Channel Thalweg Slope: Temporal Trend .................. 59 Figure 4.26 Subreach 5 Average Channel Thalweg Slope: Temporal Trend .................. 59 Figure 4.27 Subreach 6 Average Channel Thalweg Slope: Temporal Trend .................. 60 Figure 4.28 Subreach 1: SO-1641 Surveyed Cross-Sections........................................... 62 Figure 4.29 Subreach 2: SO-1683 Surveyed Cross-Sections........................................... 62 Figure 4.30 Subreach 3: EB-10 Surveyed Cross-Sections............................................... 63 Figure 4.31 Subreach 3: EB-10 (w/Floodplain) Surveyed Cross-Sections...................... 63 Figure 4.32 Subreach 4: EB-13 Surveyed Cross-Sections............................................... 64 Figure 4.33 Subreach 5: EB-20 Surveyed Cross-Sections............................................... 64 Figure 4.34 Subreach 6: EB-29 Surveyed Cross-Sections............................................... 65 Figure 4.35 Subreach 6: EB-29 (w/Floodplain) Surveyed Cross-Sections...................... 65 Figure 4.36 Subreach 6: EB-41 Surveyed Cross-Sections............................................... 66 Figure 4.37 Change in Thalweg Elevation at Range Lines (1980 – 2010) ...................... 67 Figure 4.38 Change in Average Channel Bed Elevation at Range Lines (1988-2010) ... 73 Figure 4.39 Change in Channel Thalweg Elevations at Range Lines (1988-2010)......... 74 Figure 4.40 Magnitude of Aggradation and Degradation at Range Lines (2003-2004) .. 76 Figure 4.41 Magnitude of Aggradation and Degradation at River Miles (2003-2004) .... 76 Figure 4.42 Magnitude of Aggradation and Degradation at Range Lines (2004-2005) .. 77 Figure 4.43 Magnitude of Aggradation and Degradation at River Miles (2004 to 2005) 78 Figure 4.44 Change in Thalweg Elevation from 2004 to 2009........................................ 78 Figure 4.45 Magnitude of Degradation from 2004 to 2009 ............................................. 79 Figure 4.46 Magnitude of Aggradation from 2004-2009 ................................................ 80 Figure 4.47 Reservoir Water Surface Elevation Change from 2009-2010 Resulting in
Wave 1 Channel Degradation ........................................................................................... 81 Figure 4.48 Rate of Wave 1 Propagation Upstream ........................................................ 81 Figure 4.49 Reservoir Water Surface Elevation Change from 2004-2009 Resulting in
Wave 2 Channel Aggradation ........................................................................................... 82 Figure 4.50 Rate of Wave 2 Propagation Upstream ........................................................ 83 Figure 4.51 Reservoir Water Surface Elevation Change from 1997-2004 Resulting in
Wave 3 Channel Degradation ........................................................................................... 84 Figure 4.52 Rate of Wave 3 Propagation Upstream ........................................................ 84 Figure 4.53 Reservoir Water Surface Elevation Change from 1990-1995 Resulting in
Wave 4 Channel Aggradation ........................................................................................... 85 Figure 4.54 Rate of Wave 4 Propagation Upstream ........................................................ 86 Figure 4.55 EB-10 1992 Bed Material Grain Size Distributions ..................................... 88 Figure 4.56 San Acacia Gauge: Annual Bed Material Grain Size Distributions ............. 89 - vii -
Figure 4.57 San Marcial Gauge: Annual Bed Material Grain Size Distributions ........... 89 Figure 4.58 Subreach 1 (SO-1641): Annual Bed Material Grain Size Distributions ...... 90 Figure 4.59 Subreach 2 (SO-1683): Annual Bed Material Grain Size Distributions ...... 90 Figure 4.60 Subreach 3 (EB-10): Annual Bed Material Grain Size Distributions .......... 91 Figure 4.61 Subreach 4 (EB-13): Annual Bed Material Grain Size Distributions .......... 91 Figure 4.62 Subreach 5 (EB-18): Annual Bed Material Grain Size Distributions .......... 92 Figure 4.63 Subreach 6 (EB-24): Annual Bed Material Grain Size Distributions .......... 92 Figure 4.64 Average Median Bed Material Grain Size Temporal Trends ....................... 94 Figure 4.65 Average Median Bed Material Grain Size: Subreach Temporal Trends ...... 94 Figure 4.66 Water Discharge Single Mass Curve (Larsen et al. 2007) ........................... 96 Figure 4.67 Suspended Sediment Discharge Single Mass Curve
(Larsen et al. 2007) ........................................................................................................... 97 Figure 4.68 Suspended Sediment Concentration Double Mass Curves
(Larsen et al. 2007) ........................................................................................................... 98 - viii -
LIST OF TABLES
Table 2-1: Available Daily Discharge Data ..................................................................... 21 Table 2-2: Available Suspended Sediment Data ............................................................. 25 Table 4-1 Subreach Length and Total Length Values as Measured From GIS Data ...... 41 Table 4-2 Sinuosity Values .............................................................................................. 44 Table 4-3 Average Bed Slope from Agg/Deg Surveys .................................................... 48 Table 4-4 Change in Channel Thalweg Elevation Values from Agg/Deg Surveys ......... 49 Table 4-5 Average, Maximum and Minimum Change in Channel Thalweg Elevation
Based on Agg/Deg Surveys .............................................................................................. 52 Table 4-6 Average Channel Thalweg Slopes for Subreaches 1 through 6 ...................... 60 Table 4-7 Change in Thalweg Elevation Between Select Year Sets ................................ 70 Table 4-8 Representative Range Lines for Each Subreach .............................................. 87 Table 4-9 Water Discharge (Larsen et al. 2007) .............................................................. 97 Table 4-10 Suspended Sediment Discharge (Larsen et al. 2007) .................................... 98 Table 4-11 Suspended Sediment Concentration (Larsen et al. 2007).............................. 99 ix
LIST OF APPENDICES
Appendix A:
Appendix B:
Appendix C:
Appendix D:
Appendix E:
Appendix F:
Appendix G:
Appendix H:
Range Line Survey Dates ......................................................................... 106 Daily Discharge Hydrographs……………………………………….…..117
Dates and Locations of Bed Material Samples………………………….125
Dates and Locations of USGS Gauge Bed Material Samples…………..127
Aerial Photograph Survey Dates and Information………………………129
Range Line Cross-Section Plots…………………………………………131
Change in Thalweg Elevation vs. River Mile Plots……………………..157
Bed Material Grain Size Distribution Plots……………………………..166
-x-
SECTION 1:
INTRODUCTION
The Rio Grande is about 1890 miles long (3040 kilometers), making it one of the
longest rivers in the United States (Kammerer 1990). The headwaters of the Rio Grande
begin in southern Colorado near Camby Mountain. The river then flows south through
New Mexico, and then becomes a dividing border between Texas and Mexico. For
purposes of this report, the Middle Rio Grande is defined as the 180 mile stretch of the
Rio Grande River that extends from Cochiti Dam to the narrows of Elephant Butte
Reservoir. Figure 1.1 provides a map of the Rio Grande.
Figure 1.1 Map of the Rio Grande Watershed (MRGBI 2009)
Human activities have had an impact on the river for thousands of years. However,
it was not until the late 14th century when the Spanish settled near the Rio Grande that
humans began to dramatically influence the river (Finch 2004). Since then, the water
1
discharge, sediment discharge, and cross sectional geometry have changed as a result of
human colonization.
Devastating floods were very common on the Rio Grande up until
the early 1900’s when large dams and reservoirs were constructed. In addition, large
stretches of the river were channelized. These projects helped regulate the water and
prevent extensive flooding. Mining, logging and grazing in the beginning of the 20th
century destroyed much of the vegetation, resulting in dramatic erosion and a subsequent
increase in the sediment load in the river (Scurlock 1998). The increased erosion and
sediment load caused a l3% loss of capacity within Elephant Butte Reservoir by the mid
1930’s (Clark 1987). The increased sediment and decreased flow also lead to severe
aggradation along the river. Between 1880 and 1924, the bed of the river rose 9 feet at
the San Marcial gauging station (Scurlock 1998).
1.1
Habitat and Endangered Species
Exotic plants like the Russian olive, Russian thistle, Siberian elm, tree-of-heaven,
and tamarisk, whose roots added extra shear strength to the sand near the river, were
introduced to try to keep the river more stable (Mussetter Engineering 2001). However,
due to the addition of these foreign plants, riparian vegetation, such as native cottonwood
trees and willow trees, have declined (Finch 2004, Earick 1999). New animals such as
the barbary sheep, ibex, and oryx were also introduced to the area (Finch 2004). Human
influences have caused several native species of animals that use the Rio Grande as their
habitat, such as the Rio Grande silvery minnow, Rio Grande cutthroat trout, southwestern
willow flycatcher, and whooping crane, to teeter on the brink of extinction. Human
impacts, coupled with natural events such as droughts, have also led to increased soil
erosion along much of the Middle Rio Grande (Scurlock 1998).
2
In order to resolve many problems regarding the Rio Grande, the Middle Rio
Grande Conservancy District (MRGCD) was formed in 1923.
The purpose of the
MRGCD was to “provide flood protection from the Rio Grande, and make the
surrounding area hospitable for urbanization and agriculture” (MRGCD 2006). Between
1923 and 1935, one storage dam, four diversion dams, and 817 miles of drainage and
irrigation channels had been constructed by the MRGCD (MRGCD 2006). The work
completed by the MRGCD was successful in controlling the river’s floods, and the
Bureau of Reclamation and the Army Corps of Engineers continued to repair and update
the structures established by the MRGCD. Several new levees and Cochiti dam have
been constructed to combat flooding and sedimentation problems along the river
(MRGCD 2006). A historical timeline of the Middle Rio Grande is shown in Figure 1.2.
These dams and levees were able to control the flow of the river and altered the
seasonal flooding patterns that used to exist. The magnitude of the floods within the Rio
Grande was greatly reduced due to the construction of these structures. These floods
were essential for several species’ reproduction habitats.
The Rio Grande silvery
minnow, shown in Figure 1.3, used the swampy flooded terrain as the ideal reproduction
habitat (Earick 1999; Borgan 2006). The Rio Grande silvery minnow used to flourish
within the river from Espanola, NM to the Gulf of Mexico, however, now it is present in
only 5% of its former range (Earick 1999; MRGESA 2006a). Today, about 95% of the
Rio Grande silvery minnow population is concentrated below the San Acacia diversion
dam in the San Acacia Reach of the Middle Rio Grande. It no longer exists below the
Elephant Butte Reservoir, and was placed on the endangered species list in 1994
(MRGCD 2002).
3
Bosque del Apache
Plug, 2008
Tiffany Plug
1991, 1995, 2005
Galisteo and Heron
Cochiti Flood Control
Nambe Falls
Platoro
Jemez Canyon
El Vado and MRGCD
Diversion Dams
Elephant Butte
Abiquiu
Sediment Plugs
events
9,2400
cfs
9,200 cfs
7,600 cfs
cfs
12,400 cfs
12,300 cfs
30,000 cfs
30,000 cfs
47,000 cfs
25,000 cfs
50,000 cfs
100,000 cfs
Dams
Floods1
Elephant Butte Full
Drought
Floodway clearing/mowing
Levees, channelization and jetty jacks2
LFCC Operation
1865
1875
1885
1895
1905
1915
1925
1935
(1) Flood events listed are measured at various locations between Otowi and San Marcial.
1945
1955
1965
1975
1985
1995
Year
Figure 1.2 Historical Timeline of Middle Rio Grande (Modified After Makar 2011, Pers. Comm.)
4
2005
2015
Figure 1.3: Rio Grande Silvery Minnow and Southwestern Flycatcher
The southwestern willow flycatcher (Figure 1.3) also uses the Rio Grande’s
riparian vegetation and wetlands to raise their young chicks. The altered flooding patterns
and reduced reproduction habitat have negatively impacted their population as well. In
1995 the southwestern willow flycatcher was placed on the endangered species list as a
response to their declining population (MRGCD 2002; MRGESA 2006b).
1.2
Sediment Plugs
Historically, sediment plugs have formed along the Middle Rio Grande,
completely blocking the main channel of the river. In 1991, 1995, and 2005, the Tiffany
Plug formed in the upstream end of the Elephant Butte Reach at Agg/Deg 1683 (River
Mile 70.23), as seen in Figure 1.4. In 2008, the Bosque del Apache Plug formed between
Agg/Deg 1531 and 1550 (River Mile 82.5 – 80.81), about 7 miles upstream of the
Elephant Butte Reach. Little is known about the formation of sediment plugs; why they
form, where they form, and how best to manage river flows to prevent the formation of
sediment plugs. The consequences of sediment plugs in the Middle Rio Grande are
significant. The presence of sediment plugs blocks the main channel of the Rio Grande
5
and prevents water from reaching Elephant Butte Reservoir due to increased infiltration
and evapotranspiration induced by the plugs. The current practice with sediment plugs
by the United States Bureau of Reclamation (Reclamation) is to excavate a pilot channel
through the plug to encourage water to flow again and re-channelize; this method is
expensive and time consuming. Sediment plugs occur at the location of a constriction or
channel aggradation (Burroughs 2011). As aggradation within the Elephant Butte Reach
is known to contribute to a decrease in channel capacity (Reclamation 2007), it is
important to understand the influences of Elephant Butte Reservoir levels on channel
aggradation/degradation in order to decrease the potential for future sediment plug
formation.
Figure 1.4 Aerial View of Tiffany Plug in 2005
6
SECTIO
ON 2:
2.1
SITE
S
DESCRIPT
TION AN
ND BACK
KGROUN
ND
Elepha
ant Butte Reeach
The secction of the Middle Rio
o Grande exxamined in detail in thhis report wiill be
reeferred to as the Elephan
nt Butte Reacch. This reaach spans about 30 miless, beginning from
th
he South Bo
oundary of the
t Bosque del Apachee National W
Wildlife Reffuge (River Mile
73.9) to the “narrows”
“
of
o the Elephaant Butte Reeservoir (Riiver Mile 444.65). Figurre 2.1
hows the loccation of the project areaa in New Meexico.
sh
Fig
gure 2.1: Location of thee Elephant B
Butte Reach ffrom Googlee Maps
Sedimeent plugs occcasionally form alongg the Midddle Rio Graande, complletely
blocking the main chann
nel of the riv
ver. In 19911, 1995, andd 2005, the T
Tiffany Plugg was
in
nitiated at th
he upstream
m end of thee Elephant B
Butte Reachh. In 2008,, the Bosquue del
7
Apache Plug formed just upstream of the Elephant Butte Reach. Further understanding
of the influences of Elephant Butte Reservoir levels on channel aggradation/degradation
will provide insight into proper river management practices in order to decrease the
potential for sediment plug formation.
The objectives of this study include the following:
1. Quantify temporal changes in channel widths and sinuosity from 1935 to 2010.
2. Quantify change in channel slope temporally.
3. Quantify rate of aggradation/degradation in response to a change in base-level
(i.e., change in reservoir water surface elevation).
4. Quantify aggradation/degradation wave propagation upstream.
5. Quantify spatial and temporal trends in bed material grain size.
2.2
Subreach Definition
To thoroughly evaluate the significant changes in the study area, the reach was
divided into six subreaches.
The subreach definitions were determined by initial
assessments of the channel widths and planforms from aerial photos and channel slope.
To determine the subreach divisions, the active channel widths, as measured from
edge of vegetation to edge of vegetation, were plotted for the entire Elephant Butte Reach
for years 1962, 1972, 1992, and 2002. The thalweg at each Agg/Deg-line was also
plotted for each set of years, as shown on Figure 2.2. The subreaches were chosen based
on the 2002 dataset because of the abundance of both GIS and Agg/Deg Cross-section
data during this year, but subreaches were confirmed using the 1962, 1972, and 1992
datasets.
8
Figurre 2.2 Profile off Elephant Buttee Reach Widths and Thalweg att Agg/Deg Lines
9
There are no major slope distinctions along the Elephant Butte Reach in 2002;
therefore, subreaches were primarily selected based on width trends. Subreaches 1, 3,
and 5 tend to be wider than Subreaches 2, and 4 (based on 2002 data). Subreach 6 is a
transitional subreach, which is sometimes river, and sometimes reservoir, depending on
the level of Elephant Butte Reservoir. The first subreach begins at the south boundary of
the Bosque del Apache NWR, Agg/Deg 1637, and extends to Agg/Deg 1672. The
second subreach begins at Agg/Deg 1672 and ends at Agg/Deg 1696. The third subreach
begins at Agg/Deg 1696 and ends at Agg/Deg 1728. The fourth subreach begins at
Agg/Deg 1728 and ends at Agg/Deg 1751. The fifth subreach begins at Agg/Deg 1751
and ends at Agg/Deg 1794. The sixth, and last, subreach begins at Agg/Deg 1794 and
extends to Elephant Butte Reservoir.
Figure 2.3 through Figure 2.9 show the 2008 aerial photographs of the study area
and its subreaches. Notice the low-flow conveyance channel located on the west bank of
the river. The previous temporary outfall of the low-flow conveyance channel was at
Agg/Deg 1794, which marks the end of Subreach 5 and the beginning of Subreach 6.
The Black Mesa geologic feature is located east of Subreach 3. Levee construction along
the West side of the river has prevented the river from excessive meandering. The
Tiffany Plug location is shown on Figure 2.4; the Bosque del Apache Plug is located
about 7 miles upstream of the study reach and is, therefore, not shown.
10
Figure 2.3 2008 Aerial Photo of Subreach 1
11
Tiffany Plug
(1991, 1995, 2005)
Figure 2.4 2008 Aerial Photo of Subreach 2
12
Figure 2.5 2008 Aerial Photo of Subreach 3
13
Figure 2.6 2008 Aerial Photo of Subreach 4
14
Figure 2.7 2008 Aerial Photo of Subreach 5
15
Figure 2.8 2008 Aerial Photo of Subreach 6
16
Figure 2.9 2008 Aerial Photo of Elephant Butte Reservoir
17
2.3
Available Data
The data used in this study was received from a number of different agencies:
United States Bureau of Reclamation (Reclamation), National Oceanic and Atmospheric
Administration (NOAA), the United States Geological Survey (USGS), and the Middle
Rio Grande database compiled at Colorado State University for Reclamation.
2.3.1
Survey Lines and Dates
Cross-sectional survey data was collected by Reclamation using both
Aggradation/Degradation line (Agg/Deg-line) surveys; Socorro range line (SO-line), and
Elephant Butte range line (EB-line) surveys. Agg/Deg-line elevations were derived using
photogrammetry. The Agg/Deg-lines are spaced about 500 feet apart and were surveyed
in 1962, 1972, 1992, and 2002. This information was used for the hydraulic and GIS
analyses to follow. Figure 2.10 shows the entire Elephant Butte Reach with each of the
six defined subreaches, and the Agg/Deg-lines with the 2008 GIS Elephant Butte Reach
delineation.
The range lines (SO-lines and EB-lines) were field surveyed by Reclamation
beginning in 1980. These surveys are more detailed than the channel cross-sections that
were developed from the aerial photographs (i.e., Agg/Deg lines). The spacing of these
surveys is greater than that of the Agg/Deg lines, but the field surveyed cross section
locations typically coincide with Agg/Deg line locations. Range line survey data was
available from 1980 to 2010 from Reclamation. 18 SO-lines and 102 EB-lines are
located within the reach. Figure 2.11 shows the location of the SO- and EB-lines and
Appendix A provides the dates of available survey data at each SO- and EB-line.
18
Agg/Deg 1637
Agg/Deg 1672
Agg/Deg 1696
Agg/Deg 1728
Tiffany Plug
Agg/Deg 1683
(1991, 1995, 2005)
Agg/Deg 1751
Agg/Deg 1794
Figure 2.10 Subreach Definitions and Agg/Deg Line Locations (2008 GIS Elephant
Butte Reach Delineation Shown)
19
Agg/Deg 1637
Agg/Deg 1672
Agg/Deg 1696
Agg/Deg 1728
Tiffany Plug
Agg/Deg 1683
(1991 – 1995, 2005
Agg/Deg 1751
Agg/Deg 1794
Figure 2.11 Subreach Definitions and Range Line Locations (2008 GIS Elephant Butte
Reach Delineation Shown)
20
2.3.2
Discharge Data
Mean daily discharge data was primarily used from two USGS gauges: the San
Marcial gauge (08358400, primary gauge), located in the upstream end of the study
reach, and the San Acacia gauge (08354900, secondary gauge), located approximately 44
miles upstream of the study reach. The gauge numbers and their dates of available
discharge data are shown in Table 2-1.
Table 2-1: Available Daily Discharge Data
USGS Gauging Station USGS Gauge Number Dates Available
RG at San Marcial
8358400
1949- current
RG at San Acacia
8354900
1958-current
The Elephant Butte Dam gauge (8361000), located approximately 34 miles
downstream of the Elephant Butte Reach, measures regulated reservoir releases, and was
therefore not useful in this study.
The San Antonio gauge (8355490), located
approximately 25 miles upstream of the Elephant Butte reach, only contains discharge
data for recent years (2005 – Sep 2008), and therefore was not considered. An additional
gauge is located at the Escondida Bridge, approximately 16 miles upstream of the
Elephant Butte reach. However, this gauge only records real-time discharge and not the
historical data needed for this study. Figure 2.12 shows the locations of the nearby
gauges.
21
Figure 2.12 Location of Gauges
An example hydrograph for the San Acacia and San Marcial gauges for the year
1999 is shown in Figure 2.13. The hydrograph demonstrates that there are typically two
distinct peaks on the Middle Rio Grande. The first peak occurs between mid-May until
the end of June and the second peak occurs in August. As demonstrated in Figure 2.13,
22
significant evapotranspiration losses from the river largely contribute to the typically
lower discharge measurements at the San Marcial Gauge, compared to the San Acacia
Gauge (Baird, D., Pers. Comm.). Additional daily discharge graphs from the years 19902010 are available in Appendix B.
Figure 2.13: Daily Discharge of the Rio Grande in 1999
The annual peak flow information for the San Acacia and San Marcial gauges was
obtained from the USGS website. Figure 2.14 displays a comparison of the peak flows at
the San Acacia Gauge and the San Marcial Gauge.
23
10000
San Acacia
San Marcial
9000
Annual Peak Discharge (cfs)
8000
7000
6000
5000
4000
3000
2000
1000
1959
1961
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
0
Year
Figure 2.14 Comparison of Annual Peak Flows at San Acacia and San Marcial Gauges
2.3.3
Bed Material
Bed material data was collected by Reclamation from 1986-2007 at SO- and EB-
range lines. The dates and locations of the collected bed material data are provided in
Appendix C. Additional bed material data was also obtained from the USGS gauging
stations at San Acacia, located approximately 44 miles upstream of Elephant Butte
Reach,
and
San
Marcial,
(http://nwis.waterdata.usgs.gov).
located
within
the
Elephant
Butte
Reach
The dates and locations of the data recorded are
provided in Appendix D.
2.3.4
Suspended Sediment Data
As part of this study, the suspended sediment data was used from the Escondida
Reach Report (Larsen et al. 2007). This was used since no new sediment data is available
on the USGS website for the San Acacia and San Marcial guages. Daily suspended
24
sediment data was used for this analysis. Figure 2.15 shows the annual suspended
sediment load at each gauge. Continuous suspended sediment data was not always
available for all parameters at each gauge. A blank year indicates that complete sediment
data was not available for that year.
12000000
10000000
8000000
6000000
4000000
2000000
0
1958 1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994
Year
San Marcial
San Acacia
Figure 2.15: Annual Suspended Sediment Yield at San Acacia and San Marcial Gauges
Table 2-2 gives the dates of continuous, available data at each gauge.
Table 2-2: Available Suspended Sediment Data
USGS GAUGING STATION
DATES
Oct. 1956 - July 1962
Sep. 1962 - Aug. 1966
Oct. 1966 - Sep. 1989
Oct. 1991 - Sep. 1995
Jan 1959 - Sep. 1959
Jan 1960 - Sep. 1961
July 1961
April 1962 - July 1962
Aug 1962 - Sep. 1962
March 1963 - Sep. 1996
RG at San Marcial
RG at San Acacia
25
SECTION 3:
3.1.1
RESERVOIR LEVEL ANALYSIS
Reservoir Level Analysis
A reservoir level analysis was performed for the Elephant Butte Reservoir,
located at the downstream end of the Elephant Butte Reach. Figure 3.1 shows the
Elephant Butte Reservoir level time series. Elephant Butte Dam construction began in
1908 and was completed in 1916, with water storage operations beginning in January of
1915 (Reclamation, 2008). The maximum water surface elevation (WSE) of Elephant
Butte Reservoir is 4407.0 ft. Since its inception, the WSE behind Elephant Butte Dam
has varied more than 150 ft in elevation. The reservoir was not completely filled until
1942, at which point the reservoir level dropped about 150 ft between 1942 and 1954,
due to a drought which lasted from about 1942 to about 1974 (Figure 1.2). The low flow
conveyance channel (LFCC), which was built to hydraulically efficiently transport water
to Elephant Butte Reservoir and runs the entire length of Elephant Butte Reach, was in
operation by 1955 and operated until 1986. With the operation of the LFCC during the
drought, the reservoir WSE averaged between El 4331 and El 4404. By about 1977 the
reservoir began to fill again until it was full, or essentially full, from 1985 to 1999, at
which point another drought impacted the reservoir level, which decreased to an average
WSE of about 4340 ft in 2010.
26
4450
DROUGHT
DROUGHT
LFCC OPERATION
4400
WSE (ft)
4350
4300
Annual Mean WSE
Annual Max WSE
Annual Min WSE
Figure 3.1 Elephant Butte Reservoir Level Time Series
27
2010
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
1940
1935
1930
1925
1920
4200
1915
4250
Figure 3.2 shows the historical sediment survey longitudinal profile with reservoir
sediment surveys completed in 1915, 1988, 1999, and 2007. Comparing the survey
between 1915 and 1988, up to 50 ft of aggradation has occurred within Elephant Butte
Reservoir. The decrease in longitudinal profile elevation from 1999 to 2007 can be
attributed to the consolidation of the deposited sediment during the low reservoir levels in
response to a second drought from 1999 to 2005.
In 1915, when the reservoir had just begun to fill, had the reservoir been at its
maximum WSE, then the upstream extent of the reservoir would have reached RL 10 (or
the upstream end of Subreach 3). By 2007, the upstream extent of the reservoir at its
maximum WSE would have been about RL 20 (or the upstream end of Subreach 6). This
means the maximum upstream extent of the reservoir would have shifted downstream
approximately 6 miles. The level of the reservoir impacts Elephant Butte Reach, due to
sediment deposition as a result of an increased base-level. The longitudinal profile of
Elephant Butte Reach is base-level controlled; with an increase in base-level, the channel
adjusts vertically by way of sediment deposition, resulting in channel aggradation.
28
MAX WSE
AVG. WSE
2010 AVG WSE
SR3
SR4
SR5
SR
Figure 3.2 Elephant Butte Reservoir Historical Sediment Survey Longitudinal Profile (Reclamation, 2008)
29
SECTION 4:
4.1
CHANNEL ANALYSIS
Channel Planform Analysis from Aerial Photographs
Using ArcGIS and aerial photographs supplied by Reclamation, the study reach’s
active channel was delineated for 1918, 1935, 1949, 1962, 1972, 1985, 1992, 2001, 2002,
2003, 2004, 2005, 2006, 2008 and 2010. These active channel delineations will be
referred to as planforms for purposes of this report; the active channel corresponds to the
area bounded by established vegetation. Aerial photographs were not available during
1985, and a delineation provided by Reclamation was used; the 2010 active channel was
delineated using a Digital Elevation Model (DEM). See Appendix E for survey dates and
additional information about the aerial photographs.
The active channel width was measured at each Agg/Deg line using the delineated
planforms. A mean width value was then obtained for each subreach and for the overall
reach using a weighted average method. Finally, the sinuosity was computed.
4.1.1
Channel Delineation
Figure 4.1 shows the channel planforms that were delineated in ArcGIS. Figure 4.2
through Figure 4.7 show magnified versions of Figure 4.1. Based on visual observations,
the overall channel has narrowed and changed from a multithread channel to a primarily
single-thread channel.
Subreaches 1, 2, 5, and 6 have straightened and narrowed
primarily between 1918 and 1962, and have remained relatively unchanged since then.
The multithread characteristics of the river observed from 1928 to 1949 are not repeated
after the recession of the reservoir from 2001 to 2003, because Reclamation regularly
excavated pilot channels within Subreach 6 (Baird, D., Pers. Comm.).
30
Figure 4.1 Channel Planforms from Aerial Photography
31
Figure 4.2 Subreach 1 Channel Planforms from Aerial Photography
Figure 4.3 Subreach 2 Channel Planforms from Aerial Photography
32
Figure 4.4 Subreach 3 Channel Planforms from Aerial Photography
33
Figure 4.5 Subreach 4 Channel Planforms from Aerial Photography
34
Figure 4.6 Subreach 5 Channel Planforms from Aerial Photography
35
Figure 4.7 Subreach 6 Channel Planforms from Aerial Photography
36
Note that the difference between the first set of delineations, 1918-1949, is 31
years, the second set of delineations, 1962-1985, is 23 years, the third set of delineations,
1992-2002 is 10 years, and the fourth set of delineations, 2003-2010 is only 7 years.
Based on a qualitative visual analysis, the first delineation comparison covers the longest
time period and shows the most change and the last delineation comparison shows the
shortest time period with the least change. Nevertheless, narrowing and straightening of
the reach is observed over time.
4.1.2
Channel Widths from GIS
The active channel width corresponds to the non-vegetated channel. The active
channel planforms were delineated from aerial photographs using this criterion, and
widths were measured at every Agg/Deg line and/or Range line for which the river
intersected. A distance-dependent, weighted average method was used to calculate the
average width at each subreach and for the total reach.
In general, Figure 4.8 illustrates a decreasing trend in the width over time for all
of the subreaches from 1935 to 1972. Subreaches 1 and 2 experienced an increase in
average width in 1949 due to the existence of a multithread channel; Subreach 1
increased from about 940 ft to about 1100 ft, and Subreach 2 increased from about 700 ft
to about 1700 ft. The decrease in channel width from 1935 to 1972 (on average, about
275 ft) may be attributed to lower than average discharges, a decrease in base-level, or a
combination of the two. The lower than average discharges and decrease in base-level
are both results of the drought, which lasted from 1942 to 1979. From 1935 to 2010, the
channel width decreased according to the following second order polynomial equation:
y = 0.2353x2 - 936.54x + 931904
37
Where, x is the year, and y is the average channel width (ft).
2000
1800
Average Width (ft)
1600
1400
1200
1000
800
y = 0.2353x2 ‐ 936.54x + 931904
R² = 0.9299
600
400
200
0
1910
1920 1930
Subreach 1
1940
1950 1960
Subreach 2
Year
1970
1980 1990
Subreach 3
2000
Subreach 4
Subreach 5
Subreach 6
Total (SR 1‐5)
Total (SR 1‐6)
Poly. (Total (SR 1‐6))
2010
Figure 4.8 Channel Widths from GIS (1918 - 2010)
As seen in Figure 4.9, between 1972 and 1985, the average channel width
increased, on average, about 60 ft and the base-level increased by up to 125 ft. Between
1985 and 2000, the base-level remained relatively unchanged, changing no more than 27
ft, and the average channel width, on average, changed no more than 30 ft. Between
2000 and 2004, the base-level decreased by up to 100 ft, and the average channel width
increased 26 ft from 2001 to 2003 and decreased 45 ft from 2003 to 2004. The large
decrease in channel width between 2003 and 2004 was due to mechanical excavation of
narrow pilot channels by Reclamation (Baird, D. Pers. Comm.). The base-level increased
by about 50 ft between 2004 and 2010, and the average channel width increased about 55
ft between 2004 and 2006, and decreased about 55 ft between 2006 and 2010. In general,
38
based on this dataset, the channel width tends to increase with a rise in base-level, and
decrease with a drop in base-level.
300
Average Width (ft)
250
200
150
100
50
0
1960
1970
1980
1990
2000
2010
Year
Subreach 1
Subreach 2
Subreach 3
Subreach 4
Subreach 5
Subreach 6
Total (SR 1‐5)
Total (SR 1‐6)
Figure 4.9 Channel Widths from GIS (1962 - 2010)
4.1.3
Sinuosity
Sinuosity of the entire Elephant Butte Reach, as well as the six subreaches, was
computed using aerial photographs in ArcGIS. The sinuosity was determined by using
the following equation:
S
Lc
Lv
Where S is the sinuosity, Lc is the length of the channel, and Lv is the length of the
valley.
The length of the channel, and each of the six subreaches, was measured along the
river thalweg, an estimated delineation from aerial photographs and channel delineations.
The thalweg delineation was approximate and accuracy was, in some cases, further
39
limited by the clarity and quality of the aerial photographs.
The 1985 and 1918
planforms delineated by Reclamation were used to estimate the length of the channel and
the length of the valley. For each year, the length of the valley was measured as the
straight-line distance between the upstream and downstream extents of the reach and
subreaches, as dictated by major geologic features, such as the Black Mesa. The channel
length measurements are plotted in Figure 4.10 and presented in Table 4-1. The channel
length decreased about 0.0126 miles/year between 1935 and 2010.
40.00
Channel Length (miles)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
1910
1930
Subreach 1
Subreach 4
Total Reach SB (1‐5)
1950
1970
Year
Subreach 2
Subreach 5
Total Reach SB (1‐6)
1990
Subreach 3
Subreach 6
Figure 4.10 Subreach Lengths and Total Lengths as Measured From GIS Data
40
2010
Table 4-1 Subreach Length and Total Length Values as Measured From GIS Data
Reach Measured Lengths (mi) 1918 1935 1949 1962 1972 1985 1992 2001 2002 2003 2004 2005 2006 2008 2010 Subreach 1 3.46 3.92 4.07 3.52 3.56 Subreach 2 1.51 1.54 1.59 2.39 2.21 Subreach 3 1.56 3.87 3.54 3.25 3.24 Subreach 4 2.04 2.12 2.14 2.13 Subreach 5 4.74 4.97 4.21 4.26 Subreach 6 17.39 16.11 18.12 16.14 3.30 2.25 3.10 2.13 4.13 5.56 3.38 2.27 3.18 2.13 4.36 2.04 3.34 2.26 3.18 2.13 4.24 2.03 3.34 2.28 3.21 2.13 4.30 7.67 3.42 3.34 3.30 3.27 2.31 2.28 2.27 2.31 3.17 3.19 3.17 3.14 3.26 2.13 2.15 2.15 2.13 2.14 4.27 4.38 4.32 4.23 4.36 16.73 16.93 16.48 16.48 17.11 3.32 2.27 3.20 2.11 4.26 0.79 Total Reach SR (1‐5) 6.52 16.10 16.29 15.52 15.41 14.92 15.33 15.15 15.26 9.57 15.45 15.25 15.07 15.35 15.16
Total Reach SR (1‐6) 6.52 33.48 32.40 33.64 31.55 20.48 17.37 17.18 22.93 26.31 32.38 31.73 31.55 32.46 15.96
Agg/Deg Start 1637 1637 Agg/Deg End 1708 1962 1637 1948 1637 1962 1637 1958 1637 1849 1637 1811 41
1637 1811 1637 1875 1692 1962 1637 1962 1637 1960 1637 1960 1637 1962 1637 1962 Figure 4.11 shows the sinuosity for the Elephant Butte Reach and each of the
subreaches, values are presented in Table 4-2. From 1918 to 1935 sinuosity increased for
the entire channel; though the overall sinuosity remains low, less than 1.3, Subreach 1 is
more sinuous than Subreach 2 by about 15 percent. There is not enough planform
delineated in Subreach 3 in 1918 to be considered representative of the entire subreach,
so this portion was disregarded. No planform data exists below Subreach 3 in 1918, so
sinuosity data is unavailable. From 1935 to 1949, the sinuosity for the entire channel,
and for each subreach, decreased by less than 6 percent, except Subreach 5, which
increased about by about 4 percent. Subreach 2 remained less sinuous, by about 15
percent on average and up to 20 percent, than the remaining Subreaches, which ranged in
sinuosity from 1.18 to 1.29. From 1949 to 1962, the sinuosity of Subreaches 1, 3, 4, and
5 decreased between 10 and 20 percent, while Subreaches 2 and 6 increased between 5
and 10 percent. From 1962 to 2010 sinuosity tends to increase and decrease repetitively
between a range of 1.0 and 1.15 for Subreaches 1 through 5, while Subreach 6 tends to
have a higher sinuosity than the other subreaches from 1962 to 2010 and ranges from
1.12 to 1.24. The higher sinuosities observed in Subreach 6 in the mid-2000s is because
Reclamation mechanically introduced a sinuous channel to Subreach 6 by excavating a
pilot channel after the lowering of Elephant Butte Reservoir (Baird, D., Pers. Comm.). In
general, it can be said that this channel has experienced relatively low sinuosity (less than
1.25) since 1962. From 1935 to 2010, the channel sinuosity can be described using the
following second order polynomial:
y = 6E-05x2 - 0.2196x + 219.57
Where, x is year, and y is channel sinuosity (ft/ft).
42
1.3
y = 6E‐05x2 ‐ 0.2196x + 219.57
R² = 0.8398
1.25
1.15
1.1
1.05
Year
Subreach 1
Subreach 4
Total Reach (SR 1‐5)
Subreach 2
Subreach 5
Total Reach (SR 1‐6)
Figure 4.11 Temporal Sinuosity Trends
43
Subreach 3
Subreach 6
Poly. (Total Reach (SR 1‐5))
2015
2010
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
1940
1935
1930
1925
1920
1
1915
Sinuosity
1.2
Table 4-2 Sinuosity Values
Reach Subreach 1 Subreach 2 Subreach 3 Subreach 4 Subreach 5 Subreach 6 Total Reach (SR 1‐5) Total Reach (SR 1‐6) Agg/Deg Start Agg/Deg End Year 1918 1.118 1.032 1.049 ‐‐ ‐‐ ‐‐ ‐‐ 1.108 1637 1708 1935 1.222 1.054 1.259 1.293 1.233 1.194 1.213 1.210 1637 1962 1949 1.180
1.014
1.182
1.280
1.280
1.181
1.200
1.202
1637 1948 1962 1.039
1.106
1.054
1.026
1.062
1.246
1.078
1.176
1637 1962 1972 1.110
1.013
1.004
1.034
1.069
1.137
1.081
1.121
1637 1958 1985 1.027
1.013
1.016
1.033
1.028
1.225
1.037
1.098
1637 1849 1992 1.052 1.075 1.052 1.031 1.124 1.158 1.079 1.093 1637 1811 44
2001 1.017 1.024 1.017 1.010 1.087 1.182 1.063 1.089 1637 1811 2002 1.037
1.010
1.134
1.047
1.113
1.121
1.080
1.098
1637 1875 2003 1.035
1.018
1.104
1.149
1.140
1692 1962 2004 1.062
1.002
1.008
1.012
1.145
1.162
1.095
1.135
1637 1962 2005 1.039
1.025
1.061
1.057
1.109
1.145
1.068
1.119
1637 1960 2006 1.003
1.055
1.013
1.019
1.076
1.145
1.083
1.117
1637 1960 2008 2010 1.050 1.067 1.091 1.073 1.086 1.066 1.100 1.084 1.128 1.101 1.176
1.077 1.064 1.146 1.064 1637 1637 1962 1794 4.2
4.2.1
Aggradation and Degradation from Agg/Deg Surveys
Channel Thalweg Profile from Agg/Deg Surveys
The channel thalweg profile from the Agg/Deg survey data was utilized to
demonstrate how the minimum elevation and slope of the reach has changed over time, as
shown in Figure 4.12. The average bed slope for each subreach and for the entire reach
was determined by first plotting the thalweg profile versus downstream distance, as
measured along the estimated thalweg in GIS, and fitting a linear regression trendline to
each subreach. The slope of the linear regression line was considered the average bed
slope of the respective subreach. A linear regression trendline was also fit to the total
reach thalweg profile, from which the slope of the regression trendline was considered
the average bed slope of the total reach. This method was used for 1962, 1972, 1992, and
2002. The average bed slope for each subreach and for the entire reach is shown in
Figure 4.13.
45
450
00
SR1
SR2
SR3
SR4
4
SR6
SR5
1962 Thalweg Profile
1972 Thalweg Profile
1992 Thalweg Profile
2002 Thalweg Profile
448
80
Elevation (ft)
446
60
444
40
442
20
440
00
438
80
0
20,000
40,000
4
60
0,000
80,,000
100, 000
120,0
000
Distance Downstre
D
eam of South Boun
ndary of Bosque ddel Apache NWR (ftt)
Figure 4.12
4
Thalweg Elevation
E
Profile From Agg/Deeg Surveys
46
140,00
00
160,000
0.0009
0.0008
0.0007
Bed Slope
0.0006
0.0005
0.0004
Subreach 1
Subreach 2
Subreach 3
Subreach 4
Subreach 5
Subreach 6
Total Reach (1‐5)
0.0003
0.0002
0.0001
0.0000
1960
1970
1980
Year
1990
2000
2010
Figure 4.13 Bed Slope from Agg/Deg Surveys
Between the years 1962 and 1972, the bed slope increased between 15 and 30
percent for Subreaches 1, 2, and 3; bed slope decreased 40 and 20 percent for Subreaches
4 and 5, respectively. From 1972 to 1992, bed slope decreased between 10 and 45
percent for all subreaches. From 1992 to 2002, Subreach 2 increased 10 percent and
Subreach 6 increased fourfold; all other subreaches decrease between 3 and 15 percent.
The overall decrease in bed slope along the entire reach suggests aggradation has
occurred between 1962 and 2002. The decrease in bed slope from 1972 to 1992 in
Subreach 6 could be caused by the increased Elephant Butte Reservoir level (base-level),
which increased by about 130 ft. The fourfold increase in bed slope from 1992 to 2002 in
Subreach 6 could be due to the drop base-level, which dropped about 85 feet between
1992 and 2002.
The longitudinal profile of Elephant Butte Reach is base-level
controlled; with an increase in base-level, the channel adjusts vertically by way of
sediment deposition, resulting in channel aggradation and a decrease in channel slope. It
is important to note, however, that these trends could also be due to the lack of data in
Subreach 6, especially in 1972 and 1992, which could skew the calculated bed slope
47
value to be inaccurate. Table 4-3 shows the average values of the channel slope for each
subreach and the overall reach.
Table 4-3 Average Bed Slope from Agg/Deg Surveys
Subreach 1 2 3 4 5 6 Total (1‐6) Total (1‐5) 4.2.2
Agg/Deg Lines 1637 ‐ 1672 1672 ‐ 1696 1696 ‐ 1728 1728 ‐ 1751 1751 ‐ 1794 1794 ‐ 1875 1637 ‐ 1875 1637 ‐ 1794 1962 0.000509 0.000823 0.000699 0.000855 0.000730 0.000370 0.000594 0.000710 1972 0.000675 0.000830 0.000797 0.000537 0.000600 0.000370 0.000684 0.000720 1992 0.000523 0.000480 0.000564 0.000498 0.000550 0.000205 0.000535 0.000562 2002 0.000441 0.000532 0.000538 0.000417 0.000532 0.000819 0.000495 0.000481 Change in Channel Thalweg Elevation from Agg/Deg Surveys
A weighted average of the change in thalweg elevation was computed for the
entire reach, as well as each subreach, for each year of available Agg/Deg survey data.
The average change in thalweg elevation was then compared between years to determine
the change in elevation over time. Figure 4.14 shows the average change in thalweg
elevation for each subreach, and the overall reach over time; the tabulated values are
displayed in Table 4-4. The results show that the average change in the channel thalweg
elevation decreased between 0.7 and 3.5 ft from 1962 to 1972 for all subreaches except
Subreaches 5 and 6; Subreaches 5 and 6 increased in elevation by about 0.2 to 0.4 ft. The
average change in channel thalweg elevation has been increasing since 1972.
An
increase in channel thalweg elevation indicates aggradation, whereas a decrease indicates
degradation. The entire reach has been aggrading since 1972.
48
Change in Channel Thalweg Elevation (ft)
25
20
15
10
5
0
‐5
1962 ‐ 1972
1972 ‐ 1992
1992 ‐ 2002
SUBREACH 1
SUBREACH 2
SUBREACH 3
SUBREACH 5
SUBREACH 6
TOTAL REACH
1962 ‐ 2002
SUBREACH 4
Figure 4.14 Change in Channel Thalweg Elevation from Agg/Deg Surveys
Table 4-4 Change in Channel Thalweg Elevation Values from Agg/Deg Surveys
Δ Channel Thalweg Elevation (ft) Weighted Average U/S OF EB REACH SUBREACH 1 SUBREACH 2 SUBREACH 3 SUBREACH 4 SUBREACH 5 SUBREACH 6 TOTAL REACH 1962 ‐ 1972 0.79 ‐0.67 ‐2.65 ‐3.45 ‐3.53 0.43 0.26 ‐1.33 1972 ‐ 1992 3.36 5.73 8.33 11.57 14.07 15.06 17.68 11.42 1992 ‐ 2002 1.76 1.85 3.67 4.20 5.88 7.21 6.53 4.79 1962 ‐ 2002 5.91 6.93 9.39 12.31 16.39 22.50 20.01 15.95 Analyses were done using the Agg/Deg data to show the change in thalweg
elevation at each Agg/Deg line (see Figure 4.15 to view the changes from 1962-1972,
Figure 4.16 for 1972-1992, Figure 4.17 for 1992-2002, and Figure 4.18 for 1962-2002).
Recall that Agg/Deg data does not have surveys available at every Agg/Deg line during
the years 1962, 1972, and 1992, therefore the plots only show the Agg/Deg lines for
49
which data exists. Table 4-5 shows the average, maximum and minimum changes in
channel thalweg elevation with their respective Agg/Deg line for each group of years.
4
SR 1
3
SR 2
SR 3
SR 4
SR 5
SR 6
2
1
0
‐1
‐2
‐3
‐4
‐5
1820
1804
1792
1777
1750
1733
1707
1695
1688
1678
1670
1662
1652
1645
‐6
1637
Change in Channel Invert Elevation (ft)
1962 ‐ 1972
Agg/Deg #
Figure 4.15 Change in Channel Thalweg Elevation (1962 – 1972) Based on Agg/Deg
Surveys
25
SR 1
SR 2
SR 3
SR 4
SR 5
SR 6
20
15
10
5
1809
1798
1786
1762
1750
1733
1707
1695
1688
1678
1670
1662
1652
1645
0
1637
Change in Channel Invert Elevation (ft)
1972 ‐ 1992
Agg/Deg #
Figure 4.16 Change in Channel Thalweg Elevation (1972 – 1992) Based on Agg/Deg
Surveys
50
9
SR 1
8
SR 2
SR 3
SR 4
SR 5
SR 6
7
6
5
4
3
2
1
1804
1792
1777
1751
1747
1731
1703
1695
1688
1678
1670
1662
1652
1645
0
1637
Change in Channel Invert Elevation (ft)
1992 ‐ 2002
Agg/Deg #
Figure 4.17 Change in Channel Thalweg Elevation from 1992 – 2002 Based on Agg/Deg
Surveys
30
SR 1
SR 2
SR 3
SR 4
SR 5
SR 6
25
20
15
10
5
1875
1848
1827
1809
1798
1786
1762
1747
1731
1703
1695
1688
1678
1670
1662
1652
1645
0
1637
Change in Channel Invert Elevation (ft)
1962 ‐ 2002
Agg/Deg #
Figure 4.18 Change in Channel Thalweg Elevation from 1962 – 2002 Based on Agg/Deg
Surveys
51
Table 4-5 Average, Maximum and Minimum Change in Channel Thalweg Elevation Based on Agg/Deg Surveys
Year: Subreach 1 Max Min 1962 ‐ 1972 1972 ‐ 1992 1992 ‐ 2002 1962 ‐ 2002 Δ Δ Δ Δ Agg/Deg Agg/Deg Agg/Deg Agg/Deg Thalweg Thalweg Thalweg Thalweg # # # # El (ft) El (ft) El (ft) El (ft) 1.30 1641 7.70 1652 3.14 1673.0 8.34 1662 ‐3.10 1670 3.50 1645 0.84 1652.0 4.95 1645 Average
Max Subreach 2 Min ‐0.67 ‐1.30 1692 ‐4.30 1678 1695 1678 1.85 4.35 1683.0 2.58 1695.0 Average
Max Subreach 3 Min ‐2.65 ‐2.40 1707 ‐4.70 1731 1731 1707 3.67 4.99 1731.0 3.68 1707.0 13.90 10.20 14.19 11.47 Average
Max Subreach 4 Min ‐3.45 ‐1.70 1747 ‐5.50 1733 11.57 14.60 1751 14.00 1747 4.20 6.36 1747.0 5.53 1733.0 12.31 18.66 1747 14.13 1733 Average
Max Subreach 5 Min ‐3.53 2.60 1762 ‐1.20 1777 14.07 16.30 1777 14.50 1762 5.88 7.92 1777.0 6.68 1762.0 16.39 23.78 1762 23.02 1777 Average
Max Subreach 6 Min 0.43 1820 1798 15.06 19.80 1798.00 16.70 1804 7.21 7.80 1804.0 5.20 1798.0 22.50 24.30 1809 11.50 1875 1762 1733 17.68 19.80 1798 3.50 1645 6.53 7.92 1777.0 0.84 1652.0 20.01 24.30 1809 4.95 1645 11.42 4.79 15.95 Total Reach Average
Max Min Average
1.40 ‐0.90 0.26 2.60 ‐5.50 ‐1.33 5.73 10.60 7.10 8.33 52
6.93 11.28 7.00 1692 1678 9.39 1731 1707 From 1962 to 1972 degradation occurred in all subreaches. The upstream half of
Subreach 1 aggraded from 1962 to 1972, along with five sections in Subreach 5 and
Subreach 6. Since 1972, the channel has been aggrading along all subreaches. From
1962 to 2002, a maximum aggradation of 24.30 feet has occurred at Agg/Deg 1809, at the
downstream end of the reach, with a minimum aggradation of 4.95 ft at Agg/Deg 1645, at
the upstream end of the reach. From Figure 4.18, it is clear that aggradation increases in
the downstream direction. Within Subreach 6, however, there tends to be a decrease in
aggradation in the downstream direction. The overall aggradation of the reach is due to
the increase in base-level between 1972 and 1985, at which point the base-level changed
less than 30 ft between 1985 and 2000. Between 1992 and 2002, aggradation continued
in the upstream portions of the reach, still in response to the increase in base-level
between 1972 and 1985. However, the downstream portion of Subreach 6 (Agg/Deg
1827 to Agg/Deg 1875) did not aggrade as much as the upstream portion of Subreach 6,
because of the drop in base-level of about 80 ft between 2000 and 2002.
Figure 4.19 shows the change in the thalweg elevation at selected Agg/Deg lines
from 1962 – 1992. Only Agg/Deg lines with sufficient years of sample data were plotted.
It can be inferred from this plot that as the reservoir level increases, the channel thalweg
elevation increases at each Agg/Deg line, and that the increase in channel thalweg
elevation is more pronounced in the downstream direction, closer to the reservoir.
53
4500
4480
4460
Elevation (ft)
4440
4420
4400
4380
4360
4340
4320
1950
1960
1970
1980
1990
2000
2010
2020
Year
Figure 4.19 Temporal Trend in Thalweg Elevation at Agg/Deg Lines
54
1625
1628
1633
1637
1641
1645
1648
1652
1658
1662
1666
1670
1673
1678
1683
1688
1692
1695
1703
1707
1731
1733
1747
1750
1751
1762
1777
1786
1792
1798
1804
1809
1820
1827
1835
1848
1856
1864
1875
1883
1887
1894
1908
EB Res
Figure 4.20 shows the rate of aggradation between 1972 and 1992 at each
Agg/Deg line for which there is data. A second order polynomial trendline was fit to the
data. For an increase in base-level (Reservoir WSE) of up to 13.4 ft/yr, the following
second order polynomial describes the rate of aggradation from 1972 to 1992 for the
Elephant Butte Reach:
Rate of Aggradation = -0.0014x2 + 0.0649x + 0.1832
Where, x is the distance in miles downstream of Agg/Deg 1637 (or the upstream end of
Elephant Butte Reach).
Rate of Aggradation (ft/yr)
1.2
y = ‐0.0014x2 + 0.0649x + 0.1832
R² = 0.9334
1
0.8
0.6
0.4
0.2
0
0
5
10
15
20
Miles Downstream from Agg/Deg 1637
Figure 4.20 Rate of Channel Aggradation between 1972 and 1992
4.3
4.3.1
Aggradation and Degradation from Range Line Surveys
Channel Thalweg Profile from Range Line Surveys
Figure 4.21 shows the thalweg elevation profile of the entire reach. Only years
with enough range line survey data were plotted. Not all years are presented, because the
lines on the plot would be too dense to see trends if all the years were plotted, so certain
years were chosen to represent changes. The thalweg elevation profile shows a general
55
trend of varying aggradation and degradation over time. One of the most notable trends
from this plot is the flattening of the channel slope from 2004 to 2009 in the downstream
half of the reach, which is due to the aggradation induced by a rise in base-level from
2004 to 2009. Also noteworthy is the significant aggradation in 2005 upstream of EB-10
(Agg/Deg 1707). The Tiffany Plug formed in 2005 at SO-1683 (Agg/Deg 1683), just
upstream of EB-10, which can be seen in the profile. In 1995, severe degradation can be
seen downstream of SO-1683 (Agg/Deg 1683), and virtually no change at SO-1683, even
though a sediment plug had formed upstream of SO-1683 in 1995.
This is likely
explained by the timing of the survey, which seems to have occurred after the sediment
plug was mechanically removed by Reclamation.
56
4500
Tiffany Plug, 2005,
SO-1683 (Agg/Deg 1683)
1988
1991
1994
1995
1999
2004
2005
2009
4480
Elephant Butte Reservoir
Max WSE, El 4454 (Project Datum)
4440
4420
1650
1700
SR 6
SR 5
Agg/Deg 1794
SR 4
Agg/Deg 1751
Agg/Deg 1728
4380
1600
SR 3
Agg/Deg 1696
4400
SR 2
Agg/Deg 1672
SR 1
Agg/Deg 1637
Thalweg Elevation (ft)
4460
1750
1800
1850
1900
Agg/Deg Line
Figure 4.21 Thalweg Elevation Profile From Range Line Survey Data
57
1950
2000
The channel thalweg profile from the range line survey data was utilized to
demonstrate how the minimum elevation and slope of the reach has changed over time.
The average bed slope for each subreach was determined by first plotting the thalweg
profile versus river mile, and then fitting a linear regression trendline to each subreach.
The slope of the linear regression line was considered the average bed slope of the
respective subreach. This method was used for all years for which range line survey data
was available.
The average channel thalweg slopes for each Subreach 1 through
Subreach 6 are presented in Figure 4.22 through Figure 4.27, respectively. Table 4-6
Avg Thalweg Slope (ft/mi)
presents the values of the average channel thalweg slopes for each subreach.
8
7
6
5
4
3
2
1
0
1985
1990
1995
2000
2005
2010
Year
Avg Thalweg Slope (ft/mi)
Figure 4.22 Subreach 1 Average Channel Thalweg Slope: Temporal Trend
8
7
6
5
4
3
2
1
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
Year
Figure 4.23 Subreach 2 Average Channel Thalweg Slope: Temporal Trend
58
Avg Thalweg Slope (ft/mi)
6
5
4
3
2
1
0
1985
1990
1995
2000
2005
2010
Year
Avg Thalweg Slope (ft/mi)
Figure 4.24 Subreach 3 Average Channel Thalweg Slope: Temporal Trend
6
5
4
3
2
1
0
1975
1980
1985
1990
1995
2000
2005
2010
2015
Year
Avg Thalweg Slope (ft/mi)
Figure 4.25 Subreach 4 Average Channel Thalweg Slope: Temporal Trend
6
5
4
3
2
1
0
1985
1990
1995
2000
2005
2010
2015
Year
Figure 4.26 Subreach 5 Average Channel Thalweg Slope: Temporal Trend
59
Avg Thalweg Slope (ft/mi)
5
4
3
2
1
0
1985
1990
1995
2000
2005
2010
2015
Year
Figure 4.27 Subreach 6 Average Channel Thalweg Slope: Temporal Trend
Table 4-6 Average Channel Thalweg Slopes for Subreaches 1 through 6
Channel Thalweg Slope (ft/mi) Year 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1980 SR 1 ‐‐‐‐ 3.819 2.3551 1.5905 3.3542 0.1714 2.1619 0.7829 2.7047 ‐‐‐‐ ‐‐‐‐ 3.3741 4.1195 2.3206 ‐‐‐‐ 6.8687 4.3434 2.303 4.1414 6.4848 3.6869 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ SR 2 ‐‐‐‐ 2.5421 3.2975 3.215 3.0568 5.4088 3.6974 3.3695 2.8284 ‐‐‐‐ ‐‐‐‐ 2.7141 2.5813 4.9367 ‐‐‐‐ 7.3103 2.2019 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ SR 3 ‐‐‐‐ 14.345 2.1491 3.4676 ‐‐‐‐ 0.2545 4.9293 2.9158 1.9506 ‐‐‐‐ ‐‐‐‐ 1.147 4.1364 4.3273 ‐‐‐‐ ‐6 3.0909 4.7273 3.6364 2.5273 2.9455 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 60
SR 4 3.3058 3.191 3.6395 3.6845 ‐‐‐‐ 3.7804 3.7213 3.6717 3.99 ‐‐‐‐ 5.0078 5.0078 3.7546 4.2125 2.5278 4.3334 4.3229 4.0989 3.053 4.4329 3.3211 ‐‐‐‐ 4.4677 5.1043 5.1482 3.8767 SR 5 3.9285 4.7156 4.2458 4.1554 ‐‐‐‐ 4.8768 3.1183 2.9102 2.5376 ‐‐‐‐ 2.9984 2.9984 3.2622 1.6368 2.1193 1.949 3.9316 2.6817 2.5 5.5 2.8516 ‐‐‐‐ 3.0734 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ SR 6 2.7865 2.8378 2.9771 3.1211 3.4361 3.4627 4.1643 4.2159 4.2891 2.3077 2.7499 3.2324 3.567 3.4796 4.2534 4.2116 3.5435 3.6434 4.6557 ‐‐‐‐ 4.1049 3.9154 1.7771 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ Subreaches 1 through 5 don’t appear to have a trend relating average channel
thalweg slope to time. Subreach 6, however, has a decreasing trend from 1995 to 2001
and again from 2002 to 2010. From 1995 to 2001, the channel slope decreases at a rate
of 0.32 ft/mi/yr; from 2002 to 2010, the channel slope decreases at a rate of 0.21 ft/mi/yr.
From 1995 to 2001, the base-level drops about 35 ft, while Subreach 6’s slope decreases.
From 2001-2004, the base-level drops another 60 ft, and from 2004 to 2009, the baselevel increases about 35 ft, all while the channel slope decreases. Therefore, the channel
slope is not dependent on the base-level changes within the same time-frame. Rather, the
channel slope decrease from 1995 to 2001 is due to the increase in base-level from 1982
to 1986, or from the increase in base-level from 1990 to 1995. And, the channel slope
decrease from 2001 to 2010 is due to the increase in base-level from 2004 to 2009. The
sudden jump in channel slope from 2.3 ft/mile, in 2001, to 4.3 ft/mile, in 2002, is likely a
result of the decrease in base-level between 1995 and 2004, during which the base-level
dropped by about 100 ft.
Cross-sections were plotted at select range lines for all years of available data and
are presented in Appendix F. Figure 4.28 through Figure 4.36 show representative crosssections of Elephant Butte Reach. SO-1683, Figure 4.29, is located in Subreach 2. From
2004 to 2005 the channel aggraded by about 8 ft and then degraded by about 8 ft from
2005 to 2006. This is the location of the Tiffany Sediment Plug in 2005. The sediment
plug was removed by excavating a pilot channel, which accounts for the decrease in bed
elevation from 2005 to 2006. EB-41, Figure 4.36, is located in Subreach 6. When the
reservoir was full from 1985 to 2000, this range line was inundated by the reservoir,
which is why there is only data available beginning in 2004.
61
SO‐1641
4500
2009
2008
4498
2007
4496
2006
Elevation (ft)
2005
4494
2004
2003
4492
2002
2001
4490
1999
4488
1998
1997
4486
50
100
150
Station (ft)
200
250
Figure 4.28 Subreach 1: SO-1641 Surveyed Cross-Sections
SO‐1683
4492
2009
2008
4490
2007
4488
2006
2005
Elevation (ft)
4486
2004
4484
2003
2002
4482
1999
1998
4480
1997
4478
1995
1994
4476
1993
4474
1990
0
50
100
150
Station (ft)
Figure 4.29 Subreach 2: SO-1683 Surveyed Cross-Sections
62
200
EB‐10
4482
4480
4478
Elevation (ft)
4476
4474
4472
4470
4468
4466
4464
4462
500
600
700
800
900
1000
Station (ft)
2010
2009
2008
2007
2005
2004
2003
2002
2001
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1988
1987
1986
1980
Figure 4.30 Subreach 3: EB-10 Surveyed Cross-Sections
EB‐10 (w/Floodplain)
4490
Active Channel
4485
Elevation (ft)
4480
4475
4470
4465
4460
4455
4450
0
500
1000
1500
2000
2500
Station (ft)
Figure 4.31 Subreach 3: EB-10 (w/Floodplain) Surveyed Cross-Sections
63
2010
2009
2008
2007
2005
2004
2003
2002
2001
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1988
1987
1986
1980
EB‐13
4476
2009
4474
2008
4472
2007
Elevation (ft)
2005
4470
2004
4468
2002
2000
4466
1998
1992
4464
1988
4462
1987
4460
1950
1986
2000
2050
2100
2150
2200
2250
2300
Station (ft)
Figure 4.32 Subreach 4: EB-13 Surveyed Cross-Sections
EB‐20
4465
2009
2008
2007
2005
2004
2002
2000
1999
1998
1997
1995
1994
1993
1992
1991
1990
1988
1980
4460
Elevation (ft)
4455
4450
4445
4440
4435
150
200
250
300
350
400
Station (ft)
Figure 4.33 Subreach 5: EB-20 Surveyed Cross-Sections
64
450
EB‐29
4450
2009
2008
4445
2007
Elevation (ft)
2005
4440
2004
2002
2000
4435
1999
1997
4430
1995
4425
5000
1993
5100
5200
5300
5400
5500
5600
1989
Station (ft)
Figure 4.34 Subreach 6: EB-29 Surveyed Cross-Sections
EB‐29 (w/Floodplain)
4455
2009
2008
Active Channel
2007
4450
Elevation (ft)
2005
2004
4445
2002
4440
2000
1999
4435
1997
1995
4430
1993
4425
3750
1989
4250
4750
5250
5750
6250
6750
Station (ft)
Figure 4.35 Subreach 6: EB-29 (w/Floodplain) Surveyed Cross-Sections
65
EB‐41
4416
4414
4412
2009
Elevation (ft)
4410
2008
4408
2007
4406
2004
4404
4402
4400
4398
0
50
100
150
200
250
300
Station (ft)
Figure 4.36 Subreach 6: EB-41 Surveyed Cross-Sections
4.3.2
Change in Thalweg and Average Bed Elevation from Range Line Surveys
As seen in Figure 4.28 through Figure 4.36 aggradation and degradation occur
across the entire channel bed, not just the thalweg. Therefore, the following analyses
focus on the change in thalweg elevation temporally and spatially. Figure 4.37 shows the
change in the thalweg elevation at selected range lines from 1980-2010. Only range lines
with sufficient years of sample data were plotted.
66
4500
4600
SO‐1641
SO‐1652.7
SO‐1666
4490
SO‐1673
S0‐1683
SO‐1692
4480
SO‐1701.3
EB‐10
4470
4550
EB‐13
EB‐14
EB‐16
4460
EB‐17
EB‐18
EB‐20
4450
EB‐24
4440
4500
EB‐25
Reservoir WSE (ft)
Channel Thalweg Elevation (ft)
EB‐34
4430
4420
4410
4450
EB‐26
EB‐27
EB‐28
EB‐29
EB‐30
EB‐32
EB‐33
EB‐35
EB‐36
EB‐37
4400
EB‐37.5
EB‐38
4390
EB‐39
EB‐40
4380
4400
EB‐40.5
EB‐41
EB‐42
EB‐43
4370
EB‐44
EB‐45
4360
EB‐46
EB‐47
4350
1980
1985
1990
1995
2000
Year
2005
4350
2010
EB‐48
EB‐49
EB‐50
Reservoir Level
Figure 4.37 Change in Thalweg Elevation at Range Lines (1980 – 2010)
67
From 1980 to 1988, aggradation occurred at all range lines for which there is data.
From 1988 to 1994, the thalweg elevation alternated between increasing and decreasing
elevation, typically changing no more than 3 ft in either direction. From 1994 to 1995,
mostly aggradation occurs, up to 6.2 ft, near the upstream reservoir extent; degradation
occurs just downstream of the 1995 Tiffany Sediment Plug at SO-1692 and SO-1701.3,
7.6 ft and 3.6 ft, respectively. From 1995 to 2002, the change in channel thalweg
elevation varies between aggradation and degradation. From 2002 to 2003, aggradation
occurs from SO-1641 to EB-29, ranging between 1 ft and 4 ft; degradation occurs
downstream of EB-29, up to 3.5 ft. From 2003 to 2004, the channel degraded from SO1641 to SO-1692, and from EB-20 to EB-50 by up to 10.7 ft; the channel aggraded from
SO-1701.3 to EB-18 by up to 1 ft. From 2004 to 2007, aggradation occurred from SO1641 to SO-1692, up to 2.3 ft, and from EB-40 to EB-50, up to 7.6 ft; degradation
occurred from SO-1701.3 to EB-39, up to 11 ft.
From 2007 to 2008, degradation
occurred from SO-1641 to EB-37.5, up to 2.7 ft; aggradation occurred from EB-38 to
EB-50, up to 1.4 ft. From 2008 to 2009, the channel degraded from SO-1641 to EB-37,
up to 2.6 ft; the channel aggraded from EB-37.5 to EB-50, up to 4.2 ft. From 2009 to
2010, the channel varied between aggradation and degradation, ranging between -1.8 ft
and 2.2 ft in elevation change.
A few notable changes occurred at EB-24. From 1990 to 1992 the thalweg
elevation decreased by about 12 ft, from 1992 to 1993 the thalweg elevation increased by
about 7.8 ft, and from 1994 to 1995, the thalweg elevation increased another 6.2 ft.
These changes are in direct response to the change in reservoir WSE, as the shape of the
68
thalweg elevation over time mimics the shape of the change in WSE over time, as seen in
Figure 4.37.
Table 4-7 shows the calculated values of change in thalweg elevation between
selected year sets at each range line for which there is data. The table is color-coded such
that cells highlighted with light red fill indicate degradation between the year set, while
cells highlighted with light green fill indicate aggradation, or in the case of the reservoir
level change, the colors indicate a drop in level and rise in level, respectively. A Cell
highlighted with blue fill and white text, or a cell under the area of the pink outline,
indicates the cross-section was inundated by the reservoir during the latter of the two
years associated with the year set. If the text within a cell reads “----”, then data was not
available at that range line during at least one of the two years associated with the year
set. A cell within the area of a red outline indicates the cell is associated with a “wave”
of degradation, while a cell within the area of a green outline indicates the cell is
associated with a “wave” of aggradation. If a cell is between the area of a red and green
outline, then the cell is considered a transitional area.
Four “waves” were analyzed from this dataset. The first wave is a wave of
degradation and is the result of a decrease in average reservoir level (base-level) from
2009 to 2010 of about 7 ft. The second wave is a wave of aggradation and is the result of
an increase in average base-level from 2004 to 2009 of about 35 ft. The third wave is a
wave of degradation and is the result of a decrease in average base-level from 1995 to
2004 of about 105 ft. The fourth and final wave analyzed, is a wave of aggradation and is
the result of an increase in average base-level from 1990 to 1995. No other waves were
analyzed in detail, due to the lack of available data between 1980 and 1990.
69
Table 4-7 Change in Thalweg Elevation Between Select Year Sets
2009‐
2010 2008‐
2009 2007‐
2008 2004‐
2007 2003‐
2004 2002‐
2003 1999‐
2002 1998‐
1999 1997‐
1998 1995‐
1997 1994‐
1995 1993‐
1994 1992‐
1993 1991‐
1992 1990‐
1991 1990‐
1992 1988‐
1990 1980‐
1988 ‐‐‐‐ 0.73 ‐1.35 1.65 ‐0.17 1.26 ‐1.52 ‐0.12 1.81 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐0.81 ‐2.15 2.25 ‐1.62 1.92 ‐0.30 ‐0.57 ‐1.33 0.30 2.10 1.00 ‐0.60 ‐1.62 1.77 0.15 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐0.16 1.43 ‐1.84 1.40 ‐0.40 ‐1.02 1.22 0.70 ‐1.00 ‐0.30 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐0.55 ‐1.22 0.26 ‐1.32 2.02 0.15 1.37 ‐2.22 3.70 0.50 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 0.51 ‐0.52 ‐1.04 ‐2.21 2.61 1.36 0.67 ‐1.73 0.00 1.80 0.20 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 0.66 ‐1.35 1.02 ‐1.84 1.16 ‐0.03 1.16 ‐‐‐‐ ‐‐‐‐ ‐7.60 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐0.15 ‐1.72 ‐2.74 1.22 2.38 ‐0.33 ‐0.58 1.80 3.50 ‐3.60 1.40 ‐0.60 ‐1.37 0.00 ‐1.37 ‐‐‐‐ ‐‐‐‐ EB‐10 1.27 ‐1.56 ‐0.99 ‐1.94 0.12 1.85 ‐0.77 1.06 1.91 ‐2.18 1.40 2.30 ‐1.20 ‐1.98 0.23 ‐1.75 1.25 8.10 EB‐13 ‐0.18 ‐0.78 ‐0.70 ‐4.92 0.20 2.09 1.46 ‐0.61 ‐1.87 2.43 0.90 1.20 0.40 ‐2.19 ‐0.18 ‐2.37 1.47 12.10 EB‐14 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 2.68 4.54 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 12.80 EB‐16 ‐0.75 ‐0.39 ‐0.76 ‐5.89 0.49 2.17 0.34 0.40 2.28 ‐2.28 2.00 0.20 0.70 ‐‐‐‐ ‐‐‐‐ ‐1.88 3.18 11.00 EB‐17 ‐0.15 0.06 ‐0.56 ‐4.33 ‐0.06 2.79 1.96 ‐1.90 1.01 1.49 0.30 1.20 ‐2.20 ‐0.22 ‐1.78 ‐2.00 2.70 11.90 EB‐18 ‐0.79 0.25 ‐2.39 ‐6.27 0.02 3.35 ‐1.15 ‐0.67 4.37 ‐1.70 ‐1.80 3.40 ‐‐‐‐ ‐‐‐‐ ‐0.27 ‐‐‐‐ ‐0.36 2.80 EB‐20 1.35 ‐2.58 ‐1.77 ‐7.37 ‐0.52 2.65 ‐0.71 2.90 ‐1.63 0.43 0.90 1.60 0.60 0.86 ‐2.91 ‐2.05 ‐‐‐‐ ‐‐‐‐ EB‐34 0.80 ‐0.53 ‐2.66 ‐8.56 ‐0.40 2.56 ‐0.13 ‐0.45 1.26 ‐1.21 2.50 0.70 0.90 ‐‐‐‐ ‐‐‐‐ ‐2.50 0.20 ‐‐‐‐ EB‐24 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐8.62 ‐2.11 2.38 2.23 ‐2.30 2.84 ‐2.74 6.20 ‐0.80 7.80 ‐6.36 ‐5.68 ‐12.04 ‐1.56 20.40 EB‐25 0.05 ‐0.83 ‐1.20 ‐10.40 ‐0.62 2.26 ‐0.76 0.40 0.30 ‐0.10 0.60 ‐0.80 2.40 ‐‐‐‐ ‐‐‐‐ ‐0.86 0.86 ‐‐‐‐ EB‐26 ‐0.47 ‐0.29 ‐1.48 ‐11.13 0.44 1.01 0.45 ‐1.40 1.70 ‐3.80 1.20 ‐0.17 1.87 ‐‐‐‐ ‐‐‐‐ 2.43 2.27 ‐‐‐‐ EB‐27 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐0.86 ‐1.30 ‐‐‐‐ ‐‐‐‐ 1.10 2.30 ‐2.10 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ 5.20 EB‐28 ‐0.06 ‐0.27 ‐1.07 ‐1.86 ‐8.15 2.72 ‐1.51 ‐0.26 0.05 0.75 1.50 ‐0.70 3.30 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐29 ‐0.83 0.43 ‐2.15 ‐1.06 ‐10.69 4.12 ‐0.60 ‐2.47 3.04 0.80 0.30 ‐0.50 1.20 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐30 0.32 ‐0.66 0.85 ‐0.75 ‐4.24 ‐1.03 ‐4.53 2.47 1.03 2.00 0.90 ‐0.70 0.10 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ SO‐
1641 SO‐
1652.7 SO‐
1666 SO‐
1673 SO‐
1683 SO‐
1692 SO‐
1701.3 70
Table 4-7 Change in Thalweg Elevation Between Select Years (Part 2)
2009‐
2010 2008‐
2009 2007‐
2008 2004‐
2007 2003‐
2004 2002‐
2003 1999‐
2002 1998‐
1999 1997‐
1998 1995‐
1997 1994‐
1995 1993‐
1994 1992‐
1993 1991‐
1992 1990‐
1991 1990‐
1992 1988‐
1990 1980‐
1988 EB‐32 0.02 0.53 ‐1.62 0.06 ‐0.17 ‐3.49 ‐2.74 ‐0.60 1.30 0.10 ‐0.30 0.60 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐33 ‐0.46 ‐1.21 1.07 ‐1.65 1.69 ‐2.27 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐35 ‐0.36 0.88 ‐1.91 0.09 ‐0.60 ‐1.71 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐36 ‐0.10 0.26 1.03 0.15 ‐2.28 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐37 1.80 ‐0.28 ‐0.71 ‐0.03 ‐1.86 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐
37.5 2.22 0.53 ‐0.49 ‐0.80 ‐0.89 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐38 1.54 1.27 0.20 ‐0.30 0.65 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐39 0.00 0.74 0.52 ‐0.36 ‐1.36 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐40 ‐0.98 2.31 0.25 2.32 0.85 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐
40.5 ‐1.84 1.98 0.17 2.75 ‐0.30 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐41 ‐1.05 1.86 1.40 3.70 ‐1.29 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐42 1.42 0.05 ‐0.32 4.06 ‐0.83 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐43 1.04 2.06 0.60 5.24 ‐2.68 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐44 ‐1.54 4.22 ‐0.86 4.41 0.79 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐45 0.48 1.75 1.18 6.20 ‐2.02 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐46 0.13 2.93 0.46 6.83 ‐4.28 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐47 ‐1.02 2.23 ‐0.06 7.01 ‐3.80 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐48 3.79 ‐2.25 0.19 7.59 ‐3.62 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐49 0.82 0.12 ‐0.82 6.74 ‐2.17 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ EB‐50 ‐0.21 0.11 0.74 5.65 ‐3.55 ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ ‐‐‐‐ Res ‐6.91 1.73 5.85 28.75 ‐9.07 ‐24.43 ‐51.95 ‐4.51 1.33 ‐7.17 0.12 3.23 1.41 10.64 1.29 11.94 ‐16.20 32.49 71
The change in thalweg and mean channel bed elevation were evaluated using the
range line survey data. First, the minimum channel elevation (thalweg) was calculated
for each range line at different surveyed years. Then, the change in Thalweg elevation
was compared between years at each range line where data was available. A second,
similar analysis was done by calculating the change in the average channel bed elevations
for which a weighted average was used to calculate the mean bed elevation for each
range line at different surveyed years.
Because data was not available each year for every range line, different ranges of
years had to be used to calculate the change in elevation. This is indicated by the
different colors of bars in Figure 4.38 for the change in average bed elevation analysis,
and Figure 4.39 for the change in thalweg elevation analysis. The orange bars show a
change in elevation for range lines between 1988 and 1990; the turquoise bars show a
change in elevation between 1990 and 1995; the purple bars show a change in elevation
from 1995 to 2003; the green bars show a change in elevation between 2003 and 2004;
and the red bars show a change in elevation from 2004 to 2009; and blue bars show a
change in elevation from 2009 to 2010. Note that each set of bars has a different time
increment; this is because the selected years contain data for most of the range lines, and
the year sets represent an overall aggrading or degrading trend.
72
SO‐1641
SO‐1652.7
SO‐1666
SO‐1673
SO‐1683
SO‐1692
SO‐1701.3
EB‐10
EB‐13
EB‐14
EB‐16
EB‐17
EB‐18
EB‐20
EB‐34
EB‐24
EB‐25
EB‐26
EB‐27
EB‐28
EB‐29
EB‐30
EB‐32
EB‐33
EB‐35
EB‐36
EB‐37
EB‐37.5
EB‐38
EB‐39
EB‐40
EB‐40.5
EB‐41
EB‐42
EB‐43
EB‐44
EB‐45
EB‐46
EB‐47
EB‐48
EB‐49
EB‐50
Change in Average Bed Elevation (ft)
15
SR 1
SR 2 SR 3
SR 4
1988‐1990
SR 5
1990‐1995
SR 6
10
5
0
‐5
‐10
‐15
‐20
Range Line ID
1995‐2003
73
2003‐2004
2004‐2009
2009‐2010
Figure 4.38 Change in Average Channel Bed Elevation at Range Lines (1988-2010)
SO‐1641
SO‐1652.7
SO‐1666
SO‐1673
SO‐1683
SO‐1692
SO‐1701.3
EB‐10
EB‐13
EB‐14
EB‐16
EB‐17
EB‐18
EB‐20
EB‐34
EB‐24
EB‐25
EB‐26
EB‐27
EB‐28
EB‐29
EB‐30
EB‐32
EB‐33
EB‐35
EB‐36
EB‐37
EB‐37.5
EB‐38
EB‐39
EB‐40
EB‐40.5
EB‐41
EB‐42
EB‐43
EB‐44
EB‐45
EB‐46
EB‐47
EB‐48
EB‐49
EB‐50
Thalweg Elevation Change (ft)
15
SR 1
SR 2 SR 3
SR 4
1988‐1990
SR 5
1990‐1995
SR 6
10
5
0
‐5
‐10
‐15
‐20
Range Line ID
1995‐2003
74
2003‐2004
2004‐2009
2009‐2010
Figure 4.39 Change in Channel Thalweg Elevations at Range Lines (1988-2010)
The following observations are based specifically on the change in thalweg
elevation; however, the general trends observed are similar for the change in average bed
elevation. From 1988 to 1990, primarily aggradation occurred, up to 3.2 ft. From 1990
to 1995, which includes the first instances in which the Tiffany Plug formed, there is
aggradation and degradation observed, depending on the range line; there does not appear
to be a hinge point spatially separating aggradation and degradation. From 1995 to 2003,
after the second Tiffany Plug, there is mostly aggradation between SO-1673 and EB-29,
up to 11.3 ft. From 2003 to 2004, there is degradation the majority of the reach, up to
10.7 ft. From 2004 to 2009, degradation is observed from SO-1652.7 to EB-37.5, at
which point aggradation is observed from EB-38 to EB-50. From 2009 to 2010, the
channel alternates between aggradation and degradation along the reach profile, with the
greatest magnitude of aggradation, 3.8 ft, occurring at EB-48.
4.3.3
Rate of Aggradation/Degradation from Range Line Surveys
From 2003 to 2004, shown in Figure 4.40 and Figure 4.41, degradation is
observed along the entire reach, except for at five range lines. The wave of degradation
between EB-13 and EB-50 (Wave 3) is in response to the drop in base-level (Reservoir
WSE) by about 100 ft between 1995 and 2004. Figure 4.41 shows the magnitude of
degradation from 2003 to 2004 at River Miles, which is represented by the following
second order polynomial equation:
y = -0.1601x2 + 16.209x - 410.5
Where, y is the magnitude of degradation and x is the longitudinal location along the
reach in River Miles (RM, as defined by Reclamation, where measurements begin at the
75
downstream end
e of the Middle
M
Rio Grande Rivver); this equuation is apppropriate forr RM
45.21 to RM 57.75.
2
0
‐2
‐4
‐6
‐8
‐10
‐12
Upstream
End
U t
E d
Change in Thalweg Elevation (ft)
4
Rangee Line
0 Magnitudee of Aggradaation and Deegradation att Range Linees (2003-20004)
Figure 4.40
4
2
‐2
‐4
59
57
55
51
53
River Mile
‐6
Downstream End
Upstream End
y = ‐0.1601x2 + 16.209x ‐‐ 410.5
R
R² = 0.6064
49
47
Change in Thalweg (ft)
0
‐8
‐10
‐12
45
Figure 4.41 Magnitudee of Aggradaation and Deegradation att River Milees (2003-20004)
76
From 2004 to 2005, all of the thalweg elevations decreased between SO-line 1683
and EB-26; the decrease becomes more pronounced in the downstream direction between
these range lines, as seen in Figure 4.42 and Figure 4.43. From 2004 to 2005, SO-lines
1641, 1652.7, and 1683 increased. The wave of degradation between SO-1683 and EB26 (Wave 3) is in response to the drop in base-level (Reservoir WSE) by about 100 ft
between 1995 and 2004. Figure 4.42 shows the magnitude of degradation from 2004 to
2005 at River Miles, which is represented by the following linear equation:
y = 0.8233x – 58.29
Where, y is the magnitude of degradation and x is the longitudinal location along the
6
4
2
0
‐2
‐4
‐6
‐8
‐10
‐12
SO‐1641 Upstream End
SO‐1652.7
SO‐1673
SO‐1692
SO‐1701.3
EB‐10
EB‐13
EB‐16
EB‐17
EB‐18
EB‐20
EB‐34
EB‐24
EB‐25
EB‐26
EB‐28
EB‐30
EB‐32
EB‐33
EB‐35
EB‐36
EB‐37
Downstream
EB‐37.5
EB‐38 End
Change in Thalweg Elevation (ft)
reach in River Miles; this equation is appropriate for RM 59.34 to RM 73.59.
Range Line
Figure 4.42 Magnitude of Aggradation and Degradation at Range Lines (2004-2005)
77
Downstream End
Upstream End
75
70
65
60
Change in Thalweg Elevation (ft)
6
4
2
0
‐2
‐4
‐6
‐8
‐10
‐12
y = 0.8233x ‐ 58.285
R² = 0.821
55
River Mile
Figure 4.43 Magnitude of Aggradation and Degradation at River Miles (2004 to 2005)
From 2004 to 2009, shown in Figure 4.44, degradation is observed from SO1652.7 to EB-37.5, at which point aggradation is observed from EB-38 to EB-50. These
two trends represent two distinct waves of thalweg elevation changes in response to base-
15
10
5
0
‐5
‐10
EB‐49
EB‐47
EB‐45
EB‐43
EB‐41
EB‐40
EB‐38
EB‐37
EB‐35
EB‐32
EB‐29
EB‐27
EB‐25
EB‐34
EB‐18
EB‐16
EB‐13
SO‐1701.3
SO‐1683
SO‐1666
‐15
SO‐1641
Thalweg Elevation Change (ft)
level changes, Wave 3 and Wave 2, respectively.
Range Line ID
Figure 4.44 Change in Thalweg Elevation from 2004 to 2009
The wave of degradation between SO-1701.3 and EB-26 (Wave 3) is in response
to the decrease in base-level by about 100 ft between 1995 and 2004. Figure 4.45 shows
78
the magnitude of degradation from 2004 to 2009, which is represented by the following
second order polynomial equation:
y = -0.0226x2 + 4.0x – 171.53
Where, y is the magnitude of degradation and x is the longitudinal location along the
reach in River Miles; this equation is appropriate for RM 45.21 to RM 52.03.
The wave of aggradation between EB-38 and EB-50 (Wave 2) is in response to
the reservoir WSE increase of about 35 ft between 2004 and 2009. Figure 4.46 shows the
magnitude of aggradation from 2004 to 2009, which is represented by the following
second order polynomial equation between RM 59.34 and RM 73.59:
y = -0.4355x2 + 41.11x – 962.27
Where, y is the magnitude of degradation and x is the longitudinal location along the
Upstream End
Downstream End
y = ‐0.0226x2 + 4.0052x ‐ 171.53
R² = 0.9302
75
70
65
60
River Mile
Figure 4.45 Magnitude of Degradation from 2004 to 2009
79
55
2
0
‐2
‐4
‐6
‐8
‐10
‐12
‐14
‐16
Change in Thalweg Elevation (ft)
reach in River Miles.
10
8
6
4
Downstream
End
Upstream End
55
53
51 River Mile 49
Change in Thalweg Elevation (ft)
12
y = ‐0.4355x2 + 41.112x ‐ 962.27
R² = 0.8399
47
2
0
‐2
‐4
45
Figure 4.46 Magnitude of Aggradation from 2004-2009
Appendix G presents plots of the change in thalweg elevation between selected
year sets versus river mile, along with trendlines associated with “waves” of aggradation
and “waves” of degradation.
4.3.4
Rate of Wave Propagation Upstream from Range Line Surveys
Wave 1, resulting from the decrease in base-level from 2009 to 2010, is
represented by range line EB-50. EB-50 decreased approximately 0.2 ft between 2009
and 2010. The rate of wave propagation upstream was determined by first plotting the
river mile of the upstream extent of the reservoir during the first year of the wave. Then,
the river mile of the upstream-most affected range line cross-section was determined and
plotted versus the latter year of the year set. If a wave continued beyond one year set,
then this step was repeated for each year set that the wave propagated and for which data
existed.
The upstream extent of the reservoir was determined by interpolating (or
extrapolating) the average channel thalweg slope during the first year of the wave to the
average elevation of the reservoir; where the channel slope and reservoir elevation
intersected, the river mile was calculated. Figure 4.47 shows the reservoir water surface
80
elevation change from 2009 to 2010, which induces Wave 1 degradation. Figure 4.48
shows the rate of Wave 1 propagation upstream as a result of the decrease in WSE (baselevel) from 2009 to 2010. The wave propagated upstream at a rate of 1.46 miles/year
with a decrease in base-level of 6.9 ft/year, and the upstream extent of the reservoir
receded 2.71 miles/year.
4392
4391
Reservoir WSE (ft)
4390
y = ‐6.9072x + 18267
4389
4388
4387
4386
4385
4384
4383
2008
2009
2010
2011
Year
Figure 4.47 Reservoir Water Surface Elevation Change from 2009-2010 Resulting in
Wave 1 Channel Degradation
46
River Mile (mi)
44
y = 1.4607x ‐ 2890.8
42
40
y = ‐2.7127x + 5493.5
38
36
34
32
30
2008
Chnl Bed Wave 2
Res U/S Extent
Linear (Chnl Bed Wave 2)
Linear (Res U/S Extent)
2009
Year
2010
2011
Figure 4.48 Rate of Wave 1 Propagation Upstream
Wave 2 resulted from an increase in base-level from 2004 to 2009. Figure 4.49
shows the reservoir water surface elevation change from 2004 to 2009, which induced
81
Wave 2 aggradation. Figure 4.50 shows the rate of Wave 2 propagation upstream as a
result of the increase in WSE (base-level) from 2004 to 2009. With an increase in baselevel of 6.8 ft/year, Wave 2 propagated upstream according to the following second order
polynomial:
y = -0.5522x2 + 2219.1x - 2E+06
Where, y is the upstream-most River Mile at which aggradation occurs as a result of an
increase in base-level of 6.8 ft/year, and x is the year at which River Mile y begins to
aggrade. The upstream extent of the reservoir progressed upstream at a rate of 1.36
Reservoir WSE (ft)
miles/year.
4400
4395
4390
4385
4380
4375
4370
4365
4360
4355
4350
2003
y = 6.7963x ‐ 9259.3
2004
2005
2006
2007
2008
2009
2010
Year
Figure 4.49 Reservoir Water Surface Elevation Change from 2004-2009 Resulting in
Wave 2 Channel Aggradation
82
55
y = ‐0.5522x2 + 2219.1x ‐ 2E+06
R² = 0.9969
River Mile (mi)
50
45
y = 1.3609x ‐ 2689.6
R² = 0.9633
40
Chnl Bed Wave 2
Res U/S Extent
Poly. (Chnl Bed Wave 2)
Linear (Res U/S Extent)
35
30
2003
2004
2005
2006
2007
2008
2009
2010
2011
Year
Figure 4.50 Rate of Wave 2 Propagation Upstream
Wave 3 resulted from a decrease in base-level from 1997 to 2004. Figure 4.51
shows the reservoir water surface elevation change from 1997 to 2004, which induced
Wave 3 degradation. Figure 4.52 shows the rate of Wave 3 propagation upstream as a
result of the decrease in WSE (base-level) from 1997 to 2004. With a decrease in baselevel of 14.2 ft/year, Wave 3 propagated upstream according to the following second
order polynomial:
y = 0.0692x2 - 276.2x + 275686
Where, y is the upstream-most River Mile at which degradation occurs as a result of a
decrease in base-level of 14.2 ft/year, and x is the year at which River Mile y begins to
degrade. The upstream extent of the reservoir receded at a rate of 2.9 miles/year.
83
4480
Reservoir WSE (ft)
4460
4440
4420
4400
y = ‐14.243x + 32904
4380
4360
4340
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
Year
Figure 4.51 Reservoir Water Surface Elevation Change from 1997-2004 Resulting in
Wave 3 Channel Degradation
80
y = 0.0692x2 ‐ 276.2x + 275686
R² = 0.8863
75
River Mile (mi)
70
65
60
55
50
45
40
35
30
1990
y = ‐2.9297x + 5909.5
R² = 0.9068
Chnl Bed Wave 3
Res U/S Extent
Poly. (Chnl Bed Wave 3)
Linear (Res U/S Extent)
1995
2000
Year
2005
2010
Figure 4.52 Rate of Wave 3 Propagation Upstream
Wave 4 resulted from an increase in base-level from 1990 to 1995. Figure 4.53
shows the reservoir water surface elevation change from 1990 to 1995, which induced
Wave 4 aggradation. Figure 4.54 shows the rate of Wave 4 propagation upstream as a
84
result of the increase in WSE (base-level) from 1990 to 1995. With an increase in baselevel of 3.7 ft/year, Wave 4 propagated upstream according to the following second order
polynomial:
y = -0.1222x2 + 489.03x – 489299
Where, y is the upstream-most River Mile at which aggradation occurs as a result of an
increase in base-level of 3.7 ft/year, and x is the year at which River Mile y begins to
aggrade. The upstream extent of the reservoir progressed upstream at a rate of 1.07
miles/year.
4455
y = 3.7339x ‐ 2996.4
Reservoir WSE (ft)
4450
4445
4440
Reservoir WSE
4435
4430
1989
Linear (Reservoir WSE)
1990
1991
1992
1993
1994
1995
1996
Year
Figure 4.53 Reservoir Water Surface Elevation Change from 1990-1995 Resulting in
Wave 4 Channel Aggradation
85
80
y = ‐0.1222x2 + 489.03x ‐ 489299
R² = 0.892
75
River Mile (mi)
70
65
60
y = 1.0734x ‐ 2079.6
R² = 0.8114
55
50
Chnl Bed Wave 4
45
Res U/S Extent
40
Poly. (Chnl Bed Wave 4)
35
Linear (Res U/S Extent)
30
1985
1990
1995
Year
2000
2005
Figure 4.54 Rate of Wave 4 Propagation Upstream
4.4
4.4.1
Bed Material Analysis
Grain Size Distributions
Bed material surveys taken at SO- and EB- range lines by Reclamation were used
to create grain size distribution curves for each subreach. Also, San Acacia and San
Marcial gauges’ bed material grain size distributions were plotted to study the trend of
the bed material grain size about 44 miles upstream of the study reach and within the
study reach.
Since complete temporal sequences of data related to each range line were not
available, those with the most complete set of data were chosen to represent each
subreach (see Table 4-8).
86
Table 4-8 Representative Range Lines for Each Subreach
Subreach
1 2 3 4 5 6 Range Line SO‐1641 SO‐1683 EB‐10 EB‐13 EB‐18 EB‐24 Multiple samples were collected at a given range line and for a given year. In
many cases, stations along the range line cross-section at which samples were collected
were provided. Where stations were provided, the sample locations were compared to
the surveyed range line cross-sections, which were presented in Section 4.3. If the
samples collected were from the floodplain within the cross-section, then the sample was
not included in this analysis, as bed material only is of interest. If sample locations were
not provided, then it was assumed that the sample was a bed material sample, because the
data provided was defined by Reclamation as bed material sample data. The grain size
distributions of all the collected bed material samples at a given station and in a given
year were plotted. A representative grain size distribution was selected for each range
line and for each year, from which the average mean grain size was computed. This same
procedure was applied to the San Acacia and San Marcial gauge data. For example,
Figure 4.55 shows different grain size distributions for range line EB-10 in 1992. The
most representative distribution chosen for that year is highlighted in yellow.
87
100.0
90.0
80.0
% Finer by Weight
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
0.01
0.1
1
10
Grain Size (mm)
Figure 4.55 EB-10 1992 Bed Material Grain Size Distributions
Figure 4.56 through Figure 4.63 show the compilation of representative grain size
distributions for each year at the San Acacia gauge, at the San Marcial gauge, and at each
subreach. Select bed material grain size distribution plots are provided in Appendix H.
88
100
90
% Finer by Weight
80
70
1966
1969
1975
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
60
50
40
30
20
10
0
0.001
1968
1973
1976
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
0.01
0.1
1
10
100
Grain Size Distribution (mm)
Figure 4.56 San Acacia Gauge: Annual Bed Material Grain Size Distributions
100
90
1968
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1969
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
1
10
Grain Size Distribution (mm)
Figure 4.57 San Marcial Gauge: Annual Bed Material Grain Size Distributions
89
100
2001
2002
2004
2005
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size Distribution (mm)
Figure 4.58 Subreach 1 (SO-1641): Annual Bed Material Grain Size Distributions
100
90
80
1999
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
Grain Size Distribution (mm)
Figure 4.59 Subreach 2 (SO-1683): Annual Bed Material Grain Size Distributions
90
100
1986
1988
1992
1994
1998
2002
90
80
% Finer by Weight
70
1987
1990
1993
1997
1999
60
50
40
30
20
10
0
0.01
0.1
1
10
100
Grain Size Distribution (mm)
Figure 4.60 Subreach 3 (EB-10): Annual Bed Material Grain Size Distributions
100
1986
1987
1988
1990
1999
2002
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
100
1000
Grain Size Distribution (mm)
Figure 4.61 Subreach 4 (EB-13): Annual Bed Material Grain Size Distributions
91
100
1986
1987
1988
1990
1993
1994
1997
1999
2002
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
100
1000
Grain Size Distribution (mm)
Figure 4.62 Subreach 5 (EB-18): Annual Bed Material Grain Size Distributions
100
1986
1992
1999
2002
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
Grain Size Distribution (mm)
Figure 4.63 Subreach 6 (EB-24): Annual Bed Material Grain Size Distributions
92
10
The San Acacia and San Marcial grain size distribution plots show that the bed
material has become slightly coarser over time as indicated by the grain size distribution
curves moving to the right with time. Note that the San Acacia gauge is 44 miles
upstream of this study reach and is not representative of this study reach, while the San
Marcial gauge is located at the upstream end of this study reach, and therefore represents
this study reach very well.
The grain size distributions of each subreach have
experienced minimal changes throughout the years. It should be noted that in the case of
San Acacia and San Marcial gauges, the sequences of data ranges from 1967 to 2008,
while Subreaches 3, 4, 5, and 6 data range from 1986 to 2002; Subreach 1 only ranges
from 2001 to 2005; and Subreach 2 only has data from 1999.
4.4.2
Median Grain Size
Figure 4.64 shows the change over time of the average median bed material grain
size in each subreach and at the San Acacia and San Marcial gauges, located 44 miles
upstream of the study reach and within the study reach, respectively. Figure 4.65 shows
the average median bed material grain size trends for each subreach from 1986 to 2005.
93
0.9
Average Median Grain Size (mm)
0.8
0.7
San Acacia Gauge
San Marcial Gauge
Subreach 1 (SO‐1641)
Subreach 2 (SO‐1683)
Subreach 3 (EB‐10)
Subreach 4 (EB‐13)
Subreach 5 (EB‐18)
Subreach 6 (EB‐24)
0.6
0.5
0.4
0.3
0.2
0.1
0
1965
1975
1985
1995
2005
2015
Year
Figure 4.64 Average Median Bed Material Grain Size Temporal Trends
Average Median Grain Size (mm)
0.3
0.25
Subreach 1 (SO‐1641)
Subreach 2 (SO‐1683)
Subreach 3 (EB‐10)
Subreach 4 (EB‐13)
Subreach 5 (EB‐18)
Subreach 6 (EB‐24)
Linear (Subreach 1 (SO‐1641))
Linear (Subreach 3 (EB‐10))
Linear (Subreach 4 (EB‐13))
Linear (Subreach 5 (EB‐18))
Linear (Subreach 6 (EB‐24))
0.2
0.15
0.1
0.05
0
1985
1990
1995
2000
2005
2010
Year
Figure 4.65 Average Median Bed Material Grain Size: Subreach Temporal Trends
Overall, mean grain sizes of the study reach range between 0.11 and 0.26 mm,
corresponding to very fine to medium sand (Julien 2002). In general, the bed material at
94
the San Marcial gauge has become coarser since the 1960s by about 0.002 mm/year
(from a minimum of 0.08 mm in 1991 to a maximum of 0.24 mm in 2004). The bed
material at the San Acacia gauge has become coarser by about 0.009 mm/year (from a
minimum of 0.04 mm in 1980 to a maximum of 0.85 mm in 2009), which is about five
times faster than the bed material coarsening rate at the San Marcial gauge. Note that the
rates of bed material coarsening were determined using the entire datasets for each
respective gauge that are presented in Figure 4.64.
Figure 4.65 shows that the average median grain size in Subreach 1 has become
finer at a rate of 0.0046 mm/year between 2001 and 2005; Subreach 2 has no temporal
trend, because the only data available for Subreach 2 is from 1999; the average median
grain size within Subreach 3 coarsened at a rate of 0.0027 mm/year between 1986 and
2002; the average median grain size within Subreach 4 coarsened at a rate of 0.0031
mm/year between 1986 and 2002; the average median grain size within Subreach 5
coarsened at a rate of 0.0031 mm/year between 1986 and 2002; the average median grain
size within Subreach 6 became finer at a rate of 0.0005 mm/year between 1986 and 2002.
All average median grain sizes are within the very fine to fine sand range, except
for the averages in Subreach 1 in 2001 and in Subreach 3 in 1994, which are in the low
end of the medium sand classification (0.26 mm). So, though there has been overall
coarsening of the bed material within this study reach, it is less than 0.003 mm/year, and
is still generally classified as very fine to fine sand. Figure 4.65 also shows that while the
median bed material size has coarsened with time, it tends to get finer in the downstream
direction.
95
4.5
Suspended Sediment Data
Suspended sediment data was used from the Escondida Reach Report (Larsen et
al. 2007). Single and double mass curves developed in the Escondida Reach Report
(Larsen et al. 2007) are presented below. Trends in water discharge, suspended sediment
discharge, and suspended sediment concentration are shown in Figure 4.66, Figure 4.67,
and Figure 4.68, respectively.
The single mass curve for water discharge, Figure 4.66, shows similar trends at
the San Marcial and San Acacia gauges. Both curves show breaks around 1979 and
2000. In about 1979, the discharge increased from about 600 cfs to over 2000 cfs. Table
4-9, also from the Escondida Reach Report (Larsen et al. 2007), is presented below and
shows the average discharge for each period displayed on the graph.
Cumulative Discharge (acre-ft)
3.0E+07
2.5E+07
2.0E+07
1.5E+07
1.0E+07
5.0E+06
0.0E+00
10/1/1949
9/29/1959
9/26/1969 9/24/1979
Date
SA: 1958-1979
SA: 2000-2005
SM: 1979-2000
Linear (SA: 1958-1979)
Linear (SA: 2000-2005)
9/21/1989
9/19/1999
SA: 1980-1999
SM: 1949-1978
SM: 2001-2005
Linear (SA: 1980-1999)
Linear (SM: 1949-1978)
Figure 4.66 Water Discharge Single Mass Curve (Larsen et al. 2007)
96
Table 4-9 Water Discharge (Larsen et al. 2007)
Gauge
San Acacia
San Marcial
Years
1958-1979
1980-1999
2000-2005
1949-1978
1979-2000
2001-2005
acre-ft/day
522
2856
1055
621
2263
740
R2 value
0.98
0.99
0.93
0.94
0.99
0.84
Figure 4.67 shows the single mass curve for suspended sediment discharge at the
San Acacia and San Marcial Gauges.
The San Marcial gauge has a much higher
suspended sediment discharge than the San Acacia gauge from 1956 until about 1968.
From 1968 to 1991, the two gauges both have a suspended sediment discharge of about
10,000 tons/day. From 1991 to 1996, the San Marcial gauge again shows a much higher
suspended sediment discharge. Table 4-10 shows the average suspended sediment
discharge for the periods shown on the graph.
1.8E+08
Cumulative Suspended Sediment (tons)
1.6E+08
1.4E+08
1.2E+08
1.0E+08
8.0E+07
6.0E+07
4.0E+07
2.0E+07
0.0E+00
10/1/1949
9/29/1959
9/26/1969
9/24/1979
9/21/1989
9/19/1999
SA: 1959-1967
Date
SA: 1968-1975
SA: 1976-1996
SM: 1956-1959
SM: 1960-1989
SM: 1991-1995
Linear (SA: 1959-1967)
Linear (SA: 1968-1975)
Linear (SA: 1976-1996)
Linear (SM: 1956-1959)
Linear (SM: 1960-1989)
Linear (SM: 1991-1995)
Figure 4.67 Suspended Sediment Discharge Single Mass Curve (Larsen et al. 2007)
97
Table 4-10 Suspended Sediment Discharge (Larsen et al. 2007)
Gauge
San Acacia
San Marcial
Years
1959-1967
1968-1975
1976-1996
1956-1959
1960-1989
1991-1995
tons/day
6062
9172
10066
35276
10232
16707
R2 value
0.94
0.92
0.99
0.88
0.98
0.98
Double mass curves were developed at each gauge to show the changes in
suspended sediment concentration over time, as seen in Figure 4.68.
Cumulative Suspended Sediment (tons)
1.8E+08
1.6E+08
1.4E+08
1.2E+08
1.0E+08
8.0E+07
6.0E+07
4.0E+07
2.0E+07
0.0E+00
0.0E+00
5.0E+06
1.0E+07
1.5E+07
2.0E+07
Cumulative Water Discharge (acre-ft)
2.5E+07
SA: 1959-1978
SA: 1979-1996
SM: 1956-1977
SM: 1978-1989
SM: 1990-1995
Linear (SA: 1959-1978)
Linear (SA: 1979-1996)
Linear (SM: 1956-1977)
Linear (SM: 1978-1989)
Linear (SM: 1990-1995)
Figure 4.68 Suspended Sediment Concentration Double Mass Curves (Larsen et al.
2007)
From 1959 to 1978, the two curves are very similar, with an average suspended
sediment concentration of about 13,000 mg/L. Around 1978, both curves break, and the
98
suspended sediment concentration drops to about 3,000 mg/L. The concentration at the
San Acacia gauge remains at about 3,000 mg/L through the end of the available data.
The San Marcial gauge, however, shows an increase in suspended sediment concentration
from 3,000 mg/L to 4,500 mg/L around 1990.
Table 4-11 shows the average
concentration as well as the R2 values for each segment of the graph.
Table 4-11 Suspended Sediment Concentration (Larsen et al. 2007)
Gauge
San Acacia
San Marcial
Years
1959-1978
1979-1996
1956-1977
1978-1989
1990-1995
tons/acre-ft
17.9
3.58
17.21
4.16
6.2
mg/L
13165
2633
12657
3060
4560
R2 value
0.97
0.98
0.97
0.92
0.98
From 1960 to 1989 at the San Marcial gauge, and from 1959 to 1996 at the San
Acacia gauge, the suspended sediment discharge consistently averaged between about
9,000 and 10,000 tons/day, as seen in Figure 4.67. Around 1980, the water discharge at
the San Acacia and San Marcial gauges increased four to five times the average water
discharge from 1949 to 1980. From 1942 to 1979, New Mexico experienced a state-wide
drought (Paulson et al 1988). The decrease in suspended sediment concentration in 1979
was due to the increase in water discharge following the nearly 40 year drought, and was
not due to a change in suspended sediment discharge.
99
SECTION 5:
SUMMARY AND CONCLUSIONS
The Elephant Butte Reach spans about 30 miles, beginning from the South Boundary
of the Bosque del Apache National Wildlife Refuge (River Mile 73.9) to the “narrows” of
the Elephant Butte Reservoir (River Mile 44.65), in central New Mexico.
Further
understanding of the historical and spatial changes within Elephant Butte Reach, along
with a better understanding of the influences of Elephant Butte Reservoir levels on
channel aggradation/degradation is essential for improvement in future river management
practices along the Middle Rio Grande. The objectives addressed in this study included
the following:
6. Quantified temporal changes in channel widths and sinuosity from 1935 to 2010.
7. Quantified change in channel slope temporally.
8. Quantified rate of aggradation/degradation in response to a change in base-level
(i.e., change in reservoir water surface elevation).
9. Quantified aggradation/degradation wave propagation upstream.
10. Quantified spatial and temporal trends in bed material grain size.
The average channel width and channel sinuosity for Elephant Butte Reach have
decreased since 1918.
From 1935 to 2010, the average channel width decreased
according to the following equation:
Avg. Chnl Width = 0.2353x2 – 936.54x + 931904
Where, x is the year. Since 1962, the average channel width has ranged between 50 ft
and 300 ft.
From 1935 to 2010, channel sinuosity has decreased according to the
following equation:
100
Channel Sinuosity = 6E-05x2 – 0.2196x + 219.57
Where, x is the year. Since 1962, channel sinuosity has remained lower than 1.25.
The channel slope since 1962 has primarily decreased. From 1962 to 2002, based
on Agg/Deg-line survey data, the average channel slope (Subreaches 1 through 5)
decreased about 0.03 ft/mile/year. Within Subreach 6, based on range line survey data,
the channel slope decreased 0.32 ft/mile/year from 1995 to 2001 as a result of an increase
in base-level of about 20 ft from 1990 to 1995; from 2002 to 2010, the channel slope
decreased 0.21 ft/mile/year as a result of an increase in base-level of about 35 ft from
2004 to 2009; from 2001 to 2002, the channel slope increased from 2.3 ft/ft to 4.3 ft/ft in
one year as a result of a decrease in base-level of about 100 ft from 1995 to 2004.
The rate of aggradation/degradation along the reach varied between different year
sets. Based on Agg/Deg-line survey data, from 1972 to 1992, the base-level increased
13.4 ft/year, and the channel aggraded in response as described by the following
equation:
Rate of Aggradation = -0.0014x2 + 0.0649x + 0.1832
Where, x is the distance (in miles) downstream of Agg/Deg 1637 (or the upstream end of
Elephant Butte Reach).
Between 1995 and 2004, the base-level dropped 100 ft (11.1 ft/year). The following
equations describe the rate of degradation for year sets 2003-2004, 2004-2005, and 20042009, respectively:
(2003-2004) Rate of Degradation = -0.1601x2+16.209x – 410.5
(2004-2005) Rate of Degradation = 0.8233x – 58.29
(2004-2009) Rate of Degradation = -0.0226x2 + 4.0x – 171.53
101
Where, x is the River Mile (as defined by Reclamation). From 2004 to 2009, the channel
aggraded in response to an increase in base-level of about 35 ft between 2004 and 2009
(7 ft/yr), as follows (where x is the River Mile):
(2004-2009) Rate of Aggradation = -0.4355x2 + 41.11x – 962.27
Wave 1 propagated upstream at a rate of 1.46 miles/year with a decrease in baselevel of 6.9 ft/year. Wave 2 propagated upstream following a rise in base-level of 6.8
ft/year between 2004 and 2009, as follows:
y = -0.5522x2 + 2219.1x – 2*106
Wave 3 propagated upstream following a drop in base-level of 14.2 ft/year between 1997
and 2004, as follows:
y = 0.0692x2 – 276.2x + 275686
Wave 4 propagated upstream following a rise in base-level of 3.7 ft/year between 1990
and 1995, as follows:
y = -0.1222x2 + 489.03x – 489299
Where, x is year and y is river mile.
The average median grain size in Subreach 1 has become finer at a rate of 0.0046
mm/year between 2001 and 2005; Subreach 2 only has data available in 1999; between
1986 and 2002, the average median grain size within Subreach 3, 4, and 5 coarsened at a
rate of 0.0027 mm/year, 0.0031 mm/year, and 0.0031 mm/year respectively; the average
median grain size within Subreach 6 became finer at a rate of 0.0005 mm/year between
1986 and 2002. There has been overall coarsening of the bed material within this study
reach at a rate of less than 0.003 mm/year. Lastly, the median bed material size gets finer
in the downstream direction, and is generally classified as very fine to fine sand.
102
REFERENCES
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Apache National Wildlife Refuge. Overbank Flow Analysis. 1962 - 2002. Middle Rio
Grande, New Mexico. Prepared for the U.S. Department of the Interior, Bureau of
Reclamation, Albuquerque, New Mexico. Colorado State university, Fort Collins, CO.
63 p.
Borgan, M.A., Allen, C.D., Muldavin, E.H., Platania, S.P., Stuart, J.N., Farely, G.H.,
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Haecker, C.E., and Doran, P.D. (eds.). Status and Trends of the Nation's Biological
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Bullard, K. L., and Lane, W.L. (1993). Middle Rio Grande Peak Flow Frequency Study.
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Clark, I. G. (1987). Water in New Mexico: A History of its Management and Use.
Albuquerque, NM: University of New Mexico Press. 839 p.
Earick, D. (1999). "The History and Development of the Rio Grande River in the
Albuquerque Region," from http://www.unm.edu/~abqteach/EnvirCUs/99-03-04.htm.
Finch, D. M., and Tainter, J.A. (2004). Ecology, Diversity and Sustainability of the
Middle Rio Grande Basin. Darby, PA: Diane Publishing Co. 186 p.
Julien, P. Y. (2010). Erosion and Sedimentation. 2nd ed. New York: Cambridge
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Kammerer, J. C. (1990). "Water Fact Sheet - Largest Rivers in the United States." U.S.
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to San Antonio. Hydraulic Modeling Analysis. 1962-2006. Middle Rio Grande, New
Mexico. Prepared for the U.S. Department of the Interior, Bureau of Reclamation,
Albuquerque, New Mexico. Colorado State University, Fort Collins, CO. 179 p.
MRGBI (2009). Middle Rio Grande Bosque Initiative. Dams and Diversions Along the
Rio Grande, from www.fws.gov/southwest/mrgbi/Resources/Dams/index.html
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01-2145. United States Court of Appeals, Tenth Circuit. 21 June 2002. 15 p.
103
MRGCD (2006). Middle Rio Grande Conservancy District. About the District, from
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MRGESA (2006a). Middle Rio Grande Endangered Species Act Collaborative Program.
The Rio Grande Silvery Minnow, from http://www.mrgesa.com.
MRGESA (2006b). Middle Rio Grande Endangered Species Act Collaborative Program.
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Mussetter Engineering, I. (2001). The Middle Rio Grande Geomorphology Final Report.
195 p.
NOAA (2004). NOAA National Weather Service. The North American Monsoon.
Reports to the Nation on our Changing Planet, from
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Paulson, R.W., Chase, E.B., Roberts, R.S., and Moody, D.W., Compilers (1989).
National Water Summary 1988-89. Hydrologic Events and Floods and Droughts. U.S.
Geological Survey. Water-Supply Paper 2375. 591 p.
Reclamation (2007). Middle Rio Grande River Maintenance Plan Summary - Part 1
Report. U.S. Department of the Interior, Bureau of Reclamation, Albuquerque, NM. 39 p.
Reclamation (2003). Geomorphologic Assessment of the Rio Grande, San Acacia Reach.
U.S. Department of the Interior, Bureau of Reclamation, Albuquerque, NM. 75 p.
Reclamation (2008). Elephant Butte Reservoir 2007 Sedimentation Survey. U.S.
Department of the Interior, Bureau of Reclamation, Denver, CO, 154 p.
Scurlock, D. (1998). From the Rio to the Sierra: An Environmental History of the Middle
Rio Grande Basin. General Technical Report RMRS-GTR-5. Fort Collins, CO: U.S.
Department of Agriculture, Forest Service, Rocky Mountain Research Station. 440 p.
104
APPENDICES
105
Appendix A: Range Line Survey Dates
106
Table A.1 Range Line Survey Dates
Range Line 80 86 SO‐1638.8 SO‐1641 SO‐1643.1 SO‐1644.8 SO‐1645 SO‐1646.9 SO‐1649.1 SO‐1650 SO‐1650.7 SO‐1652.7 SO‐1656.1 SO‐1657.7 SO‐1660 SO‐1662 SO‐1663 SO‐1664 SO‐1665 SO‐1666 SO‐1667 SO‐1668 SO‐1668.4 SO‐1670 SO‐1671.5 SO‐1673 SO‐1674.8 SO‐1676.4 SO‐1679.4 SO‐1680.8 SO‐1683 87 88 89 90
x
x
x
x
91
92
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
99 x x x x x x x x x x x x x x x
x x
x
x
x
x
x
x
x
x
93
94
96
x
x
x
x
x
x
95
Year
97 98
x
x
x
x
x
107
x
x
x
x
x
00 01
02
03
04
05
06
07
08
x
x
x
x
x
x
x
x
x
x
09
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
10
Range Line 80 86 SO‐1684.7 SO‐1686.4 SO‐1689.9 SO‐1692 SO‐1694.9 SO‐1696.7 SO‐1698.9 SO‐1701.3 EB‐5 x EB‐9 x EB‐9.2 EB‐9.4 EB‐9.5 EB‐10 x x EB‐10.1 EB‐10.2 EB‐10.3 EB‐10.45 EB‐10.5 EB‐10.7 EB‐10.9 EB‐11 EB‐11.1 EB‐11.5 EB‐11.9 EB‐12 EB‐12X EB‐12.4 EB‐12.7 87 x x 88 x x x x x 89 x 90
x
x
91
92
x
x
x
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x
x
x x
x
x
x
x
x x x x
x x
x
x
x
x
x
x x x
x x x x
x x x
x
108
01
02
03
04
05
06
07
08
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
10
x
09
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐13 EB‐13.9 EB‐14 EB‐14.3 EB‐14.5 EB‐14.7 EB‐15 EB‐15.1 EB‐15.4 EB‐15.7 EB‐15X EB‐16 EB‐16.5 EB‐17 EB‐17.1 EB‐17.2 EB‐17.3 EB‐17.35 EB‐17.4 EB‐17.5 EB‐17.6 EB‐17.7 EB‐17.8 EB‐17.85 EB‐17.9 FC‐1754 EB‐18 EB‐18.5 EB‐18.9 80 86 x x x x x x x x x x 87 x x x x x 88 x x x x x x 89 90
x
x
x
x
91
x
92
x
x
x
x
x
x
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x
x
x
x
x x x
x
x x x
x x x
x
x
x
x
x
x
x x x
x
x
x
x
x x x x
x
x
x
x
x
x x 109
01
02
x
03
x
04
x
05
x
06
x
07
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
08
x
x
x
x
x
x
x
x
x
x
09
x
x
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐19 EB‐19.1 EB‐19.3 EB‐19.5 EB‐19.7 EB‐19.8 EB‐20 EB‐20.3 EB‐20.7 EB‐21 EB‐22 EB‐22.2 EB‐22.6 EB‐23 EB‐23.05 EB‐23.1 EB‐23.2 EB‐23.3 EB‐23.4 EB‐23.5A EB‐23.5B EB‐23.6A EB‐23.6B EB‐23.8 EB‐23.9 EB‐23.9A EB‐24 EB‐24‐A EB‐24.3 80 86 x x x 87 x 88 x x x x x x 89 x 90
x
x
91
x
x
92
x
x
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x x x
x
x
x
x
x
x x x x x x x x x
x
x
x
x
x
x x x
x
x
x
x
x
110
01
02
x
03
x
04
x
05
x
x
06
x
x
07
x
x
08
x
x
x
x
x
x
x
x
x
x
x
x
x
09
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐24.4 EB‐24.5 EB‐24.6 EB‐24.8 EB‐24.9 EB‐24B EB‐25 EB‐25.2 EB‐25.3 EB‐25.4 EB‐25.5 EB‐25.6 EB‐25.8 EB‐25.9 EB‐26 EB‐26.3 EB‐26.6 EB‐26.7 EB‐26A EB‐26B EB‐26C EB‐26D EB‐26E EB‐26F EB‐26G EB‐26H EB‐26I EB‐26J EB‐26K 80 86 x 87 88 x x 89 x 90
x
x
91
92
x
x
x
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x
x
x
x
x
x x x
x
x
x
x
x
x 111
01
02
03
04
05
06
07
08
09
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line 80 86 EB‐27 x EB‐27.3 EB‐27.6 EB‐27A EB‐27B EB‐27C EB‐27D EB‐27E EB‐28 EB‐28 TCH EB‐28.3 EB‐28.5 EB‐28.7 EB‐28A EB‐29 EB‐29 TCH EB‐29.1 EB‐29.2 EB‐29.3 EB‐29.5 EB‐29.7 EB‐29.8 EB‐30 EB‐30.3 EB‐30.5 EB‐30.6 EB‐31 EB‐32 EB‐32.1 87 88 x 89 x x x 90
91
92
x
x
x
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x
x
x
x
x x x
x
x
x
x
x x x
x
x
x
x
x x x
x
x
x
x
x x x
x
x
x
x
x 112
01
x
x
x
02
x
x
x
03
x
x
04
x
x
05
06
x
x
07
x
x
x
08
09
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐32.3 EB‐32.5 EB‐32.7 EB‐33 EB‐33.3 EB‐33.6 EB‐33.65 EB‐33.7 EB‐33.8 EB‐34 EB‐34.5 EB‐34.8 EB‐35 EB‐35.2 EB‐35.5 EB‐35.8 EB‐36 EB‐36.3 EB‐36.6 EB‐37 EB‐37.2 EB‐37.5 EB‐37.7 EB‐38 EB‐38.1 EB‐38.15 EB‐38.2 EB‐38.3 EB‐38.4 80 86 87 88 x 89 90
x
91
92
x
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 x
x
x
x
x
x x 113
01
x
x
x
x
02
03
x
04
x
05
x
06
x
07
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
08
x
x
x
x
x
x
x
x
09
x
x
x
x
x
x
x
x
x
x
x
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐38.6 EB‐39 EB‐39.1 EB‐39.3 EB‐39.6 EB‐40 EB‐40.2 EB‐40.4 EB‐40.5 EB‐40.7 EB‐40.9 EB‐41 EB‐41.4 EB‐41.8 EB‐42 EB‐42.3 EB‐42.5 EB‐42.8 EB‐43 EB‐43.6 EB‐44 EB‐44.6 EB‐45 EB‐45.6 EB‐46 EB‐46.4 EB‐47 EB‐47.3 EB‐47.7 80 86 87 88 89 90
91
92
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 114
01
02
03
04
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
05
06
x
x
07
x
x
08
x
x
09
x
x
10
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Range Line EB‐48 EB‐48.3 EB‐48.5 EB‐48.7 EB‐49 EB‐49.5 EB‐49.7 EB‐50 EB‐50.3 EB‐50.7 EB‐51 EB‐51.3 EB‐51.7 EB‐52 EB‐52.4 EB‐52.7 EB‐53 EB‐53.3 EB‐53.7 EB‐54 EB‐54.4 EB‐54.7 EB‐55 EB‐55.3 EB‐55.7 EB‐56 EB‐56.4 EB‐56.7 EB‐57 80 86 87 88 89 90
91
92
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 115
01
02
03
x
04
x
x
x
x
x
05
06
07
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
08
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
09
x
x
x
x
x
x
x
x
10
x
x
x
x
x
x
x
x
Range Line EB‐57.3 EB‐57.5 EB‐57.8 EB‐58 EB‐58.4 EB‐58.6 EB‐59 EB‐59.5 EB‐60 80 86 87 88 89 90
91
92
Range Line Survey Dates (Continued) Year
93 94 95 96 97 98 99 00 116
01
02
03
04
05
06
07
x
x
x
x
x
x
x
x
x
08
x
x
x
x
x
x
x
x
x
09
10
Appendix B: Daily Discharge Hydrographs
117
3000
Discharge (cfs)
2500
2000
1500
1000
500
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.1 1990 Daily Discharge Data
8000
Discharge (cfs)
7000
6000
5000
4000
3000
2000
1000
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.2 1991 Daily Discharge Data
7000
5000
4000
3000
2000
1000
Month
San Marcial
Figure B.3 1992 Daily Discharge Data
118
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
6000
San Acacia
7000
Discharge (cfs)
6000
5000
4000
3000
2000
1000
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.4 1993 Daily Discharge Data
Discharge (cfs)
8000
6000
4000
2000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.5 1994 Daily Discharge Data
7000
5000
4000
3000
2000
1000
Month
San Marcial
Figure B.6 1995 Daily Discharge Data
119
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
6000
San Acacia
6000
Discharge (cfs)
5000
4000
3000
2000
1000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.7 1996 Daily Discharge Data
6000
Discharge (cfs)
5000
4000
3000
2000
1000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.8 1997 Daily Discharge Data
4000
3500
2500
2000
1500
1000
500
Month
Figure B.9 1998 Daily Discharge Data
120
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
3000
San Acacia
6000
Discharge (cfs)
5000
4000
3000
2000
1000
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.10 1999 Daily Discharge Data
1600
Discharge (cfs)
1400
1200
1000
800
600
400
200
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.11 2000 Daily Discharge Data
3500
2500
2000
1500
1000
500
Month
San Marcial
Figure B.12 2001 Daily Discharge Data
121
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
3000
San Acacia
2500
Discharge (cfs)
2000
1500
1000
500
Month
San Marcial
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.13 2002 Daily Discharge Data
2500
Discharge (cfs)
2000
1500
1000
500
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.14 2003 Daily Discharge Data
3500
2500
2000
1500
1000
500
Month
San Marcial
Figure B. 15 2004 Daily Discharge Data
122
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
3000
San Acacia
7000
Discharge (cfs)
6000
5000
4000
3000
2000
1000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.16 2005 Daily Discharge Data
6000
Discharge (cfs)
5000
4000
3000
2000
1000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Month
San Marcial
Figure B.18 2007 Daily Discharge Data
123
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
4000
3500
3000
2500
2000
1500
1000
500
0
Jan
Discharge (cfs)
Figure B.17 2006 Daily Discharge Data
San Acacia
6000
Discharge (cfs)
5000
4000
3000
2000
1000
San Marcial
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Acacia
Figure B.19 2008 Daily Discharge Data
Discharge (cfs)
4,000
3,000
2,000
1,000
San Acacia
Month
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
0
San Marcial
Figure B.20 2009 Daily Discharge Data
4,000
3,000
2,500
2,000
1,500
1,000
500
Month
San Acacia
Figure B.21 2010 Daily Discharge Data
124
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Discharge (cfs)
3,500
San Marcial
Appendix C: Dates and Locations of Bed Material Samples
125
Table C.1 Available Bed Material Data at Range Lines
Range Line
SO-1641
86
87
88
90
92
93
94
Year
96 97
SO-1652.7
98
X
99
01
X
02
X
X
SO-1666
X
X
X
SO-1670
X
SO-1683
X
SO-1701.3
X
EB-5
X
X
X
EB-10
X
X
X
X
EB-13
X
X
X
X
EB-14
X
X
X
EB-16
X
X
X
EB-17
X
X
X
X
X
X
X
X
X
X
X
X
X
X
FC-1754
X
EB-18
X
X
X
X
X
X
X
X
X
EB-20
X
X
X
X
X
X
X
X
X
EB-34
X
X
X
EB-24A
X
X
X
X
X
X
X
X
X
X
X
EB-26
X
EB-26.6
X
EB-27
X
EB-28
X
EB-29
X
EB-29.5
EB-30
07
X
SO-1665
EB-25
05
X
X
SO-1660
EB-24
04
X
X
X
EB-36
X
126
Appendix D: Dates and Locations of USGS Gauge Bed Material Samples
127
Table D.1: Available Bed Material Data at USGS gauging stations: San Acacia and San
Marcial
Gauging station
Year
San
Acacia
1966
x
Gauging station
San
Marcial
1967
Year
San
Acacia
San
Marcial
1988
x
x
1989
x
x
1968
x
x
1990
x
x
1969
x
x
1991
x
x
1970
1992
x
x
1971
1993
x
x
x
1994
x
x
1972
1973
x
1974
x
1995
x
x
x
1996
x
x
1975
x
x
1997
x
x
1976
x
x
1998
x
x
x
1999
x
x
1977
1978
x
x
2001
x
x
1979
x
x
2002
x
x
1980
x
x
2003
x
x
1981
x
x
2004
x
x
1982
x
x
2005
x
x
1983
x
x
2006
x
x
1984
x
x
2007
x
x
1985
x
x
2008
x
x
1986
x
x
2009
x
x
1987
x
x
2010
x
x
128
Appendix E: Aerial Photograph Survey Dates and Information
129
Table E.1 Aerial Photo Survey Dates and Information
Mean Daily Discharge
Date
San Acacia
San Marcial
Scale
1918
No Data
No Data
1:12,000
1935
No Data
No Data
1:8,00
1949
No Data
No Data
1:5,000
March
1962
25 cfs
0 cfs
1:4,800
April 1972
4 cfs
0 cfs
1:4,800
March
1985
1900 cfs
1320 cfs
1:4,800
February
1992
1020 cfs
630 cfs
1:4,800
February
2001
770 cfs
560 cfs
1:4,800
March
2002
310 cfs
150 cfs
1:4,800
December
2003
Winter
2004
628 cfs
439 cfs
1:28,800
Date
Unknown
Date
Unknown
1:4,800
April 2005
2270 cfs
1680 cfs
1:4,800
January
2006
Date
Unknown
Date
Unknown
1:4,800
June
2008
3990 cfs
3460
1:45,720
2010
Date
Unknown
Date
Unknown
130
Notes
(1918-2002:from Novak 2006
2005: from ArcGIS metadata)
Hand-drafted linens (39 sheets).
USBR Albuquerque Area Office.
Surveyed in 1918. Published in 1922.
Black and white photography. USBR
Albuquerque Area Office. Flown in
1935. Published in 1936.
Photo-mosaic. J-Ammann
Photogrammetric Engineers, San
Antonio, TX. USBR Albuquerque
Area Office.
Photo-mosaic. Abram Aerial Survey
Corp, Lansing, MI. USBR
Albuquerque Area Office.
Photo-mosaic. Limbaugh Engineers,
Inc., Albuquerque, NM. USBR
Albuquerque Area Office.
Orthophoto. M&I Consulting
Engineers, Fort Collins, CO. AeroMetric Engineering, Sheboygan, MN.
USBR Albuquerque Area Office.
Ratio-rectified photo-mosaic. Koogle
and Poules Engineering,
Albuquerque, NM. USBR
Albuquerque Area Office.
Ratio-rectified photo-mosaic. Pacific
Western Technologies, Ltd.,
Albuquerque, NM. USBR
Albuquerque Area Office.
Digital ortho-imagery. Pacific
Western Technologies, Ltd.,
Albuquerque, NM. USBR
Albuquerque Area Office.
Digital ortho-imagery. USBR
Albuquerque Area Office.
Digital ortho-rectified imagery. USBR
Albuquerque Area Office.
Digital ortho-rectified imagery. AeroMetric, Inc., Fort Collins, CO. USBR
Albuquerque Area Office.
Digital ortho-rectified imagery. AeroMetric, Inc., Fort Collins, CO. USBR
Albuquerque Area Office.
Digital ortho-rectified imagery. USBR
Albuquerque Area Office.
LiDAR Optec 3100 EA LiDAR 3m.
Aero-Metric, Inc., Fort Collins, CO.
USBR Albuquerque Area Office.
Appendix F: Range Line Cross-Section Plots
131
4500
2009
2008
4498
2007
2006
4496
Elevation (ft)
2005
4494
2004
2003
4492
2002
4490
2001
1999
4488
1998
1997
4486
0
50
100
150
200
250
300
Station (ft)
Figure F.1 SO‐1641 Cross‐Section
4496
2009
2008
2007
2006
2005
2004
2003
2002
1999
1998
1997
1995
1994
1993
1991
1990
4494
Elevation (ft)
4492
4490
4488
4486
4484
50
150
250
350
450
Station (ft)
Figure F.2 SO‐1652.7 Cross‐Section 132 4492
2006
4490
2002
1999
Elevation (ft)
4488
1998
1997
4486
1995
1994
4484
1992
1991
4482
1990
4480
750
800
850
900
950
1000
Station (ft)
Figure F.3 SO‐1666 Cross‐Section 4492
2009
2008
4490
2007
Elevation (ft)
4488
2005
4486
2004
2002
4484
1999
4482
1998
1997
4480
1995
4478
1994
4476
600
650
700
750
Station (ft)
800
Figure F.4 SO‐1673 Cross‐Section 133 850
900
4492
2009
2008
4490
Elevation (ft)
2007
4488
2006
4486
2004
2003
4484
2002
1999
4482
1998
4480
1997
4478
1994
1993
4476
1990
4474
0
50
100
150
200
Station (ft)
Figure F.5 SO‐1683 Cross‐Section 4484
2009
4482
2008
2007
Elevation (ft)
4480
2006
2005
4478
2004
2002
4476
1999
1998
4474
1994
4472
50
100
150
200
Station (ft)
Figure F.6 SO‐1692 Cross‐Section 134 250
2009
2008
2007
2006
2005
2004
2002
1999
1998
1997
1995
1994
1993
1992
1991
1990
4484
4482
Elevation (ft)
4480
4478
4476
4474
4472
4470
4468
0
100
200
300
400
Station (ft)
Figure F.7 SO‐1701.3 Cross‐Section 135 500
4482
4480
2010
2009
2008
2007
2005
2004
2003
2002
2001
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1988
1987
4478
Elevation (ft)
4476
4474
4472
4470
4468
4466
4464
4462
500
600
700
800
900
1000
Station (ft)
Figure F.8 EB‐10 Cross‐Section 4490
4485
4480
Elevation (ft)
4475
4470
4465
4460
4455
4450
4445
0
500
1000
1500
2000
Station (ft)
2500
2010
2009
2008
2007
2005
2004
2003
2002
2001
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1988
1987
1986
1980
Figure F.9 EB‐10 (w/Floodplain) Cross‐Section 136 4476
2009
4474
2008
2007
Elevation (ft)
4472
2005
4470
2004
2002
4468
2000
4466
1998
4464
1992
1988
4462
4460
1950
1987
1986
2000
2050
2100
2150
2200
2250
2300
Station (ft)
Figure F.10 EB‐13 Cross‐Section 4475
1999/2001
4470
1998
1997
Elevation (ft)
4465
1996
1988
4460
1980
4455
4450
4445
150
200
250
Station (ft)
300
350
Figure F.11 EB‐14 Cross‐Section 137 400
4472
2009
4470
2008
Elevation (ft)
4468
2007
2005
4466
2004
2002
4464
2000
4462
1999
1998
4460
1997
4458
1994
1993
4456
100
150
200
250
300
350
1992
Station (ft)
Figure F.12 EB‐16 Cross‐Section 4474
4472
4470
Elevation (ft)
4468
4466
4464
4462
4460
4458
4456
4454
4452
50
100
150
200
250
2009
2008
2007
2005
2002
2001
1999
1998
1997
1996
1995
1994
1993
1992
1991
1988
1980
Station (ft)
Figure F.13 EB‐17 Cross‐Section 138 4468
2009
Elevation (ft)
4466
2008
4464
2007
4462
2003
2004
4460
2002
4458
2000
4456
1999
1998
4454
1997
4452
1996
4450
600
650
700
750
800
850
900
950
1000
Station (ft)
Figure F.14 EB‐18 Cross‐Section 2009
2008
2007
2005
2004
2002
2000
1999
1998
1997
1995
1994
1993
1992
1991
1990
1988
1980
4465
4460
Elevation (ft)
4455
4450
4445
4440
4435
150
200
250
300
350
400
450
Station (ft)
Figure F.15 EB‐20 Cross‐Section 139 4462
2009
4458
2008
4456
2007
4454
2005
Elevation (ft)
4460
2004
4452
2002
4450
2000
4448
1999
4446
1998
4444
1997
4442
1996
4440
250
300
350
400
450
500
550
600
Station (ft)
Figure F.16 EB‐34 Cross‐Section 4460.00
2007
2005
4455.00
2004
Elevation (ft)
4450.00
2002
2000
4445.00
1999
1998
4440.00
1997
4435.00
1989
1980
4430.00
4425.00
5800
6000
6200
6400
6600
Station (ft)
Figure F.17 EB‐24 Cross‐Section 140 6800
7000
4460
2009
2008
2007
2005
2004
2002
2000
1998
1999
1996
1995
1994
1993
1989
Elevation (ft)
4455
4450
4445
4440
4435
4750
4800
4850
4900
4950
5000
Station (ft)
5050
5100
5150
5200
Figure F.18 EB‐25 Cross‐Section 4455
2009
2008
2007
4450
2005
Elevation (ft)
2004
2002
4445
1999
1998
1997
4440
1996
1995
4435
1994
1993
4430
4800
1980
4900
5000
5100
Station (ft)
Figure F.19 EB‐26 Cross‐Section 141 5200
5300
4452
2002
4450
2000
1999
Elevation (ft)
4448
1998
1995
4446
1993
4444
1992
4442
1989
1988
4440
1980
4438
4700
4800
4900
5000
5100
5200
5300
Station (ft)
Figure F.20 EB‐27 Cross‐Section 4460
2002
4455
2000
1999
4450
Elevation (ft)
1998
4445
1995
1994
4440
1993
4435
1992
1989
4430
1988
1980
4425
4420
0
2000
4000
6000
8000
Station (ft) Figure F.21 EB‐27 (w/Floodplain) Cross‐Section 142 10000
4448
2009
4446
2008
4444
2007
Elevation (ft)
4442
2005
4440
2002
4438
2000
4436
1999
4434
1998
4432
1995
4430
1992
4428
4980
5030
5080
5130
5180
5230
Station (ft)
Figure F.22 EB‐28 Cross‐Section 4450
2009
4448
2008
4446
2007
Elevation (ft)
4444
2005
4442
2002
4440
2000
4438
1999
4436
1998
4434
1995
4432
1993
4430
4428
4000
1992
5000
6000
7000
8000
9000
Station (ft)
Figure F.23 EB‐28 (w/Floodplain) Cross‐Section 143 10000
2009
4450
2008
2007
4445
2005
Elevation (ft)
2004
4440
2002
2000
4435
1999
1997
1995
4430
1993
4425
5000
1989
5100
5200
5300
5400
5500
5600
Station (ft)
Figure F.24 EB‐29 Cross‐Section 2009
4455
2008
2007
4450
2005
2004
Elevation (ft)
4445
2002
4440
2000
1999
4435
1997
1995
4430
1993
4425
3750
1989
4250
4750
5250
5750
6250
6750
7250
Station (ft)
Figure F.25 EB‐29 (w/Floodplain) Cross‐Section 144 4440
2009
4438
2008
2007
Elevation (ft)
4436
2006
4434
2005
4432
2004
2002
4430
2000
1997
4428
1995
4426
1993
4424
3590
1992
3690
3790
3890
3990
Station (ft)
Figure F.26 EB‐30 Cross‐Section 2009
4442
2008
Elevation (ft)
4440
2007
4438
2006
4436
2005
2004
4434
2002
4432
2000
4430
1999
1997
4428
1995
4426
4424
2000
1993
1992
3000
4000
5000
6000
7000
8000
9000
10000
Station (ft)
Figure F.27 EB‐30 (w/Floodplain) Cross‐Section 145 4436
2009
2007
4434
2006
Elevation (ft)
4432
2005
2004
4430
2002
4428
1999
4426
1997
1995
4424
1993
4422
4420
5200
1989
5300
5400
5500
5600
5700
5800
Station (ft)
Figure F.28 EB‐32 Cross‐Section 4438
2009
4436
2007
4434
2006
2005
Elevation (ft)
4432
2004
4430
2002
4428
1999
1997
4426
1995
4424
1993
4422
4420
3750
1989
4250
4750
5250
5750
Station (ft)
Figure F.29 EB‐32 (w/Floodplain) Cross‐Section 146 6250
4434
4432
Elevation (ft)
4430
2009
2008
4428
2007
4426
2005
4424
2004
4422
4420
4418
5100
5200
5300
5400
5500
5600
5700
5800
Station (ft)
Figure F.30 EB‐33 Cross‐Section 4432
4430
4428
2009
Elevation (ft)
4426
2008
4424
2007
4422
2005
4420
2004
4418
4416
4414
3500
3600
3700
3800
Station (ft)
3900
Figure F.31 EB‐35 Cross‐Section 147 4000
4100
4430
4428
4426
2010
Elevation (ft)
4424
2009
4422
2008
4420
2007
4418
2005
4416
2004
2003
4414
4412
5400
5500
5600
5700
5800
Station (ft)
Figure F.32 EB‐36 Cross‐Section EB‐37
4430
4428
Elevation (ft)
4426
4424
2010
4422
2009
4420
2008
4418
2007
2005
4416
2004
4414
2003
4412
4410
3000
3100
3200
3300
3400
3500
3600
3700
3800
Station (ft)
Figure F.33 EB‐37 Cross‐Section 148 4428
4426
2010
4424
2009
Elevation (ft)
4422
2008
4420
2007
4418
2006
2005
4416
2004
4414
2003
4412
4410
0
100
200
300
400
500
Station (ft)
Figure F.34 EB‐37.5 Cross‐Section 4428
4426
Elevation (ft)
4424
4422
2009
4420
2008
4418
2007
4416
2006
4414
2005
4412
4410
4408
2800
2900
3000
3100
3200
3300
3400
Station (ft)
Figure F.35 EB‐38 Cross‐Section 149 4428
Elevation (ft)
4426
4424
2010
4422
2009
4420
2008
4418
2007
4416
4412
2006
Perpindicular
2004
4410
2003
4414
4408
4406
‐100
0
100
200
300
400
Station (ft)
Figure F.36 EB‐39 Cross‐Section 4425
4420
Elevation (ft)
2010
2009
4415
2008
2007
4410
2004
2003
4405
4400
4550
4600
4650
4700
4750
4800
4850
4900
Station (ft)
Figure F.37 EB‐40 Cross‐Section 150 4430
4425
2010
Elevation (ft)
4420
2009
2008
4415
2007
2004
4410
2003
4405
4400
‐50
0
50
100
150
200
250
300
350
Station (ft)
Figure F.38 EB‐40.5 Cross‐Section 4416
4414
4412
2009
Elevation (ft)
4410
2008
4408
2007
4406
2004
4404
4402
4400
4398
0
50
100
150
200
250
300
Station (ft)
Figure F.39 EB‐41 Cross‐Section 151 4416
4414
4412
2010
Elevation (ft)
4410
2009
4408
2008
4406
2007
2004
4404
2003
4402
4400
4398
‐100
‐50
0
50
100
150
200
250
300
350
Station (ft)
Figure F.40 EB‐42 Cross‐Section
4420
4415
2010
Elevation (ft)
4410
2009
2008
4405
2007
2004
4400
2003
4395
4390
‐100
0
100
200
300
400
Station (ft)
Figure F.41 EB‐43 Cross‐Section 152 4414
4412
Elevation (ft)
4410
4408
2010
4406
2009
2008
4404
2007
4402
2004
4400
2003
4398
4396
4394
‐100
‐50
0
50
100
150
200
250
300
Station (ft)
Figure F.42 EB‐44 Cross‐Section 4420
4415
2010
Elevation (ft)
4410
2009
2008
4405
2007
2004
4400
2003
4395
4390
‐100
0
100
200
Station (ft)
Figure F.43 EB‐45 Cross‐Section 153 300
400
4416
4414
Elevation (ft)
4412
4410
2009
4408
2008
4406
2007
4404
4402
4400
4398
0
50
100
150
200
250
300
Station (ft)
Figure F.44 EB‐46 Cross‐Section 4420
4415
2010
Elevation (ft)
4410
2009
2008
4405
2007
2004
4400
2003
4395
4390
0
50
100
150
200
250
300
Station (ft)
Figure F.45 EB‐47 Cross‐Section 154 4410
4405
Elevation (ft)
2010
2009
4400
2008
2007
4395
2004
2003
4390
4385
‐100
0
100
200
300
400
Station (ft)
Figure F.46 EB‐48 Cross‐Section 4420
4415
Elevation (ft)
4410
2010
2009
4405
2008
2007
4400
2004
4395
2003
4390
4385
0
100
200
300
400
500
600
Station (ft)
Figure F.47 EB‐49 Cross‐Section 155 4410
Elevation (ft)
4405
4400
2009
2008
2007
4395
2006
4390
4385
0
50
100
150
200
250
300
Station (ft)
Figure F.48 EB‐50 Cross‐Section 156 350
400
450
Appendix G: Change in Thalweg Elevation vs. River Mile Plots
157
3.0
2.0
1.5
1.0
Change in Thalweg (ft)
2.5
0.5
0.0
61
59
57
55
53
51
49
47
45
River Mile
Wave 4 1990‐1992
Figure G.1 1990‐1992 Thalweg Change 2
y = 4.1023x ‐ 253.93
R² = 1
1
‐1
‐2
‐3
‐4
Change in Thalweg (ft)
0
‐5
‐6
‐7
63
62.5
62
61.5
61
60.5
60
River Mile
Wave 4 1991‐1992
Linear (Wave 4 1991‐1992)
Figure G.2 1991‐1992 Thalweg Change 158 10
6
y = ‐0.0992x2 + 11.97x ‐ 358.74
R² = 0.1623
4
2
0
Change in Thalweg (ft)
8
‐2
‐4
70
65
60
55
50
45
River Mile
Wave 4 1992‐1993
Poly. (Wave 4 1992‐1993)
Figure G.3 1992‐1993 Thalweg Change 4.0
3.5
2.5
2.0
1.5
y = 0.0008x2
+ 0.0616x ‐ 6.2002
R² = 0.285
1.0
0.5
0.0
Change in Thalweg (ft)
3.0
‐0.5
‐1.0
‐1.5
70
65
60
55
50
45
River Mile
Wave 4 1993‐1994
Poly. (Wave 4 1993‐1994)
Figure G.4 1993‐1994 Thalweg Change 159 7
6
y = ‐0.0179x2 + 2.1771x ‐ 64.765
R² = 0.0227
4
3
2
1
0
Change in Thalweg (ft)
5
‐1
‐2
‐3
70
65
60
55
50
45
River Mile
Wave 4 1994‐1995
Poly. (Wave 4 1994‐1995)
Figure G.5 1994‐1995 Thalweg Change 4
3
1
0
‐1
‐2
y = 0.0683x2 ‐ 8.6959x + 276.42
R² = 0.0933
Change in Thalweg (ft)
2
‐3
‐4
‐5
70
65
60
55
50
45
River Mile
Wave 4 1995‐1997
Wave 3/4 Transition 1995‐1997
Poly. (Wave 4 1995‐1997)
Figure G.6 1995‐1997 Thalweg Change 160 5
4
2
1
y = 0.274x2 ‐ 36.539x + 1219.1
R² = 0.2054
0
Change in Thalweg (ft)
3
‐1
‐2
‐3
70
65
60
55
50
45
River Mile
Wave 4 1997‐1998
Wave 3/4 Transition 1997‐1998
Poly. (Wave 4 1997‐1998)
Figure G.7 1997‐1998 Thalweg Change 4
2
1
0
‐1
y = 0.0553x2 ‐ 7.4734x + 252.98
R² = 0.08
Change in Thalweg (ft)
3
‐2
‐3
75
70
65
60
55
50
45
River Mile
Wave 3 1998‐1999
Wave 4 1998‐1999
Wave 3/4 Transition 1998‐1999
Poly. (Wave 4 1998‐1999)
Figure G.8 1998‐1999 Thalweg Change 161 3
1
0
‐1
y = 0.0309x2 ‐ 4.2878x + 148.76
R² = 0.0832
‐2
‐3
‐4
y = ‐2.2408x + 120.61
R² = 1
75
70
65
60
55
50
Change in Thalweg (ft)
2
‐5
45
River Mile
Wave 3 1999‐2002
Wave 3/4 Transition 1999‐2002
Poly. (Wave 4 1999‐2002)
Wave 4 1999‐2002
Linear (Wave 3 1999‐2002)
Figure G.9 1999‐2002 Thalweg Change 5
y = ‐0.0127x2 + 1.6943x ‐ 54.451
R² = 0.1822
4
2
1
0
‐1
Change in Thalweg (ft)
3
‐2
y = 0.885x2 ‐ 96.405x + 2622.5
R² = 0.6265
‐3
‐4
80
75
70
65
60
55
50
45
River Mile
Wave 3 2003‐2004
Wave 4 2003‐2004
Wave 3/4 Transition 2003‐2004
Poly. (Wave 3 2003‐2004)
Figure G.10 2002‐2003 Thalweg Change 162 4
0
‐2
y = 0.0402x2 ‐ 5.7666x + 205.93
R² = 0.3261
‐4
‐6
y = ‐0.009x2 + 0.963x ‐ 27.412
R² = 0.0059
‐8
Change in Thalweg (ft)
2
‐10
‐12
80
75
70
65
60
55
50
45
River Mile
Wave 3 2003‐2004
Wave 3/4 Transition 2003‐2004
Poly. (Wave 4 2003‐2004)
Wave 4 2003‐2004
Poly. (Wave 3 2003‐2004)
Figure G.11 2003‐2004 Thalweg Change 10
80
75
70
65
60
Wave 2 2004‐2007
River Mile
Wave 3 2007‐2008
Poly. (Wave 2 2004‐2007)
Poly. (Wave 4 2004 ‐ 2007)
‐5
‐10
‐15
55
50
45
Wave 2/3 Transitional 2004‐2007
Wave 4 2004 ‐ 2007
Poly. (Wave 3 2007‐2008)
Figure G. 12 2004‐2007 Thalweg Change 163 0
Change in Thalweg (ft)
‐ 21.993x + 676.35
R² = 0.5992
y = ‐0.3485x2 + 32.295x ‐ 741.44
R² = 0.8947
y = 0.1679x2 ‐ 23.548x + 825.83
R² = 0.4563
5
y = 0.1767x2
2.0
y = ‐0.0069x2 + 0.7283x ‐ 18.716
R² = 0.0311
1.5
0.5
y = ‐0.0064x2 + 0.864x ‐ 30.281
R² = 0.1006
0.0
‐0.5
‐1.0
‐1.5
Change in Thalweg (ft)
1.0
‐2.0
‐2.5
‐3.0
80
75
70
65
60
55
50
45
River Mile
Wave 2 2007‐2008
Wave 2/3 Transitional 2007‐2008
Wave 3 2007‐2008
Poly. (Wave 2 2007‐2008)
Poly. (Wave 3 2007‐2008)
Figure G.13 2007‐2008 Thalweg Change 5
3
2
y = 0.0078x2 ‐ 0.9912x + 30.863
R² = 0.0929
1
0
‐1
Change in Thalweg (ft)
4
y = ‐0.2133x2 + 20.808x ‐ 505.26
R² = 0.3004
‐2
‐3
80
75
70
Wave 2 2008‐2009
65
60
River Mile
Wave 3 2008‐2009
55
45
Wave 2/3 Transitional 2008‐2009
Poly. (Wave 2 2008‐2009)
Poly. (Wave 3 2008‐2009)
Figure G.14 2008‐2009 Thalweg Change 164 50
4
2
y = 0.0363x2 ‐ 4.054x + 112.8
R² = 0.5874
1
0
y = 0.074x2 ‐ 9.3306x + 293.35
R² = 0.8984
‐1
Change in Thalweg Elevation (ft)
3
‐2
‐3
70
65
60
55
50
45
River Mile
Wave 1 2009‐2010
Wave 2 2009‐2010
Wave 2/3 Transition 2009‐2010
Wave 3 2009‐2010
Poly. (Wave 2/3 Transition 2009‐2010)
Poly. (Wave 3 2009‐2010)
Figure G.15 2009‐2010 Thalweg Change 165 Appendix H: Bed Material Grain Size Distribution Plots
166
100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.1 SO‐1641 2001 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
Grain Size (mm)
Figure H.2 SO‐1641 2002 Grain Size Distribution 167 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.3 SO‐1641 2004 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
Grain Size (mm)
Figure H.4 SO‐1641 2005 Grain Size Distribution 168 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.5 SO‐1683 1999 Grain Size Distribution 169 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.6 EB‐10 1986 Grain Size Distribution 170 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
Grain Size (mm)
Figure H.7 EB‐10 1987 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.8 EB‐10 1988 Grain Size Distribution 171 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.9 EB‐10 1990 Grain Size Distribution 172 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.10 EB‐10 1992 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.11 EB‐10 1993 Grain Size Distribution 173 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
Grain Size (mm)
Figure H.12 EB‐10 1994 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H. 13 EB‐10 1997 Grain Size Distribution 174 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.14 EB‐10 1998 Grain Size Distribution 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.15 EB‐10 1999 Grain Size Distribution 175 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.16 EB‐10 2002 Grain Size Distribution 176 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.17 EB‐13 1986 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.18 EB‐13 1987 Grain Size Distribution 177 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.19 EB‐13 1988 Grain Size Distribution 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.20 EB‐13 1990 Grain Size Distribution 178 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.21 EB‐13 1999 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.22 EB‐13 2002 Grain Size Distribution 179 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.23 EB‐18 1986 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.24 EB‐18 1987 Grain Size Distribution 180 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.25 EB‐18 1988 Grain Size Distribution 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.26 EB‐18 1990 Grain Size Distribution 181 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.27 EB‐18 1993 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.28 EB‐18 1994 Grain Size Distribution 182 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.29 EB‐18 1997 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.30 EB‐18 1999 Grain Size Distribution 183 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
1000
Grain Size (mm)
Figure H.31 EB‐18 2002 Grain Size Distribution 184 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.32 EB‐24 1986 Grain Size Distribution 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.33 EB‐24 1992 Grain Size Distribution 185 100
90
% Finer by Weight
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
Grain Size (mm)
Figure H.34 EB‐24 1999 Grain Size Distribution 100
90
80
% Finer by Weight
70
60
50
40
30
20
10
0
0.01
0.1
1
10
Grain Size (mm)
Figure H.35 EB‐24 2002 Grain Size Distribution 186