Meeting the Need for Water in the Lower
Colorado River by Diverting Water from the
Mississippi River - A Practical Assessment
of a Popular Proposal
Keywords: Drought, Colorado River Basin, Mississippi River, water diversion, climate change, water
Roger Viadero, Jr., E. Dave Thomas, and Samuel Babatunde
Western Illinois University
Institute for Environmental Studies
Monday, October 17, 2022
The decades-long drought that has impacted the southwestern US has renewed interest in plans to
divert a portion of the Mississippi River to help meet the need for water in the Colorado River Basin.
Ater seeing this suggestion in editorials and news articles in local, regional, and national venues, we
noticed a lack of information that can be used by the public to weigh the practical aspects of these
proposals. This has created a void that’s being ﬁlled by proposals that lack realistic goals, violate a
number of physical laws, and convey a poor understanding of scale, among other issues. To help
people understand these proposals, we’ve conducted an assessment based on credible data that are
available to the public. We’ve also clearly deﬁned our assumptions - including basic engineering
constraints - and we’ve “shown our work” so everyone can see where our numbers come from.
While there are many things that can be done, most large-scale projects are limited by economic,
social, and/or political realities. It can be easy for some to decry these limitations as artiﬁcial
boundaries set by people who lack the will to make things happen. However, there are a number of
legitimate challenges that are set by the scale of the proposed work. By considering a few of these
issues, the magnitude of this proposal becomes more evident. For example, regardless of the dire
need for water in the west, it is unlikely that a pipeline ranging in length from 1,200 to 1,600 miles
with a diameter of 88 t will be built across multiple states in the near future. Likewise, even at a
penny per gallon, the ~$135 BILLION water bill to ﬁll Lake Mead and Lake Powell is enough to keep this
proposal on the back burner.
As you might suspect, there is no single approach that will meet all of the water needs of people in the
Colorado River Basin. Hopefully, ater considering this assessment, people will consider pursuing
more practical measures to meet the immediate requirements of the region while also working to
develop a combination of eforts to meet longer-term water needs.
Roger Viadero, Jr., Ph.D. E. Dave Thomas Samuel Babatunde
Director and Professor Doctoral Student Doctoral Student
email@example.com firstname.lastname@example.org email@example.com
Western Illinois University, Moline and Macomb, IL
The Colorado River Compact 5
Mandatory Water Reductions 6
Previous Studies of Water Diversion 7
An Assessment of the Diversion of Mississippi River Water to Reﬁll Lake Powell and Lake Mead 8
Our Approach 8
Problems from the Start 8
USBR Discharge Data, 1906 - 1920 8
USGS and USBR River Discharge Data from 1920 through 2022 9
How Much Mississippi River Water is Available for Diversion? 10
Mississippi River Discharge from 2002 - 2022 10
The Proposed Diversion Rate in Relation to Mississippi River Discharge 11
The Impacts of Drought are Widespread 11
Could Diverting Water Help Reduce Flooding? 12
Assessing the Alleged Beneﬁts of Water Diversion 14
Could Diverting Water Save Taxpayers Money on Flood Response and Recovery? 14
Moving Water to the West is a Matter of Scale 15
An Open Channel 16
A Water Super Highway?! 17
Piping Water to the West 18
Other Factors 18
The “Elephant in the Room” - Elevation 18
Invasive Species 19
Water Quality 19
Final Thoughts 20
Conversion Factors 21
The monumental scale of the water resource projects built in the 1930s provided water to support
unprecedented growth in the population and productivity in the Colorado River Basin through the
balance of the 20th century. Simultaneously, global climate change has brought rapid declines in the
availability of water to people from across the globe. For example, waterborne commerce on the
Rhine River in Germany is being adversely afected by record-low water levels.1Likewise, the low
water level on the Yangtze River has caused the Chinese to limit irrigation and power generation.2In
the United States, these same trends are relected in a record twenty-plus year-long drought that’s
led to an unprecedented water shortage in the Lower Colorado River Basin.
It is abundantly clear that a critical source of water for around 40 million people and farms across the
western United States is in serious peril. This has doubtlessly led to tangible losses to agricultural
producers as well as to the recreation and tourism industries. Eforts by federal and state
governments to manage this challenge have largely failed. Recently, people have revisited the idea of
diverting a portion of water from the Mississippi River to replenish major western water reservoirs.
While the issue was rekindled by a proposal in the Arizona State legislature in 2021,3this idea gained
new traction ater a recent editorial in the Palm Springs Desert Sun that went viral. In his June 26,
2022, editorial, Mr. Don Siekes of San Leandro, California, proposed the diversion of water from the
Mississippi River westward to reﬁll Lake Powell and Lake Mead.4This proposal has sparked
4Siekes, Don. 2022. “We could ﬁll Lake Powell in less than a year with an aqueduct from Mississippi River.” The Desert
Sun, June 30, 2022.
3Arizona House Concurrent Memorial 2004, May 11, 2021,
2Davidson, Helen. 2022. “China drought causes Yangtze to dry up, sparking shortage of hydropower.” The Guardian,
August 22, 2022.
1Wittels, Jack, Kwaku Gyasi, and Laura Malsch. 2022. “Europe’s Rhine River Is on the Brink of Efectively Closing.”
widespread discussions of the issue in venues including USA Today, the Los Angeles Times, and the
Waterways Journal.5 6 7
To help people better understand these issues, an assessment of popular proposals and ideas was
performed using publicly available information.
The huge water resource projects of the 1930s provided water to support unprecedented growth in
the population and productivity in the Colorado River Basin through the balance of the 20th century.
Due to a combination of climate change, population growth, and intensive agricultural production,
the seven states in the Colorado River Basin are facing an unprecedented water shortage. This issue is
exacerbated by a lack of coherent water resource planning, mistrust among Colorado River Basin
states, and a rising sense of desperation over the current and future impacts on people and
The Colorado River Compact
The Colorado River extends ~1,450 miles through seven US and two Mexican states. To avoid federal
intervention in the allocation of water rights on the Colorado River, Wyoming, Colorado, Nevada, New
Mexico, Utah, and California signed the Colorado River Compact to help divide water from the
Colorado River equitably among the seven states it passes through.8The Compact was ratiﬁed in
November 1922. In 1944, Arizona signed the Compact. Through this agreement, the Colorado Basin
was divided into an upper (Colorado, New Mexico, Utah, and Wyoming) and lower basin (Arizona,
California, and Nevada) at Lees Ferry, AZ.9Using this division, water allocations were made by basin -
not by state. This issue remains at the heart of modern disagreements over the allocation of water
resources and is a large factor that limits the likelihood of any new agreements on water allocation in
9"Colorado River Compact," Article 2 (1922).
8"Colorado River Compact," Article 1 (1922).
7Waterways Journal Editorial Board, “Drought Revives Mississippi River Pipe Dreams,” Waterways Journal, JULY 22, 2022,
6Los Angeles Times. 2021. “A water pipeline from the Mississippi River to the west?” July 13, 2021.
5Wilson, Janet. 2022. “Climate change has dried the West. Could a pipeline be the answer?” USA Today, August 15, 2022.
In June 1922, the US Supreme Court established the law of prior
appropriation as the legal means by which water rights were
allocated in the American West. Under the Law of Prior
Appropriation,10 whoever used a water source ﬁrst had the ﬁrst
right of use. This applied regardless of state boundaries. This
serves as the basis for the Law of the River that establishes the
relationship between the Upper and Lower Colorado River
The states ultimately agreed to allocate 7.5 million acre-feet (MAF) per year of water from the
Colorado River system in perpetuity for “beneﬁcial use” to both the upper and lower basins.11 This was
believed to be enough water to meet current needs while also allowing for future development. In
fact, this initial premise was a gross overestimation of the actual amount of water available in the
Basin. Further, the Compact stipulated that upper basin states could not cut the low of water to lower
basin states. The allocation of 1.5 MAF of water from the Colorado River to Mexico was negotiated
through a treaty that was ratiﬁed in 1944.12 Since its inception, the allocation of water to speciﬁc
states has been afected by the passage of legislation and federal regulations including the Boulder
Canyon Project Act (1928),13 the Colorado River Storage Project Act (1956),14 the Colorado River Basin
Project Act (1968),15 and the Colorado River Interim Guidelines for Lower Basin Shortages and
Coordinated Operations for Lake Powell and Lake Mead (2007),16 among others.
Mandatory Water Reductions
In 2021, the federal government declared a Tier 1 water shortage on the Colorado River system which
required water use reductions of 18, 7, and 5% in AZ, NV, and NM, respectively. This step was taken
under the assumption that diminishing water levels would be replenished by winter rains and snow
16 72 FR 62272 - Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell
and Lake Mead, https://www.govinfo.gov/app/details/FR-2007-11-02/E7-21417.
12 “Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande, Treaty Between the United States of
America and Mexico”( 1944).
11 "Colorado River Compact," Article 3 (1922).
10 Wyoming v. Colorado, 259 U.S. 419 (1922), https://supreme.justia.com/cases/federal/us/259/419/
melt. Unfortunately, the actual water recharge was much less than anticipated and water levels
continued to fall across the basin. In June 2022, a Tier 2 water shortage was declared. As a result, the
federal government will further reduce water allocations to Arizona by 21%, Nevada by 8%, and
Mexico by 7% beginning in January 2023.17
Previous Studies of Water Diversion
Many proposals have been made to supplement water in the Colorado River. The Columbia River, the
Mississippi River, and Lake Superior are among the most common proposed sources of supplemental
water. The most recent credible study was published by the US Bureau of Reclamation (USBR) in
2012.18 In this document, the USBR summarized a number of possible approaches to increasing the
supply of water to/in the Colorado River Basin; this included desalination of ocean water, water reuse,
and rainwater harvesting. Importing water from the Mississippi, Green, Snake, and Yellowstone
Rivers was also considered. Diverting water from the Mississippi River was noted to be a 30-year-long
project while importing water from the other rivers was thought to take around 15 years. The USBR
also recommended a number of options to reduce the demand for water. In this study, it was
predicted that the conservation of agricultural water would yield 1.0 MAF per year by 2035. Over the
same time period, the diversion of water from each of the rivers noted above would only add ~0.76
MAF per year. This lends strength to the belief that some combination of eforts will be needed to
address the water shortage.
Despite these studies, in 2021, the Arizona legislature petitioned the US Congress to conduct a study
on the diversion of Mississippi River water to the Lower Colorado River Basin.19 According to
Representative Tim Dunn, a member of the Arizona Legislature and cosponsor of the bill, “… A new
water source could help augment Colorado River supplies. One promising possibility involves piping
water that is harvested from Mississippi River lood waters. Diverting this water, which is otherwise
lost into the Gulf of Mexico, would also help prevent the loss of human life and billions in economic
damages when such looding occurs. …”20
20 News Release: Arizona Legislature Urges Congress to Study Feasibility of Harvesting Mississippi River Floodwaters to
Replenish Colorado River Supply, May 11, 2021, https://www.azleg.gov/press/house/55LEG/1R/210511DUNNHCM2004.pdf.
19 Arizona House Concurrent Memorial 2004, 2021,
18 “Colorado River Basin Water Supply and Demand Study, US Bureau of Reclamation, US Department of the Interior
17 Briscoe, Tony. 2022. "As Talks On Colorado River Water Falter, U.S. Government Imposes New Restrictions". Los Angeles
An Assessment of the Diversion of Mississippi River Water to
Reﬁll Lake Powell and Lake Mead
Since Mr. Siekes’ editorial appeared to be the driving force behind this most recent round of debate
and discussion of moving water from the Mississippi River to the west, the assertions and
assumptions from his article were used as a starting point in this assessment. This approach is based
on three main premises. (1) “Citizens of Louisiana and Mississippi south of the Old River Control
Structure do not need all that water. All it does is cause looding and massive tax expenditures to
repair and strengthen dikes.” (2) “The best solution would be for the U.S. Army Corps of Engineers to
build an aqueduct from the Old River Control Structure on the Mississippi to Lake Powell, ﬁll it, and
then send more water from there down the Colorado to ﬁll lake Mead.” and (3) “Within a year and
eight months of the aqueduct’s ﬁnish, both reservoirs would be ﬁlled and most of the Southwest’s
water problems would be gone.” The underlying assumptions that support these claims include the
●About 4.5 million gallons of Mississippi River water low past the Old River Control Structure
(ORCS) every second.
●250,000 gallons of water per second will be diverted westward.
●The water shortage in Lake Powell and Lake Mead is 13.5 trillion gallons (5.5 trillion gallons in
Lake Powell and 8 trillion gallons in Lake Mead).
These statements and the underlying assumptions beg a number of important questions that remain
unanswered. For example, how much Mississippi River water is actually available for potential
diversion? Many proponents of water diversion fail to recognize how drought conditions afect the
entire US - including in the Mississippi River Basin. It’s equally unclear how the diversion of water to
the west would reduce looding downstream of the ORCS or save taxpayers money from future lood
response. Likewise, the actual scale of a proposed diversion structure is not addressed. In this case,
the saying “the devil’s in the details” is not a cliche.
Problems from the Start
USBR Discharge Data, 1906 - 1920
Before considering any particular aspect of recent proposals, it is necessary to understand the
provenance of the data that are used to make water allocation decisions in the west. For example, the
initial water allocation of 7.5 million acre-feet of water per basin was reportedly determined based on
data provided by the USBR. At the time, the USBR estimated the annual Colorado River low rate at
Lees Ferry, AZ, to be 16.4 million acre-feet.21 However, the average natural low rate of the Colorado
River at Lees Ferry, AZ, from 1906 to 1920, is 17.7 MAF based on data published by the USBR (Figure
1).22 This corresponds to an 8% disagreement between data from the USBR. Regardless of the
disparity in these data, it's important to recognize that the annual average natural low rate of the
Colorado River failed to exceed 15 MAF thirty percent of the time. At the very least, it’s fair to say that
decision-makers of the time had an optimistic view of the future availability of water in the west.
Figure 1. Natural Flow Rate at Lees Ferry, AZ, between 1906 and 1920.
USGS and USBR River Discharge Data from 1920 through 2022
The US Geological Survey (USGS) maintains a network of streamgages that provide continuous water
level and discharge (low rate) data on over 8,500 streams. Before the advent of modern
21 National Research Council, Committee on the Scientiﬁc Bases of Colorado River Basin Water Management, Water
Science and Technology Board, Colorado River Basin Water Management: Evaluating and Adjusting to Hydroclimatic
Variability, 2007, at https://www.nap.edu/read/11857/chapter/1.
instrumentation, hydrologists would manually make these measurements. Discharge data have
been measured at a USGS gage station at Lees Ferry, AZ, since 1921. From 1921 to August 2022, the
average measured discharge at Lees Ferry was 14,457 cfs (10.5 MAF/yr).23 In contrast, the average
annual natural low rate reported by the USBR over the same time period was 14.2 MAF, which is 35%
higher than the discharge measured by USGS. The diferences between data from these two sources
is largely the result of diferences in terminology and data reduction methods, which are addressed in
a 50-page-long Scientiﬁc Investigation Report issued by the USGS in 2018.24 However, even the
appearance of a diference in these data is a needless complication to the already contentious issues
surrounding water abundance and availability in the Colorado River Basin. Regardless, the annual
allocation of 15 MAF between the Upper and Lower Colorado River Basins could never be satisﬁed using
either set of average annual low data from 1921 through August 2022.
The diference between the amount of water promised and the amount of water that’s actually
available remains at the heart of almost all water issues across the Colorado River Basin. When
combined with the impacts of climate change, this disparity will only become greater over time.
How Much Mississippi River Water is Available for Diversion?
Mississippi River Discharge from 2002 - 2022
According to Mr. Siekes, “About 4.5 million gallons a second low past that structure on the
Mississippi.” The source of his data was not provided. To assess this premise, low, average, and high
water discharge data for the Mississippi River from 2002 to 2022 at the USGS streamgage located
immediately above the ORCS were obtained and are summarized in Table 1.25 From these data, the
discharge of 4.5 M gal/s overstates the 20-year average by 38%.
In reality, 4.5 M gal/s corresponds to the highest low rate based on the most recent 20 years of water
which occurred in 2019 during the most signiﬁcant Mississippi River looding event in recent times.
On a related note, the low of water past the ORCS serves a number of additional purposes that might
not be immediately apparent. For example, the low of sediment-laden Mississippi River water below
25 USGS National Water Information System, https://waterdata.usgs.gov/nwis/uv?site_no=07289000, accessed August 31,
24 Bruce, B.W., Prairie, J.R., Maupin, M.A., Dodds, J.R., Eckhardt, D.W., Ivahnenko, T.I., Matuska, P.J., Evenson, E.J., and
Harrison, A.D., 2018, Comparison of U.S. Geological Survey and Bureau of Reclamation water-use reporting in the Colorado
River Basin (ver. 1.1, September 2019): U.S. Geological Survey Scientiﬁc Investigations Report 2018–5021, 41 p.,
the ORCS is vital to eforts to reduce the further disappearance of the Louisiana coastline and barrier
Table 1. Mississippi River Discharge at Vicksburg, MS, Station 07289000 (from 8/24/02 to 8/31/22).
Discharge (8/24/02 to 8/31/22)
250,000 gal/s diversion as a % of
The Proposed Diversion Rate in Relation to Mississippi River Discharge
At the average Mississippi River discharge rate, the diversion of 250,000 gal/s is less than 8% of the
total average low (Table 1). However, when the lowest discharge conditions are considered, the proposed
diversion is nearly 17% of the river low. This diference is not negligible. In fact, this is similar to the
21% reduction in Colorado River water that will be imposed in January 2023 as a result of a Tier 2
water shortage. As people in the west know all too well, careful consideration should be given before
suggesting that the allocation of water to any population should be reduced by 17%. In light of this
analysis, the argument that “Citizens of Louisiana and Mississippi south of the Old River Control
Structure don’t need all that water” becomes much more tenuous.
The Impacts of Drought are Widespread
The western US is experiencing a signiﬁcant drought that is having long-term hydrologic and
ecological efects. Based on data from the National Drought Mitigation Center (NDMC), the states
that make up the Colorado River Basin have been under drought conditions since at least 2000.
However, over the same period, other parts of the nation - including the Mississippi River Basin have
also experienced drought conditions. To place this into context, the extent of drought conditions
across the continental US in 2002, 2012, and 2022 are presented in Figure 2.27
27 U.S. Drought Monitor. National Drought Mitigation Center, U.S. Department of Agriculture, and the National Oceanic
and Atmospheric Administration, https://droughtmonitor.unl.edu.
26 Cornwall, Warren. “Unleashing the Big Muddy: By Sending Mississippi Waters on a New Course, Engineers Hope to
Build New Land—and Test Ways to Save a Retreating Coast,” Science, 22 April 2021.
In 2012, the severity of the drought was greater in the Upper and Lower Mississippi River Basins than
in the Upper and Lower Colorado River Basins (Figure 2, middle). Fortunately, the severe drought
along the Mississippi River Basin was relatively short-lived. However, drought conditions still exist in
Minnesota, Wisconsin, Iowa, Illinois, Missouri, Arkansas, Kentucky, Tennessee, and Mississippi. While
the duration and severity of the drought in the Mississippi River Basin are substantially less than in
the Colorado River Basin, the presence of drought conditions in the east cannot be neglected -
particularly if plans involve moving water from the Mississippi River to the west. The widespread
impacts of drought continue to afect the entire nation and beyond. For instance, in late September
2022, a drought along the Mississippi River Basin caused low water conditions that had adverse
impacts on waterborne commerce.28 29 Further, the severity of dry conditions has become worse over
time. Given the length and geographic extent of these dry conditions, it is unlikely that this will abate
under natural circumstances.
Could Diverting Water Help Reduce Flooding?
Could the diversion of 250,000 gal/s of Mississippi River water reduce the cost of looding? Earlier,
we saw that diverting 250,000 gal/s from the Mississippi River would reduce the average downstream
low by 7.7% (~8%). Under looding conditions, the average downstream low would be reduced by
only 5.6%. This diversion would reduce the low to Baton Rouge, New Orleans, and other locations
that are downstream from the ORCS. During the height of a looding event, it’s reasonable to assume
that local people would welcome the diversion of even the smallest fraction of water. However,
Mississippi River looding isn’t limited to the ﬁnal reach of the River. Consequently, the proposed
beneﬁt of diverting Mississippi River water from the ORCS to the west would be of little signiﬁcance
to basin-wide looding.
For a water diversion project to have a meaningful impact on looding downstream from the ORCS,
any system would have to be able to accommodate a large surge in water volume over a relatively
short period of time. Accommodating a surge low of water has its own challenges that include the
need for a large pumping capacity and a place to send the water.
29 Chris Isidore, Amanda Watts, Judson Jones and Brandon Miller “Another supply chain crisis: Barge traﬁc halted on
Mississippi River by lowest water levels in a decade,” CNN Business, October 8, 2022,
28 Press, Jim, "Low Water On The Mississippi River Impacting Barge Traﬁc". www.STLtoday.Com, September 30, 2022,
Figure 2. Drought conditions in the Continental United States, 2002, 2012, and 2022.
Assessing the Alleged Beneﬁts of Water Diversion
Could Diverting Water Save Taxpayers Money on Flood Response and Recovery?
Any natural disaster - including looding - has expensive consequences. In the United States, the
federal government provides support (skilled workers, supplies, rescue capabilities, and money) to
help communities respond to and recover from these events. In this regard, many people suggest
that the water shortage in the western US should be treated like any other natural disaster. However,
others cast the issue in diferent terms. It has been suggested that diverting water from the
Mississippi River to reﬁll Lake Powell and Lake Mead would save taxpayers money by reducing the
need to build and maintain levees and other infrastructure along the Mississippi River and its major
A number of approaches can be used to weigh this assertion, though none are ideal. To use
contemporary data, we considered the cost associated with looding across the Mississippi River
Basin in 2019 as the worst case in terms of economic impact. While there have been numerous loods
along the Mississippi River in the intervening years, the next most recent rival to the looding in 2019
occurred in 1993. According to the National Oceanic and Atmospheric Administration (NOAA), the
total cost of the 2019 lood in the midwest was approximately $20 billion ($20,000,000,000).30 31 This
estimate included costs associated with lood response and recovery, reconstruction and/or
relocation, and other direct economic losses. At the rate suggested by Mr. Siekes, 21.6 billion gallons
of water would be diverted from the Mississippi River each day.
This is enough water to ﬁll the Washington Monument (~8,200,000 gallons) more than 2,600 times
each day. Laid end-to-end, this would be a distance of 1,430,000 t. or a little less than 271 miles.
A cost must be assigned to a gallon of water to carry the assessment further. For the sake of argument,
assume that water is worth $0.01 per gallon. Mr. Siekes estimated that 624 days would be needed to
ﬁll both Lake Powell and Lake Mead and that the rate of water drawdown remains constant. Under
these conditions, the cost of water to ﬁll both lakes would be $134.8 billion or ~6.7 times the cost of
the response to the basin-wide Mississippi River looding in 2019. This is the cost of water and doesn't
include the cost to acquire land, design and construct a conveyance system, treat the water, and provide
for annual operation and maintenance.
Moving Water to the West is a Matter of Scale
Any assessment of the diversion of water to the west should include an estimate of the actual scale of
any new infrastructure. For example, a water diversion rate of 250,000 gal/s was suggested, though
no rationale was provided. However, that ﬁgure plays a large role in determining the overall
feasibility of any proposal. The water discharge rate is directly related to the water velocity and
cross-sectional area of the channel or pipe that’s used to move the water. To operate pumps at
reasonable eﬁciencies while also minimizing mechanical wear to the pump, valves, and other
ﬁxtures, a maximum luid velocity range is used. For water conveyance systems, a maximum
average32 water velocity of 3 to 8 t/s is common (5.5 t/s average).33 In this case, a cross-sectional area
of ~6,100 t2would be needed to meet the proposed low requirement.
33 Engineering ToolBox (2003). Water Systems - Maximum Flow Velocities.
https://www.engineeringtoolbox.com/low-velocity-water-pipes-d_385.html (accessed 18 August 2022).
32 This isn’t a typographical error. “Maximum average” is correct.
An Open Channel
In theory, this cross-sectional area would correspond to a channel that’s 100 t wide and 61 t deep, or
1,000 t wide and 6.1 t deep. Alternatively, 10 channels that are 100 t wide and 6.1 t deep could also
be used. For perspective, the lanes of an interstate highway are 12 t wide with a 4 t wide let
shoulder and a 10 t wide right shoulder. If the median is 50 t wide, an interstate that’s two lanes in
each direction would be around 126 t wide from shoulder to shoulder. When considering the need
for a foundation and a right-of-way, a 100 t wide water aqueduct would occupy a footprint that’s
similar to an interstate highway in a nonurban area. However, the “highway” would be at least 61 t
deep and extend at least 1,200 miles (see Figure 3).
Figure 3. Possible routes for a water diversion project from the Old River Control Structure on the
Mississippi River in LA, to Lake Powell, AZ.
A Water Super Highway?!
The comparison of a water channel to an interstate has been made by some who have proposed
building the water conveyance structure next to existing interstate highways. Unfortunately, the
shortest route between the ORCS and Lake Powell when following existing interstate highways is
around 1,600 miles long (see Figure 3). That’s approximately 1.4 times the distance of a straight-line
path. This corresponds to around 1.9 billion yd3of excavated material for the channel, alone. This
channel would have to be lined and would require additional excavation to build a suitable
foundation. Construction along existing interstates is further complicated by the presence of ten
metropolitan areas with populations ranging from ~82k to 5.1 million people (2010) along the route.
Piping Water to the West
Some have suggested using a closed pipe to minimize the loss of water to evaporation in an open
channel. Under the constraints established earlier, such a pipe would require a diameter of around 88
t. This is more than 1.5 times the length of a standard semi-trailer (53 t long)!
The “Elephant in the Room” - Elevation
Beyond any of the previous issues, the single most signiﬁcant limiting factor in this proposal is the
diference in elevation between the Mississippi River at the ORCS and the highest point the water
would need to be lited before lowing into the Colorado River or a tributary. Any overland route
would have to go over the Western Continental Divide. For example, if a direct overland route were
taken from the ORCS to Lake Powell, a pipeline or aqueduct would have to traverse a path with a
maximum elevation of just under 11,000 t (around 12 miles east of Santa Fe, NM). Regardless of the
height of any particular mountain peak, the elevation diference between the Mississippi River at the
ORCS and Lake Powell is ~4,600 t. This is substantially diferent from other aqueduct systems that
rely on gravity to move water; the most well-known of these systems is the water supply for New York
City which begins in the Catskill Mountains.
Some have noted that the US Army Corps of Engineers (USACE) has pumps that can move huge
volumes of water. This is true. They believe these pumps could be used to move water westward to
the Colorado River Basin. This is not true. When selecting a water pump, engineers consider several
factors including the discharge low rate and the height that water needs to be lited. The pumps
used to respond to looding are capable of very high discharge rates, while their lit capabilities are
relatively low. When compared to the diference in elevation between the ORCS and Lake Powell, the
lit capacity of these pumps is irrelevant. Rather, new pumps and infrastructure would be required.
In addition to the factors above, other, less obvious issues must be considered. For example,
Mississippi River water is home to a wide range of aquatic organisms that aren’t native to the Colorado
River Basin. It would be beneﬁcial for those who consider this to be a trivial concern to learn more
about the proliferation of silver and bighead carp (Hypophthalmichthys molitrix and
Hypophthalmichthys nobilis, respectively) along the Mississippi River and its tributaries.34 Likewise,
similar lessons can be learned by considering the impacts of zebra mussels (Dreissena polymorphaon)
that were introduced into freshwater habitats in the Upper Mississippi River Basin through ballast
It is also worthwhile to consider the quality and characteristics of the Mississippi River water before
exporting it westward. Lake Mead is known to contain elevated concentrations of nitrogen and
phosphorus. According to the USBR, nitrate concentrations in Lake Mead range from 0.28 to 0.50
35 Chou, P. 1999. "What Is The Current Status Of The 'Invasion' Of Non-Native Zebramussels In The Great Lakes? Has The
Invasion Been Stopped Or Controlled? And Whatecological Damage Has This Creature Caused Other Than The Clogging
Of Drainagepipes?". Scientiﬁc American. https://www.scientiﬁcamerican.com/article/what-is-the-current-statu/.
34 "Asian Carp Overview - Mississippi National River and Recreation Area (U.S. National Park Service)". 2022. Nps.Gov.
mg/L (0.39 mg/L average). This corresponds to a nitrogen concentration of 0.09 mg/L NO3as N.
According to data from the USGS, in 2021, the average concentration of nitrate and nitrite in the
Mississippi River at Vicksburg was 0.61 mg/L NO3and NO2as N. Consequently, on average, the
concentration of nitrogen in the water from the Mississippi River is 6.8 times greater than the
concentration in Lake Mead. At a rate of 250,000 gal/s with an average nitrate concentration of 0.61
mg/L NO3as N, a total of 68,605,828 lb of nitrogen would be sent westward during the 624 days
proposed to ﬁll Lake Powell and Lake Mead. That’s almost 69 million pounds of nitrogen! For the sake
of argument, assume that Lake Powell and Lake Mead are at about 27% of their full volume. Ater
reﬁlling the lakes with water from the Mississippi River, the concentration of nitrogen will be around
0.47 mg/L NO3as N or 2.1 mg/L NO3. To avoid the known adverse impacts of increased nitrogen
loading, treatment would be needed at a considerable additional expense.
It is abundantly clear that a critical source of water for the southwest US is in serious peril. In response
to the failed eforts of federal and state governments to manage this challenge, people have renewed
their interest in ideas that include diverting water from the Mississippi River to replenish major
western water reservoirs. Unfortunately, time, space, ecology, ﬁnances, and politics aren’t on the side
of this proposal. While the proposal is interesting, the diversion of Mississippi River water is not likely
to help anyone meet the increasingly dire need for water in the west. As water levels continue to
decrease in major reservoirs that are used for hydropower production, the current water deﬁcit is
increasingly becoming a water and power crisis. Hopefully, this work will allow people to gain a
better understanding of a few popular proposals and will be able to give a more practical combination
of approaches that lead to a sustainable supply of water in the west.
1 mi = 5,280 t
1 Ac = 43,560 t2
1 day = 86,400 sec
1 Ac-t = 32,5851 gal = 43,560 t3
1 t3= 7.48 gal (US)
1 gal (US) = 3.785 L
1 yd3= 27 t3
1 lb = 453.6 g
1 mg/L NO3= 0.226 mg/L NO3as N