contents of this site
How do dams impose
values on the Colorado River or any other river's uses?
This problem's features:
Questions to consider:
|Few people ever
see this sight or may even be able to experience the view from
the bottom of the chasm, thus the argument for the dams went. Two
dams on this river above and below the Grand Canyon National Park
would not interfere with the greatest number of people's experience
of the Grand Canyon's scenic monumentalism.
Marble Canyon Dam site:
The upper of the two proposed dams was proposed to
flood Marble Canyon. At the time of the proposal (1960s) the Grand
Canyon National Park property line began south of Marble Canyon,
shown in the photo on the lower left.
||Based on its scenic, archaeological, and importance
to native American peoples the opponents of the dam site were able
to argue against Marble Canyon being flooded.
Every ecological problem
has three facets that answer the question of where do environmental
impacts alter the assimilative capacity of a particular resource
1: Physical dimensions of the case.
2: Biological conditions of a case.
3: Social characteristics of the case.
Three dimensions of any case derive
from three aspects of any ecological problem:
desert, riparian, canyons, oases,
minerals & forests
cheap electricity &
Comprehensive River basin planning influenced the
Central Arizona Project.
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An artifact of time and working elements:
Canyon's converge where the Colorado and the Little
Colorado Rivers meet.
The red wall limestone of Cretaceous & Permian
eras' rocks rise above the juncture.
The biodiversity of the Canyon's
ecosystems are today threatened by insufficient flooding since the
flow of the river is controlled by Glen Canyon dam upstream to provide
electrical power for Los Angeles and southern California rate payers.
Dams were once a symbol of progress and
conservation's promise in the arid west. But as the number and sizes of
dams increased their utilitarian function became viewed as an intrusion
in an otherwise wild landscape.
Water and Power
Colorado River water for the central Arizona project underwrites
the state's development, especially mining and suburban land use. Dams
across the west produce a significant proportion of the electrical power
needed by residents of the southwest, especially in metro areas such as:
Phoenix, Los Angeles, Tucson, Las Vegas, Salt Lake City, & San Diego.
Electricity is the easiest, cleanest
and most effective means of delivering power, but it was not always that
Dual demands for energy intensive
baseload power supply
peak power supply
|The term for producing electricity to
meet a constant level of need. The amount of power demanded at the
least busy time of the day and year.
Usually industrial facilities that work around the
clock with three shifts of workers require electricity at a constant
level of output, though manufacturing plants can vary.
|This is the term used to describe a spike
in demand at busy times of a day or year. Daily there are two spikes
or "twin peaks" early in the morning (6 AM to 9 AM) and late in the
afternoon and early evening (4PM to 7 PM) when people and commercial
users and industrial consumers all demand electricity simultaneously.
Their combined demand creates the spike or peak in the need for electrical
|Water and electricity are partners
in creating the world we have come to depend upon for work, services,
goods and even recreation.
is used to make electricity, because turbines that generate a current
of electrons are turned by steam. The super heated water flashes
into steam and is still hot when it condenses. Cooling towers, seen
here on the extreme left of the photograph are used -- as are cooling
ponds-- to lower the water temperature so it will not scald living
Electricity is also used to run pumps that
move water from the ground into the surface network of pipes, towers,
and waste water treatment plants that bring running water to commercial,
municipal, residential and industrial users.
Supply side issue:
Base load capacity of the plants is a technical capability
of all generators to produce a steady supply of electrical power at
all times of the day. Dams generate base load power very inexpensively
& can be used for peak load.
Demand side issue:
Peak load is power needed well in excess of the baseload
requirement when every customer demands electricity at certain times
of the day. A graph of the demand would peak at those hours of
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Two agencies in competition for limited
|Army Corps of Engineers
control of navigable rivers:
dredges harbors, maintains canals and
reservoirs, builds breakwaters,
beach renourishment, levees, dams.
|Bureau of Reclamation
Department of Interior
control of floods on rivers:
irrigation, reservoirs, levees, dams and canals.
Bureau estimated the Colorado River has an annual
flow of 17.5 million acre feet of water (1922).
Reisner, pp. 124-125.
Panama Canal, 1910
Intracoastal waterway dredged from Maine to Mexico,
Kings & Kern Counties Project, 1937
large farmers with extensive
built fortifications in the Revolutionary war,
1775 - 83.
officially created in 1794.
to maintain navigation on all interstate or navigable
Powell's Irrigation survey of 1888
created in 1902 by Theodore Roosevelt
western water interests
Hoover Dam 1928
acreage limitation: small farmers
Kern County Land 413 k acres
Salyer, Miller & Lux 80 k acres
The canyon is the deepest fissure, cut by a flowing river,
in the world.
The river is longer than the canyon, but the Grand Canyon
is impressive by any account:
277 miles long
10 mile wide on average
15 miles wide at its broadest
4000 feet deep from the top of
Temperatures swing from 56 to over
106 degrees from winter to summer respectively, at the bottom of
This immense landscape feature stretches from below the
Paria River at Lee's Ferry -- the dividing line between the Upper and
the Lower Colorado River basins-- to boulder canyon, since 1928, the site
of Hoover Dam.
Twenty million people live in the Colorado River basin
that stretches from Colorado and Utah to California, Arizona, Nevada and
northern Mexico. About 2.4 to 3 inches of rainfall annually collects in
the basin, much of the river rises from snow melt in the central Colorado
Rockies. Four million visitors annually go to the Grand Canyon National
This is the largest river in the southwest. Although
it is large, the flow of the Colorado River is but a fraction of the flow
of the larger Columbia River in the Pacific Northwest and the Columbia
is a fraction of the Missouri and Mississippi Rivers' annual flow.
The Precambrian rock at the bottom of the canyon is washed
by the river's frigid waters (53 degrees Fahrenheit) and scoured by the
silt brought downstream at flood times
The earth is full of locations where numerous remnants
persist of evidence that a previous ecological association of plants &
animals existed in prehistory on the same sites. Ancient sea creatures
revealed the origins of the limestone that line the towering walls of
Layers of dinosaurs, beneath layers of flowers are found.
From between 3,000 and 5,000 years ago resident people
have occupied the Canyon, itself, though the Hopi Mesas to the south reveal
occupation to 10,000 ago or more.
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