Ocean water 97.2%
Polar Ice 2.15%
97.2 + 2.15 = 99.35%
.65% of global water supply is the amount
generally available for human use.
The problem(s) with water…
Uneven Distribution… some areas have
too much water, others much less than
Water Quality: When it is present, the water
is often in a condition that makes it
unacceptable for specific uses… e.g. salty
or polluted or full of sediment
The approximate location of the 100th Meridian… the traditional
dividing line between the humid east and the arid west
Water Laws… east vs. west
East of the 100th Meridian in the US, water is
The law governing water allocation in the
East is the same as in Europe… the
West of the 100th Meridian, water is
governed by an entirely different set of
assumptions Prior Use doctrine or
Water flowing in defined watercourses is treated
under riparian doctrine.
Rights arise from ownership of real property
underlying or bordering a stream or river.
A riparian right is the right to use water flowing in a
stream on riparian land. No right to divert a
specific quantity of water is obtained.
A riparian may use all water necessary for
domestic use (drinking, bathing, cooking, laundry,
livestock watering, and other uses essential to the
preservation of life and health).
If there is insufficient flow to maintain all domestic
and non-domestic uses, domestic uses have
Riparian Doctrine contd.
Riparian users are entitled to "reasonable use"
which may cause some diminution of streamflow
so long as other riparians are not "unreasonably"
The landowner does not own the water itself but
rather the right to use it on his riparian land.
Based on English ‘Common Law’ adjudicated in
Appropriation (Prior Use)
First in time of use is first in right (i.e.,
the earliest appropriator on a stream has
the first right to use the water), and
Application of the water to a beneficial use
is the basis and measure of the right.
The law in virtually all western states.
Water in the west…
Eighty percent of the Nation’s water is used in
the West—most of it for agriculture
Water left in the stream is considered ‘wasted’
Water rights exist as a legal entity independent
of the land.
BLUE states generally use riparian doctrine.
GREEN states generally are considered regulated riparian.
RED states generally use the prior appropriation doctrine.
GRAY states use mixed approaches.
Beneficial use has two components: the
nature or purpose of the use and the
efficient or non-wasteful use of water.
Keeping water in the stream is
The issue of anadromous fish!
Water and Wildlife
The special case of Salmon in the Pacific
In the Columbia River basin, development
was modeled on the Tennessee River
The entire river system is controlled by a
series of dams that provide hydroelectric
power, make the river navigable and provide
Salmon…. More than resource… a
spiritual identity for the region
“IN Stream flow”
There is a benefit to fish (esp. temperature
sensitive fish species like salmon and trout)
of keeping water in the stream
This benefit can be expressed in economic
Some of the most successful programs
transfer $ from advocacy groups to ranchers
to purchase forage crops for their cattle…
forgoing using their water rights to irrigate
Withdrawal vs. consumption
irrigation consumes the
highest percent (81 percent)
commercial the lowest (1
The difference between the
volume of water withdrawn
and that consumed is the
81% of water used for Irrigation is ‘consumed’...
Removed from the water system
(evapo-transpiration) and it is by far the most
consumptive use of water.
Technology has made irrigation much more
Drip Irrigation has single emitters for each plant
Flood or Furrow Irrigation
Center-Pivot Spray irrigation
Domestic water use
consumes 50100 gallons
This pie chart
shows how an
in Akron, OH
Figure 15.28, S&S p. 538
How much water is consumed? How much is returned to the hydrologic cycle?
Issues: non-point source pollution
The 1977 “Clean Water Act” provided
federal guidelines and control over point
Non-Point source pollution... Who is
responsible? How can it be controlled?
Agricultural land use... The sacred institution
of ‘the family farm’
According to the USGS, in 2000 21% of
water used in the United States
69.8 Billion gallons /day came from groundwater sources
68 percent, was used for irrigation
19 percent was used for public water
99% of ‘self supplied’ water sources were
ground water (a well)
• Occurs below the water
table, where the soil is
• Aquifer = underground
zone where water can be
extracted at useful rate
• Depletion by wells causes
drawdown a cone of
depression in the water
S&S Figure 15.12, p. 519
In some areas, notably the Ogallala Basin in
the central great plains groundwater
withdrawal has exceeded recharge of the
Wells are constantly drilled deeper, bigger
pumps installed... The end of a region?
The Ogallala Aquifer
• Composed of water bearing sands
and gravel, i.e. groundwater
• …filled during melt of ice sheet in last
• …current 20 x overdraft, -> 1.74 feet
per year (1,082,631 acre ft).
– North Plains Groundwater
Conservation District (http://
Cost of water?
Abundant water is available virtually everywhere
on the planet…
Cheap water is available in only a limited number
Water will run uphill to $
The Los Angles Basin sits next to/on the largest
body of water on the planet! But ocean water is
salty…the technology to remove salt is simple and
available… however it is expensive. It is cheaper
to acquire water from other regions and ship it.
Cost of water…
If the cost of water is not reflected in its allocation
then inefficiency is bound to occur.
Irrigation rights… no additional cost for the last
water used…. There is no incentive to conserve.
Subsidized water… some estimates place the
subsidy as high as 90% for American agriculture
(the farmer pays just 10% of the cost of the water)
… incentives to conserve are limited
Inter basin transfers
The Owens valley project
North American Water and Power Alliance
Making beneficial use of ‘excess’ or ‘wasted’