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					           Water Resources
Water Use and Management
           Water Pollution
Water Use and Management
 Identify patterns of global water use.
 Explain how water is treated so that it can be used for
 Identify how water is used in homes, in industry, and
  in agriculture.
 Describe how dams and water diversion projects are
  used to manage freshwater resources.
 Identify five ways that water can be conserved.
Water Use and Management
 If you are camping in the desert, what are some ways
 you might get water?
Water Use and Management
 List all the ways that you use water in your daily life.
Water Use and Management
 List all the ways that you use water in your daily life.

 It takes 400 gallons of water to produce a cotton shirt.
 It takes 49 gallons of water to produce a glass of milk.
 Can take more than 2,000 gallons of water to produce a
  single steak.
Water Use and Management
 “We all live downstream.”
 A common expression that really means that when a
  water supply is polluted or overused, everyone
  downstream can be affected.
 Number of people relying on the Earth’s limited
  freshwater reserves is increasing daily.
 A shortage of clean, fresh water is one of the
  world’s most pressing environmental problem.
 World Health Organization says that more than 1
  billion people lack access to a clean reliable source of
  fresh water.
Water Use and Management
 Potable – suitable for drinking water.

 Pathogen – A virus, microorganism, other
 substance that causes disease; an infectious

 Irrigation – A method of providing plants with
 water from sources other than direct
Water Use and Management
 Dam – A structure that is built across a river to
 control a river’s flow.

 Reservoir – An artificial body of water that usually
 forms behind a dam.

 Desalination – A process of removing salt from
 ocean water.
Global Water Use
 Key to understanding the factors affecting the
  world’s supply of fresh water, we must understand
  how people use water.
 Three major uses for water:
   Residential use
   Agricultural use
   Industrial use
Global Water Use
 Most of the fresh water used worldwide is used to
 irrigate crops.

 Patterns of water use are not the same everywhere.

 Certain factors influence the pattern of water
   Availability of fresh water
   Population size
   Economic conditions
Global Water Use
 Asia
    80 % of water use is agriculture related.
 Europe
    38 % of water use is agriculture related.
 North America
    45% of water use is agriculture related

   *Industry accounts for about 19% of the water used in the
   US and Europe are the highest percentage with a 39% and
     45% of their total use.
   Globally, about 8% of water is used by households for
     activities such as drinking and washing.
Residential Water Use
 Differences in residential water use throughout the world.
 Average person in the US uses about 300 L (80 gal) of
  water a day.
 Average person in India uses only about 41 L per day.
 In US, about half of residential water is used for
  activities within the home:
    Drinking
    Cooking
    Washing
    Toilet flushing
Residential Water Use
 Remainder of water residentially is used outside the
 home for activities like watering lawns and washing
      Daily Water Use in the United
            States (per person)

                  USE                WATER (L)
Lawn watering and pools                 95
Toilet flushing                         90
Bathing                                 70
Brushing teeth*                         10
Cleaning (inside and outside home)      20
Cooking and drinking                    10
Other                                    5
*with water running
 You will be assigned a country.
 Investigate its water resources.
 Answer the following questions:
    What percentage of water is used by households, by
     industry, and by agriculture?
    What are the country’s water resources?
    What are the major threats to the country’s water
    Due on Friday 1/14/11 
Water Treatment
 Most must be treated to make it potable. water
 It removes elements such as mercury, arsenic, and
  lead, which are poisonous to humans even in low
 These are found in polluted water, but also occur
  naturally in groundwater.
 Treatment of water also removes pathogens.
 Bacteria, viruses, protozoa, and parasitic worms
  are common pathogens.
Water Treatment
 Pathogens are found in water contaminated by sewage
  or animal feces.
 Several methods to treat water and make it potable.
 A common method uses both physical and
  chemical treatment of the water.
Water Treatment
 1. First Filtration
    Source of water supply is filtered to remove large
     organisms and trash.
 2. Coagulation
    Alum is rapidly mixed into the water and forms sticky
     globs called flocs. Bacteria and other impurities cling to
     the flocs, which settle to the bottom of a tank.
 3. Second Filtration
    Layers of sand gravel, and hard coal filter the remaining
Water Treatment
 4. Chlorination
    Chlorine is added to prevent bacteria from growing in
     the water.
 5. Aeration
    Air is forced through the water to release unwanted
     gases, which reduces odor and improves taste.
 6. Additional Treatment
    In some communities, fluoride may be added to prevent
     tooth decay. Sodium compounds or lime may also be
     added to soften hard water. Treated water is then
     pumped from storage tanks to homes and businesses.
Water Treatment
Industrial Water Use
 19 percent of water used in the world.
 Used for manufacturing goods.
 Disposing of waste.
 Generate Power.

 How much is used in manufacturing?
Industrial Water Use
 Nearly 1,000 L of water are needed to produce 1 kg of
 500,00 L of water are needed to manufacture a car.
 Vast amounts of water are required to produce
  computer chips and semiconductors.
Industrial Water Use
 Most industrial water is used to cool power plants.
 Water is released as steam from nuclear power plants.
 Power-plant cooling systems usually pump water
  from a surface water source like a river or lake and
  carry the water through pipes in a cooling tower,
  and then pump the water back to the source.
 Water returning is usually warmer than the source, but
  is usually clean and can be reused.
Industrial Water Use
 Why is buying a computer so expensive?
 Computer manufacturing has a huge impact on our
   Computer chips go through an elaborate cleaning process
    involving large amounts of water and 500 to 1,000 different
    chemicals, such as arsenic.
   Production process generates toxic wastes, and can
    contaminate groundwater and soil.
   Process consumes vast amounts of electricity and water.
   A chip manufacturing plant can use millions of gallons of
    water every day.
Industrial Water Use
 Wastewater from the process is chemically treated and
    released into the city’s water treatment centers.
   Silicon Valley, the heart of computer-chip manufacturing
    in the US is one of the23 Superfund sites created by high-
    tech industry.
   Superfund is the federal government's program to
    clean up the nation's uncontrolled hazardous waste
   The disposal of computers presents additional problems.
   Deteriorating hard drives and monitors can release toxic
    metals, such as lead, cadmium, and mercury.
Industrial Water Use
Industrial Water Use
 European manufacturers include the cost of recycling
  a computer in the purchase price.
 Should the cost of clean-up be included in the price of
  a computer?
Agricultural Water Use
 300 L (80 gal) of water to produce one ear of corn.
 Agriculture accounts for 67 % of the water used in
  the world.
 Plants require a log of water to grow, but 80% of the
  water used in agriculture evaporates and never reaches
  plant roots.
 Dryer regions of the world are known to have fertile
   Use irrigation when there is insufficient water.
   Irrigation – a method for providing plants with water
    from sources other than direct precipitation.
   Earliest form involved flooding fields with water
    from a nearby river.
   Many different techniques used from shallow
    water-filled ditches to high-pressure overhead
Water Management Projects
 We have been altering streams and rivers to make
  them more useful for thousands of years.
 Romans built aqueducts, huge canals that brought
  water from the mountains to the dry areas of France
  and Spain nearly two thousand years ago.
 Engineering skills have since improved and our
  water projects have become more complex.
Roman Aquaducts
 The Romans were very advanced when it came to their
  architectural structures and knowledge of engineering. One their
  major achievements were a series of 11 major aqueducts to carry
  water from the hills to the distribution reservoirs in Rome. These
  aqueducts were built between 312 B.C. and 226 A.D. The longest
  Aqueduct was 59 miles long. The most visually dramatic part of
  the aqueducts was the arches that were built to carry the final
  portion of the aqueduct within the city. However, the majority of
  the aqueduct was a simple channel cut through the rock from
  where the water started in the hills outside Rome, until the
  aqueduct was raised up on arches to provide an adequate
  pressure head as the water entered the city. In order to maintain
  the gradient of the aqueduct, they took roundabout roots that
  followed the contours of the land.
Water Management Projects
 People still tend to live in areas where the natural
  distribution of surface water is inadequate.
 Projects like dams and water diversion canals allow us
  the opportunity to do this.
 Water management projects can have a variety of
   Bringing water to make a dry area habitable
   Creating a reservoir for recreation or drinking
   Generating electric power.
Water Management Projects
 Water Management Projects have changed the
  American Southwest
 All or part of the water from a river can be piped in
  allowing people to live and grow crops in desert
The Colorado River
 Diverted to provide water for several states.
 Begins as a glacial stream in the Rocky Mountains and
    quickly grows larger as it is fed by other streams.
   Water is diverted as it goes south to meet the needs of 7
    western states.
   Much of the water is diverted for irrigation and drinking
    water in Arizona, California, and Utah
   So much water that it runs dry before it reaches Mexico and
    flows into the Gulf of California.
   The Colorado River reaches the Gulf ONLY in the wettest
Dams and Reservoirs
Dams and Reservoirs
 Dam – a structure built across a river to control the
  river’s flow.

 Reservoir – an artificial lade formed behind the dam
  when a river is dammed.

 Reservoir water can be used for flood control,
  drinking water, irrigation, recreation, and
Dams and Reservoirs
 Some dams used to generate electrical energy.

 Hydroelectric dams use the power of flowing
 water to turn a turbine that generates electrical

 About 20% of the world’s electrical energy is
 generated by hydroelectric dams.
Dams and Reservoirs
 Can have far-reaching consequences.

 When land behind a dam is flooded, people are
 often displaced and entire ecosystems can be

 Around 50 million people worldwide have been
 displaced by dam projects.
Dams and Reservoirs
 Changes the land below the dam as well.
 Rivers entering reservoir slow down and deposits
  some of the sediment it carries.
 Fertile sediment builds up behind a dam instead
  of enriching the land farther down the river.
 Cause less productivity in the farmland below the
Dams and Reservoir
 Dams can also fail.

 Failure would result in massive amounts of water being
  released in the river below the dam.

 In US, the era of large dam construction is probably
 In developing countries, like Brazil, India, and China,
  the construction of large dams continues.
Dams and Reservoirs
 The nearly 8100 major dams in the United States in
 The National Inventory of Dams defines a major dam
  as being 50 feet (15 m) tall with a storage capacity of at
  least 5,000 acre feet (6,200,000 m3), or of any height
  with a storage capacity of 25,000 acre feet (31,000,000
Dams and Reservoirs in US
 Of Oklahoma's many lakes and reservoirs, most (and
  all of the large lakes) are man-made, created by
  constructing dams across streams.
 Most lakes were made for flood control, water supply,
  recreation, fish, wildlife, and/or hydroelectric power.
 Lakes on the Arkansas and Verdigris rivers also aid in
  maintaining navigation along the McClellan-Kerr
  Navigation System.
 The major lakes in Oklahoma have been constructed
  by the U.S. Army Corps of Engineers, the U.S. Bureau
  of Reclamation, and the Grand River Dam Authority.
 Other large lakes are owned and operated by various
  state and federal agencies, by cities, and by other
 Additionally, a great number of smaller lakes and
  ponds have been built by farmers and other
 Lake Texoma (dam completed in 1944) is the only reservoir
  on the Red River in Oklahoma.
 It holds the largest volume of water (greater than 2.6
  million acre-feet) in the state and has the second largest
  surface area (88,000 acres).
 Tributaries to the Red River have many other important
  man-made lakes and reservoirs, such as (from west to east)
  Altus (1948), Foss (1961), Ellsworth (1962), Waurika (1977),
  Arbuckle (1967), McGee Creek (1985), Sardis (1982), Hugo
  (1974), Pine Creek (1969), and Broken Bow (1970); four of
  them are among the twenty largest lakes in the state.
 The Arkansas River has a series of locks and dams (the McClellan-Kerr
  Navigation System) that link Oklahoma with barge traffic from the Port
  of Catoosa (on the Verdigris River, northeast of Tulsa) down to the
  Mississippi River and New Orleans. Major man-made lakes and
  reservoirs on the main stem of the Arkansas River include (from the
  east) Robert S. Kerr (1970), Webbers Falls (1970), Keystone (1965), and
  Kaw (1976), each of which is among the twenty largest lakes in
  Oklahoma. Eufaula Lake (1964), on the Canadian River in eastern
  Oklahoma, has the largest surface area (102,200 acres) and the second
  largest volume (greater than 2.3 million acre-feet) in the state.
  Tributaries to the Arkansas River have many other important lakes and
  reservoirs, such as (from west to east) Canton (1948), Great Salt Plains
  (1941), Hefner (1943), Overholser (1919), Thunderbird (1964), Carl
  Blackwell (1938), Hulah (1951), Skiatook (1985), Oologah (1974), Fort
  Gibson (1953), Hudson (1964), Tenkiller Ferry (1953), and Wister (1949),
  and ten of them are among the twenty largest in the state.
 The only natural lakes in Oklahoma are a series of
 oxbow and playa lakes. The typically crescent-shaped
 oxbow lakes are found in abandoned channels
 (oxbows) of a meandering stream and occur mainly on
 flood plains of the major rivers, such as the Red,
 Arkansas, Washita, North Canadian, and Verdigris
 Rivers in eastern and central Oklahoma. Oklahoma
 has sixty-two oxbow lakes, each of which covers at
 least ten acres, and the largest, near the Red River in
 McCurtain County, is 272 acres.
 Playa lakes form in shallow, saucer-like depressions
 scattered across the semiarid High Plains region of
 northwestern Oklahoma and the Panhandle. These
 water bodies are characterized by internal drainage
 and have no outflow. They hold water during and after
 rainy seasons, and most of the water is lost through
 evaporation and/or seepage into the ground. Only a
 few playa lakes last year-round, but the intermittent or
 ephemeral playa lakes number about six hundred and
 appear following thunderstorms
Water Conservation
 As water sources become depleted, water becomes
  more expensive.
 Wells must be dug deeper, water must be piped greater
  distances, and polluted water must be cleaned up
  before it can be used.
 Water conservation is one way that we can help ensure
  that everyone will have enough water at a reasonable
Water Conservation in Agriculture
 Most water loss in agriculture comes from
  evaporation, seepage, and runoff, so technologies
  that reduce these problems go a long way toward
  conserving water.
 Drip irrigation systems offer a promising step
  towards conservation.
 Small amounts of water are delivered directly to
  plant roots by using perforated tubing.
 Water is released to plants as needed and at a
  controlled rate.
Water Conservation in Agriculture
 Systems are many times managed by computer
  programs that coordinate watering times by using
  satellite data.
 Using precise information, a well-designed drip
  irrigation system loses very little water to evaporation,
  seepage, or runoff.
Water Conservation in Industry
 As water resources have become more expensive,
  industries have developed water conservation plans.
 Most widely used practice involves the recycling
  of cooling water and wastewater.
 Instead of discharging used water into nearby
  river, businesses often recycle water and use it
 The production of 1kg of paper now consumes less
  than 30% of the water it required 50 years ago.
Water Conservation in Industry
 Some cities will pay small businesses to introduce
  water conservation measures.
 Program will save money for the city and for the
  businesses and also makes more water available for
  agricultural and residential use.
Water Conservation at Home
 A few changes to residential water use will make a
  significant contribution to water conservation.
 People can conserve water by changing a few
  everyday habits and by using only the water that
  they need.
 Water –saving technology can also help reduce
  household water.
 Some of these devices are required in some new
Water Conservation at Home
 Some cities will pay residents to install water-saving
  equipment in older buildings.
 About 1/3 of the water used by the average
  household in the US is for landscaping.
 Water the lawns at night, reduces amount of water
  lost to evaporation.
 Xeriscaping – involves designing a landscape that
  requires minimal water use.
Water Conservation at Home
 Can one person make a difference?

 When you multiply one by the millions of people
 who are trying to conserve water – in industry, on
 farms, and at home – you can make a big
What You Can Do to Conserve
 Take shorter showers.
 Avoid baths unless you keep low water level.
 Install a low-flow shower head in your shower.
 Install inexpensive, low-flow aerators in your
 water faucets at home.
What You Can Do to Conserve
 Purchase a modern, low-flow toilet.
 Put a water-saving device in your toilet
 Simply place a water-filled bottle inside your
 toilet tank to reduce the water used for each
What You Can Do to Conserve
 Do not let the water run while you are brushing
  your teeth.
 Fill the sink with water rather than letting water
  run while you are shaving, washing your hands or
  face, or washing dishes.
 Wash only full loads in dishwasher and washing
 Water your lawn sparingly.
Solutions for the Future
 Some places, conservation alone is not enough to
  prevent water shortages, and as populations grow,
  other sources of fresh water need to be developed.
 Two possible solutions:
   Desalination
   Transporting Fresh Water
 Desalination – is the process of removing salt
    from salt water.
   Some coastal communities rely on this process.
   Middle Eastern countries have built desalination
    plants to provide fresh water.
   Most plants heat salt water and collect the fresh
    water that evaporates.
   Process consumes a lot of energy and is too
    expensive for many nations to consider.
Transporting Water
 Water can be transported from other regions to areas
  where freshwater is scarce.
 Example:
   Greek islands have had an increase in tourism which has
    taxed the fresh water supply.
   Ships travel regularly from the mainland towing
    enormous plastic bags of water, anchor in port, and
    the fresh water is pumped onto the islands
Transporting Water
 Solution is being considered in US
 Alaska has a lot of fresh water.
 If huge bags are filled with water from Alaskan rivers,
  it can then be towed down the coast to California
  where the water supply is often short.

 76% of the freshwater is frozen, so it too is
  another possible source.
Section 2 Review
 1. Describe the drinking water treatment process in
  your own words.
 2. Describe the benefits and costs of dams and water
  diversion projects.
 3. List some things you can do to help conserve the
  world’s water supply. Give at least three examples.
 4. Describe three ways that communities can increase
  their freshwater resources.

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