1. Water Resources 14
CHAPTER
Placeholder opening page, but maybe we can duplicate the look of the SE chapter opener page by using the same fonts and colors (and maybe that Ch 14 icon?)

2. Looking for Water . . . in the Desert
The 2300-kilometer Colorado River once flowed deep and wide across the Southwest to Mexico’s Gulf of California.
Since the Colorado River Compact, in 1922, seven states— Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming—have relied on the river’s water for human use.
Today, drought, dams, and diversion have caused the once-raging Colorado River to run nearly dry.
Las Vegas, Nevada city officials have turned to an unlikely source for water—the desert.Their proposal to mine groundwater from beneath a scenic area of the Great Basin Desert is controversial.
Talk About It Is the human need for fresh water reason enough to mine in an area that may threaten area ecology? What other ideas might states in the Colorado River Basin try?

3. Lesson 1.1 Earth: The Water Planet
Although the vast majority of Earth is covered in water, one in eight people lacks access to clean freshwater.

4. Objectives Discuss how fresh water can be both renewable and limited
Explain the significance of a watershed
Explain how most groundwater is accessed

5. Water, Water Everywhere
Water is everywhere
Falls from sky as rain and snow
Covers Earth’s poles as ice
Fills oceans

6. Where Is Our Water? Fresh water a renewable resource
Lesson 14.1 Earth: The Water Planet
Where Is Our Water?
Fresh water a renewable resource
Water cycle constantly recycles water
Cycling water redistributes heat, erodes mountain ranges, builds river deltas, maintains organisms and ecosystems, shapes civilizations
As water cycles, it changes state but very little is gained or lost

7. Where is Our Water? Fresh water is a limited resource
Some water is unusable for human needs
You can’t water crops with ice
You can’t drink salt water
Less than 0.5% of Earth’s water is fresh and liquid
Did You Know? If all Earth’s water were in a two-liter bottle, only about two capfuls would be fresh, liquid water.

8. Where is Our Water Fresh water is a limited resource
People do not always live in areas with ample access to water
Some places have high population density but not a lot of water
Other places have plenty of water but not a lot of people
Parts of the world experience rainy and dry seasons
Even if fresh water is available, it may not be available when needed

9. Lesson 14.1 Earth: The Water Planet
Surface Water
Surface water includes still bodies of waters and river systems.
Sources of surface water include rainfall & melting snow/glaciers/ice caps
Water travels from source to body of water as runoff
Water that flows over land and has not been absorbed into the ground
Watershed – all of the land area that supplies water to a particular river system
Imagine tracing the path of a drop of water in a river to where it fell as precipitation
Did You Know? The Mississippi River Basin covers 3 million square kilometers (1.2 million sq mi), making it the third largest watershed in the world. It drains 41% of the land area of the contiguous US.

10. Surface Water Each watershed is made up of many smaller watersheds
Watersheds are interconnected
Managing water sustainability requires the cooperation of everyone living within a watershed
Watersheds of the U.S.

11. Groundwater
Ground water – precipitation that did not evaporate, flow into a river, or get taken up by organisms; instead seeped downward through soil
Permeable layer – rock and soil containing spaces or pores through which water can pass
Impermeable layer – few or no pores
Aquifier – sponge-like formations of rock, sand, or gravel that hold water
Zone of aeration – aquifier’s upper layer that has pores water can flow through
Zone of saturation – aquifier’s lower layer pores are completely filled with water
Makes up about 1/5th of Earth’s freshwater supply

12. Lesson 14.1 Earth: The Water Planet
Groundwater
The water table separates the zone of saturation from the zone of aeration.
Affected by shape of land and amount of water available
Recharge zone – any area where surface water soaks into the ground and reaches an aquifer below
An Aquifer
Did You Know? The average age of groundwater is 1400 years. Groundwater recharges very slowly.

13. Groundwater World’s largest aquifer is Ogallala under the Great Plains
Lesson 14.1 Earth: The Water Planet
Groundwater
• Aquifers release 1.9 trillion L (492 billion gal) of groundwater to the surface each day via springs, geysers, and wells.
World’s largest aquifer is Ogallala under the Great Plains
Enables American farming
Image - (Creative Commons licensed)
Geyser info source - National Park Service:
Old Faithful, a well-known geyser in Yellowstone National Park, shoots groundwater over 100 feet into the air many times a day.

14. Lesson 14.2 Uses of Fresh Water
One third of all the people on Earth are affected by water shortages.

15. Objectives List the three primary categories of freshwater use
Relate the causes of surface water depletion to their effects
Explain the major causes and effects of groundwater depletion
Describe strategies for addressing water depletion

16. How We Use Water Three main uses of fresh water include:
Lesson 14.2 Uses of Fresh Water
How We Use Water
Three main uses of fresh water include:
Agricultural (70%)
Industrial (22%)
Personal (8%)
Did You Know? The average American uses 250 L of fresh water a day for personal uses, such as bathing and brushing teeth.

17. How We Use Water Agriculture Industry
400 gallons of water are needed to produce 2.2 lbs of wheat
3,960 gallons of water are needed to produce 2.2 lbs of grain-fed beef
Industry
A standard bottle of water requires twice as much water to produce than it holds
American factories use 18 billion gallons of water everyday to make and transport products
Water used in power plants that generate electricity to cool machinery
In the refining process, 1 – 2.5 gallons of water is needed to refine a gallon of gasoline

18. How We Use Water Personal
Average person in U.S. drinks 2-5 liters of water
10 minutes shower = 40 gallons
Flushing a toilet = 6 gallons
Dishwasher = 6 gallons
Watering the average suburban lawn = 750 gallons
Filling the average swimming pool = 19,000 gallons
Personal water uses inside the home are called residential uses
Leaky pipes = 9.5 gallons a day

19. Lesson 14.2 Uses of Fresh Water
Using Surface Water
Most freshwater used in the U.S. is surface water. (77%)
Water Diversion – moving water from its source to places where humans use it
Surface water is diverted by canals and dams.
Drought and overuse have caused significant surface water depletion.
Did You Know? The Aral Sea was once the fourth largest body of fresh water.
Aral Sea, 1997
Aral Sea, 2009

20. Using Surface Water Benefits of Dams Costs of Dams
Clean power generation
Crop irrigation
Flood control
Shipping
New recreational opportunities
Habitat alteration
Fisheries decline
Population displacement
Sediment capture
Loss of fertile farmland
Risk of failure
Lost recreational opportunities

21. Using Groundwater Groundwater recharges very slowly
Lesson 14.2 Uses of Fresh Water
Using Groundwater
Groundwater recharges very slowly
Longer to replace a given amount of water taken from an aquifer than a lake or pond
Ground water use is unsustainable
68% of groundwater in the U.S. is used for irrigation, most of which is very inefficient.
Half a football field of irrigated land for each person
Irrigated land has nearly doubled since 1960 because of population growth
Water lost to runoff and evaporation

22. Using Groundwater
Groundwater mining turns groundwater into a nonrenewable resource because it is withdrawn from the ground faster than it can be replaced.
When groundwater is depleted, the falling water tables can cause cities to sink, and undrinkable saltwater to move into the depleted aquifers.

23. Solutions to Freshwater Depletion
Lesson 14.2 Uses of Fresh Water
Solutions to Freshwater Depletion
Increase supply:
Desalination: “Making” fresh water by removing salt from saltwater.
Expensive, requires a lot of energy, produces concentrated salty waste
Reverse osmosis: Forcing saltwater through artificial membranes to filter out salt
Desalination

24. Solutions to Freshwater Depletion
Decrease demand:
Agricultural:
Drip-irrigation
reduces water loss due to evaporation and runoff
Can cut agricultural water use in half
climate-appropriate plants
Industrial: Water-conserving processes, recycling wastewater to cool machinery.
Personal:
Xeriscaping – Reduce outdoor water consumption by choosing outdoor plants adapted for arid conditions
Water conservation – low flow toilets, faucets, showerheads, appliances

25. Lesson 14.3 Water Pollution
3,800 children die every day from diseases associated with unsafe drinking water.

26. Objectives Discuss the main categories of water pollution
Explain why groundwater pollution is difficult to clean up
Discuss the sources and effects of major pollutants found in the ocean
Describe how water is regulated and treated

27. Types of Water Pollution
Lesson 14.3 Water Pollution
Types of Water Pollution
Point-source pollution: From a discrete location, like a factory or sewer pipe
Nonpoint-source pollution: From many places spread over a large area, such as when snowmelt runoff picks up pollutants along its path
Point source oil pollution Oil after a spill, Trinity Bay, Texas

28. Lesson 14.3 Water Pollution
Nutrient Pollution
Excess phosphorous and other nutrients in the water is nutrient pollution.
Eutrophication occurs naturally, over a long period of time, sometimes centuries
Eutrophic in Greek means “good food”
Sped up by humans
THE PROCESS OF EUTROPHICATION
Nutrients build up in water.
Algae and aquatic plant growth increases.
Organisms die. Decomposition requires oxygen.
Dissolved oxygen levels decrease.

29. Nutrient Pollution Cultural/Artificial Eutrophication
Nutrient pollution by humans
Typically occurs from phosphorus-rich fertilizers and detergents in runoff or wastewater
Algal Bloom – sudden explosion of algae growth
Can be thick and cover water’s surface preventing sunlight from reaching plants below causing them to die

30. Toxic Chemical Pollution
Lesson 14.3 Water Pollution
Toxic Chemical Pollution
Occurs when harmful chemicals are released into waterways
Can be organic or inorganic
Organic – petroleum, petroleum based products, fertilizers, detergents
Inorganic – mercury, arsenic, lead
Harms ecosystems and causes human health problems

31. Sediment Pollution Sediment pollution:
Lesson 14.3 Water Pollution
Sediment Pollution
Sediment pollution:
Unusually large amounts of sediment that change an aquatic environment
Results from erosion.
Large-scale land clearing, mining, clear-cutting, clearing land to build houses, careless farming practices
Can degrade water quality, cause photosynthesis rates to decline as water clouds up, and disrupt food webs

32. Thermal Pollution
A heat source that raises the temperature of a waterway
Water used for cooling industrial processes and power plants
Removal of trees or plants that provide shade
Heated water holds less oxygen.

33. Lesson 14.3 Water Pollution
Biological Pollution
Biological pollution occurs when pathogens (disease causing organisms and viruses) enter a waterway.
Can be caused by human and animal waster
Biological pollution causes more human health problems than any other form of water pollution.
Water treatment reduces biological pollution.
Cholera bacteria
Did You Know? Giardiasis is the most common form of waterborne disease in the U.S.

34. Groundwater Pollution
Lesson 14.3 Water Pollution
Groundwater Pollution
Sources of groundwater pollution include
natural sources
Aluminum, flouride, nitrates, sulfates occur naturally in groundwater but are toxic at high concentrations
surface pollutants leaching through soil
Chemicals in fertilizers, pesticides
leaky underground structures.
Wells, leaky storage tanks, sewage, gasoline
Did You Know? The EPA repairs and replaces leaky underground gas storage tanks to reduce groundwater pollution. Over the last 25 years, over 1.7 million tanks have been repaired or replaced.
Acid drainage from a coal mine

35. Groundwater Pollution
Chemicals break down more slowly in groundwater than in surface water.
Groundwater contains less dissolved oxygen, microbes, minerals, and organic matter so decomposition is slow
DDT banned in 1972 still found widely in U.S. aquifers
Alachlor (herbicide) declines by 50% after 20 days in soil; in groundwater, the same decline takes 4 years
Most efforts to reduce groundwater pollution focus on prevention.

36. Lesson 14.3 Water Pollution
Ocean Water Pollution
Common practice to dump trash and sewage into ocean
Oil pollution in the ocean comes from many widely spread small sources; not large tanker spills.
Leakage from boats
Runoff from human activities
Natural seeps
Naturally occurring deposits on the sea floor
Largest single source (46%)
A 2004 oil spill off the Alaskan coast
Did You Know? According to the U.S. Oil Pollution Act of 1990, by 2015, all oil tankers in U.S. waters must have double hulls to help prevent against leaks.

37. Mercury and Nutrient Pollution
Ocean organisms bioaccumulate mercury pollution.
Swordfish, shark, albacore tuna
Mercury causes neurological damage especially in fetuses, babies, and children
Nutrient pollution can cause red tides.
Algae produces red pigments
Caused by excess nitrogen
Closes beaches, stops fishing

38. Controlling Water Pollution
Lesson 14.3 Water Pollution
Controlling Water Pollution
Legislation, technology, & citizen action all help decrease water pollution.
The Clean Water Act
Set water pollution standards
Required permits to release point-source pollution
Funded sewage treatment plant construction
Lake Erie
Did You Know? The Great Lakes show that humans can change their ways and clean up trouble spots. In the 1970s, Lake Erie was declared “dead” but is now home to some flourishing species, especially the walleye.

39. Lesson 14.3 Water Pollution
Water Treatment
Drinking water is treated to remove pollutants before humans consume it.
Wastewater is treated to remove pollutants before human-used water is released back to the environment.
Septic systems are the most popular method of wastewater disposal in rural areas of the U.S.