1. Best Dam Lecture Ever!!

2. US has 75,000 Large Dams (25 ft or higher)
China = 80,000 Dams

3. Colorado River Dams Hoover Dam
Used to provide energy and water to So. Calif and Vegas.
Reservoir: lake formed behind dam.
Lake Mead
Hoover Dam

4. Hoover Dam

5. 3 Gorges Dam Largest Dam, 1 mi. long on Yangtze River
Helps switch from coal  hydroelectricity.
Dislocation of 1 mill. peeps, burial of artifacts, loss of fertile soil on floodplains.
1` 32en

7. Aswan Dam, Nile River: Creates Lake Nasser

8. How this Dam Water Works
Water released from behind reservoir
Enters Dam
Water spins a turbine machine in dam
Turbine gens. hydroelectricity
Electricity delivered 2 cities via power lines.
Glen Canyon Dam

10. Dam Pros Supply water year round Electrical Power
Recreation benefits; boating & fishing
No air pollution
Water used for agriculture
Inexpensive electricity
Long economic life

11. Dam Cons Expensive to build, loss of human lives
Sediments don’t flow downstream  loss of nutrients
Evaporation of fresh water behind dam  increases salinity
Fish can’t travel upstream.

12. Dam failure  flood

13. Increased risk of disease  stagnant water (Mosquitoes and malaria)

14. Case Study: Steelhead/ Rainbow Trout
Born in freshwater rivers (rainbow)
Swim out to ocean (steelhead)
Return to same river (travel upstream) to have their babies.
If dam is in place, cannot return to have babies  die

15. Case Study: Columbia River
Story about fish…
Fixing problem

16. Fish Ladder
Series of steps the fish hop over to travel upstream (get over dam).

17. Water Diversion Diverts or directs water to places in need.
(Irrigation, Drinking Water)
Exs: LA and Colorado Aqueducts

18. Sharing Water Resources
3/4 of the worlds major river basins are shared b/t at least 2 nations
International cooperation!!

19. Water Diversion Disaster
Aral Sea: In Glorious Nation of Kazakhstan
Rivers to inland sea have been diverted for irrigation

20. Case Study: Aral Sea
Evaporation has increased salinity, no fish species exist
Salt is blown to surrounding area health problems and decreasing crop production

21. Aral Sea-Was the 4th largest freshwater lake
1989
2003

22. And Now, 2009

24. Water Conservation

25. Irrigation
Farmers must heavily irrigate-water crops- so plants can grow and to remove salt
Efficient irrigation systems exist to lessen water: use of lasers, central pivot watering systems, timers.
Central Pivot System

26. Agriculture H2O Conservation
Water crops at night (less evaporation)
Breed/select crops that are drought tolerant
Cover surface with mulch

27. Reducing City Water Use
Use Reclaimed Water: Treated Sewage Water: irrigate crops/water parks
City Conservation Efforts: Consumer ed. (If it’s yellow, be mellow; if it’s brown, flush it down)

28. Conserving Water at Home
Install low flow shower heads
Install low flush toilets
Use dishwasher rather than by hand
Take shorter showers (once a day, 10 mins/less)

30. Personal Fix leaks Don’t use water to clean sidewalks
Reduce amount of grass