1. Bellringer 1. 1. Write the expression shown below, and explain what it means: “We all live downstream.” 2. 2. List all the ways you use water in a typical day. 3. 3. List ways you could conserve water without severely altering your lifestyle. 4. 4. Name some reasons people would experience a water "shortage".

2. Water Use and Management Section 11.2 Objectives: 1. 1. Identify sources of local drinking water. 2. 2. Explain how water is treated. 3. 3. Identify principal uses of water. 4. 4. Describe water conservation methods.

3. Global Water Use 3 major uses for water: 1. 1. Residential use 2. 2. Agricultural use 3. 3. Industrial use Which way(s) do you use water? Would different countries use water differently?

4. Global Water Use (cont.) (Fig.5, p.277)

5. 1. Residential Water Use In the U.S., each person uses about 300 L (80 gal) a day; in India, 41 L a day. How do you think we use it? Table 1, p.277

6. 1. Residential Water Use (cont.) Water treatment Potable: safe to drink Removes poisons and pathogens: organisms that cause disease or illness Drinking-water treatment steps (p.276) 1. 1. Filtration – removes trash and large organisms 2. 2. Coagulation – Alum forms sticky globs that stick to bacteria 3. 3. 2 nd filtration 4. 4. Chlorination – prevents growth of bacteria 5. 5. Aeration – Air forced in to remove unwanted gases 6. 6. Additives – fluoride, water softeners

7. 2. Industrial Water Use 19% of water used worldwide Most is used to cool power plants. Pull water from surface sources, run it through pipes in a cooling tower, and pump it back to its source. How would this cool the power plant? How would this affect the temperature of the water in the pipes? How would this affect the surface water source?

8. 3. Agricultural Water Use 67% of water used worldwide! Irrigation: providing plants with water 1. 1. Shallow ditches 2. 2. Overhead sprinklers – most lost to evaporation

9. Water Management Projects Water diversion projects – diverting water to areas that need it (EX: canals) Dams and Reservoirs Dams: structures built across rivers to control water flow Reservoirs: artificial lakes formed behind dams

10. Water Management Projects, continued….. What would be some advantages to building dams and reservoirs? Pros: Water can be used for drinking water, irrigation, electrical energy, flood control, recreation What would be some disadvantages to building dams and reservoirs? Cons: floods upstream, lack of sediments downstream (less fertile land), dam failure

11. Water Conservation Why conserve water? In agriculture Most loss is due to evaporation, runoff, and seepage Drip irrigation systems deliver small amounts of water directly to the roots through perforated tubes (Think soaker hose)

12. Water Conservation (cont.) In industry - recycling cooling water and wastewater At home Can one person make a difference? Table 2, p.282

13. Other Solutions 1. 1. Desalination: the process of removing salt from salt water 2. 2. Transporting fresh water 1. 1. In Greece, ships tow large plastic bags full of fresh water to the islands. 2. 2. U.S. is considering towing fresh water from Alaska to California. 3. 3. Why would AK have extra and CA not have enough? 4. 4. Towing icebergs to other locations has long been considered, but not figured out. (What problems would there be?)