2. Conversano, Wheres the Water? March, 2013 2 The Truth about Fresh Water Scarcity

3. Conversano, Wheres the Water? March, 2013 3 What is a Water Crisis? Definition: the available fresh water within a region is less than that regions demand –Causes may include Increased population growth Lower-than-usual annual rainfall Contamination of local water supplies –Effects may include Government regulation on water usage Increased water costs Increased food costs

4. Conversano, Wheres the Water? March, 2013 4 Water Crisis in Los Angeles Los Angeles Water Supply is NOT Sustainable –Most fresh water is imported from 100+ miles away Sierra Nevada mountains Major rivers and deltas –Less than 50% of LA water is from local sources This can be increased in times of drought for short periods of time

5. Conversano, Wheres the Water? March, 2013 5 Where Does LAs Water Come From? Los Angeles San Joaquin Delta 370 miles Colorado River 280 miles Owens River 210 miles Top 3 Sources of LA Water

6. Conversano, Wheres the Water? March, 2013 6 The Proposed Solution Reduce Use of Non-Local Water –Use local reservoir reserves Reduce imported water –Increase use of groundwater (water below Earths surface) 30% of LA water comes from groundwater (60% in a drought) Groundwater (LA Source) Reservoirs (LA Source) Mountain Spring (Imported Source)

7. Conversano, Wheres the Water? March, 2013 7 Natural Water Requires Purification Passive Filtering and Purification –Gravity pulls water through filter Each filter stage traps different types of particles and microbes Has difficulty separating extremely small particles (i.e. dissolved solutions) Active Filtering and Purification –Pumps force water through filter Pressurized water can be forced through smaller filter holes Able to capture dissolved particles High energy requirements = EXPENSIVE

8. Conversano, Wheres the Water? March, 2013 8 Water Filtration Activity You will now… –Build a water filtration tower with 4 filter stages Gravel –Traps large particles in gaps between gravel pieces Sand –Traps smaller solid particles in gaps between grains Active carbon –Traps / absorbs substances inside small holes in surface »FUN FACT: 1 gram of active carbon has more surface area than a basketball court Filter paper –Very small holes strain out the smallest contaminants –Filter different types of dirty / contaminated water –Analyze the effectiveness of the water filter tower –Use what you learn to solve the LA Water Crisis