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Water Issues

Water Issues. Where is the Water? Hydrologic Cycle Water Quality and Pollution Dams, Irrigation, and River Regulation Invasive Species. Hydrologic Cycle. Evapotranspiration Surface Water: streams, lakes Soil Water: used by plants Ground water: depends on soil porosity

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Water Issues

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  1. Water Issues • Where is the Water? • Hydrologic Cycle • Water Quality and Pollution • Dams, Irrigation, and River Regulation • Invasive Species

  2. Hydrologic Cycle • Evapotranspiration • Surface Water: streams, lakes • Soil Water: used by plants • Ground water: depends on soil porosity • Springs and wells: artesian and subartesian

  3. Water Under Foot

  4. POLLUTANTS IN WATER:toxins(cause damage to human body, often kidneys or liver, or cause disease or cancer) • Natural: selenium, arsenic (Bangladesh), others • Anthropogenic (human-caused): Point Source: • Industry: • heavy metals such as mercury, cadmium, chromium, lead, others (metal smelters, steel plants, dumping of sewage sludge) • thalium, mercury, selenium, arsenic ( coal burning power plants) - harms infants and pregnant women, others • Petroleum spills from ships (e.g., Exxon Valdez, 1984) and wells (e.g., Santa Barbara Channel, 1969 and Gulf of Mexico, 2010) • Agriculture: • animal waste encourages toxic bacteria growth (e. coli and others), fertilizer causes excess nitrogen and phospate/eutrophication, dioxins (from herbicides), hormones, antibiotics, DDT • Sewage: leaks, overflows - E. Coli infections result

  5. Water Quality • Non-point source: • Urban Storm Run-Off : • Oil Changes, Anti-Freeze, Detergents, Lawn Fertilizers, and plastics become lodged in river and marsh sediments, endangering wildlife and plants. Eutrophication

  6. 40% of U.S. rivers, lakes, and streams are not fit for swimming, fishing, or drinking. Source: U.S. Environmental Protection Agency. 1994. Nonpoint Source Pollution: The Nation's Largest Water Quality Problem. Data from National Water Quality Inventory. http://water.epa.gov 

  7. 80% of China’s rivers are unfit for human contact. Aquatic life in these rivers is in decline. Dongxiang, China  Source: State Environmental Protection Administration (SEPA), 2002. Report on the State of the Environment in China 2002. Environmental Information Centre (SEPA), Beijing.

  8. Radioactive Dumping Sites

  9. Plastic Trashin Pacific Ocean Gyre • Click Map for PBS NewsHour Video

  10. Gulf of Mexico Oil Spill, 2010

  11. Dams and Global River Degradation Shasta Dam, CA AswanDam, Egypt Lake Nasser

  12. The Geography of Large Dams • Over 39,000 large dams by 1986

  13. The Impact of Dams • Northern third of the world: 77% overall impacted by dams and river regulation. (Dynesius and Nilsson, 1994) • Industrialized countries - more impact! • USA: 98% (Escheverria et. al., 1989)

  14. Upstream Impact of Dams • Loss of terrestrial/riparian habitat and species • Creation of artificial lacustrine (lakes) system • exotic species introductions (see next slide) • Reservoir/storage concentrates contaminants

  15. Huge Catfish in Lake Powell

  16. Upstream Impact of Dams • Cultural / social • Loss of cultural resources • Displacement of families (villages, regions) • Water quality hazard • Economic • Shift in land use / economy • Water loss via evaporation • Water loss via seepage • Aesthetic • landscape inundated

  17. Upstream Impact of Dams • Built 1956-1966. • Aesthetics: Glen Canyon, Colorado River

  18. DownstreamImpacts of Dams • Altered hydrology - no seasonality • Altered water quality/character • Modify nutrient cycling • Reduce sediment supply • Channel adjustments • Habitat modification • Species impacts • River fragmentation

  19. Flow of the Colorado River

  20. The ‘Damned’ Balance • Some dam removal (small dams) or operational changes (larger dams) • Bruce Babbitt (Secretary of the Interior) oversaw the creative destruction of two California dams in 2000 (Saelzer Dam on Clear Creek near Redding, for Salmon, and Matilija Dam in SoCal). • By 2010, 500 had been destroyed in U.S.! • Dams continue to be built until good sites are gone or it is not economic to build them. • Global numbers? We do not know.

  21. Three Gorges Dam • World's largest hydroelectric dam, Three Gorges, on Yangtze River. • 1.24 million were relocated. • Power creation roughly equal to 18 nuclear plants. • The entire project was completed in 2008. • Contributed to extinction of Baiji, blind Yangtze River dolphin.

  22. California’s Water System • California’s Water Projects • Los Angeles Aqueduct • Salton Sea • Colorado Aqueduct • Mono Lake Decisions

  23. California Hydrography

  24. Native Water Issues Distribution of surface water: 70% is in 20% of state, mostly in north. Population is mainly in south and central. Sacramento River System: 1/4 of total flow - 1/3 of this water is from the northwestern tributaries. Only 1/10 from San Joaquin. Seasonal Variation: Dry summer: water arrives when farmers least need it. Irrigation and storage are necessities. Winter flooding: In 1840’s the only way to get to Sacramento from the west was by skiff, not horse. Seasonal floods and native streams provide habitat for spawning fish, including steelhead trout and salmon. Threatened by damns and water control.

  25. California Aqueducts

  26. California Dams and Reservoirs

  27. Los Angeles Aqueduct (DWP)Eastern Sierra • Started in 1908 by William Mulholland • appropriated water feeding Owens Valley • taps surface flow from Eastern Sierra south • 250 miles, cost $25,000,000 and took five years • pipe and flume, tunnel, and trench • gravity feed, no pumping • generates hydroelectric power • L.A. purchased riparian land, used appropriation rights to get away with this. Ranchers in Owens Valley fought back with dynamite and guns - California’s only range war.

  28. Mono Lake • In 1941, L.A. DWP started diverting Mono Basin streams to add to L.A. Aqueduct. • Mono Lake’s volume halved while salinity doubled. The simple ecosystem began to fail and threatened migrating birds and nesting gulls. • The State of California and courts now mandate raising the level of the lake 17 feet. It will take about 20 years.

  29. The Salton Sea • Man-made by accident in 1905. • Unusually heavy spring runoff and lack of control gates caused a two-year flood into the Salton Sink. • Hoover Dam now controls Colorado and prevents delivery of sediment to Yuma and the delta.

  30. Flow of the Colorado River

  31. Colorado River Delta, Mexico

  32. The Aral Sea • Once the 4th largest lake on earth. • Water diverted for Soviet Union cotton irrigation upstream on the Amu Darya and Syr Darya Rivers.

  33. The Aral Sea

  34. The Aral Sea

  35. A very similar problem is now occuring at Lake Orumieh in Iran.

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