CSULA - Geology 357: Water

Topic #6 - Water
Geol 357: Urban Geology

I. Hydrologic Cycle

A. Water Basics
- 1. Sea water - 97.2%
- 2. Fresh Water - 2.8%
  - a. Polar ice & glaciers - 2.15%
  - b. Groundwater - 0.62%
  - c. Lakes and Rivers - 0.01%
    Show Rainfall Charts
B. The Three Fates of Precipitation
- 1. Infiltration
  - a. The movement of water into rocks or soil through cracks and pore spaces
- 2. Runoff
  - a. Water that flows over the land
- 3. Transpiration/Evapotranspiration
  - a. The release of water vapor to the atmosphere by plants
    Show Hydrologic cycle chart
C. Running water is the single most important agent sculpturing Earth's land surface
- 1. Begins as sheetflow
- 2. Sheetflow develops into tiny channels called rills
D. Infiltration capacity of the soil is controlled by:
- 1. Intensity and duration of rainfall
- 2. Soil saturation
- 3. Soil texture
- 4. Slope of the land
- 5. Nature of the vegetative cover

II. Principles Of Groundwater

A. Introduction
- 1. Water found in the pores and fractures of soil and bedrock
- 2. Largest reservoir of fresh water
- 3. Tends to be less polluted than surface water
B. An important erosional agent
- 1. Groundwater is often mildly acidic
- 2. Contains weak carbonic acid
- 3. Forms caverns at or just below the zone of saturation
- 4. Karst topography on the surface
C. Equalizer of streamflow
- 1. Most water percolates down into the Earth
- 2. Forms underground "streams"
D. Terms
- 1. Porosity - Percentage of void space in a rock/soil
- 2. Permeability - The ability of a material to transmit a fluid
- 3. Specific retention - The portion whish is retained as a film on particles, rock surfaces, and pore spaces
- 4. Specific yield - The portion which will drain under gravity
  - a. In general, Porosity = Specific retention + Specific yield
- 5. Aquifer
  - a. A zone of Earth material capable of supplying groundwater at a useful rate from a well
  - b. Mostly sands and gravels deposited in stream channels in California
- 6. Aquitard
  - a. A zone of Earth material that holds water but cannot transmit it fast enough to pump from a well
  - b. Usually forms a confining layer
E. Groundwater basins (http://www.waterplan.water.ca.gov/groundwater/gwdefinition.htm)
- 1. "an area underlain by permeable materials capable of furnishing a significant supply of groundwater to wells or storing a significant amount of water"
- 2. Groundwater basin boundaries (http://www.waterplan.water.ca.gov/groundwater/gwdefinition.htm)
  - a. Impermeable Bedrock - Impermeable bedrock consist of rocks of low water yielding capacity. These include rocks of marine origin and crystalline/or metamorphic rock.
  - b. Constrictions in Permeable Materials - A narrow gap in impermeable material, even though filled with permeable stream channel materials, generally forms a basin boundary due to groundwater flow constriction in these areas.
  - c. Fault - A fault that crosses permeable materials generally forms a barrier to groundwater movement. This is usually indicated by noticeable difference in water levels and/or flow patterns on either side of the fault.
  - d. Low Permeability Zone - Areas of clay or other fine-grained material that have significant aerial or vertical extent generally forms a barrier to groundwater movement.
  - e. Groundwater Divide - A groundwater divide generally forms a barrier to groundwater movement. Groundwater divides have noticeably divergent groundwater flow directions on either side of the divide with the water table sloping away from the divide.
  - f. Adjudicated Basin Boundaries - The basin boundaries established by court order were used for all adjudicated basins.
F. Movement of Groundwater
- 1. Very slow - centimeters/day
- 2. Measuring groundwater flow
  - a. Primarily done with dyes & Carbon-14
- 3. Pollution implications
G. Getting Groundwater Out of the Ground
- 1. Extraction Methods
  - a. "Natural" Methods
    - (1) Springs
      - (a) Occur where the water table intersects Earth's surface
    - (2) Hot Springs
      - (a) The water for most hot springs is heated by cooling of igneous rock
    - (3) Geysers
      - (a) Intermittent hot springs
  - b. Man-made Methods
    - (1) Wells
H. Artesian well/spring
- 1. A situation in which groundwater under pressure rises above the level of the aquifer
- 2. Types of artesian wells
  - a. Nonflowing - pressure surface is below ground level
  - b. Flowing - pressure surface is above the ground
I. Problems with groundwater removal

1. Non-renewable resource
2. Subsidence
3. Contamination

III. Groundwater In Southern California

A. Geological Setting
- 1. S. California is broken into fault blocks of different elevation
- 2. Sediment deposited on the lower blocks forms the aquifers
B. Coastal Plain
- 1. These areas are formed by alluvial deposits of the LA, San Gabriel, and Santa Ana Rivers
  - a. These rivers start in the mountains, flow across the inland valleys, through the narrows and onto the coastal plain
- 2. Unconfined aquifers lie just beyond the narrows
  - a. Confined aquifers along the coast
C. Inland Valleys
- 1. Water here drains in the subsurface through the narrows to the coastal plain
- 2. San Fernando Valley
  - a. Has extensively used groundwater for agriculture and domestic needs
    - (1) Now polluted with TCE - a Superfund site
  - b. Has also used Owens Valley water since 1915
- 3. San Gabriel Valley
  - a. Groundwater is heavily used
  - b. Basin has the storage capacity of 10 million acre feet
    - (1) Entire State Water Project stores 6.84 million acre feet
  - c. The San Gabriel Basin is polluted with cancer causing chemicals
    - (1) trichloroethylene (TCE) - first found in Irwindale in 1979
    - (2) perchloroethylene (PCE)
    - (3) carbon tetrachloride (CTC)
  - d. San Gabriel Valley became a Superfund site in 1985
    - (1) Clean up progress has been slow
    - (2) Cost is estimated at $800 million (1990)
  - e. More than 1 million people rely on the San Gabriel aquifer for drinking water.
    - (1) As pollution spreads, pressure on other water sources will intensify.
    - (2) Economic impact could be staggering

IV. Sea Water Intrusion

A. Introduction
- 1. This is a worldwide problem
  - a. First recognized here at Redondo Beach in 1912
- 2. LA County Department of Public Works is responsible for prevention
B. The Barrier Projects
- 1. Explain how a barrier works
  - a. In the 1950’s, construction began on the first of three “barriers” in an attempt to halt saltwater intrusion. Each barrier consists of a series of injection wells that essentially form a subsurface wall of freshwater designed to keep saltwater from penetrating further into aquifers. The barriers are only partly effective; saltwater continues to infiltrate in some areas.
- 2. West Coast Basin Barrier Project - 142 injection wells
  - a. 10 miles from El Segundo to Palos Verdes
- 3. Dominguez Gap Barrier
  - a. 6 miles from San Pedro to Long Beach
- 4. Alamitos Barrier Project
  - a. 7 miles from Long Beach to Seal Beach

V. Methods Of Augmenting Local Water Supplies

A. Water Importation by Aqueducts
B. Water Reclamation
- 1. LA County reclaims 200 million gallons per day
C. Desalination
- 1. This is already underway in Catalina and Santa Barbara
D. Icebergs

VI. History Of Aqueducts In California

A. Owens Valley Aqueduct
- 1. Concept resulted from the drought of 1892-1904 which threatened the growth of LA
- 2. Aqueduct was conceived by Mayor Fred Eaton and William Mulholland
  - a. Mulholland - engineer and superintendent of L.A. Water Department
  - b. Eaton - Former
- 3. US Reclamation Service interested in area for irrigation purposes
  - a. J.B. Lippincott, supervising engineer for the Reclamation Service, made sure that only public land was set aside for future development
- 4. 1904 - LA agents secretly buy options on land with water rights
  - a. Residents thought the land Eaton was purchasing was for the irrigation project
  - b. Result = they got no water for development / irrigation
- 5. 1905 - Preliminary bond measure approved
  - a. 100,000 people of LA approved a bond issue for $1.5 million in 1905
- 6. 1906 - Congress grants aqueduct right of way over federal land with strong backing from President Theodore Roosevelt
- 7. 1907 - Full bond measure for $25M approved
- 8. 1913 - Construction of aqueduct completed
  - a. Initially 233 miles long
    - (1) System was extended to the Mono Basin by 1940 - 338 miles long
  - b. Supplies 450,000 acre-feet/yr average over 20 years
    - (1) Equals 60 to 80% of LA's needs
    - (2) A future environmental reduction to 380,000 acre-ft is planned
    - (3) Supplies San Fernando Valley and the western part of the city
- 9. 1915 - San Fernando Valley annexed into LA
- 10. 1924 - Owens Lake and ~50 miles of the Owens River are dry
- 11. 1930 - 95% of Owens Valley farmland owned by Los Angeles; $40M bond issue approved to expand aqueduct into Mono Basin
- 12. 1940 - Extension completed, diversions begun
- 13. 1963 - plans for a second aqueduct approved
- 14. 1970 - DWP plans to fill new aqueduct by:
  - a. Reducing irrigation water
  - b. Diverting surface water from Inyo and Mono counties
  - c. Pumping groundwater
- 15. 1972
  - a. Inyo county successfully sued to stop groundwater pumping increase
  - b. Wetland meadows, seeps, springs, and marshes dried and disappeared, well water levels dropped, and vegetation in the valley began to change.
- 16. Opposition to the aqueduct
  - a. Began in Owens Valley with the first land acquisitions in 1905
  - b. Still controversial today
B. Colorado River Aqueduct
- 1. Droughts from the mid-1920's to early 1930's resulted in 500,000 people of LA approving a $220 million bond issue in 1931 for a new aqueduct
- 2. The MWD (128 cities, 12 million people) built the Colorado River Aqueduct
  - a. Extends 242 miles from Lake Havasu behind Parker Dam
    - (1) 4 pumping stations
  - b. Supplied 1.2 million acre-ft/year to S. California for many years
    - (1) Now reduced to 550,000 acre-ft/year
  - c. Supplies 6% of LA's needs
  - d. Supplies East LA, the Harbor & part of the central city
C. California Aqueduct
- 1. 2.5 million people of LA approved a $1.75 billion water project
  - a. Supplies the Great Valley and large parts of Southern California
- 2. Aqueduct stretches 444 miles from Oroville Dam
  - a. 257' wide and 36' deep in its northern parts
  - b. Pumps in the Tehachapi Mtns use 650MW
- 3. Deliveries began in 1971
  - a. Supplies a small amount to northern parts of the city
D. Future Aqueducts are unlikely
- 1. Belief that more water means more people and more pollution
  - a. Opposition arose to all new water sources - Columbia River, desalination, cloud seeding, water reclamation, etc
- 2. Water rationing first occurred in LA on July 1, 1977

VII. Who Does What With Water

A. Federal Level
- 1. USGS - measures water resources
- 2. EPA
  - a. Pollution control and enforcement
B. State Level
- 1. Department of Water Resources
C. County Level
- 1. Department of Public Works
- 2. County Sanitation Districts
D. City Level
- 1. LA Department of Water and Power
- 2. Metropolitan Water Districts - 128 cities
- 3. Local water companies
- 4. Local sewage companies

VIII. The Use Of Water

A. Agriculture - by far the greatest user
- 1. Uses 83% of state water
- 2. Great waste here
B. Residential 14.5% of state water
- 1. Some examples of water use at home
  - a. Full bathtub - 36 gallons
  - b. Shower - 25 gallons per 4 minutes
  - c. Wash dishes - 30 gallons
  - d. Flush toilet - 7 gallons
  - e. Sprinkle lawn - 10 gal/minute, usually 1500 gallons
  - f. Brushing teeth with water running - 10 - 40 gallons
C. Fish and Wildlife
- 1. 2% of state water
D. Power Plant Cooling
- 1. 0.1% of state water

IX. Water Quality - Nation Wide

A. Legislation and Enforcement
- 1. Major Legislation - Federal
  - a. Federal Water Pollution Control Act (Clean Water Act) of 1948
    - (1) "…comprehensive programs for eliminating or reducing the pollution of interstate waters and tributaries and improving the sanitary condition of surface and underground waters…conserve waters for public water supplies, propagation of fish and aquatic life, recreational purposes, and agricultural and industrial uses" (http://laws.fws.gov/lawsdigest/fwatrpo.html)
  - b. Water Quality Improvement Act of 1970
    - (1) "…amended the prohibitions on discharges of oil to allow such discharges only when consistent with regulations to be issued by the President and where permitted by Article IV of the 1954 International Convention for the Prevention of Pollution of the Sea by Oil (33 U.S.C. 1321). In issuing regulations, the President was authorized to determine quantities of oil which would be harmful to the public health or welfare of the U.S., including, but not limited to, fish, shellfish, and wildlife, as well as public and private property, shorelines and beaches." (http://laws.fws.gov/lawsdigest/fwatrpo.html)
  - c. Water Pollution Control Act 1972
    - (1) "…stipulated broad national objectives to restore and maintain the chemical, physical, and biological integrity of the Nation's waters." (http://laws.fws.gov/lawsdigest/fwatrpo.html)
  - d. Toxic Substance Control Act 1976
  - e. Clean Water Act 1977 (http://laws.fws.gov/lawsdigest/fwatrpo.html)
  - f. Clean Air Act of 1990
    - (1) This will greatly help reduce acid rain
    - (2) "The primary objective of the Clean Air Act is to establish Federal standards for various pollutants from both stationary and mobile sources and to provide for the regulation of polluting emissions via state implementation plans. In addition, the amendments are designed to prevent significant deterioration in certain areas where air quality exceeds national standards, and to provide for improved air quality in areas which do not meet Federal standards ("nonattainment" areas)." (http://laws.fws.gov/lawsdigest/clenair.html)
- 2. EPA requires that states establish and enforce water quality standards
  - a. Standards in California are established by the State Dept of Water Resources
B. Acid Rain
- 1. Acid rain has become an international problem
  - a. US - Canada
  - b. England - Norway
- 2. Acid rain appears to be killing lakes, streams, forests, and people
  - a. Acid rain may kill 50,000 people per year in the US (LA Times - 1/1982)
- 3. Acid rain is caused by:
  - a. CO₂ from cars and power plants
  - b. NO_x from cars
  - c. SO₂ from power plants

I. Hydrologic Cycle

II. Principles Of Groundwater

III. Groundwater In Southern California

IV. Sea Water Intrusion

V. Methods Of Augmenting Local Water Supplies

VI. History Of Aqueducts In California

VII. Who Does What With Water

VIII. The Use Of Water

IX. Water Quality - Nation Wide

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