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California Water Issues

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California Water Issues AGST 3000 Agriculture, Society and the Natural World Whiskey s for drinkin and water s for fighting for . Mark Twain – PowerPoint PPT presentation

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Title: California Water Issues


1
California Water Issues
  • AGST 3000
  • Agriculture, Society and the Natural World
  • Whiskeys for drinkin and waters for fighting
    for.
  • Mark Twain

2
Californias Major Water Users
  • Agriculture irrigated farm land, a huge
    economic engine for the state.
  • Environment fish and other wild life have
    specific water requirements.
  • Families human factor, showers, dishes,
    swimming pools and golf courses.
  • Manufacturing processing, cooling produce jobs
    for the state which generate a tax base.

3
Water Terminology
  • Acre-foot
  • An acre-foot equals the amount of water needed
    to cover an acre of land to the depth of one foot
    (326,000 gallons) and is approximately the amount
    of water used by an average family of four during
    one year.
  • Overdraft
  • The deficit between pumped water from a
    groundwater basin and the long-term recharge.

4
Californias Tug of Water
  • Geologic Tugs
  • Geologic Tug 1 The North 75 25 South
    precipitation distribution circumstance
  • Geologic Tug 2 The Coast Range and Sierra
    Nevada Mountains rain shadow effects
  • Geologic Tug 3 The Drought/Flood cycles El
    Nino and La Nina
  • Geologic Tug 4 Calif. is the number 1 ground
    water using state, but has little regulation

5
Californias Tug of Water
  • Water Use Tugs
  • Water Use Tug 1 80 of water demand occurs
    south of Sacramento North versus South
  • Water Use Tug 2 There is also an East versus
    West use conflict
  • Water Use Tug 3 Water demand is highest in the
    summer when availability is lowest
  • Water Use Tug 4 Environmental water use
    conflicts with agriculture, urban need.
  • Water Use Tug 5 Agriculture versus Urban use
    who gets how much and when, etc.?
  • Water Use Tug 6 What are the water rights for
    various interest groups in the future?

6
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7
  • Figure 1. Freshwater Consumption as a Percentage
    of Local Average Annual Precipitation. (Source
    USDA-NRCS, 2001)

8
Californias Water Supply
  • Californias ground water
  • Californias groundwater basins store about 850
    million acre-feet of water. (Less than 50 is
    unavailable for use due to depth of water table.)
  • For long term sustainability, groundwater cannot
    be removed that will not be replenished.
  • 15 million acre-feet of groundwater is pumped
    each year.
  • 20 of the states water requirements are met
    with pumped groundwater.
  • CA is operating on a 1.3 million acre-foot
    overdraft.
  • CA groundwater is recharged by
  • 1) Nature rain snow (7 million acre-foot
    annually)
  • 2) After usage agriculture industry (6.65
    million acre-feet /yr.)
  • 3) Recharge programs Los Angeles municipal water

9
Californias surface water
  • Comes from an average annual statewide
    precipitation of almost 24 inches. (Ranging from
    almost nothing in the deserts to more than 100
    inches in the northern mountains)
  • Sixty percent of the precipitation is evaporated
    or transpired by trees and vegetation.
  • The remaining forty percent equals about 71
    million acre-feet of stream flow (in an average
    rainfall year).
  • Colorado River flows diverted to California
    supply 4.8 million acre-feet.

10
Californias surface water continued
  • Inflow streams from Oregon add an addition 1.4
    million acre-feet.
  • This means in an average year California has
    available slightly more than 78 million acre-feet
    of water.
  • However, not all of this water can be collected
    for use (almost 29 million acre-feet occurs in
    the north coast region alone and much of it is
    unavailable for use).

11
Agricultures Water Use
  • 80 of developed supply (reservoir storage,
    irrigation districts, state and federal water
    projects)
  • 28-35 million acre-feet depending on yearly
    rainfall
  • Irrigated acres 2002-8,709,353 1997-8,886,693
  • Irrigated acreage is declining due to urban
    growth and water cut backs by federal/state
    projects.
  • A large percentage of agriculture water
    percolates back into ground or streams (around 5
    million acre-feet contributes to re-charge)

12
Urban and Environmental Water Use
  • CA urban use is about 7.8 million acre-feet.
  • One acre of houses uses approximately the same
    amount of water as an acre of agriculture crops
    (what happens to this water?)
  • 26 million acre-feet is diverted to environmental
    uses during normal years less in drought years)
  • 9.56 million acre-feet for the Delta
  • 17.8 for wild and scenic river flows
  • This amount is expected to increase

13
Regional Water Use
  • Central Valley 19 million acre-feet
  • Sacramento River 11.7 million acre-feet
  • South Coast 4.6 million acre-feet
  • Colorado River 4 million acre-feet

14
Groundwater supply initially huge
  • Maybe as much as 750,000,000 acre feet
    accumulated over thousands of years
  • Efficient pumps developed around 1920
  • Irrigated acreage rapidly expanded several fold
  • Groundwater levels began to drop precipitously
  • subsidence ground is actually sinking.

15
IRRIGATION
  • A. Definition Supplying water to plants in an
    artificial manner. (39 of all freshwater in
    the US is used to irrigate crops)
  • 1. Ancient practice first irrigation used
    ditches to divert rivers and streams.
  • 2. California agriculture relies on
    irrigation.
  • a. Mediterranean climate
  • b. Crop diversification
  • c. Economics

16
Population Water Needs
  • According to U.S. Census Bureau figures,
    Californias population currently is 35.1
    million, and is projected to hit 49.3 million by
    2025.
  • 1998 California Water Plan update the state
    Department of Water Resources (DWR) forecast a
    gap between water supply and demand ranging from
    2.4 million acre-feet during normal years up to
    6.2 million acre-feet in drought years by 2020.
  • The next water plan is due in 2003

17
An acre-foot
  • An acre-foot of water is about 326,000 gallons
  • enough to cover an acre of land, about the size
    of a football field, 1 foot deep and
  • meet the average needs of between one and two
    residential households

18
Sources of Water
  • Rain and Snow replenishes the surface water and
    underground aquifers
  • Ground Water (aquifers)
  • Surface Water (rivers, lakes, reservoirs)

19
Sources of Surface Water
  • California, there are two major arteries serving
    as the sources of surface water for urban and
    agricultural areas
  • The Sacramento-San Joaquin Delta (Bay-Delta) and
  • The Colorado River

20
The Delta
  • Delta serves as a major water source for
    approximately two-thirds of the state over 22
    million people
  • The region is fed by two major rivers the
    Sacramento from the north and the San Joaquin
    from the south

21
The Delta
  • Mixture of fresh water from these two waterways
    and numerous tributaries combine with salty ocean
    water from San Francisco Bay to create the
    largest estuary on the West Coast of North
    America - The San Joaquin Delta.
  • Massive pumps at the southern end of this marsh
    pull approximately 5.5 million acre-feet annually
    of fresh water southward to Central Valley
    farmland via the Central Valley Project and
    ultimately, to the southern California region via
    the State Water Project.

22
Federal Central Valley Project
  • FDR and U.S. Reclamation Service looking for
    projects, took over CVP in 1935, began
    construction in 1937
  • Eventually completed in 1950s
  • Final cost more than 500 million
  • Distributes more than 3,000,000 acre feet of
    water
  • Almost all used for agriculture
  • No connections to Southern California initially

23
The Colorado River
  • Colorado River winds its way through the
    southwestern United States before terminating in
    the Gulf of California in Mexico.
  • Provides water to seven states including
    California, with each state's water use
    determined by the Colorado River Compact of 1922.
  • California permitted to use 4.4 million acre-feet
    annually.
  • For over a decade, California has been using well
    beyond the 1922 allotment.
  • As water conditions have tightened in several of
    the other states, the secretary of the Interior
    has demanded that California reduce its use of
    the Colorado River - a major challenge to river
    water users.

24
Basic Types of Irrigation
  • Flood Explain
  • used in almonds, peaches, walnuts, rice, alfalfa

25
  • Flood in the West, Border in the East

26
Flood Irrigation continued
  • Advantages
  • inexpensive
  • less labor
  • large amounts of water leach salts
  • rodent control

27
Flood Irrigation continued
  • Disadvantages
  • land must be leveled or contoured
  • uses large amounts of water
  • water loss through evaporation
  • may cause disease in some crops if applied
    incorrectly
  • run off water can cause problems (silt buildup in
    rivers, may contain pesticides)

28
Furrow Irrigation
  • Used in row crops such as beans, tomatoes, corn,
    sugar beets other vegetable crops.
  • Similar advantages and disadvantages to flood
    irrigation.

29
Furrow Irrigation
30
Sprinkler Irrigation
  • Many types micro-sprinklers, solid set, aluminum
    pipe
  • a. Advantages use less water, more precise
    amounts of water can be applied, less run off
    (tail water), may be used on slightly hilly land
  • b. Disadvantages expensive (installation,
    labor, filters, maintenance), salt buildup

31
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32
  • Better spray version of center pivot for water
    conservaton

33
Drip Irrigation
  • Used on specific crops, such as grapes, trees
    (such as almonds, cherries, peaches)
  • a. Advantages
  • uses less water
  • very precise amounts as well as fertilizer
  • b. Disadvantages
  • expensive to install, (labor, equipment,
    maintenance)

34
Drip Irrigation
35
Subsurface Irrigation
36
Questions on Irrigation
  • 1. Where does irrigation water come from?
  • a. Wells underground aquifers
  • b. River Riparian rights or water rights
  • c. Irrigation Districts provide water from
    large water sources, lakes, reservoirs (dams)

37
  • What are concerns people have over the use of
    irrigation in agriculture?
  • a. Overdraft of underground water supplies
    (aquifers).
  • b. Water pollution silt, herbicides,
    pesticides added to irrigation water runs off
    into lakes, rivers, etc.
  • c. Concerns over water waste flood irrigation
    uses a lot of water
  • d. Production of crops in California that are
    not water efficient alfalfa and cotton.

38
  • How has agriculture addressed the publics
    concerns over water usage?
  • a. The 1 water user in California is
    ___________________________.
  • (set the record straight)
  • California and Texas are the only 2 states that
    do not have regulations on groundwater pumping.

39
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40
Water Problems
  • Erosion
  • Pollution
  • Waste

41
Erosion
  • Power of a droplet of water striking the soil
    surface
  • Moves tons of soil
  • Runs off to rivers and streams (siltation)
  • Tons of soil lost

42
Pollution
  • What types of water pollution?
  • Underground water supplies
  • Surface runoff (erosion and contamination from
    crop and animal activities)
  • Soil water (salts)
  • Pre-ag existance
  • Ag production induced

43
Water Pollution Mitigation
  • A couple of Answers
  • Total containment of runoff or drainage from
    intensive animal facilitieslagoons
  • soil polymers adhere to water particles
    preventing their runoff
  • use of IPM and GMOs (reduce the need for
    chemicals)

44
Water Waste
  • Caused by evaporation, infiltration, runoff
  • Flood irrigation is the largest waste of water
  • Drip and micro sprinkler use
  • Cost/economics as the price of water increases,
    farmers can afford to use less and must become
    more efficient.

45
Economics Driven Politics
  • For specific types of Agriculture production
  • Special Treatment, Government Subsidies and
    Corporate Welfare
  • Water Projects
  • Non-point source pollution in the past
  • Subsidies from government that encourage
    production of high water use commodities (Cotton
    and Milk)
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