California Water Issues

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California Water Issues

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

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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.

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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.

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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

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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?

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

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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

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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.

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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).

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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)

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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

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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

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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.

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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

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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

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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

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Sources of Water

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

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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

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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

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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.

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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

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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.

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Basic Types of Irrigation

• Flood Explain
• used in almonds, peaches, walnuts, rice, alfalfa

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• Flood in the West, Border in the East

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Flood Irrigation continued

• Advantages
• inexpensive
• less labor
• large amounts of water leach salts
• rodent control

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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)

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Furrow Irrigation

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

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Furrow Irrigation
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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

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• Better spray version of center pivot for water
  conservaton

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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)

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Drip Irrigation
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Subsurface Irrigation
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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)

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• 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.

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• 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.

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Water Problems

• Erosion
• Pollution
• Waste

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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

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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

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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)

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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.

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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)