Water andWater andIrrigationIrrigation

Read “From Farms to Floodplains & Filtration Read “From Farms to Floodplains & Filtration Systems”Systems”

…in class writing assignment…in class writing assignment

Read “Irrigation Drainwater Contamination in the Read “Irrigation Drainwater Contamination in the San Joaquin Valley”…Journal Writing AssignmentSan Joaquin Valley”…Journal Writing Assignment

AGST 3000AGST 3000

Agriculture, Society and the Natural WorldAgriculture, Society and the Natural World

IrrigationIrrigation

"Whiskey's for drinking; water's for fighting over" – "Whiskey's for drinking; water's for fighting over" –

Cities, farmers and environmentalists have battled Cities, farmers and environmentalists have battled over who will control California's water foreverover who will control California's water forever

Why? Our Valley Climate!Why? Our Valley Climate! Irrigated surface water scarce in spite of floodingIrrigated surface water scarce in spite of flooding Extended summer droughtExtended summer drought Southern and western portions quite drySouthern and western portions quite dry

Groundwater supply initially hugeGroundwater supply initially huge

Maybe as much as 750,000,000 acre feet Maybe as much as 750,000,000 acre feet accumulated over thousands of yearsaccumulated over thousands of years

Efficient pumps developed around 1920Efficient pumps developed around 1920

Irrigated acreage rapidly expanded several foldIrrigated acreage rapidly expanded several fold

Groundwater levels began to drop rapidlyGroundwater levels began to drop rapidly

IRRIGATIONIRRIGATION

A. Definition: Supplying water to plants in an A. Definition: Supplying water to plants in an artificial manner. (39% of all freshwater in artificial manner. (39% of all freshwater in the US is used to irrigate crops)the US is used to irrigate crops)

1. Ancient practice – first irrigation used 1. Ancient practice – first irrigation used ditches to divert rivers and streams.ditches to divert rivers and streams.

2. California agriculture relies on irrigation.2. California agriculture relies on irrigation.

a. Mediterranean climatea. Mediterranean climateb. Crop diversificationb. Crop diversificationc. Economicsc. Economics

Population Water NeedsPopulation Water Needs

According to U.S. Census Bureau figures, According to U.S. Census Bureau figures, California’s population currently is over 36 California’s population currently is over 36 million, and is projected to hit 49.3 million by million, and is projected to hit 49.3 million by 2025. 2025.

1998 California Water Plan update: the state 1998 California Water Plan update: the state Department of Water Resources (DWR) forecast Department of Water Resources (DWR) forecast a gap between water supply and demand a gap between water supply and demand ranging from 2.4 million acre-feet during normal ranging from 2.4 million acre-feet during normal years up to 6.2 million acre-feet in drought years years up to 6.2 million acre-feet in drought years by 2020. by 2020.

An acre-foot =An acre-foot =

An acre-foot of water is about 326,000 An acre-foot of water is about 326,000 gallons – gallons –

enough to cover an acre of land, about the enough to cover an acre of land, about the size of a football field, 1 foot deep andsize of a football field, 1 foot deep and

meet the average needs of between one meet the average needs of between one and two residential householdsand two residential households

Sources of WaterSources of Water

Rain and Snow replenishes the surface Rain and Snow replenishes the surface water and underground aquiferswater and underground aquifers

Ground Water (aquifers)Ground Water (aquifers)

Surface Water (rivers, lakes, reservoirs)Surface Water (rivers, lakes, reservoirs)

Water Cycle HandoutWater Cycle Handout

Sources of Surface WaterSources of Surface Water

California, there are two major arteries California, there are two major arteries serving as the sources of surface water for serving as the sources of surface water for urban and agricultural areas: urban and agricultural areas:

The Sacramento-San Joaquin Delta (Bay-The Sacramento-San Joaquin Delta (Bay-Delta) andDelta) and

The Colorado River The Colorado River

Major R

ivers

The DeltaThe Delta

Delta serves as a major water source for Delta serves as a major water source for approximately two-thirds of the state – approximately two-thirds of the state – over 22 million people over 22 million people

The region is fed by two major rivers: the The region is fed by two major rivers: the Sacramento from the north and the San Sacramento from the north and the San Joaquin from the south Joaquin from the south

The DeltaThe Delta

Mixture of fresh water from these two waterways and Mixture of fresh water from these two waterways and numerous tributaries combine with salty ocean numerous tributaries combine with salty ocean water from San Francisco Bay to create the largest water from San Francisco Bay to create the largest estuary on the West Coast of North America - The estuary on the West Coast of North America - The San Joaquin Delta.San Joaquin Delta.

Massive pumps at the southern end of this marsh Massive pumps at the southern end of this marsh pull approximately 5.5 million acre-feet annually of pull approximately 5.5 million acre-feet annually of fresh water southward to Central Valley farmland via fresh water southward to Central Valley farmland via the Central Valley Project and ultimately, to the the Central Valley Project and ultimately, to the southern California region via the State Water southern California region via the State Water Project. Project.

State

Pro

jects

Federal Central Valley ProjectFederal Central Valley Project

FDR and U.S. Reclamation Service looking for FDR and U.S. Reclamation Service looking for projects, took over CVP in 1935, began construction projects, took over CVP in 1935, began construction in 1937in 1937

Eventually completed in 1950’sEventually completed in 1950’s

Final cost more than $500 millionFinal cost more than $500 million

Distributes more than 3,000,000 acre feet of waterDistributes more than 3,000,000 acre feet of water

Almost all used for agricultureAlmost all used for agriculture

No connections to Southern California initiallyNo connections to Southern California initially

Feder

al Pro

jects

Loca

l Pro

jects

A

ll P

roje

cts

and

Riv

ers

The Colorado RiverThe Colorado River Colorado River winds its way through the southwestern United Colorado River winds its way through the southwestern United

States before terminating in the Gulf of California in Mexico. States before terminating in the Gulf of California in Mexico.

Provides water to seven states including California, with each Provides water to seven states including California, with each state's water use determined by the Colorado River Compact of state's water use determined by the Colorado River Compact of 1922. 1922.

California permitted to use 4.4 million acre-feet annually. California permitted to use 4.4 million acre-feet annually.

For over a decade, California has been using well beyond the For over a decade, California has been using well beyond the 1922 allotment. 1922 allotment.

As water conditions have tightened in several of the other states, As water conditions have tightened in several of the other states, the secretary of the Interior has demanded that California reduce the secretary of the Interior has demanded that California reduce its use of the Colorado River - a major challenge to river water its use of the Colorado River - a major challenge to river water users. users.

FloodFlood – Explain – Explainused in almonds, peaches, walnuts, rice, alfalfaused in almonds, peaches, walnuts, rice, alfalfa

Basic Types of IrrigationBasic Types of Irrigation

Flood in the West, Border in the EastFlood in the West, Border in the East

Flood Irrigation continued…Flood Irrigation continued…

Advantages:Advantages:

• inexpensiveinexpensive• less laborless labor• large amounts of water leach large amounts of water leach saltssalts

• rodent controlrodent control

Flood Irrigation continued…Flood Irrigation continued…

Disadvantages:Disadvantages:

land must be leveled or contouredland must be leveled or contoured uses large amounts of wateruses large amounts of water water loss through evaporationwater loss through evaporation may cause disease in some crops if applied may cause disease in some crops if applied

incorrectlyincorrectly run off water can cause problems (silt buildup run off water can cause problems (silt buildup

in rivers, may contain pesticides)in rivers, may contain pesticides)

Furrow IrrigationFurrow Irrigation

Used in row crops such as beans, tomatoes, Used in row crops such as beans, tomatoes, corn, sugar beets corn, sugar beets other vegetable crops.other vegetable crops.

Similar advantages and Similar advantages and disadvantages disadvantages to flood irrigation.to flood irrigation.

Furrow IrrigationFurrow Irrigation

Sprinkler IrrigationSprinkler Irrigation

Many types micro-sprinklers, solid set, aluminum Many types micro-sprinklers, solid set, aluminum pipepipe

a. a. Advantages: Advantages: use less water, more precise use less water, more precise amounts of water can be applied, less run off amounts of water can be applied, less run off (tail water), may be used on slightly hilly land(tail water), may be used on slightly hilly land

b. b. Disadvantages: Disadvantages: expensive (installation, expensive (installation, labor, filters, maintenance), salt labor, filters, maintenance), salt buildupbuildup

Better spray Better spray version of center version of center pivot for water pivot for water conservatonconservaton

Drip IrrigationDrip IrrigationUsed on specific crops, such as grapes, trees (such as Used on specific crops, such as grapes, trees (such as

almonds, cherries, peaches)almonds, cherries, peaches)

a. a. Advantages: Advantages:

uses less wateruses less water very precise amounts as well as fertilizervery precise amounts as well as fertilizer

b. b. Disadvantages:Disadvantages:

expensive to install, (labor, equipment, maintenance)expensive to install, (labor, equipment, maintenance)

Drip IrrigationDrip Irrigation

Subsurface IrrigationSubsurface Irrigation

Questions on Irrigation:Questions on Irrigation:

1. Where does irrigation water come 1. Where does irrigation water come from?from?

a. Wells – underground aquifersa. Wells – underground aquifersb. River – “Riparian rights” or water b. River – “Riparian rights” or water

rightsrightsc. Irrigation Districts – provide water c. Irrigation Districts – provide water

from large water sources, lakes, from large water sources, lakes, reservoirs (dams)reservoirs (dams)

What are concerns people have over the use of What are concerns people have over the use of irrigation in agriculture?irrigation in agriculture?

a. Overdraft of underground water supplies a. Overdraft of underground water supplies (aquifers).(aquifers).

b. Water pollution – silt, herbicides, pesticides b. Water pollution – silt, herbicides, pesticides added to irrigation water runs off into lakes, added to irrigation water runs off into lakes, rivers, etc.rivers, etc.

c. Concerns over water waste – flood irrigation c. Concerns over water waste – flood irrigation uses uses a lot of watera lot of water

d. Production of crops in California that are not d. Production of crops in California that are not water water efficient – alfalfa and cotton.efficient – alfalfa and cotton.

How has agriculture addressed the public’s How has agriculture addressed the public’s concerns over water usage?concerns over water usage?

a. The #1 water user in California is a. The #1 water user in California is ___________________________.___________________________.

(set the record straight)(set the record straight)

*California and Texas are the only 2 states that *California and Texas are the only 2 states that do not have regulations on groundwater do not have regulations on groundwater pumping.pumping.

Water ProblemsWater Problems

ErosionErosion

PollutionPollution

WasteWaste

ErosionErosion

Power of a droplet of water striking the soil Power of a droplet of water striking the soil surfacesurface

Moves tons of soilMoves tons of soil

Runs off to rivers and streams (siltation)Runs off to rivers and streams (siltation)

Tons of soil lostTons of soil lost

PollutionPollutionWhat types of water pollution?What types of water pollution?

Underground water supplies…Underground water supplies…

Surface runoff (erosion and contamination Surface runoff (erosion and contamination from crop and animal activities)from crop and animal activities)

Soil water (salts)Soil water (salts) Pre-ag existancePre-ag existance Ag production inducedAg production induced

Water Pollution MitigationWater Pollution Mitigation

A couple of AnswersA couple of Answers

Total containment of runoff or drainage from Total containment of runoff or drainage from intensive animal facilities…lagoonsintensive animal facilities…lagoons

soil polymers – adhere to water particles soil polymers – adhere to water particles preventing their runoff preventing their runoff

use of IPM and GMO’s (reduce the need for use of IPM and GMO’s (reduce the need for chemicals)chemicals)

Water WasteWater Waste

Caused by evaporation, infiltration, runoffCaused by evaporation, infiltration, runoff

Flood irrigation is the largest waste of waterFlood irrigation is the largest waste of water

Drip and micro sprinkler useDrip and micro sprinkler use

Cost/economics – as the price of water Cost/economics – as the price of water increases, farmers can afford to use less increases, farmers can afford to use less and must become more efficient.and must become more efficient.

Economics Driven PoliticsEconomics Driven Politics

For specific types of Agriculture production…For specific types of Agriculture production…

Special Treatment, Government Subsidies and Special Treatment, Government Subsidies and Corporate WelfareCorporate Welfare

Water ProjectsWater Projects Non-point source pollution in the pastNon-point source pollution in the past Subsidies from government that Subsidies from government that

encourage production of high water use encourage production of high water use commodities (Cotton and Milk)commodities (Cotton and Milk)