1. California’s Water Resources
Chapter 13A, Section 2

2. California’s Water Supply
The main sources of California’s freshwater supply are precipitation, surface water, and groundwater
California receives an average of about 58 cm of precipitation per year
Northern CA and mountains receive most of the precipitation
Some of CA’s precipitation flows back into the lakes, rivers, and streams that make up the state’s drainage basins; supplies half of the freshwater needs for the year
One of CA’s major sources of fresh water is the Colorado River
Some precipitation seeps into the ground to become groundwater; accounting for 30% of fresh water used
Most groundwater is used in the area from which the water is withdrawn
Desalination – removal of salt from ocean water to obtain fresh water

3. California’s Average Annual Precipitation

4. California’s Drainage Basins

5. Concept Check What is desalination?
Desalination is the removal of salt from ocean water to obtain fresh water.

6. California’s Water Projects
To meet freshwater needs throughout the state, California has an intricate network of water storage and distribution systems, or water projects
Aqueduct – pipe, or channel, through which water flows from a higher elevation to a lower elevation
The Los Angeles Aqueduct carries water 359 km from the Owens River east of the Sierra Nevada, providing L.A. with water since 1913
California’s State Water Project (SWP) is one of the nation’s largest water distribution systems, transporting water from northern CA to southern
The federal government has also constructed major water projects in CA

7. California’s Water Projects
Yellow = Federal
Green = Local
Red = State

8. Water Needs Most of California’s water supply is used to grow crops
The rest is used in homes, businesses, and industries, or has been set aside for recreation or wildlife use
About 80% of fresh water used each year goes toward irrigating crops
Think of all the ways you use water, this adds up to about 380 liters per person per day
The major use of water in industry is as a coolant—either to cool products or the equipment used to make products
CA preserves some streams and rivers as fisheries and as recreation zones, not diverting the water from these areas

10. Assignment Read Chapter 13A, Section 2 (pg. CA 13-CA 19)
DO Section 13A.2 Assessment #1-7 (pg. CA 19)