13A.2 – California’s Water Resources

Do NowWhat are the main sources

of California’s fresh water?

Do NowWhat are the main sources

of California’s fresh water? PrecipitationSurface WaterGroundwater

Key Words

Transpiration

Vocab Words

Aqueduct Desalination

California’s Water Supply The main sources of California’s water supply

are precipitation, surface water, and groundwater.

Entire world is only covered in 1% of freshwater.

Much of the state’s water begins as snowfall up in the northern part of the state. More than half of all precipitation in the state is lost

to evaporation or transpiration. Only about 35% of all precipitation in California

stays at the surface or seeps into the ground to produce our groundwater supply.

Precipitation California receives an average of about 58 cm of

precipitation per year. This is not evenly distributed though

Northern California and the state’s mountains receive most of the precipitation.

Surface Water Some of California’s

precipitation flows back into the lakes, rivers, and streams that make up what is called the state’s drainage basins or watersheds.

One of California’s major sources of water is the Colorado River, which starts in the Rocky Mountains of Colorado and travel all the way to Arizona crossing through California.

GroundwaterWhen precipitation seeps into the

ground it then is stored naturally and becomes groundwater.

Groundwater accounts for 30% of the freshwater used in California.

Groundwater is not transported like other water is in the state, instead it is used for the area where it is located.

Desalination of Sea Water Most of California’s fresh water comes

from surface water or groundwater, but desalinated ocean water is growing in some importance of fresh water for coastal communities.

Desalination is the removal of salt from ocean water to obtain fresh water.

This water can be used for non-drinking purposes; such as watering the lawn, running laundry, etc.

Desalination Process

California’s Water Projects

To meet freshwater needs throughout the state, California has an intricate network of water storage and distribution systems, or local water projects.

This is needed since California’s precipitation is unevenly distributed throughout the state.

Local Water Projects Aqueducts

A 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) to Los Angeles.

These provide fresh water for cities, counties and agricultural areas in southern California.

They can also share water with other states.

State Water ProjectCalifornia’s State Water Project

(SWP) is one of the nation’s largest water distribution systems. It transports rain and melted snow

from the Feather River in Northern California to points farther south.

It also supplies most of the water used in the valley for agriculture.

Federal Water ProjectsAll-American CanalThe Coachella CanalThe Central Valley Project

Most of this water is used for irrigation and wildlife refuges.

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 wildlife use.

Agriculture 80% of the fresh

water used in California each year goes toward irrigating crops.

2/3 of the water used in agriculture is surface water. The remaining 1/3 is from groundwater.

Houses and Businesses Drinking, cleaning,

cooking, washing, bathing, flushing, and watering the lawn and household plants.

About 380 liters per person per day.

In the future, more of California’s drinking water may come from desalination plants.

Industry Beverages or paper uses water to create

these things. Power plants also require water to produce

steam that is used to generate electricity.

Recreation and Wildlife California preserves some streams and rivers as

fisheries where fish as trout and salmon are grown.

Other bodies of fresh water set aside for wildlife are wetlands, which provide habitats for wildlife such as birds, amphibians and fishes.

Group ActivityOn page CA 18, complete the

Quick Lab at the top of the page. Make sure to record questions 1-4 in your notebook.