HOW DO
COMMUNITIES GET
WATER?
Chapter 4, Lesson 2
Rivers and Reservoirs
• Rivers give drinking water to millions
of Californians.
• Rivers are not reliable sources of
water, however.
• California has built many dams and
reservoirs to make runoff from rain
and snow last through the year.
Rivers and Reservoirs
• A reservoir is a place that collects and
holds water.
• Fresh water is not always close by to the
people who need it.
Rivers and Reservoirs
• Aqueducts are used to move water from
faraway places.
• An aqueduct is a system of channels,
pipes, and tunnels that carries water a
long distance.
Rivers and Reservoirs
• Most rain falls in California between
October and April.
• But crops still need to be watered all
summer.
• Reservoirs and aqueducts help collect
water that can be used for irrigation.
Rivers and Reservoirs
• Irrigation is the supplying of fresh
water to farm fields.
• Dams have other uses too.
• Water rushing past dams can be
used to create electricity.
• People can boat, swim or fish in the
reservoirs the dams create.
Groundwater
• The source of most groundwater in
California is rain and melted snow
that sinks into the ground.
• It sinks until it reaches a layer of
solid rock or clay.
• It fills the spaces above this layer.
Groundwater
• An underground layer of rock or soil
that water can easily move through is
called an aquifer.
• When all the spaces in the ground are
soaked with water, we say that it is
saturated (soaked).
Groundwater
• The surface of a layer of saturated
ground is called a water table.
• It is the soaked layer of ground just
above the groundwater.
• The water table is usually hidden
underground.
• But, sometimes you can see it. A
wetland is usually at the level of the
water table.
Groundwater
Groundwater
• People also get to groundwater by drilling
down into aquifers.
• A well is a hole dug under ground to a
place filled with water.
• Pumps bring the water to the surface.
• A spring is a natural flow of water from
below the ground.
Water to You
• A watershed is a piece of land that drains
into a river.
• Your drinking water may come from a
watershed.
• The water is treated and cleaned at a
purification plant.
• After water is used, it goes into the sewer
system. Then it goes to a water treatment
plant.