Dams
Every day, millions of gallons of water is used in houses
and work places. Dams have been built across rivers to
trap the water on one side to form a huge lake called a
reservoir. The reservoir collects the water when it rains
and then it can be used when there is a dry spell. The
water in the reservoir is also used to help irrigate the surrounding farmland.
By storing water in reservoirs this also helps prevent floods by halting torrential rain which
can cause rivers to burst their banks. Occasionally though, the reservoir that forms by
flooding the land can seriously damage the environment.
There are two main types of concrete dam. One is the arched dam which are tall, curved
structures. Because of their arch shape, which makes them very strong, they do not burst.
The Hoover Dam (above) in the US is one of the world's highest dams. It is an arch dam and
is 221 m high. Lake Mead, which is the reservoir behind the dam is 185 km long, and it
supplies water to Arizona, California, and Nevada.
The other type of concrete dam is the gravity dam. These large dams use their great weight
to stop them from collapsing.
The biggest dams are made by piling a huge barrier of rocks and earth around a concrete
centre, which stops the water seeping through. The side is covered in stones to protect it
from the water. This type is called an embankment dam. Some dams contain hydro-electric
power stations which are powered by the strength of the water flowing from the reservoirs,
and this provides electricity.
© Primary Leap Ltd. 2012
www.primaryleap.co.uk - Primary Resources
Score
10
05-05-01-006-s
Name:
Date:
Subject: Year 5 Geography
Sheet: Water
Read the information sheet about dams on the previous page and then answer the
questions.
a) Think of three ways that water is used in your house?
______________________________________________________________________
b) In your own words explain the meaning of the word 'drought'?
______________________________________________________________________
c) How many types of concrete dams are there? ____
_______________________________
d) Write down the different types of concrete dam?
_______________________________________________________________________
e) What is the name of the reservoir behind the Hoover Dam? _______________________
f ) Underline the correct answer. How high is the Hoover Dam?
1. 212 m
3. 211 m
2. 112 m
4. 221 m
g) Where is the Hoover Dam? _________________________________________________
h) The Hoover Dam is a gravity dam. Is this sentence true or false? ____________________
i) Name two places in the world that suffer from serious drought problems?
______________________________________________________________________
j) Dams help save water so that when droughts occur, people are still supplied with water.
Think of five things you could do to help save water.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
© Primary Leap Ltd. 2012
www.primaryleap.co.uk - Primary Resources