Hydropower
Dams
Photo credit: Noodle snacks, Wikimedia
Gordan Dam, a dammed hydro facility in Tasmania
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Purpose of Dams
• To store water to make up for the up and
down changes in river flow or in demand
for water and energy.
• To raise the level of the water upstream to
enable water to be diverted into a canal.
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Essential Questions
1. What is a hydropower dam?
2. How is a hydropower dam useful?
3. Can hydropower dams help prevent
flooding?
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Enduring Understandings
1. Hydropower dams, also known as
impoundment facilities, are powered by
kinetic energy.
2. Hydropower dams are used to create a
barrier between upstream and
downstream waters.
3. Hydropower dams can help with flood
control.
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The Hydropower Dam
• Conventional hydro turbines are typically
installed either within or next to dams. The
kinetic energy of flowing water spins a
turbine, producing mechanical energy that
is converted into electricity by a generator.
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The Hydropower Dam
(Continuation)
• The function of a hydropower dam is to increase
the elevation (head) between water surfaces
and thus the amount of kinetic energy that can
be converted into electricity as water flows or
cascades through its turbines.
• Releases of water stored in the reservoir behind
a dam can be timed to boost hydro generation
during periods of high demand.
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Benefits of Hydropower Dams
• One of the country’s most important renewable
energy resources
• Reliable
• Produces little solid wastes
• Emits essentially none of the potentially harmful
atmospheric emissions, such as nitrogen and
sulfur oxides and greenhouse gases.
• Can provide sources for water supply, flood
control and recreation
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A Major Risk
of Hydropower Dams
• Hydropower dams can greatly impact
ecosystems:
 They can take over terrestrial habitats,
forever changing and damaging aquatic
habitats.
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