Yakima WATERS Mini Lesson
Dam Characteristics Background and Unit Conversion
Targets and Assessment
WA Science Standards Addressed:
 9-12 SYSB A1.8B
 9-12 SYSC
 9-12 INQG
 9-12 APPE
 9-11 ES2D
Lesson Parameters
Content Area: Interdisciplinary
Overview: This lesson allows students to practice unit
conversions, while thinking about the pros and cons of
constructing dams on rivers.
Grade Level: 9-12
Assessment
 Correct answers on the worksheet
 Ask questions relating to the lesson to enhance
student understanding
Suggested Time: 50 minutes
Special Materials:
 Calculator
 Student Worksheet (See attached document Dam
Unit Analysis and Background)
Learning Outcomes:
Knowledge: Students will be able to evaluate the pros and cons related to the building of dams.
Skill: Students will be able to accurately convert units in the metric to standard systems of measurement.
Science Concept Background:
With growth of the human population, the demand for energy increases. The damming of rivers
provides the population with a relatively clean form of energy. Dams may also be constructed for other
reasons besides hydroelectricity. For example, a dam may be built to control flooding on a river, or to provide
a source of irrigation, or to meet transportation needs. While these dams provide many benefits, they also
create problems by disturbing the natural flow of the river. This worksheet will compel students to think
about the various pros and cons of dam construction, while practicing the conversion of units.
Materials:
Calculator
Student Worksheet (See attached document Dam Unit Analysis and Background)
Procedure:
This worksheet is tailored towards questions about the Yakima River watershed, but it may be
modified for the specific region you live in. I found that once the worksheet is handed out, it might be
beneficial to let the students work in small groups of two or three. You may want to go over the first couple of
problems in the Unit Conversion section. Once the students have completed the conversion section, ask for
student volunteers to discuss their equations and answers in front of the class.
For the next section, Why Build a Dam, allow students to again work in small groups. Encourage
creative thinking, because many effects of a dam are not straightforward.
Focus Questions and Topics
Dams may be built for flood control, irrigation and transportation needs.
Most dams release water from the bottom of the lake. How might the temperature of the water
downstream of a dam be different from the natural temperature of the water? How might this effect
organisms that rely on the river?
Rivers carry and deposit a lot of sediment and nutrients as they flow across the land. What happens to
this sediment when the river flows into a reservoir behind a dam? Through time, how will this influence the
effectiveness of the dam both upstream and downstream?
What happens to migrating animals that use the river, such as fish, when a dam is constructed?
What are some things you might like to do during the summer (i.e. boating, fishing, etc…), and where
might you do these activities?
Extension(s):
When the students are done with the worksheet, bring the class together and discuss their answers for
the ‘Why Build a Dam’ section. Ask them to give reasons for their answers.
Teaching Tips:
I found that some students had never seen a dam before, so they knew very little about them. You
may want to preface this worksheet with a brief introduction to dams. A fun thing to do after you collect the
worksheets is make a list of the students’ answers for the last question involving changes we could make to
existing dams. I made a short PowerPoint presentation on these answers and shared it with my classes. It was
fun for the students to see the different, creative ways their fellow classmates came up with. It also got them
thinking of other ideas for which it might be possible to lessen some of the problems created by dams.
Supplements:
Student Worksheet (See attached document Dam Unit Analysis and Background)
Authors: Caitlin Orem, Yakima WATERS Project, CWU, Spring 2009
Christopher Markley, Yakima WATERS Project, CWU, Fall 2009