Measuring the Flow of a Stream
handout exerciseactivity exercisesuggested grade levels: 7-12

view Idaho achievement standards for this lesson

Idaho has more than 93,000 miles of streams, rivers, and creeks. We depend heavily on these waters for irrigation, power, fishing, and other things. Rivers have shaped our landscape. The following activity will expose students to the concept of stream flow. This activity can be done at a local stream as part of a field trip.

1. Students will be exposed to the Digital Atlas of Idaho.
2. Students will understand the concept of stream flow.
3. Students will learn how to take quantitative measurements.

Tape measure (meters) Watch (with second hand)
Meter sticks Small ball or stick
Clipboard with pen and paper  

1. Encourage students to use the Surface Hydrology section Digital Atlas of Idaho. To get there: Click on Atlas Home, mouse-over Hydrology, then click on Ground & Surface Water Concepts. Scroll down and encourage students to read the section on Instantaneous Streamflow Measurement. This section will describe how to measure streamflow.
2. Have a class discussion on the role of streams and their importance in watershed systems. Also mention erosion, organisms influenced by streamflow, human influence, etc.
3. Go outside with the class to give students the opportunity to have a hands-on learning experience. Measure off a 30-meter section of a stream using a tape measure.
4. Float an object (ball or stick) down the 30-meter section and time how long it takes. Repeat two more times and take the average in meters per second. Record all data on a clipboard.
5. Have the students measure the width of stream at three different places and take the average. Use meters.
6. Measure the depth in meters on a line running perpendicular to the stream. Measure in 5-8 locations and take the average.
7. Calculate stream flow using the equation given in the Digital Atlas. Be sure to report your velocity, width, and depth as the averages calculated. Stream Flow = Velocity X Width X Depth (Answer should be in cubic meters per second)
8. Have discussion on stream flow.
   1. What did we measure?
   2. What time of year is streamflow usually the highest?
   3. How could we have measured streamflow more accurately?

Handouts/Activity links:
These are links to access the handouts and printable materials.
Ground & Surface Water Concepts

Related Lesson Topics:
Hydrology: Hydrology Topics

Lesson plan by James Scannell and Stefan Sommer, 2001
Idaho Achievement Standards (as of 7/2001) met by completing this activity: