Hands-on Activity: Faucet Flow Rate

Contributed by: Civil and Environmental Engineering Department, Colorado School of Mines

A graphic showing a water tap and a water drop.
Students determine the flow rate of faucets.
Copyright © https://openclipart.org/detail/169893/water-by-scyg


Students conduct experiments to determine the flow rate of faucets by timing how long it takes to fill gallon jugs. They do this for three different faucet flow levels (quarter blast, half blast, full blast), averaging three trials for each level. They convert their results from gallons per second (gps) to cubic feet per second (cfs).

Engineering Connection

Civil engineers design the systems that bring water from natural sources, such as rivers, lakes, glaciers, watersheds or aquifers, to the towns and cities where that water is needed. Civil engineers also manage natural systems for purposes of flood control and drought mitigation. Students who complete this activity gain a greater understanding for what civil engineers who design water systems do and the skills they use in their careers.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

Suggest an alignment not listed above

Learning Objectives

After completing this activity, students should be able to:

  1. Define flow rate.
  2. Conduct an experiment to determine the flow rate of a faucet.
  3. Calculate flow rates from experimental data.
  4. Convert flow rates from gps to cfs units.

Materials List

Each group needs:

  • Faucet Flow Rate student handout and worksheets (provided as attachments to this document)
  • water faucet
  • gallon jug or empty milk jug
  • stopwatch (or a wristwatch or wall clock with a second hand)
  • Flow Rate Experiment Student Guide (see Attachments section)


To take full advantage of today's activity, we need to able to relate a flow rate from a river to something they are familiar with. By experimentally determining the flow rate of a faucet, we will develop a frame of reference for gauging the magnitude of flow rates in rivers.


One important aspect of good experiments is repeating the experiment and averaging the data from numerous trials. Averaging the data from repeated trials reduces data error, which is why it is suggested that students perform three trials at each faucet level. If time is limited, have each group do one trial for each faucet level.

  1. Gather materials and make copies of the Flow Rate Experiment Student Guide.
  2. Hand out the Faucet Flow Rate student handouts.
  3. As a class, explain the experiment and read the procedure.
  4. Divide the class into groups of three or four students each.
  5. Have students begin the experiment; assist as necessary. Make sure that they record the data in the correct worksheet locations (Table 1 for the quarter blast data, Table 2 for the half blast data, and Table 3 for the full blast data)
  6. When students are finished with the faucet, timing and jug filling, instruct them to dry their lab area and begin graphing and calculations. The calculation of flow rates in gallons per second takes place in Tables 1, 2 and 3. The calculation of flow rates in cubic feet per second takes place in Table 4.
  7. If necessary, assign calculations as homework.



At activity end, convene the class to share and compare results. Point out how these are the sorts of calculations engineers make when analyzing natural resources for the amount of water flow they could provide to a community. Use this forum to make sure students have gained familiarity with the units and the flow rates at the different faucet flow levels, which prepares them for the next step (conducting the associated River Flow Rate activity), to relate this sense of scale to the movement of water in a local river.

Activity Extensions

Have students determine flow rate of faucets, shower heads and garden hoses they use in their homes, yards and school.

Have students compare data across different teams. This can be accomplished in a number of ways. If the room faucets are similar, then the various group data should fall on the same line on a graph. You could provide the data from all groups to every team, and have them prepare graphs of all the data. If the faucets are different, then students could hypothesize why the flow rate vs. time plots are different, for example, cross sectional area of faucet is bigger/smaller, water pressure is different from faucet to faucet, etc.


Bobby Rinehart; Karen Johnson; Mike Mooney


© 2013 by Regents of the University of Colorado; original © 2005 Colorado School of Mines

Supporting Program

Civil and Environmental Engineering Department, Colorado School of Mines


This curriculum was created with support from the National Science Foundation. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.