Water Usage

Prepared by:

Joseph Malkevitch
Department of Mathematics
York College (CUNY)
Jamaica, New York 11451



web page:



Stuart Weinberg
Mathematics Education
Teachers College
New York, New York 10027

The prolonged drought in California has called attention to ways to reduce strain on California's dwindling water sources. Appeals are being made to individuals to help out by encouraging them to find ways of personally using less water. One source of individual use of water is when a person has a shower or a bath. This raises the question of which of these - shower or bath - uses more water?

1. Construct a mathematical model to help advise a person who would like to cut down on the volume or cost of water used in taking a bath or a shower.


a. Use a modeling approach to estimate the volume of water that a "typical" bathtub contains. What "familiar" shape(s) might one use to model the shape of a bath tub?

2. Model different approaches that a family might use to conserve water by the way that they would use a dishwasher versus washing dishes by hand.


a. Does your model address household size? Number of hours people are at home per day? Ages of the household members? Number of times per week guests eat at this location?

3. Develop some other water usage modeling problems that might apply to either an individual or a company.