In the previous two posts, I reported that almost half of all water consumed in the United States is used for power generation. Irrigation is the second largest use. The population of a state and its land area account for about 74% of the variance in water consumption between states. The states with the largest “excess” water consumption compared to their population and size were Idaho, Nebraska, and Montana.

As you look at the following charts, keep in mind that the USGS may not have estimated all sources of water withdrawal identically across all years. Some of the differences may be due to gaps and changes in the way the data was gathered, and I don’t know which data might be affected.

The first chart at right shows that for the United States as a whole, water consumption seems to be increasing slowly, from 395,801 million gallons per day in 1985 to 407,273 million gallons per day in 2005, an increase of about 3%.

The second chart at right shows water consumption by state for 1985, 1990, 1995, 2000, and 2005. The chart is a bit hard to read because the columns are so small. Click on it to enlarge it on your screen to get a better view.

For some states, consumption doesn’t seem to change much, for instance, Kentucky. For other states, water consumption seems to jump around inconsistently, for instance, California, Colorado, and Kansas. In some states, water consumption seems to be consistently declining, for instance Delaware, Massachusetts, and Nevada. In other states, it seems to be consistently increasing, for instance Arkansas, Florida, and Missouri.

Sources:

The following sources were used to create the charts. They are all available on the United States Geological Service website at Water Use in the United States, http://water.usgs.gov/watuse.

1. Estimated Use of Water in the United States in 2005.
2. Download 2000 Data For Counties.
3. Download 1995 Data for Counties and Watersheds.
4. Download 1990 or 1985 Data for Counties and Watersheds.