Problem: What is the primary difference between water use and water consumption? Water consumption is how much water humans consumes, whereas water use is for all other uses such as cooling systems or irrigation. Water use means that the water goes back into the hydrologic cycle; water consumption means that the water never goes back into the hydrologic cycle. There is no difference; they are two different words for the same thing. They both describe how water is taken out of the hydrologic cycle for our use, but consumption means that it doesn't go back to where it came from; the water is diverted into another source.