In my mind, the commercial water-use category is important because, without it, we wouldn't have any steak restaurants, pizza houses, ice-cream parlors, hot-dog stands, milk-shake joints, chicken shacks, and other eateries. Along with the eateries, commercial water supplies motels, offices, prisons, military institutions, and fish hatcheries.
Compared to the total amount of water used in the United States, the amount going to commercial purposes is not large. In 1995, the last year when commercial water-use data was compiled, about 2.9 of the 340 billion gallons per day (Bgal/d) of fresh water used was withdrawn by the commercial sector. But, another 6.7 Bgal/d was delivered to commercial facilities by public-suppliers, such as the local water department. Yep, the same water departments that supply your home with water also send some to the local pizza joints.