The water being poured into the bathtub is renewable and can be recycled, filtered, and renewed. But, metaphorically, each time you use electricity you drain a little water from the "bathtub" or the electric grid.
According to the most recent data from the U.S. Bureau of Labor Statistics, in 2013 the average American household spent about 10% of its total budget on food.
For example if you have income of $6000, you will spend $600 on food.
