Question: how many gallons of water does a toilet use per flush?
Answer: Although toilets all look pretty much alike, the amount of water released by flushing varies widely from one toilet to another. Generally speaking, the older the toilet, the more water it uses. Toilets built before 1982 use 5 to 7 gallons per flush. Now, toilets are designed to flush using only 1.6 gallons of water.