If you can afford to make only one repair at home, fix that leaky toilet. The average family of four in the United States uses about 400 gallons of water every day. That's for showers, washing clothes and dishes, flushing toilets and more. If you have a leaky toilet in just one bathroom, you can waste up to about 200 gallons of water every day, or half your daily average use. Multiply that by additional leaky toilets, and not only are you wasting water, but money is literally going down the drain. The repair costs to fix the toilet will pay for itself over time.