Interior Bathrooms Toilets

It’s All in the Flush! The High Impact of Low-Flow Toilets

Most homes still have one or more older models that waste a phenomenal amount of water compared to today’s new low-flush toilets. If all of these inefficient toilets were converted to high-efficiency models, Americans could save more than 640 billion gallons of water per year!
Donna Boyle Schwartz Avatar
Low Flow Toilets

We may earn revenue from the products available on this page and participate in affiliate programs. Learn More ›

Average Americans are flushing money down the drain. Oh, maybe not literally money—but most US homes still have one or more older models that waste a phenomenal amount of water compared to today’s new low-flush toilets.

Toilets use more water than any other appliance or fixture in the home, with older toilets using between 3.5 and 7 gallons of water per flush, according to the Environmental Protection Agency’s WaterSense program.

The EPA estimates that if all of the inefficient toilets in homes were converted to WaterSense high-efficiency models, Americans could save more than 640 billion gallons of water per year—the equivalent to 15 days of flow over Niagara Falls.


Advantages of Low-Flow Toilets

Since 1994, federal law has mandated that new household toilets use no more than 1.6 gallons of water per flush. The early low-flush toilets certainly helped save money, but today’s high-efficiency models are even more effective, with WaterSense models using just 1.28 gallons of water per flush.

According to EPA figures, since the WaterSense program’s inception in 2006, consumers have saved more than 287 billion gallons of water and over $4.7 billion in water and energy bills by switching to more efficient toilets.

Replacing even one toilet can make a big difference: According to the National Association of Home Builders (NAHB), one high-efficiency toilet used by a family of four can save 8,760 gallons of water per year.

dual flush toilet effectiveness graph

Types of Low-Flow Toilets

When making the switch to a more efficient toilet, there are several options to consider:

  • Single-Flush High-Efficiency Toilets. A single-flush high-efficiency toilet uses the same amount of water for every flush. This is the most common model and generally the least expensive, with prices as low as $100.
  • Dual-Flush High-Efficiency Toilets. A dual-flush toilet offers the user two options for flushing, one for a full flush (designed for solid waste) and another low-output flush designed for fluid-only waste. This type of dual-flush system can average out water usage to as low as .96 gallons per flush. Dual-flush models generally range in price from $200 to $1,000.
  • Pressure-Assisted Toilets. These models use pressurized air to propel water through the system with greater force and therefore can work with as little as .8 gallons per flush. These typically require a separate electrical hookup for the pump and can range in price from $300 to $2,000.
  • Composting Toilets. Also known as biological toilets, these models use little or no water and do not release waste into sewage system or septic tank. These toilets collect liquid and solid wastes, holding them in storage bins either underneath the toilet or in a separate storage tank, breaking the waste down into compost. Used properly, composting toilets are sanitary and odor-free but may not be suitable for urban environments. Prices for composting toilets vary greatly, depending on capacity and style, but range from $350 to as high as $7,500.

Conservation and Savings

Regardless of which option you choose, many local utilities and state agencies offer rebate programs for switching out older models with new low-flush toilets.

Nearly all major bathroom fixture manufacturers offer some form of high-efficiency toilet, and the EPA site lists more than 1,500 models that qualify for WaterSense certification.

The water savings can be impressive. Over the course of a lifetime, an average person flushes the toilet nearly 140,000 times, according to the EPA. Installing a WaterSense toilet allows a family to save 4,000 gallons per year—about a third of a million gallons during a lifetime.

The EPA further estimates that a family of four that has replaced its home’s older toilets with WaterSense-labeled models will, on average, save more than $90 per year in reduced water utility bills, adding up to $2,000 over a toilet’s average lifetime. Now that is a lot of dough that doesn’t have to be flushed down the drain!