WaterSense Toilet Buyer's Guide: Rebates, Savings, and Models That Qualify (2026)

What WaterSense actually certifies

WaterSense is an EPA program that certifies plumbing fixtures meeting two criteria: (1) maximum water use of 1.28 gallons per flush (20% below the federal 1.6 GPF cap) and (2) flush performance verified by third-party MaP testing at 350 grams of solid waste removal in a single flush. The label has been in use since 2007 and now applies to over 1,200 toilet models from 40+ manufacturers.

The water savings, in concrete numbers

A standard pre-1992 toilet uses 3.5-7 GPF. A federal-minimum 1.6 GPF toilet uses 1.6. A WaterSense 1.28 GPF toilet uses 1.28. For a 4-person household flushing an average of 20 times daily, the annual water use is:

Pre-1992 (5 GPF average): 36,500 gallons
1.6 GPF: 11,680 gallons
1.28 GPF: 9,344 gallons
0.8 GPF high-efficiency (Niagara Stealth): 5,840 gallons

Switching from a 1.6 GPF to WaterSense 1.28 saves 2,336 gallons per year per toilet — typically $25-50 in water-and-sewer charges, depending on local utility rates. In drought-prone regions (CA, AZ, NM, TX, NV), some utilities charge a tiered water rate where the marginal savings are 2-3x higher.

Rebates: the often-overlooked savings

Many municipal water utilities offer rebates of $50-$200 per WaterSense toilet installed, with extra incentives for replacing pre-1994 fixtures. As of 2026, programs in Los Angeles, San Francisco, San Diego, Austin, Phoenix, Las Vegas, Denver, Albuquerque, and Tampa offer at least $100 per replacement. Check your local utility's website for the "rebate" or "conservation" page.

Verifying a model is WaterSense certified

Look for the WaterSense logo on the box, the manufacturer spec sheet, or the EPA WaterSense product database (lookforwatersense.epa.gov). The label includes both 1.28 GPF (single-flush) and dual-flush models (where the full flush is 1.28 GPF or less; the partial flush can be 0.8-1.0).