How to Save Water With Your Toilet: Lower Your Bills by $125/Year
Discover simple, low-cost ways to cut toilet water use and save up to $125 annually on water and sewage bills effortlessly.

Toilets are one of the biggest water consumers in homes, accounting for 20-30% of indoor usage according to the U.S. Environmental Protection Agency. A family of four can flush thousands of gallons annually, driving up water and sewage bills. Fortunately, simple, inexpensive tweaks can reduce this usage significantly, potentially saving $125 or more per year. This guide covers proven strategies, from tank modifications to habit changes, backed by real calculations and official data.
Use Less Water in Your Toilet
The easiest way to save is by reducing the water volume per flush without replacing your toilet. Older models use 3.6-7 gallons per flush, while modern low-flow ones use 1.28-1.6 gallons. Displacement devices and diverters minimize tank refill water, saving up to
1.3 gallons per flush
.A fill cycle diverter redirects water from the bowl to the tank, filling the bowl faster and saving 0.5 gallons per flush. These cost under $5 and install in minutes.
A displacement device occupies tank space, like a brick wrapped in plastic, a water-filled jug, or commercial products like Tank Bank (displaces 0.8 gallons). Avoid using them in ultra-low-flow toilets to ensure proper flushing.
- Family of four: 5 flushes/person/day = 20 flushes/day.
- 1.3 gallons saved/flush × 20 = 26 gallons/day.
- Annual: 9,490 gallons saved.
- At $3.59/HCF (748 gallons/HCF), savings =
$45/year
on sewage alone.
Combine both tools for maximum effect. The EPA notes such devices are effective for pre-1994 toilets using over 3 gallons/flush.
Flush Less Often
This zero-cost hack leverages the motto: “If it’s yellow, let it mellow.” Skip flushing liquid waste, only flushing solids. For hygiene, flush every other liquid use or keep the lid down.
Caveats: Monitor toilet paper to prevent clogs; keep a plunger ready. Ideal for private bathrooms; pause for guests.
- Assume 60% of flushes are liquid (12/20 daily for family of four).
- Halve liquid flushes: Save 6 flushes/day = 2,190 gallons/year.
- Full adoption (all liquid): Save 12 flushes/day = 17,245 gallons/year =
$82/year
savings.
Partial use still cuts bills noticeably. U.S. Geological Survey data shows residential toilets dominate water use, making this impactful.
Reuse Shower Water
Capture warm-up water from showers (often 1-2 gallons) in a 5-gallon bucket. Pour into the toilet tank post-flush to refill without tap water.
- 7 showers/week: 2 gallons/shower = 1,274 gallons/year reused for showers + 1,274 for flushes = 2,548 gallons total.
- San Diego rates: $5.82/HCF water + $3.59/HCF sewer =
$16/year
; more showers/older heads = $25-$30.
Safety note: Buckets pose drowning risks for kids—store securely or door closed. This repurposes wasted water effectively.
| Method | Cost | Annual Savings | Water Saved (Gallons/Year) |
|---|---|---|---|
| Less Water in Toilet | <$10 | $45 | 9,490 |
| Flush Less | $0 | $82 | 17,245 |
| Reuse Shower Water | $0 (bucket) | $15-25 | 2,548 |
| Total | <$10 | $142-152 | 29,283 |
Composting or Waterless Toilets
For maximum savings and eco-impact, consider composting or waterless toilets. These eliminate flush water entirely, ideal for off-grid or adventurous users. Composting systems turn waste into fertilizer; waterless use air seals or chemicals.
Upfront costs: $100-$1,000, but lifetime savings exceed $125/year plus maintenance-free operation. The Humanure Handbook details safe implementation. EPA supports alternatives reducing residential water by 30%. Best for cabins or committed eco-homes.
Additional Tips for Toilet Water Savings
Enhance savings with these:
- Fix leaks: Dripping flappers waste 30 gallons/day. Replace for $5, saving $115/year.
- Upgrade to low-flow: 1.28 GPF models pay back in 3-5 years ($150 cost).
- Check toilet age: Post-1994 models are efficient; test by food coloring in tank (color in bowl = leak).
- Multi-person households: Scale savings proportionally.
California studies confirm toilets average 21% of home water use.
Frequently Asked Questions (FAQs)
Will bricks or bottles damage my toilet?
No, if wrapped/sealed properly to avoid crumbling or leaking. Use in older toilets (>3 GPF); test flush power.
How much do low-flow toilets save?
Compared to 3.6 GPF, 1.28 GPF saves ~2 GPF/flush, or thousands of gallons/year for families.
Is ‘let it mellow’ hygienic?
For healthy adults in private settings, yes; flush solids and every few liquids. Odor minimal with lid down.
Can I combine all methods?
Yes, for up to $150+ savings. Start with free habits, add devices.
What’s the ROI on devices?
<$5 tools pay back in weeks at $45/year savings.
Are composting toilets legal?
Yes, in most U.S. areas with permits; check local codes.
Implementing these strategies not only trims bills but conserves water amid growing shortages. Start small—your wallet and planet will thank you.
References
- WaterSense Residential Toilet Guide — U.S. Environmental Protection Agency. 2024-10-15. https://www.epa.gov/watersense/toilets
- Residential Water Use in the U.S. and Canada — U.S. Geological Survey. 2023-05-20. https://www.usgs.gov/mission-areas/water-resources/science/residential-water-use-united-states-and-canada
- California Single-Family Water Use Study — California Energy Commission. 2022-11-01. https://www.energy.ca.gov/data-reports/reports/single-family-water-use-study
- Water Efficiency Management Guide — Federal Facilities — U.S. Department of Energy. 2025-01-10. https://www.energy.gov/femp/water-efficiency-management-guide-federal-facilities
- Indoor Water Use in the United States — U.S. Environmental Protection Agency. 2024-06-12. https://www.epa.gov/watersense/statistics-and-facts
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