How to Save Water When Washing Dishes
Compiled and fact-checked from cited sources, reviewed by our editorial team.
Washing dishes is one of the biggest sources of water use in the kitchen — especially if you keep the tap running the whole time. The good news: a few simple habits can cut the water you waste by up to two-thirds. In this guide we cover the most effective ways to save water by hand (including the scientifically proven two-basin method), how hand-washing compares with a dishwasher, and how to save water in the machine.
How much water does washing dishes use?
The numbers vary a lot depending on your habits. Washing by hand with the tap running can use up to 100 litres (sometimes more) in a single go, because an open tap pours out roughly 6–12 litres per minute.[5] By contrast, a full and efficient dishwasher does the same job with about 13–15 litres — meaning that, used correctly, the machine uses ~80% less water than hand-washing.[2]
The best ways to save water by hand
If you have to wash by hand, three core habits dramatically cut water use:
- Effect~66% saving
- DifficultyEasy
- Needs2 basins/tubs
- EffectHigh
- DifficultyEasy
- NeedsA scraper
- EffectHigh
- DifficultyVery easy
- NeedsA tap aerator
1) Two-basin method: According to a 2020 University of Michigan study, this is the most water-efficient way to wash by hand.[1] We walk through it step by step in the next section.
2) Scrape & soak, don’t pre-rinse: Instead of rinsing dishes under a running tap, scrape the food off with a spatula. If you wash before food dries on, you won’t need to rinse at all; soak stubborn, stuck-on food in hot soapy water for 15–30 minutes.[3]
3) Don’t leave the tap running + aerator: Turn the tap off while you scrub; only turn it on to rinse. A tap aerator fitted to the spout lowers the flow rate and cuts water use significantly.
How to use the two-basin method
Step by step:[1]
- Wash basin: Fill a basin with hot water and add a few drops of dish soap.
- Rinse basin: Half-fill a second basin with clean, warm water. (If you have only one sink, use a plastic tub or bucket for the second basin.)
- Scrub the dishes in the wash basin, then dip them in the rinse basin to rinse.
- Refresh the rinse water once or twice when it gets soapy. The savings come from never leaving the tap running.
Hand-washing or dishwasher?
Contrary to what most people assume, a full and efficient dishwasher usually uses less water than washing by hand.[4]
| Method | Approx. water | Note |
|---|---|---|
| Hand-washing, tap running | Up to 100 L | Most wasteful |
| Two-basin method | ~66% less than running tap | Best hand method |
| Full, efficient dishwasher | ~13–15 litres | ~80% less than hand-washing |
Source: Which? and Whirlpool comparisons.[2] The key condition: run the machine full and don’t pre-rinse.
Saving water in the dishwasher
If you have a machine, these rules keep water use to a minimum:
- Always run it full; half-loads waste water.
- Don’t pre-rinse — rinsing plates under the tap is unnecessary; just scrape the scraps off.[6]
- Use the eco/economy programme; it uses a lower temperature and less water.
- When you replace your appliance, choose a water/energy-efficient (A-class) model.
The biggest mistake: Pre-rinsing dishes under the tap before loading the machine (or when washing by hand). This one habit wipes out most of the savings all on its own. Scrape, don't rinse.
Extra tips
- Fix a dripping tap: A leaky tap can lose dozens of litres a day.
- Fit an aerator: A cheap spout attachment can lower the flow rate by 30–50%.
- Reuse the rinse water: The final, lightly soapy rinse water can be used to water potted plants.
- Wash in batches: Letting dishes pile up and washing them in one go is more efficient than turning the water on and off again and again.
Frequently asked questions
Which uses less water — hand-washing or a dishwasher? A full and efficient dishwasher usually uses far less (about 80% less) water than hand-washing with the tap running.
What’s the best method for washing by hand? The two-basin method (wash in one basin, rinse in the other); it saves about 66% compared with leaving the tap running.
Do I need to pre-rinse? No. Scraping the scraps off is enough; pre-rinsing wastes water.
How much water does a tap pour out per minute? About 6–12 litres; an aerator brings this down.
How do I remove stubborn, dried-on food? Instead of scrubbing under running water, soak it in hot soapy water for 15–30 minutes.
Sources
- University of Michigan — A guide to greener dishwashing (two-basin study). https://news.umich.edu/fighting-climate-change-at-the-sink-a-guide-to-greener-dishwashing
- Which? — Dishwasher vs handwashing research. https://www.which.co.uk/news/article/which-research-reveals-how-little-water-dishwashers-use-compared-to-hand-washing-aUDng9Y2iK8E
- Consumer Reports — The Best Way to Hand-Wash Dishes. https://www.consumerreports.org/home-garden/cleaning/best-way-to-hand-wash-dishes-a1749842004/
- Whirlpool — Do Dishwashers Save Water? https://www.whirlpool.com/blog/kitchen/do-dishwashers-save-water.html
- Water Footprint Calculator — Dish Washing and Saving Water. https://watercalculator.org/posts/dish-washing/
- KitchenAid — Dishwasher vs. Hand Washing. https://www.kitchenaid.com/pinch-of-help/major-appliances/dishwasher-vs-hand-washing.html