Reducing mains water use at home can lower household bills, reduce the energy needed to heat water and make a property less dependent on treated water supplies. The most effective changes are usually straightforward: repair leaks, reduce unnecessary shower and tap use, run appliances efficiently and collect rainwater for suitable outdoor tasks.
More substantial options include water-efficient plumbing fittings, rainwater harvesting and greywater reuse. However, expensive equipment is rarely the best starting point. A household can often reduce consumption considerably by identifying where water is being wasted and making a few inexpensive changes.
Where should you start to reduce mains water use?
Start with the activities that use the most water or involve avoidable waste. Showers, toilets, baths, washing machines and taps are responsible for much of a household’s consumption. Garden watering can add significantly to demand during dry weather.
Not every improvement requires buying equipment. The following priorities provide a practical starting point.
| Measure | Cost or effort | What it achieves |
|---|---|---|
| Repair leaking toilets and taps | Low to moderate, depending on repair | Eliminates continuous water waste |
| Take shorter showers | Free | Reduces water and heating energy use |
| Turn off unnecessary running taps | Free | Reduces everyday water waste |
| Use full appliance loads and eco programmes | Free | Reduces water consumed per item washed |
| Fit suitable water-saving devices | Low to moderate | Reduces water flow or flushing volume |
| Collect rainwater in a water butt | Low to moderate | Replaces mains water for suitable garden tasks |
| Install permanent rainwater harvesting | High | Can replace mains water for toilets and other non-potable uses |
For most homes, checking for leaks and changing shower habits should come before investing in a permanent rainwater collection system.
Check your water use before making changes
A water meter provides a useful way to establish how much mains water the household actually uses. In England and Wales, metered consumption is generally recorded in cubic metres, with one cubic metre equal to 1,000 litres.
Take an actual meter reading, then repeat it after seven days. Subtract the first reading from the second to calculate consumption during that period. Multiply by 1,000 and divide by seven to obtain an average daily figure in litres.
For example, using 3.5 cubic metres over seven days equals 3,500 litres, or 500 litres per day. Repeat the exercise after making changes, ideally across comparable weeks with similar household occupancy and activities.
Meter readings can also reveal unexpected consumption. If water use increases without an obvious explanation, check for leaks before assuming that ordinary household activities are responsible. Smart water meters may provide more frequent readings and notifications of continuous use.
For households without meters, the Consumer Council for Water’s water meter calculator offers an estimate based on household size and water-using activities. It can also help households in England and Wales consider whether metered billing might be cheaper.
Find and repair water leaks
Leaks are worth investigating early because they can waste water continuously, including overnight when nobody is using taps or appliances.
A leaking toilet is particularly easy to overlook. Water may trickle into the bowl without making much noise or appearing on the floor. The Consumer Council for Water reports that a leaking toilet can waste up to 400 litres a day. At that rate, a single fault could waste more water than several people save through shorter showers.
Inspect toilets for persistent trickling, cisterns that refill unexpectedly and flush mechanisms that fail to close properly. Check dripping taps, pipe joints, outdoor taps and any damp patches around plumbing.
If a water meter is fitted, turn off all taps and water-using appliances and check whether the meter continues to register consumption. If it does, there may be a leak. Where safe and practical, closing the internal stop valve can help distinguish an internal plumbing leak from a possible leak on the external supply pipe.
Do not attempt to lift heavy or unsafe meter covers. Contact your water company or an appropriately qualified plumber if the source cannot be identified. Tenants should report suspected leaks promptly to their landlord or managing agent.
Reduce the amount of water used by showers
Showering can account for a substantial proportion of household mains water consumption. Flow rate matters as much as duration. The Consumer Council for Water gives typical figures of approximately 15 litres per minute for power or mixer showers and 6 litres per minute for electric showers.
Reducing a daily shower by two minutes at 12 litres per minute saves 24 litres each time. Over 365 days, that represents 8,760 litres, or 8.76 cubic metres, assuming the same saving occurs every day.
The quickest improvements are to shorten showers, avoid leaving the water running unnecessarily and use a suitable water-efficient showerhead. The Energy Saving Trust’s guidance on saving water at home explains how these changes can also reduce the energy required for hot water.
Measure your shower’s flow rate
Before buying a replacement showerhead, measure the existing flow. Place a suitable measuring container beneath the shower, run it at a normal setting for 10 seconds and record the amount collected.
Multiply the collected volume in litres by six to estimate the flow rate per minute. For example, collecting 2 litres in 10 seconds indicates approximately 12 litres per minute.
This makes it easier to estimate potential savings from reducing shower duration or changing the showerhead. For mixer and power showers, a compatible lower-flow showerhead may be worthwhile.
Electric showers generally have lower flow rates already. Do not fit an additional flow restrictor or unsuitable showerhead without checking the manufacturer’s instructions, as restricting flow can interfere with the shower’s operation.
Reduce toilet flushing water
Toilet flushing uses drinking-quality mains water even though the task does not require drinking-quality water. Waterwise estimates that toilets account for around a quarter of household water use.
Modern dual-flush toilets typically use around 4 to 6 litres per flush, while some older toilets use considerably more. Using the smaller flush appropriately and repairing defective mechanisms are straightforward ways to reduce consumption.
Older cisterns may accept a suitable displacement device that reduces the water used per flush. Some water companies supply these devices free of charge. Check compatibility with the cistern and ensure that the toilet continues to clear waste properly. Do not put bricks or improvised objects into the cistern, as they can damage components or interfere with flushing.
When replacing a toilet, compare the manufacturer’s stated flushing volumes rather than assuming that every dual-flush model is equally efficient.
For homes seeking greater independence from mains supplies, rainwater can also be used to flush a conventional toilet manually during an ordinary water supply interruption, provided the drainage system is working normally. A permanent rainwater-fed toilet requires a more substantial, properly designed plumbing installation.
Use less water at kitchen and bathroom taps
Running taps can waste water quickly. The Consumer Council for Water gives a typical consumption figure of around 9 litres per minute for a running tap.
Turn taps off while brushing teeth or shaving. When washing dishes by hand, use a washing-up bowl rather than leaving the tap running continuously. Avoid running cold drinking water down the drain while waiting for it to become cooler. A covered jug of drinking water in the fridge can provide a convenient alternative.
Water-saving tap aerators can reduce the flow without necessarily making ordinary handwashing and rinsing less convenient. Check the fitting type before purchasing, as not every tap is compatible.
Water efficiency should not come at the expense of hygiene. Continue washing hands properly, cleaning food preparation surfaces and following any household or medical hygiene requirements. The aim is to eliminate unnecessary running water, not reduce the water needed for safe everyday activities.
Run washing machines and dishwashers efficiently
Washing machines and dishwashers can use water efficiently when loaded and operated correctly. Running frequent small loads, however, increases consumption over time.
- Wash full loads: Use the recommended capacity without overloading the drum or compromising cleaning performance.
- Select suitable eco programmes: These often reduce water and energy consumption, although cycle times may be longer.
- Avoid unnecessary pre-rinsing: Scrape food from plates before loading the dishwasher, following the appliance manufacturer’s recommendations.
- Choose the right programme: Heavily soiled items may need a different cycle. Rewashing poorly cleaned items wastes more water.
- Maintain appliances: Clean filters and follow maintenance instructions to preserve washing performance.
Water efficiency should be considered when replacing an appliance, but buying a new washing machine or dishwasher solely to save a relatively small quantity of water may offer poor financial value.
Compare water consumption per cycle alongside energy use, capacity, cleaning performance and purchase price. A well-maintained existing appliance used sensibly may be the more economical option.
Collect rainwater instead of using mains water outdoors
Collecting rainwater is one of the simplest ways to replace mains water for tasks that do not require drinking-quality supplies. A water butt connected to a downpipe can provide water for established garden plants and other suitable outdoor uses.
The Royal Horticultural Society’s guidance on collecting and reusing water recommends collecting roof runoff in covered water butts, keeping debris out and positioning containers on firm, level supports.
A water butt can also be useful during a temporary mains supply interruption by providing non-drinking water for appropriate sanitation tasks. However, stored rainwater is not automatically safe for drinking, cooking or personal hygiene.
How much mains water a water butt saves depends on rainfall, roof collection area, tank capacity and actual outdoor demand. A full water butt that is rarely used may provide little annual saving, while one that is regularly emptied and replenished can replace more mains water.
Make the garden less dependent on watering
Reducing outdoor water demand is often more effective than simply increasing storage capacity. A garden designed to retain moisture needs less intervention during dry periods.
- Mulch beds and borders: Organic mulch helps reduce evaporation and improve moisture retention in the soil.
- Choose suitable plants: Match planting to local soil, exposure and typical rainfall rather than relying on frequent watering.
- Water the soil: Apply water around plant roots rather than spraying foliage and surrounding surfaces unnecessarily.
- Use watering cans: They provide more control over the quantity delivered than a continuously running hose or sprinkler.
- Adjust lawn care: Allow established lawns to tolerate ordinary dry periods rather than maintaining an artificially green appearance through constant watering.
- Improve the soil: Incorporating suitable organic matter can improve water retention and reduce the need for irrigation.
During prolonged dry weather, prioritise newly planted trees, vulnerable plants and containers that dry out quickly. Established plants and lawns may need less attention.
Where temporary water restrictions apply, follow the exact instructions issued by the local water company. Restrictions vary by area and can change, so do not assume an activity permitted elsewhere is allowed at your property.
Can you reuse household water?
Some water can be used more than once without installing specialist equipment. For example, clean water left in a drinking glass may be suitable for houseplants, while cooled, unsalted vegetable cooking water may be used for appropriate garden plants.
Greywater is water previously used for washing, such as water from baths, showers and certain laundry rinse cycles. It can sometimes be reused for garden watering, but it may contain soap, detergents, grease and microorganisms.
The Royal Horticultural Society advises that untreated greywater should not be stored for longer than 24 hours and is generally more suitable for short-term use on ornamental plants than edible crops. Water containing bleach, disinfectants or harsh cleaning chemicals should not be used for this purpose.
Greywater should not be confused with toilet wastewater, which is unsuitable for casual household reuse. Do not connect greywater directly to drinking water plumbing or improvise permanent pipework modifications.
For ordinary homes, modest reuse through a watering can is generally simpler than a permanent greywater recycling system. The latter requires appropriate design, treatment, maintenance and safeguards against contamination.
Is a permanent rainwater harvesting system worthwhile?
Permanent rainwater harvesting can replace mains water used for toilet flushing and certain other non-potable purposes. A typical system collects roof runoff, filters it, stores it in a tank and delivers it through dedicated pipework.
However, domestic installations can be expensive because they may require substantial storage, pumps, filtration, controls and alterations to plumbing. Maintenance and electricity consumption also need to be considered.
Rainwater must not be connected directly to the mains drinking water supply. Where a permanent system has mains backup, the appropriate separation and backflow protection arrangements must be provided. Water Regs UK’s guidance on alternative water supplies explains these requirements and the relevant notification obligations.
Such systems are most worth investigating during new builds and major renovations, when dedicated plumbing can be installed more conveniently. Retrofitting an existing property solely to reduce water bills may not produce an attractive financial return.
A rainwater harvesting system also needs enough rainfall and storage to meet demand. It should not be treated as a guaranteed independent supply during prolonged dry weather or a power cut, particularly where pumps are needed.
Can reducing mains water use lower household bills?
For metered households in England and Wales, reducing mains water consumption normally reduces the variable water supply charge. Depending on the charging arrangements, it may also reduce the variable wastewater charge.
To estimate annual water savings, divide the litres saved by 1,000 to convert them into cubic metres. Multiply this by the relevant water tariff per cubic metre. Include any applicable reduction in wastewater charges, while recognising that fixed standing charges generally remain payable.
For example, saving 25 litres daily amounts to 9,125 litres, or 9.125 cubic metres, over 365 days. The financial value depends on the household’s actual tariff, not on a single national price.
Unmetered households in England and Wales generally do not receive an immediate reduction in their water bill from using less water. Their charges are normally based on historical property values rather than measured consumption. However, reducing hot water use can still save energy.
Domestic charging arrangements differ in Scotland and Northern Ireland. Scottish households generally pay water and wastewater charges through Council Tax arrangements, while Northern Ireland households do not currently receive separate direct domestic water bills. Water efficiency can still reduce energy costs and demand on public supplies.
Check for free water-saving devices before buying anything
Many water companies provide free or subsidised water-saving equipment to eligible customers. This can include shower timers, tap fittings, cistern displacement devices and equipment for detecting leaking toilets.
The Consumer Council for Water’s Get Water Fit service helps households in England and Wales assess their water use and find available water-saving products.
Check eligibility, availability and compatibility before ordering. Some devices suit older plumbing but offer little benefit with newer, already efficient fittings.
A practical plan to reduce mains water consumption
A staged approach helps avoid unnecessary spending and makes it easier to judge which changes genuinely work.
- Establish a baseline: Record water meter readings or estimate consumption using a recognised household calculator.
- Check for leaks: Inspect toilets, taps, visible pipework and the water meter for signs of continuous water use.
- Change everyday habits: Reduce unnecessarily long showers, running taps and inefficient appliance use.
- Look for free equipment: Check water company schemes before purchasing showerheads, tap fittings or cistern devices.
- Reduce outdoor demand: Use mulch, appropriate planting and targeted watering to make the garden less dependent on mains water.
- Collect rainwater: Install a suitable water butt where roof drainage and outdoor space allow.
- Measure the results: Compare consumption over similar periods before deciding whether further equipment is worthwhile.
Reducing mains water use need not involve major changes to a property’s plumbing. For many households, the biggest improvements come from repairing faults, using hot water more efficiently and avoiding unnecessary consumption. Rainwater collection provides an additional benefit by replacing treated water for appropriate outdoor uses and making a small reserve of non-drinking water available when supplies are interrupted.
Mains water saving resources
- Consumer Council for Water: How much water do you use? provides typical water consumption figures for showers, baths, toilets, appliances and taps, helping households identify where reductions are possible.
- Energy Saving Trust: How to save water at home explains practical water-saving measures and how reducing hot water consumption can lower heating costs and environmental impacts.
- Waterwise: How to save water offers room-by-room recommendations for household water efficiency, including water-saving fittings and its Water Impact Widget.
- Consumer Council for Water: Get Water Fit helps households identify practical savings and find free water-saving equipment offered through participating water companies.
- Consumer Council for Water: Suspected water supply leaks explains how to use meter readings to investigate leaks, identify possible supply pipe problems and approach water companies about repairs.
- Royal Horticultural Society: Collecting, storing and reusing water provides guidance on water butts, rainwater collection, garden watering and safe short-term greywater reuse.
- Water Regs UK: Alternative water supplies outlines the plumbing regulations and contamination safeguards relevant to permanent rainwater and other non-potable water systems.
- UK Government: Droughts explains how households can conserve water during dry periods, follow restrictions and maintain essential drinking water and hygiene needs.
