Domestic water conservation reduces unnecessary demand, improves water-use efficiency, prevents losses, and substitutes treated drinking water with rainwater or reused water where safe. These methods conserve freshwater and can improve household water security.
This is core SL and HL content in subtopic 4.2, Water access, use and security. Reducing household withdrawals from reservoirs, rivers, and aquifers helps keep use within sustainable limits.
| Technique | How it conserves water |
|---|---|
| Repair leaks | Prevents waste of treated water. |
| Low-flow taps, showerheads, and dual-flush toilets | Reduce water used per service. |
| Efficient appliances | Washing machines and dishwashers use less per cycle. |
| Behaviour changes | Shorter showers, closed taps while brushing, and full appliance loads lower demand. |
| Rainwater harvesting | Stores roof runoff for gardens or toilet flushing, replacing treated water. |
| Greywater reuse | Reuses water from showers or sinks where treatment and regulations permit. |
| Efficient landscaping | Native or drought-resistant plants, mulch, and drip irrigation reduce evaporation. |
| Meters and leak detectors | Reveal abnormal consumption and encourage rapid action. |
Effectiveness depends on climate and infrastructure: rainwater harvesting works best with sufficient rainfall and storage, while metering is strongest when users respond to price or feedback.
A common misconception is that all captured or reused water is safe to drink. Greywater and rainwater may contain pathogens or pollutants. Their use therefore depends on treatment, local regulations, and exposure risk.
Cape Town’s 2018 water crisis shows how household restrictions, shorter showers, leak repair, and public monitoring can rapidly lower urban demand. However, affordability matters: efficient devices may benefit wealthier households first, so equitable subsidies support .
