We take it for granted that fresh clean water will always be available but there is only a certain amount of water in our rivers, streams, groundwater, and dams, and sometimes demand is greater than supply. Even before we run out of water, reduced river flow can harm fish and other wildlife.
Water in New Zealand is used for agricultural, domestic, industrial, and energy use. When it comes to conserving water, we can make a difference at home and work. The average New Zealander uses around 200 litres of water per person per day. Listed below are ways you could greatly reduce your consumption and lessen your impact on freshwater quantity.
Pay close attention to the BIG4 water users around the house – showers, washing machines, toilets and outdoor uses. Together, these account for about three-quarters of typical household water use.
How you can save water around your home
In the bathroom:
- BIG4: Showering accounts for about a quarter of household water use. Your choice of shower head is important. Measure your shower head flow rate by timing how long it takes to fill a 10 litre bucket. If it takes less than a minute, look for a shower head that uses less than 8 litres per minute at your local hardware store, or the WELS water efficiency website. Where possible choose having a shower over having a bath.
- BIG4: Toilets consume about a fifth of household water. Most people already have dual-flush cisterns, which typically use about half the water per-day compared to single-flush. If replacing your toilet, look at the WELS water efficiency label. A 5 Star rated toilet will uses just 4.5 litres for a full flush.
- Turn off the tap while brushing your teeth or shaving.
In the laundry
- BIG4: A top-loading washing machine uses about 150 litres of water for one cycle. Make sure you have a full load when you turn on the washing machine, or set it at half level for smaller loads. Next time you buy a washing machine, look at the number of stars on WELS water efficiency label. An efficient front-loading washing machine uses about half the water of a conventional top-loader. For most people, this will be the single biggest gain you can make in reducing water use around the house.
In the kitchen
- When washing vegetables, put the plug into the sink rather than letting the tap run.
- If you have a dishwasher, use it only for full loads. Each load typically uses 28-40 litres of water.
- When you buy a new appliance that uses water, look for WELS water efficiency rating. A 5 star rated dishwasher uses about 10-12 litres per wash.
Stop those leaks!
- Leaks waste water 24 hours a day, seven days a week. A dripping tap can waste up to 3,600 litres a year - that's more than a bath full a week.
- Check taps and pipes for leaks. If you have a header tank in your house make sure the plumbing is kept in good repair. Don't let the header tank overflow.
- Check your toilet flushing system and the overflow pipe on the outside wall for leaks.
- Check your hot water cylinder overflow pipe (on the roof.) If the pressure valve isn't working properly, the cylinder will leak hot water - a waste of both water and electricity.
- If your house has a water meter, carry out regular checks for leaks. First, make sure all the taps in the house are turned off. Take the meter reading, then re-check the meter after an hour. If the reading has advanced and no one has used any water during the period, you probably have a leak.
How you can save water outdoors
- BIG4: Irrigating cool-season grasses to keep them green through drought will maximise your water use at a time when water infrastructure and stream ecosystems are most stressed. Let your lawn transition from cool-season to warm-season grasses each summer without extra water. If it’s a big drought, let it go brown. Your lawn's drought tolerance is improved by setting your mower higher (more than 5 cm) and by mulch mowing to return organic matter to the soil.
- There are often restrictions on watering your garden in the summer in urban areas. Make sure you stay within the restrictions - a hose running at full volume uses 2000 litres of water per hour. This would fill 28 baths to the top.
- Soak your garden once every few days rather than giving it a quick drink every night. Light watering makes the plants shallow rooted and most of the water is wasted through evaporation. Soaking the ground every few days encourages the roots to go deeper into the soil to seek out moisture.
- In drought prone areas or areas where water restrictions are common, grow plants that flourish in dry conditions. Many of the hardy plants are only drought tolerant once established, so time your plantings during the wetter seasons.
- Water the ground, not the leaves of trees and shrubs. Watering leaves just increases water loss through evaporation, and on sunny days may damage them. Avoid watering in the heat of the day or in windy weather when water will evaporate rather than soak into the ground where it is needed.
- Mulch your garden with grass clippings or compost. Mulching can prevent up to 70% of water loss through evaporation. The best mulch is well rotted compost which will also improve the soil's ability to hold moisture.
- Grey water from baths, showers, sinks and washing machines can be used for watering the garden. This water also contains nutrients that are beneficial to the garden.
- If you leave the hose running while washing the car you could use 500 litres of water. Get a trigger nozzle for the garden hose or, better yet, try washing your car without the hose. A bucket of water and sponge will do a good job, followed by cloth to dry off.