Water crisis: How to save 20 litres a day

Aucklanders could save the required 20 litres of water per person per day by showering for one or two minutes less, flushing the toilet three times less each day or halving the number of clothes washes a week.

Watercare has asked people to cut water use by 20 litres, or one-eighth of the current average of 160 litres per person per day, until sediment in the waterlogged Hunua Ranges drops enough to stop clogging the water treatment plants.

A 2013 Watercare report said showers accounted for the biggest single item (24 per cent) in the average household's water usage in summer.

Clothes washing was a close second (23 per cent), followed by toilets (18 per cent) and outdoor use such as swimming pools, spa pools and watering the garden (17 per cent).

Aucklanders showered for an average of 6.6 minutes in summer, using an average of 10 to 20 litres of water a minute. That means we could save 20 litres by showering for one or two minutes less each day.

Toilets used an average of 6.7 litres of water per flush and were flushed on average just under five times a day per person. We could save 20 litres by each flushing the toilet only twice a day instead of five times.

Washing machines used an average of 122 litres for every load, with an average 0.35 loads (43 litres) per person per day. We could save 20 litres each a day by halving the number of washes we do each week.

Outdoor water use accounted for about a sixth of total residential usage in summer. Only a small number of households, mainly those with both a swimming pool and a spa pool, were responsible for the high usage.

One in every 10 households at the time of the report had leaky taps, accounting for 4 per cent of total residential usage.

Auckland water usage

56% residential
25% commercial/industrial
4% Papakura bulk supply
14.5% water losses

Residential usage - summer

24% showers
23% washing machines
18% toilets
17% outdoors
11% taps
2% baths
1% dishwashers
4% leaks