Wellingtonians may be indulging in much longer showers than other cities, judging by the region's water use.

Every day, a single person in the Wellington metropolitan region uses about 220 litres in residential water. By comparison, Melbourne residents use around 150 litres a day.

Wellington Water network strategy and planning group manager Mark Kinvig said every drop saved was a win for the environment.

"It's not about using water, but about valuing it and using it more efficiently - everything from turning off the tap while brushing your teeth and using full loads in the washing machine and diswasher."

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Residential water use in Auckland and Dunedin is much lower at about 180 and 200 litres per person each day respectively.

Small actions would keep water in rivers and aquifers, reduce carbon emissions, and avoid the cost and environmental impacts of building new water sources, Kinvig said.

"Every drop people saved will reduce our carbon emissions and energy use, will leave more water in the environment, and reduce the amount of wastewater we have to treat."

ROBERT KITCHIN/STUFF If Wellington doesn't reduce consumption, Wellington Water will need to progress the development of new water sources in the next 10 to 20 years.

People could conserve water by using watering cans instead of hoses, watering in the morning or the evening, not leaving taps running, getting leaks fixed and taking shorter showers, he said.

"Showers use about 16 litres a minute."

Wellington's water needs were no different to any other city.

"The difference might relate to people believing there is plenty of water out there, so there's no pressing need for action."

123rf Wellingtonians appear to be indulging in much longer showers than residents in other cities.

People also tended to believe what they were doing was enough, he said.

Wellington's water comes from three sources: Hutt River/Te Awakairangi, the combined flow of the Wainuiomata and Orongorongo rivers and the Waiwhetu Aquifer - a natural underground reservoir beneath the Hutt Valley that is fed by river-water seeping down into the ground.

Wellington Water only took the water needed from the rivers, but there were times where there wasn't enough f to meet public demand.

When the water in the rivers gets low, typically during summer,, Wellington Water supplements supply with water stored in Macaskill Lakes at Te Marua.

If no one acted, the city would need more - recent and expected population growth had reduced capacity in the existing water sources, Kinvig said.

"If we don't reduce consumption we will need to progress the development of new water sources in the next 10-20 years.

"This will cost the region several hundred million dollars and have a sizeable carbon and environmental footprint.

ROSS GIBLIN/STUFF Wellington residents are tap-happy - the region has a residential water consumption of about 220 litres per person each day.

"Reducing water use is about our community's overall sustainability and resilience, and not just seeing us through the summer."

However, residents weren't entirely to blame - Wellington's water network was causing water loss.

"A relatively large proportion of our network is at or approaching its designed replacement date, so we will also be increasing our efforts to optimise our maintenance and renewal programme."

The region has residential garden watering restrictions in place during daylight savings and year-round in the Upper Hutt.

Residents can use a single watering system (sprinkler, irrigation system, soaker hose, or unattended hose) between 6-8am and 7-9pm on alternate days, based on their house number.

WAYS TO REDUCE WATER USE

* Turn the tap off while brushing your teeth and take shorter showers

* Use full loads in the washing machine and dishwasher

* Install low-flow shower heads and garden irrigation systems

* Use watering cans instead of hoses in the garden, and collect water in a rainwater tank for the garden

* Water the garden in the morning or evening

* Get leaks fixed

* Wash cars on the lawn so that run-off is absorbed