What you need to know about water restrictions

The FAQs below and many more are available on Wellington Water's website.

What’s the point of water restrictions?

Wellington’s daily water supply has a limit, as the treatment plants can only supply so much. If demand exceeds what the treatment plants can supply there’s a risk that the water levels in the storage reservoirs across the region are drawn down too low, causing water quality issues and in an extreme scenario even depressurising areas of the network. This can be dangerous as it increases the risk of contamination of drinking water, and boil water notices may need to be issued to stop people getting sick.

This means we have to be very careful to manage the daily water supply and demand, and don’t use too much. That’s where water restrictions come in. They help everyone understand how they can best manage their personal water use, so there’s enough to go round for the necessities.

Level 1 splits outdoor water use between odd and even houses, to spread the load of daily water demand. This means people can water their gardens regularly without everyone using a lot of water all at once. It also reduces waste by restricting watering to the morning and evening, when water is less likely to evaporate in the heat of the day.

Level 2 makes sure people are watering their gardens only when they really need to, with no sprinklers or irrigation systems, and only watering gardens by hand.

Level 3 comes into play when we need to take serious action, and all residential outdoor water use must be stopped. We know that people put a lot of hard mahi and love into their gardens, so consider using grey water to water your garden – just not your vegetables, or any plants you’re planning on eating.

Level 4 means we’re in a significant water shortage. On top of stopping all outdoor water use, we must reduce indoor use. This could include 2-minute showers and reducing laundry to one load per person, per week.

How can you ask me to restrict my water use, when we’re losing so much water because of leaks?

Finding and fixing leaks is one of Wellington Water’s top priorities, but with the resources available they can’t fix them all. They’re working on the issue, but it won’t happen overnight. The risk of a water shortage this summer and tighter water restrictions is real, and the situation may shift quickly.

To ensure there’s enough water to go around for the necessities, we need everyone to do their bit. Water restrictions help people understand how they can best save water at their place, and when to do so. If people follow the restrictions, it reduces the chance of moving to higher levels.

Water restrictions are enforced through council bylaws. Wellington Water recommend the level of restrictions for their council shareholders to implement.

How would a water shortage affect me?

If Wellington experiences tighter water restrictions, we may ask you to reduce your indoor use as much as possible. At Level 3, we ask you to consider using less water indoors, i.e. taking shorter showers or ensuring that you’re doing full loads of laundry. At Level 4, we ask people to reduce their showers to 2 minutes each, and do one load of laundry per person, per week.

If we can’t get demand down far enough and face a severe water shortage, we may need to issue boil water advisory notices, as low reservoir levels and low water pressure in pipes can increase the risk of contamination. A boil water notice is when you must boil tap water for at least one minute before drinking, using it to prepare food or in cleaning.

What happens if the current level of restriction isn't enough?

If the current restriction level doesn't decrease demand to match available supply, then we may have to move to the next level of water restrictions.

Why is this summer more serious than previous summers?

Over the past two summers, there has been a real risk of tighter water restrictions – but they’ve been narrowly avoided thanks to substantial and unusual rainfall in summer because of ex-tropical cyclones Dovi and Gabrielle. We can’t assume that this will happen again. El Niño conditions are forecast, and we’re expecting a hotter, drier summer than the previous two.

This combination of increasing leaks, population growth, above average water use, and forecast El Niño conditions all increase the risk of tighter water restrictions.

We’ve had all this rain, how could tighter water restrictions be on the cards?

Rain helps us fill the storage lakes during winter, so we can use it during summer when river levels drop. But this storage has a limit – once it’s full, it’s full, and more rain in winter doesn’t change that.

We’re only able to take water from the rivers when they’re above a certain water level. But heavy rain can be just as bad as not enough! When there’s short bursts of heavy rain, it can fill rivers with dirt, sticks and debris. This makes it harder to treat (make safe to drink) and risks blocking the pipe and tunnels that supply the treatment plants. This means that sudden downpours are much less helpful than they seem.

Currently, the two storage lakes (the Macaskill Lakes, at Te Mārua) store up to 3.35 billion litres of water – enough to supplement supply for 2 – 3 months in summer. Wellington Water and their council owners are progressing plans to increase the available water storage.

Why is there a risk of a water shortage this summer?

Wellington Water’s modelling shows that if we have an average summer – meaning no significant rainfall – their councils will have to put tighter water restrictions in place to reduce the risk of an acute water shortage. This comes down to water demand and supply capacity. Water use in the metropolitan Wellington region is at an all-time high. Leaks are increasing due to the water network being old, population growth is driving up the demand for water and Wellingtonian’s simply use more water than comparable regions.

There's also a finite amount of water that can be treated and supplied on any given day. This includes a ‘buffer’ that allows for varying levels in daily water usage, unplanned outages, or planned maintenance work. However, the increase in leaks in the network means the available ‘buffer’ is becoming increasingly tight.

In winter, when there is plenty of rain and the river levels are healthy, Wellington Water can supply up to about 220 million litres of water per day. But in summer, when it’s hot and dry and river levels drop, this can go down to about 170 million litres of water per day. 170 million litres might sound like a lot, but Wellington is using and losing more water than ever before – often getting up to 205 million litres per day in summer!

You can see that those numbers don’t work. When demand is higher than the available supply from the rivers and aquifer, then we have to dip into the water stored in the storage lakes. But this stored water is precious and is critical for getting through a long dry period, and in summer it’s harder to refill the lakes. So over time, they get lower and lower, leaving Wellington with less and less water stored and available until next winter.

What will happen if we run out of water?

Wellington Water has emergency plans in place and will work with Wellington City Council, their other council owners, and WREMO (Wellington Regional Emergency Management Office) to provide emergency water to residents.

We encourage people to be prepared at home too, by having their own storage of emergency water. This is also really important to prepare for a significant earthquake that could happen at any time.

You can read more on Wellington Water’s Emergency Water webpage.

Can I still water my garden?

Level 2: Yes - you can use handheld watering devices to water your garden during a sprinkler ban. E.g. a handheld hose. We recommend that you only water between the hours of 6-8am and 7-9pm so the soil better retains the moisture. You can water your garden with water collected from your roof, or with grey water collected from your bath, shower, washing machine or kitchen sink.

Level 3 and 4: Under Levels 3 and 4 there is a ban on all outdoor water use. However, vegetable gardens are a vital source of food for many households. Watering of vegetable gardens is permitted using a watering can or bucket. This helps reduce unnecessary water use and to keep water used to a minimum. Please restrict your water use to only what is needed to sustain your vegetable garden, and use the watering can or bucket before 8am or after 7pm to minimise evaporation and make the best use of the water for your vegetables.

What are some other ways that I can water my garden?

You can water your garden with grey water collected from your bath, shower, washing machine or kitchen sink.

If you do use grey water check to make sure your detergents are biodegradable. The Ministry of Environment advice on choosing products for use in grey water systems is to use “appropriate soaps and detergents – avoid washing powders that whiten or have enzymes, and avoid detergents or cleaners containing boron”.

Can I still wash my car during Level 2 water restrictions?

Yes you can, by hand — we recommend using a bucket and a trigger nozzle on a hose.

Can I still fill my pool during Level 2 water restrictions?

Yes, but you must be holding the hose as it fills the pool – any unattended watering is not permitted.

However, please consider using our fantastic swimming pool facilities as an alternative, including our outdoor pools Thorndon Pool and Khandallah Pool.

Can I still waterblast my house during water restrictions?

Level 2: Yes – attended hand-held hosing (including water blasting) is still ok. But please consider holding off on water blasting until a later date if possible, or only use it carefully and when necessary (i.e. not for sweeping the driveway).

Level 3 and 4: All domestic outdoor water use would be banned – so that would mean no DIY water blasting.

My business relies on outdoor water use, what can I do?

I.e. house cleaners, nurseries etc.

You can continue to operate as normal, however we ask that you are pragmatic and responsible when watering. Check out Wellington Water's Key Guidelines for Non-Residential Water Restrictions.

Why can councils use water outdoors while there are water restrictions?

Water restrictions and where they apply are council decisions. Wellington Water provides advice to their client councils on what level of watering restrictions are appropriate for them to approve, and we help implement them.

We appreciate that it can be frustrating to see council properties using water while residential restrictions are in place. Councils run many public outdoor spaces, that service a large number of community groups and activities – everything from sports fields to botanic gardens. These often freely accessible communal spaces offer a huge benefit to the community and are very expensive to implement and maintain. If the plants and grassed areas at these facilities were to dry out and die off, significant investment would be needed to get them back to good condition, with the cost of this being covered by the community as a whole through rates.

Council parks and gardens staff work to minimise water use in many ways, for example, by using underground irrigation, mulching, watering as early in the day as possible, minimising overthrow and conducting new planting in autumn, winter and early spring, but not in summer - when more watering would be required. Council staff also water less often but more deeply thereby avoiding multiple light applications which don’t penetrate the root zones and lead to water being wasted and plants being placed under unnecessary stress.

Find out what Wellington City Council is doing to minimise its water use in this story.

If we’re being told to conserve water, can I fill up my emergency water tank?

It’s important for all households to store water in case of an emergency. We encourage all households to fill their emergency water tanks while restrictions aren’t in place or during Levels 1 and 2, so it is ready for use in tighter water restriction levels or in case of an emergency. No water restriction level directly restricts filling up your emergency water tank. Please be sensible and responsible with your water use, particularly under the higher levels.

When do annual water restrictions begin?

For Wellington City, Porirua and Lower Hutt, Water Restriction Level 1 happens every year at the start of Daylight Savings. It’s tied to seasonal changes, not current weather – so it happens even when it’s raining. Upper Hutt and South Wairarapa are on Level 1 year-round.

Wellington Water carefully watch things like public demand, weather forecasts, river levels, and storage levels to see whether we need to change restriction levels. We’ll always keep the latest water restriction level information on our website, and work with our councils to share the message.

Visit Wellington Water’s website for more about the current situation and other water-related FAQs and check out these water-saving tips.