Wellington Water has announced the region will move to level 2 restrictions from midnight on Wednesday.
"This decision has been made due to very high demand, peaking at 195 million litres on Tuesday, January 9," Wellington Water said.
"Wellington City, Porirua City, Hutt City and Upper Hutt City will move to level 2 water restrictions at 12:01am on Wednesday, January 17."
Residents in the areas listed above will be banned from using sprinklers and irrigation systems. Wellington Water said people can still water their garden by hand, so long as hoses aren't left unattended.
"The ban applies to all irrigations systems, soaker hoses and unattended watering systems."
Wellington Water said the level 2 restrictions are necessary as it expects "demand to increase further in the coming weeks without intervention, with temperatures increasing and more people returning from their holidays elsewhere".
It said forecast brief periods of rainfall are unlikely to help the situation.
Wellington Water's Laurence Edwards said by implementing level 2 restrictions now it reduces the risk of longer, more severe curbs later.
"The restrictions apply to residential properties only. However, we do ask that businesses across the district take steps to reduce their water usage where possible.
"We are working with our client councils to provide guidance for non-residential customers, including on the restrictions that may apply at level 3 and 4. If we all do our bit, then we can hopefully avoid further restrictions."
An ageing pipe system and population growth have caused hundreds of leaks to pop up across Wellington, with about 45 percent of its water leaking into the gutters.
"We also want to assure residents that we are continuing to find and fix as many leaks as we can within the funding and resources we have available - our crews are out there every day working on leaks," Edwards added.
"In the meantime, we encourage everyone to make simple changes to reduce their water use. Small changes such as taking shorter showers (no more than 4 minutes), not running the tap while brushing your teeth and only doing full loads of washing can all make a real difference."
Dry weather forces restrictions in Marlborough
The Marlborough District Council (MDC) has also announced a temporary ban on hosing in Picton and Waikawa amid ongoing hot weather leading to short supply.
"Water restrictions requiring Picton and Waikawa residents to limit their sprinkler use to alternate days have made a small impact and we appreciate people's efforts. However, this has not been as effective as we had hoped," council operations and maintenance engineer Stephen Rooney said.
"We are now asking locals to do more to save water immediately. Don't use sprinklers or the garden hose, take a short shower, turn off the tap when you are brushing your teeth and don't wash your car."
The curbs would come into force from Friday.
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