The Wellington region may have to go into level three water restrictions in the next two weeks.
Councils and emergency authorities have been preparing for the possibility of an acute water shortage this summer.
Currently Wellington, Upper Hutt, Lower Hutt and Porirua are in level two restrictions which ban household garden sprinklers and irrigation systems.
Wellington Water's latest modelling shows that water usage remains high, with last week's daily use peaking at 194 million litres.
The agency said if water use stayed the same, they might need to move to level 3 in the next one to two weeks.
Level three restrictions would ban all outdoor residential water use and ask households to reduce indoor water use.
Under this level Wellington Water would also prepare water regulator Taumata Arowai to declare a drinking water emergency.
Under the Water Services Act 2021, the regulator can declare a drinking water emergency to protect public health.
The declaration of a drinking water emergency also makes some broad and flexible powers available to Taumata Arowai, which can require water suppliers and others to take or cease certain actions to manage risks to public health.
Taumata Arowai has said it is "actively monitoring" both Wellington Water and its council owner, to make sure it is "ready to act if required" so metropolitan residents can continue to have enough water for drinking and sanitary needs in coming weeks.
Wellingtonians have been preparing for the potential for a water shortage with 200-litre storage tanks sold at a discounted rate by councils being in high demand in recent weeks.
Earlier this month a queue of people waited hours in the hot sun to purchase the tanks at the Wellington City Council's southern landfill's Tip Shop.
Porirua City Council has also introduced a pre-order scheme for the tanks due to the demand.
The Wellington region's water woes have repeatedly made headlines this summer with threats of tougher water restrictions and large leaks cropping up almost daily.
Wellington Water has said it needs a share of $760 million from the region's councils to fix the broken network.
Mayor Tory Whanau told Nine to Noon water infrastructure was a top priority for the council.
"It's receiving $110 million this financial year. When we get to our LTP [Long Term Plan] in the next couple of weeks we're looking at increasing our funding... We kind of have no choice, we have to increase our funding so I'm confident that will go through.
Timaru council introduces water restrictions
Water restrictions, including a ban on watering lawns, are now in place in Timaru, ahead of a dry weather forecast for the region.
Timaru District Council introduced level 1 water restrictions for all urban areas, as well as users of the Seadown rural scheme, to take effect from Thursday.
Drainage and water manager Andrew Lester said making small changes now was the best way to avoid more significant restrictions down the track.
Residents were being asked to reduce their usage and at the very minimum stop watering their lawns.
"Most lawns are able to handle a dry period and will bounce back as soon as the rain starts again. Letting your lawn go a bit yellow means there's water for your plants that need it more.
"We've been reasonably lucky so far this summer with regular rainfall, but it's forecast to be drier than usual over the next few months, so every drop will count."
Lester said while the council has good water infrastructure and storage in place, capacity was not unlimited and the system could not support the increasing level of peak demand.