There are fears water restrictions might be needed over summer in Hamilton and around the Waikato, following the driest 12 months for the region on record.
Water levels in Lake Taupō, which feeds the all-important Waikato River, have been lower than usual. If it gets too low, the amount flowing into the Waikato River could drop.
"While Hamilton city has a resource consent to take water from the river, this is not an unlimited supply," said Hamilton City Council city waters manager Maire Porter.
"Additionally, if Waikato River levels drop significantly due to low levels in Lake Taupō, it could limit how much water we can physically take from the river during summer this year."
All of Hamilton's water comes from the river. Mercury Energy manages the level of Lake Taupō as part of its resource consent.
"In the last 12 months, we have not had one month with above average rainfall," said Mercury Energy commercial advisor Larnie Chrystall. "The last 12 months - November 2019 to October 2020 - were the driest we have on record for that timeframe."
Mercury Energy manages the level of the lake as part of its resource consent. Less water into the lake means less can be allowed to flow out.
"NIWA has advised that we're in for a hot and humid summer, and with Lake Taupō's water levels being below normal for much of the winter period affecting the levels in the Waikato River and how much we can take for Cambridge and surrounds," said Waipā District Council water services manager Martin Mould.
"Last year we had a particularly challenging year in Waipā, moving to alert level 4 for the first time ever in Te Awamutu, Pirongia and Ohaupō. With below normal rainfall this winter, our catchments haven’t fully recharged yet, so we will need to be mindful of this starting now."
There are currently no restrictions on water usage in Hamilton. Under alert level 4, no one is allowed to use water outside.
Restrictions are currently in place in Auckland, which gets around 33 percent of its water from the Waikato. It currently has permission to take 175 million litres a day, the maximum its treatment facilities can process, when the river is in normal flow, and an extra 100 million litres a day when it's above normal.
Earlier this year water levels in the super city's lakes fell below 50 percent for the first time in 25 years. They've since improved to 72 percent, which is still well below the 91 percent normal for this kind of year.
Newshub has contacted Hamilton City Council and Auckland's Watercare for more information on how lower Waikato River levels could impact Auckland.
NIWA (the National Institute of Water and Atmospheric Research) says this summer is likely to be hotter than usual with northwesterly winds thanks to La Niña conditions in the Pacific Ocean. While this means possibly normal rainfall for the north and east of the country, the rest is likely to be drier. NIWA forecast mapping show the Waikato region right on the boundary between normal weather and dry.
In its latest outlook summary, NIWA said rainfall would be "near normal in the north of the North Island and about equally likely to be near normal or below normal for all remaining regions".
"Marine heatwave conditions may develop in the ocean surrounding New Zealand over the coming three month period, with air temperatures very likely to be above average in all regions of the country."
