The Heretaunga Plains have experienced several consecutive months of significantly below-normal rainfall.
Water restrictions have begun in Hastings and Napier as consistent dry conditions create record-low aquifer levels in parts of the district.
Hastings District and Napier City councils are asking residents to conserve water, introducing Level 2 water restrictions on Tuesday.
At Level 2, hoses and sprinklers can only be used from 6am-8am and 7pm-9pm every second day, with odd-numbered homes on odd dates and even-numbered homes on even dates.
Waimārama in the Hastings District remains at Level 3 water restrictions.
With summer still three weeks away and rainfall in Hastings well below average, locals around the Paritua–Karewarewa Stream at Bridge Pā said last week it had already run dry.
Hawke’s Bay Regional Council (HBRC) said Paritua-Karewarewa Stream wasn’t the only stream or river across Hawke’s Bay with low flows.
“The southern areas of the region have had below-average rainfall and dry soils for much of the year, but the Heretaunga Plains has been hardest hit,” the council said.
“Some streams naturally stop flowing at times, while others are fed by groundwater and usually flow year-round.
“Overall, river flows across the region are well below normal, especially south of the Mohaka River.”
The council said over the past year, the Heretaunga Plains had experienced several consecutive months of significantly below-normal rainfall, with four months receiving less than 40% of average monthly totals.
“This prolonged dry period has led to severely depleted soil moisture and suppressed recharge to shallow groundwater, resulting in record-low aquifer levels across many parts of the plains – including areas directly adjacent to the Paritua-Karewarewa system.
“In response to dry soils and rising spring temperatures, irrigation use began earlier than usual, further reducing groundwater levels in some areas, particularly along the plains margin near Bridge Pā.”
The council said the Paritua-Karewarewa Stream behaved differently along its course.
“The upper section (Washpool to Raukawa Road) often dries up during dry conditions. The middle section near Mangaroa and Korongata Marae varies with rainfall, groundwater, and water use. The lower section (Rosser Road to Pakipaki) usually gains water from the ground and flows more consistently.”
Balancing low rainfall and irrigation in the Paritua-Karewarewa catchment relied on a mix of factors – community collaboration, science and strong policy.
Rainfall was the main factor, with drying during times of low rainfall being natural, even when water use was restricted.
“We work closely with local landowners and tangata whenua on projects to support the stream, such as wetland restoration, improving streambeds and planting along the banks,” the council said.
“This helps the stream to be more resilient, but it will always be sensitive to dry conditions.”
Hawke’s Bay Regional Council chair Sophie Siers said water was a taonga (treasure) for all of the region.
“Through working closely with tangata whenua, landowners and the local community, we are focused on supporting the stream into the future.”
The council’s Tank plan, developed in 2012, alongside representatives from tangata whenua, the primary sector, environmental groups, land users and councils, outlines how the land and water, including the aquifer, in the Heretaunga Plains’ Tūtaekurī, Ahuriri, Ngaruroro and Karamu catchments would be allocated.
But growers say the plan risks harming the region’s economy if it implements newly proposed water allocations they claim are based on incomplete data.
This plan is under appeal and will go before the Environment Court in 2026.
Earth Sciences New Zealand meteorologist Chester Lampkin said its New Zealand Drought Index (NZDI) and its soil moisture mapping indicated it was unusually dry in rural Hastings.
Lampkin said Hastings’ last rainfall above 10mm was 18.4mm on October 14, with total rainfall for the month 38.44mm, well below the average of 65.3mm.
“Hastings was also dry in August and September with November dry so far this month, with no rain recorded so far, with the average at 36mm.”
In Napier, the last rain above 10mm at Napier Airport was on October 28, when 15.8mm fell.
Before that, 28.2mm fell on October 14. October rain was near average at 56.0mm. The average was 55.9mm.
Napier was also dry in August and September and so far in November, there had been just 0.2mm. The average was 55.9mm.
A tropical low was moving southward across New Zealand from Wednesday through to Friday, with a good chance for rain on Wednesday night and into Thursday.
While Earth Sciences New Zealand never predicts drought, it does make seasonal climate predictions.
“Our summer outlook will be out at the end of November. Our current three-month outlook covers through the end of January. That forecast is for normal amounts of rain for the east of the North Island, including Hawke’s Bay. A developing La Nina is expected to be a factor in our forecast, though variability was anticipated.
LDR is local body journalism co-funded by RNZ and NZ On Air.