Napier residents were on Wednesday warned against flushing as heavy rain threatened to force wastewater discharges into the Ahuriri Estuary.
The warning was issued via the Napier City Council's Facebook page about 10.45am on Wednesday, saying there'd been more than 100mm of rain overnight and another 64mm was forecast.
"Our wastewater system has been overloaded by over 24 hours of heavy rain," the post said.
"If we all work together to reduce the amount of wastewater we're producing, we hope to avoid an emergency discharge into the estuary.
"In order to prevent an emergency discharge from the network into Ahuriri Estuary, Napier City Council asks that the community flush toilets only when necessary, and hold off using showers, dishwashers or washing machines if possible.
"If an emergency discharge is carried out, this should prevent wastewater backing up and overflowing into city streets and properties.
"Toilets, showers, dishwashers and washing machines all drain into the city's wastewater network, which is also affected by infiltration of stormwater."
An NCC spokesperson said Hawke's Bay Regional Council had been informed of the situation.
SCHOOL'S OUT
Hastings Intermediate School told students they could stay home because of the bad weather.
"As a consequence of major flooding in the school playground and more rain forecast, we recommend where possible that students do not attend school today," a post on Facebook said.
"Students that do attend should wear gumboots. To be clear ... the school is open but if alternative arrangements can be made today then that would be wise."
FLIGHT WOES
The weather was also causing havoc for flights in and out of Napier.
An Air NZ spokeswoman said several flights in and out of Napier were delayed on Wednesday due to visibility at Hawke's Bay Airport.
NZ5005 from Auckland to Napier was diverted to Palmerston North due to the low cloud.
Homeowners were also nervously watching rising water in the Tukituki River in the coastal Hawke's Bay settlement of Haumoana.
Hastings District councillor Ann Redstone said on Wednesday morning "houses down at the beginning of Haumoana Rd are under threat" due to the rising Tukituki River mouth.
A Hawke's Bay Regional Council spokeswoman said the river mouth in Haumoana was "not blocked".
"There are big swells running which aren't allowing the river water to get out to sea."
She said there was surface flooding on lawns around Haumoana Rd, but not a "huge risk" to homes.
There was also surface flooding on orchards around Raupare Stream in the Twyford area.
A HBRC spokeswoman said the weather situation had peaked by 2.30pm and the rivers have coped very well.
Rivers have not reached alert levels and are expected to start to drop as the day goes on and the weather clears as forecast.
There were no concerns about logs in rivers, she said.
PLENTY OF WORK FOR WINEGROWERS
The belts of heavy rain may not have created any damage to the region's grape vines but they had set the scene for "plenty of work" according to winegrowers.
Mission Estate viticulturist Steve Wheeler said although the two days of rain had created plenty of surface water across nearby paddocks it had created no major issues for the vines.
"But it creates a bit more work for us as the grass and weeds will really grow so there will be lots of mowing."
Hawke's Bay Winegrowers chairman Michael Henley agreed.
"If we get a good patch of warm weather over the next week it's going to take off."
He had not heard of any major serious surface flooding across the region's vineyards at this stage, although with rain continuing to linger it was something of a wait and see situation.
The rain had arrived at a time when many viticulturists would have been considering beginning some irrigation.