Hawke's Bay has been hammered with two months' rain in 72 hours.

MetService's Napier rain gauge recorded 93.8mm of rain in the 72 hours to 4pm this afternoon, almost twice September's usual monthly average.

The Wairoa gauge had seen 200.8mm of rain in the same period, more than twice the usual monthly average for September.

The highest volume of rain fell in the ranges, which saw more than 300mm of rain in a 72-hour period.

Preliminary predictions from Hawke's Bay Regional Council put it at a one in five year event, although in the hill country around Wairoa it could be a one in 10-15 year event.

The worst of the weather is behind the region, however, with MetService meteorologist Ciaran Doolin saying rain would be easing tomorrow and Sunday.

In clearing weather, the thoughts turn to the clean-up, although at this point councils are unable to confirm how much damage had been done across the region.

A spokesperson for regional council said it would be compiling a list of damages/issues early next week, once the storm had finally ended.

Hastings District Council's incident manager, Alison Banks, said it could take two to three weeks to clean up.

"However, by prioritising we will ensure that the issues with the most impact are dealt with as quickly as possible."

A spokesperson for HDC said their water systems had coped well, although about eight properties were unable to flush their toilets on Thursday due to wastewater backup.

The council said they would be investigating the issue, but believed it was due to storm water entering the wastewater system in those areas.

Napier experienced major issues with stormwater and its wastewater systems, and to stop sewage leaking into the streets, reduced pressure by releasing wastewater into Ahuriri Estuary yesterday.

At this point the council was still collating data and was unable to confirm how much wastewater had entered the estuary.

Napier City Council chief executive Wayne Jack said they were well aware of issues in Napier's stormwater and wastewater systems, and had committed $20.6 million to address the issue.

Central Hawke's Bay District Council's group manager - community infrastructure and development, Josh Lloyd, said their wastewater was at capacity but had no water restrictions in place.

"It is just about keeping a very close eye as pumping equipment has been working for 78 hours constantly now."

Wairoa District Council asked residents to reduce water usage, as the Wairoa Water Treatment Plant was unable to produce water, meaning the town had to use stored water from its reservoirs.

Electricity distributor Unison said there were isolated power cuts across the region, and they were prepared for more, as the combination of sodden ground and wind increased the chance of slips and trees playing havoc with powerlines.

"We just remind people to make sure they are prepared for power outages, that they have got their emergency kits in place, just make sure they are prepared should power go out," Unison's relationship manager Danny Gough said.

The rain will be easing over the weekend and into next week.

Monday and Tuesday will bring cloud and isolated showers.

It may not be sunshine, but it is safe to say the worst of the rain is over.