Northland storm: Whangārei mayor Sheryl Mai gives district's infrastructure a 7/10

Despite reports of flooded homes and sewage overflow, Whangārei mayor Sheryl Mai felt the district's infrastructure coped well with Friday night's storm. Photo / File

Whangārei mayor Sheryl Mai has given her district's infrastructure a 7/10 with how it dealt with Friday's deluge.

From 6pm to 10pm on Friday, 156mm of rain was recorded at the Whangārei Airport weather station with over 200mm falling in seven hours. By 2pm yesterday, a total of 256mm had fallen in the area.

While she acknowledged reports of flooded homes and sewage overflow, Mai said the district's storm management infrastructure had performed well.

"On the whole, I'm really relieved and pleased so I would give it a 7/10."

The BP on Riverside Drive (pictured) was well under water after Friday's rain. Photo / Paul Shaw

Minister of Civil Defence and Northlander Peeni Henare said he suspected significant Government funding would be announced to aid in the cost of the region's flood recovery.

Mai said it would be "irresponsible" to suggest what the financial impact of the storm was before all assessments had been done. However, she was heartened to hear assistance would come.

"It's times like these that we really rely on assistance from central government because this is an unprecedented storm and the damage for our district, because of the volume of rain, we will be uncovering more and more," she said.

Mai, seen here prior to the construction for the Town Basin rolling ball clock, said it would be days until the true cost of the storm was revealed. Photo / File

In the coming days, assessments would be done to evaluate the cost of turning the water treatment plant on and diversions in the wastewater network, as well as testing the structural integrity of local bridges and roads.

Mai hoped these assessments wouldn't take more than a couple of weeks.

Friday's rain created a number of scary and potentially deadly situations for Northlanders.

Whangārei's Hātea river certainly changed complexion after the weekend's rainfall. Photo / Paul Shaw

Multiple people were rescued from partially submerged cars and evacuated from flooded houses. Kathy Pope in Tikipunga had to grab her late husband's ashes and treasured photos before leaving her home which was deemed unsafe due to land subsidence.

One 29-week pregnant Kaikohe woman had to be flown to Auckland after she almost gave birth in a Kaikohe GP clinic on Saturday morning. Fortunately, midwives were able to slow her labour and the Northern Advocate understands both Mum and baby are doing well.

Whangārei's Mitre 10 MEGA carpark submerged in water. Photo / Supplied

Businesses also experienced damage, one of which was Whangārei's Mitre 10 MEGA. After a creek which ran behind the building overflowed, the store's garden centre and timber yard were heavily affected with the owner speculating a financial cost in the tens of thousands.

Despite a deluge of rain over the weekend, residents in Whangārei and Paihia are being asked to reduce water usage this week after storm-damaged treatment plants left reservoirs low.

Whangārei and Far North District Council warned residents to urgently conserve water on Saturday after Friday night's downpour left water treatment plants in Whangārei and Paihia out of action.

While most affected plants are now operating again, councils are asking people to conserve water this week after reservoir levels dropped dramatically.

Initially, Friday's storm was described by MetService and media as a "once-in-500-years" event.

MetService meteorologist Rob Kerr said while the storm was extraordinary, it being dubbed as a storm only seen every 500 years was slightly misleading.

Kerr explained that term was established through a tool which examined how likely an event was to happen at a particular station. Using the fact that 200mm of rain had fallen in seven hours at the Whangārei Airport weather station, it was adjudged such a deluge would only happen once every 500 years.

The Otuihau (Whangārei) Falls were raging on Saturday morning. Photo / Paul Shaw

However, Kerr said records at that station had only been collected since 1993 and the margin of error was "quite large". He referenced a Northland storm from 1975 which saw 330mm of rain fall in just eight hours.

"Make no mistake, it was certainly a remarkable event to get such intense rainfall over several hours like that and to get it over pocketed areas as well."

While there could be some showers through today and tomorrow, Kerr said there would be little rain towards the end of the week with cool southwesterly winds set to hit Northland on Wednesday.