Ratepayer pigeons come home to roost

Raw sewage overflows from Kaitaia's wastewater system dozens of times a year thanks to years of neglect and under-investment according to the Far North District Council. Mayor John Carter said years of under-investment mean the town's sewerage system could no longer cope with even modest storms, and fixing that would cost millions.

And that wasn't the only bad news. Mr Carter said Kaitaia' sewage woes were just one example of a district-wide maintenance backlog. Water supplies, roads and halls were in a similar state.

A report that is due to go before the council today says sewage spills have occurred in Kaitaia for at least a decade, with little public awareness. One outlet in Bank Street alone had overflowed 35 times last year.

The report adds that in the event of a storm of a magnitude that could be expected once a year, 60 per cent of water entering sewerage pipes didn't reach the treatment plant, ponds, resulting in overflows of about 1750 cubic metres. Any overflows were likely to enter the Tarawhaturoa Stream, a tributary of the Awanui River, which drained into Rangaunu Harbour.

The report, by engineer Barry Somers, says the major problem is the aging sewer network's lack of capacity. There are also problems with stormwater intrusion via gully traps and illegal downpipes, and groundwater getting into the pipes.

Mr Somers said the problem had been investigated several times since 2004, but there was no evidence that anything had been done. The 2004 study put the cost of fixing inflow and infiltration problems at $3.8 million. A 2006 study lifted that to $6.6 million, but concluded that the main problem was the poor state of the infrastructure.

Mr Somers estimated upgrading the system to cope with one-in-one-year storms would cost more than $12.5 million. An upgrade capable of handling one-in-five-year storms, with bigger pipes and more storage, would cost more than $23.1 million.

The cost, which was likely to be borne by Kaitaia ratepayers, would be significant whatever approach was taken, he added. Every individual property owner could be paying up to $1500 if they were required to fix their own wastewater pipes.

Mr Somers has recommended that the council investigate further, set aside $25,000 for a business plan and install sensors at the Bank Street and Pukepoto Road outlets to acquire better data about the frequency and volume of spills. (The network has seven outlets, allowing sewage to overflow when the system is overloaded, their purpose being to prevent spills on to private property).

With no money set aside for the upgrade, it would have to be included in the council's 2015-25 Long Term Plan, Mr Somers said.

Infrastructure committee chairman John Vujcich said the new councillors only learned of the problem a few weeks ago, and immediately informed the Northland Regional Council.

"We weren't aware how bad it was," he said.

The amount of stormwater entering the system was far greater than it was designed for, while the fact that much of Kaitaia was flat made it difficult to move large volumes of water quickly.

When sewage ended up on farmland or in streams it was heavily diluted by rainwater, but Cr Vujcich said that was still unacceptable. The council was looking for a solution that was both affordable and resilient.

Meanwhile Mr Carter said deferred maintenance was a serious challenge facing the entire Far North, involving not only wastewater systems but also water supplies, roads and community facilities such as halls.

Once the council had quantified the problem in dollar terms it would hold a series of public meetings.

"This is a serious issue, and the people in this district need to understand that," he said.

]"I can tell you now there will masking the reality, no secrets or hidden agendas. We'll be telling people everything we know just as soon as we have a grasp on the whole picture. And I don't expect that picture to be pretty."