A children's slide, barbecue grilles and shoes caused a major sewerage blockage in Maraenui on Thursday.
The blockage on Hilary Crescent, which came to light on Thursday morning after a resident could not flush their toilet, took nearly two days for council to clear.
Napier City Council director of infrastructure, Jon Kingsford, said the clog was caused by a "plethora of material that had been illegally dumped in the drain" through a manhole on private property including half a children's slide, toys, shoes and bicycles.
"We get sewerage blockages from time to time, it's not uncommon. Fats and other materials like grease, tissue paper and nappies but I haven't seen anything like that before."
The call came from a resident in Maraenui on Thursday morning and it took some time to find the root of the problem before a council drainage crew and two large contracted sucker trucks were sent to clear the blockage, he said.
"This incident had the potential to impact on sewer services to a large area of Maraenui, including the Maraenui shopping centre," he said.
"A blockage of this nature can cause a prolonged sewer overflow event that presents a significant public health risk to our communities and would be very expensive to remedy.
"Given the nature of the material removed from the drain and its close proximity to the shopping centre, there was a very real and significant risk of having to excavate in the roadway and around shops to restore the drains to operational conditions."
The sewerage line branches out and connects to at least 100 houses and businesses. So if it was left longer it could have caused sewage overflow and meant many people would not be able to flush their toilets while the problem was being fixed, Mr Kingsford said.
The occupiers of the house where it was believed to have been caused were spoken to but had only lived at the property for a few days and were unlikely to be the culprits.
Council would continue to investigate and if it found irrefutable evidence pointing to an individual or individuals then council would seek reimbursement of costs.
There is an annual budget for sewerage blockages but this event would probably equate to at least 10 or 20 normal obstructions and could push them over the budget, he said.
Council communications and marketing manager Fiona Fraser said the blockage was expensive to fix with the trucks alone costing about $10,000-$15,000 to come out and help.
"The sewerage pipe was in such a state that it came very close to flooding a lot of houses and businesses in the area."
Council staff and contractors spent all Thursday and some of Friday to clear with the sewer now being restored to full operational, unimpeded flow.
Anyone who sees people dumping of this sort of material into drains should contact their local council immediately because if left it could affect a lot of people.
What can go into sewerage:
Domestic sewerage - i.e number 1s & 2s plus toilet paper
Grey water (laundry and dishwasher)
What can't go into sewerage:
Anything solid that is larger than can fit in your closed fist
Definitely not slides, bikes, barbecue grills, toys, plastic bags etc.
And never lift a manhole cover.