The “Tasman Tempest” has starkly shown up issues in Auckland – Water infrastructure needs billions in investment
Infrastructure NZ says wastewater and stormwater systems in the region could need up to $20 billion of work.
A wastewater biologist, meanwhile, says partially-treated or untreated wastewater is pumped into Manukau Harbour more than 20 times a year on average, because the city’s largest treatment plant cannot cope with large rainfalls.
But she said the volume of water entering the Mangere Wasterwater Treatment Plant – Auckland’s largest – was likely to have exceeded 16.5 cubic metres per second.
At that point, the water was not even screened, meaning solid faecal matter was likely to have been pumped into Manukau Harbour, Ms Allen said.
“I think [the amount] will just absolutely shock Auckland.”
That was not even a rarity, she said.
Once water entering the plant exceeded nine cubic metres per second, it bypassed part of the treatment system. That happened 20 to 22 times a year, Ms Allen said.
There are no surpluses in NZ right now, not in any real sense. There is only debt, negative externalities and deferred costs.