The use of cocaine in Auckland was a stand-out increase, with the total grams detected per week having jumped from 36g in June, to 95g in November.
Commentary on the police report released today said there were "growing concerns" around the increase of methamphetamine and cocaine seen domestically.
The report also pulled observations about New Zealand's ecstasy market, based on MDMA levels.
"The level of MDMA detected has informed agencies that actual MDMA is present in
New Zealand's ecstasy market, though it is likely many analogues and substitutes are still used," it said.
Figures showed a significant increase in the use of MDMA across both sites over the past six months - and shockingly revealed use in Christchurch is nearly double that in Auckland.
A big increase in MDMA was detected in Christchurch, where 599g was detected in November versus 199g in June. Likewise, 265g of the drug showed up in Auckland's wastewater testing in November - up from 85g back in June.
Despite this, both regions saw big fluctuations in use of the drug month to month.
Use of methamphetamine was significantly up in Christchurch - from 640g in June to 708g in November.
Further north, high levels of methamphetamine were found in Whangarei's wastewater treatment plant.
Police said the programme, which was run in conjunction with the Institute of Environmental Science and Research, aimed to help better understand the geography of drug use.