Police have seized thousands of cannabis plants and other Class A and B drugs in raids across several districts.
Central District Police recovered 6,649 cannabis plants in the annual nationwide drug recovery operation.
Senior Constable Dave Kirk said the Operation Jasmin was making a difference to the drug supply chain in the area.
"Over the past few years we have seen a gradual decrease in the number of plants recovered in the District."
NZ Air Force Iroquois and NH90 helicopters were used to winch officers to cannabis plots where they hauled out the plants.
Police also seized dried cannabis, firearms, ecstasy tablets, LSD and methamphetamine during the raids.
Canterbury Police recovered 2829 plants, mostly from locations south of the Rakaia River in mid-south Canterbury.
With Air Force help, police completed a two day aerial recovery in March, and other officers carried out search warrants.
Dozens of people have been arrested, resulting in hundreds of charges ranging from cultivation of cannabis to the supply of the drug.