A reduction in flying hours combined with wet weather reduced the number of cannabis plants police could potentially destroy during their annual operation in Northland.
But the destruction of 21,531 cannabis plants was still a significant amount of illegal drugs to take out of circulation, says the officer in charge of Northland's Organised Crime Squad Detective Sergeant Stephen Chamberlain, who headed the drug blitz targeting commercial cannabis growers.
"There are still large commercial crops being grown and we know from experience the bulk of cannabis grown in Northland is generally tied into organised crime like gangs," Chamberlain said.
"Any amount of illegal drug we can take out of circulation and reduce its availability to find its way into the community has an impact."
Police suspected a bulk of the crop that they were unable to destroy would be shipped out of the region and go to markets such as Auckland and further south.
Chamberlain said fewer flying hours along with three days being a washout due to inclement weather had impacted on the number of plants sprayed or ripped out this season.
While the statistics are were well down from a record haul in the 2015/16 season when records show 68,499 plants were destroyed and 124 people were charged, the numbers were up on last season when 16,307 cannabis plants were destroyed.
During the latest operation police involved carried out 24 search warrants, made 24 arrests, seized $14,000 cash, and recovered $5000 of stolen property which was mainly tools.
Four indoor cannabis growing units were discovered and dismantled along with three labs producing cannabis oil.
During the summer-time operation there was 3.6kg of dried cannabis plant found, 8 firearms seized along with 5g of methamphetamine.
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And during Operation Piano two properties were restrained under the Proceeds of Crimes Act.
A couple's house and surrounding property had been seized and they have been charged with cultivating cannabis after police discovered the biggest plot of the operation with 1267 plants.
Chamberlain said another plot of 800 plants was found near Rawene and a house and land had been restrained.
Depending on the outcome of the court cases the land could be sold with the money going to the Crown.
Other charges included producing cannabis oil, receiving stolen property, selling methamphetamine, selling cannabis and possession of methamphetamine for supply.
Two drivers were also nabbed as police moved between searches, one was charged with driving while disqualified and the other was found to have an excess breath alcohol level.
There were 23 warnings given out to people police did not consider needed to be charged given a variety of circumstances.
"It's a discretion we use with lesser amounts and depends on the circumstances. We weigh up a number of factors and whether it's appropriate to deal with it by alternative resolutions."
The warning was noted against the person in the police system.
The release of the Northland drug operation figures come just a week after two new polls show more people would prefer the status quo than have recreational cannabis legalised in a regulated market.
A 1News Colmar Brunton Poll this month showed 52 per cent opposed legalisation, while 39 per cent favoured legalisation.
A Newshub Reid Research poll showed 48 per cent preferred the status quo and 41.7 per cent wanted legalisation.
Other earlier polls showed majority support for legalisation.
Prime Minister Jacinda Ardern said the Government did not have a position on whether cannabis should be legal, and that was why the public would decide.
The referendum is part of the Labour-Greens confidence and supply agreement. According to both new polls, Green voters were the most likely to vote "yes" in next year's referendum, while National Party voters were most likely to vote "no".
Chamberlain said it was the role of the police to enforce the law.