He said the range of charges could include possession for supply, cultivating cannabis and theft of electricity.
"These guys divert electricity for growing. They're stealing power, effectively."
Electricity theft was not new and growers did it to avoid paying large power bills from the use of lights and heating needed to grow cannabis.
Cultivating cannabis can carry a sentence of up to seven years in prison.
The operation lasted about three weeks and involved 35 police officers at his height
Mr Foster said the anonymous Crimestoppers phone line had been a huge help, with more and more people providing information about drug-related offending.
The operation comes on the heels of Tuesday's imprisonment of three people busted by the Eastern Organised Crime Unit last year, in relation to methamphetamine offences.
Mr Foster headed up two operations last year, resulting in 15 people being charged with drug offences. The first three offenders to go through the courts were imprisoned on Tuesday.
In a statement released at the time, Mr Foster said the organised crime unit would continue to target drug offending.
"We will continue to focus on drug dealing within Hawke's Bay and Gisborne because of the harm it is causing to our community.
"There will be no let-up in our fight against drug supply."