Officers who were carrying out proactive patrols stopped the vehicle in Welham Road, Retford, after it appeared to be speeding at around 10.30pm on Sunday (November 10).
Two men fled the vehicle and ran into nearby fields.
Officers found the vehicle to be packed full of bin bags containing 25 mature cannabis plants with a total street value of over £20,000.
The driver, a 26-year-old man, was detained nearby and arrested on suspicion of production of cannabis and being concerned in the supply of cannabis.
He has since been questioned and released under investigation pending further enquiries. Enquiries are continuing to trace the other man who fled the vehicle.
Inside they found the cellar had flooded, making the bypassed electricity supply to a cannabis grow upstairs dangerous. Officers seized one remaining cannabis plant and growing equipment from the attic.
Sergeant Tony Rungay, of Nottinghamshire Police, said: "What started as a relatively routine vehicle stop led to the discovery of a large quantity of drugs.
"The flooding has had a big impact on the town of Worksop, causing misery for a number of families who have had to leave their homes. However, it appears it has also had the impact of flushing out some criminal activity by halting some large-scale cannabis production."
Anyone with information is urged to contact Nottinghamshire Police on 101, or Crimestoppers anonymously on 0800 555 111, quoting incident number 946 of November 10.