From next month Dutch coffee shops will only be allowed to sell marijuana to Dutch citizens who have registered as members and each shop is limited to having 2,000 members.
The stringent new rules will likely affect Germany's drug tourism to the Netherlands, and police fear that users will make bulk purchases over the next two weeks in preparation for the coming cannabis famine.
According to police in the small town of Viersen, young people returning from drug runs in the Netherlands have caused considerable problems in the past.
"We have a special problem because it's just a three-kilometre walk to the Dutch border," police spokesman Bernd Klein told The Local.
The Viersen police organized a "drug-trail" taskforce in 2008 to patrol and restrict the drug tourism passing through the town.
"Some of the drug tourists urinated in front gardens, left rubbish and sometimes it came to loud and physical confrontations as well as robberies," a police statement published on Monday said.
"They came from all over the region – from as far as Düsseldorf or Cologne," Klein told The Local.
"There used to be a few more of them in the school holidays."
"We have the problem largely under control now, but we're introducing more patrols as a preventative measure," said Klein. "We're looking to maintain the increased controls after May 1 as well."