Thousands of students are expected to gather on Ezra Avenue in Waterloo on Sunday for another unsanctioned St. Patrick's Day event.
Waterloo Regional Police and Wilfrid Laurier University remind people to be "intelligent, safe and respectful."
The police will have a significant presence in this area and will run driving programs throughout the weekend.
In the media update on Sunday morning the police said that some events and meetings have already begun.
"Today, our priority is public safety, crowd management as well as law enforcement", Const. Ashley Dietrich said.
"Our officers are here and will enforce roads as well as laws. They are ready to issue tickets to anyone who violates the law. "
While the police do not tolerate any illegal gatherings, drinking or using drugs, Dietrich said that people who choose to consume drugs or alcohol are encouraged to do so safely.
Kevin Petendra, deputy head of the Waterloo Paramedic Services Region, said everyone who attends the event is encouraged to wear an ID in the event of a medical emergency.
Maintaining the range of the ambulance throughout the region will be a priority throughout the day, he added.
"We have implemented a significant number of additional resources to actively counteract the negative effects of this unauthorized collection on our website", Petendra said.
In a tweet, university officials say: "Laurier is actively discouraging unsanctioned street assemblies." Students who violate any university laws or policies may be subject to sanctions in accordance with the school's Code of Conduct.
Information on the police approach to St. Patrick's Day, fines and university policy is published on the Laurier website.
Over 22,000 people attended the event last year. The police paid 619 charges and 52 people were hospitalized.