The new rule comes after Mayor Naheed Nenshi said he received complaints of council members being drunk and using illicit substances.
The rules will mirror what city staff have to follow.
An exception was made if councillors are hosting community functions.
Nenshi alleged some councillors have served and consumed booze in their offices over the years and on occasion, drank too much at public events.
Councillors also paved the way to hiring an integrity commissioner that would deal with complaints made about council members.
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