111. The permanent volume retention system must be open.
The minimum retention capacity of the temporary detention of the system corresponds to the water volume associated with a 100-year return period whose flow corresponds to the flow referred to in subparagraph 2 of the first paragraph of section 79. The capacity is calculated from the location where the water begins to be discharged by the flow control device.
871-2020O.C. 871-2020, s. 111.