Changes

A large number of studies have shown the beneficial effect of LID on reducing peak flows for more frequent events. They do this by detaining flows and releasing them over longer time periods (see figure below).  However, as discussed in the previous section, larger events overwhelm the capacity of these LID practices to provide significant flood mitigation because most practices are designed with overflows that rapidly discharge incoming runoff to storm sewers once the design capacity of the practice has been exceeded.

A large number of studies have shown the beneficial effect of LID on reducing peak flows for more frequent events. They do this by detaining flows and releasing them over longer time periods (see figure below).  However, as discussed in the previous section, larger events overwhelm the capacity of these LID practices to provide significant flood mitigation because most practices are designed with overflows that rapidly discharge incoming runoff to storm sewers once the design capacity of the practice has been exceeded.

[[File:Screenshot 2025-09-22 113355.png|600px|thumb|center|Peak flow reductions of different LID types during frequent rain events. Top left: Grey and green roof at York University; bottom left: Kortright permeable pavement and asphalt; right: permeable pavement, bioretention and asphalt at Seneca College.]]

[[File:Screenshot 2025-09-22 113355.png|600px|thumb|center|Peak flow reductions of different LID types during frequent rain events. Top left: Grey and green roof at York University; bottom left: permeable pavement, bioretention and asphalt at Seneca College; right: Kortright permeable pavement and asphalt.]]

==Literature Review==

==Literature Review==