From the Executive Summary:
"Stormwater Planning: A Guidebook for British Columbia provides a framework for effective stormwater management throughout the province. The stormwater planning guidebook — a new tool for local governments — presents a methodology for moving from planning to action that focuses on implementing early action where it is most needed. The guidebook approach is designed to eliminate the root cause of negative ecological and property impacts of stormwater by addressing the spectrum of rainfall events."

See the Guidebook [PDF].