Correlation of basement flooding with overland drainage & topographic risk factors during severe storms (Toronto, Ontario, May 12, 2000, August 19, 2005, July 8, 2013 severe storms). Outline: Severe Basement Flooding Events – Toronto, ON Risk Factor Mapping Overland Drainage (on table land, beyond regulated valley / river flood vulnerable area) Catchment Relief (topographic slope factors) Correlation of Observed Flooding, Flood Density and Risks Joint Back-up and Overland Peril Considerations De-risk Opportunities Next Steps for Further Study