Executive Summary: N/A

Background:

On August 28, 2020, over 100 mm of rain fell in some areas of the City over a short period of time causing substantial instances of basement flooding.

At the September 14th meeting of Council, Councillor Francis asked the following council question:

CQ 25-2020

As a result of heavy rainfall that occurred on Friday, August 28, 2020, many homes in South Windsor experienced significant basement flooding. In addition, to sustaining property damage, residents also incurred substantial loss of personal property. In many cases, the losses experienced will be far greater than what their insurance will cover. While other areas of the City received significant amounts of rain and experienced some basement flooding, the greatest concentration of basement flooding occurred in Ward 1. As a result, I request that Administration provide a full analysis of why and how flooding occurred in Ward 1 on August 28, 2020. Please include within your analysis all contributing factors from outside jurisdictions and further, please identify any immediate improvements necessary to mitigate future risks of basement flooding. Please also identify any elements of the Sewer Master Plan that, once in place, will reduce future instances of basement flooding within this area.

As part of the response to CQ 25-2020, information regarding the concentrated area of flooding which also occurred in Ward 9 will also be provided for Council’s information.

Discussion:

The City of Windsor experienced a significant rainstorm event on August 28th, 2020. The City’s rain gauges recorded amounts ranging between a low of 64 mm on the City’s east side (East Banwell Pumping Station) and 122 mm recorded on the City’s west side (Lou Romano Water Reclamation Plant). Rain gauges located in the west and south areas of the City recorded significantly more rain than the rain gauges located on the east side of the City. (See Appendix A for Rain Gauge Data).

While the rain event led to flooding in areas throughout the entire City (calls regarding basement flooding were received from each of the City’s 10 Wards), significant, concentrated flooding occurred in the Roseland West neighbourhood and accounted for 241 of the City’s 413 calls received by 311 reporting flooded basements. (See Appendix B for August 28, 2020 Storm Event Flooding Map).

Another smaller area of concentrated flooding (22 reports of basement flooding) also occurred in the southeastern corner of the Devonshire Heights neighbourhood.

The two areas of localized flooding were investigated as to why and how the flooding occurred and to determine if there were any identifiable issues that caused or contributed to flooding in these areas.