The cause of flooding was different in the two areas. Flooding in Ward 1 was determined to be largely as a result of stormwater entering the sanitary system while flooding in Ward 9 was largely related to overland stormwater flooding. Administration investigated the status of the City’s stormwater infrastructure during the August 28 th storm event. A summary is provided below:

Storm sewers

The City’s storm sewers were inspected and no blockages were found. However, there were indications of surcharge (in both Ward 1 and Ward 9). The indication is that the storm sewers were overwhelmed due to the significant amount of rainfall received.

Ditches

Ditches were also observed to be full due to the significant amount of rainfall received. The high Detroit River water level backed up Turkey Creek, which is the outlet for various drains in the area including the Lennon Drain. As a result of the high Detroit River water level, the ditches aren’t able to flow as quickly and don’t discharge as well as when the river is at a lower level.

Roadways

In certain areas of the City, some roadways were also observed to be overwhelmed. Please see Appendix C for various pictures taken during the storm as well as corresponding pictures taken afterwards.

Catch basins

The sump of catch basins are on a four-year cleaning cycle. More frequent cleaning of catch basin sumps would not help as only the heavy material sinks. The flow of the drain is not impeded by material located in the sump.

Pollution Control Plants

During the August 28th, 2020 storm event both Wastewater treatment plants operated as designed with no major issues. All systems functioned to capacity as designed.

The primary treatment capacity of the Lou Romano Water Reclamation Plant (LRWRP) is 545,000 m3/d and the secondary treatment capacity is 436,000 m3/d. During the August 28th, 2020 storm event the LRWRP exceeded the primary and secondary treatment capacities and was overflowing. The primary overflow started at 2:48 a.m. and continued for 32 hours and received primary treatment and disinfection prior to leaving the facility. In addition, the LRWRP experienced a raw overflow starting at 5:20 a.m. and continued for 24 hours. The raw overflows received coarse screening, grit removal and disinfection.

The Little River Pollution Control Plant (LRPCP) has a rated capacity of 72,800 m3/d, during the rain event the plant was treating 2.0 times Dry Weather Flow as designed (115 m3/d). Similar to the LRWRP the LRPCP exceeded the Plant 1 & 2 treatment capacity and was overflowing an additional 90 m3/d raw influent to Little River. The