Ontario city suggests damage following unprecedented rainfall could have been worse

Sault Ste. Marie saw more than 86mm of rain over just four hours starting late on Sept. 9, but the city suggests the resulting damage was mitigated by changes made to municipal storm and channel diversion programs in recent years.

Overall on Sept. 9 and 10, the Sault Ste. Marie Region Conservation Authority (SSMRCA) reported rainfall was equal to 140.2mm.

Characterizing the heavy rainfall as extraordinary and unforeseen, a City of Sault Ste. Marie press release issued Sept. 12 states “the extreme amount of rain caused significant damage to city infrastructure and private homes.”

Both sewage treatment plants and all pumping stations performed as designed during the storm period, notes the statement.

“Were it not for the significant improvements made in recent years to the city’s storm and channel diversion programs, damage would have been much worse.”

A report by the Sault Star notes there were varying amounts of precipitation throughout the region, with the storm being very localized and featuring very intense, but short, periods of rain.

The article adds the city had received “hundreds” of calls about basement flooding, there were reports of 17 manhole covers being blown off (perhaps caused by water backing up), and isolated power outages occurred, the largest one believed to be the result of a lightning strike.

The city statement notes that damage assessment and repairs by municipal work crews will continue until all areas affected by the storm have been addressed. Crews will continue to work around the clock to avoid further loss, it adds.

Accumulated high water in creeks and soil erosion caused varying degrees of structural damage to local bridges, with several of these still requiring engineering inspections to allow further usage. In addition, more than 20 km of roadway shoulders experienced erosion damage and many ditches were filled with debris during the rainstorm, the city reports.

Municipal public works and transportation crews were immediately called upon to open up flooded roadways; clean debris collected on main roads; clear plugged storm grates; and provide assistance to the SSMRCA to ensure local flood channels were clear of debris, the statement adds.

Although barricades were installed on roadways damaged from high water levels and erosion, most of the 16 roadways closed because of the storm had been cleared and were open as of last Thursday. Several private driveway entrances have also been repaired.

On Sept. 12, SSMRCA ended the flood warning issued to residents related to current river conditions, pointing out that that water levels on local rivers and streams were receding.

“The flow of water remains higher than normal and public safety remains a concern,” the statement adds. “All residents and visitors are advised to stay away from all rivers, creeks and streams. Higher than normal levels and flows can be dangerous and stream banks are slippery.”

Environment issued a frost warning mid-afternoon Sept. 15 that applies to the Sault Ste. Marine-St. Joseph Island area. A building ridge of high pressure will allow skies to clear and winds to become light over much of Northern Ontario, the warning notes. Temperatures are expected to fall just below the freezing mark tonight into early Monday morning. As a result, frost is expected.

The City of Sault Ste. Marie waived the gate fee at the City Landfill site for the week of Sept. 9 to 14, and that period has been extended to Sept. 21 to assist residents affected by flooding to dispose of damaged household goods.

The city has not yet declared a state of emergency, but will reconsider this position once final information is received regarding structural loss.

Last October, heavy rainfall in the Municipality of Wawa prompted the declaration of a state of emergency. In late October, Wawa called on the province to provide assistance after heavy rainfall and runoff resulted in flooding-related damage that the municipality expected could amount to tens of millions of dollars.

Among other things, the rain caused the Catfish Creek to overflow, washing out all major roads and a large section of the Trans-Canada Highway. Road closures stranded the Michipicoten First Nation from the municipal road system.