This week, the Oldman River is under a high streamflow advisory, but as of Tuesday morning the streamflow was approximately 615 cubic metres per second.
According to the City of Lethbridge, provincial forecasting shows the river peaking on Wednesday evening, between 750 m3/s and 1,000 m3/s.
“That’s higher than we’ve seen in a few years, but well below the threshold for overland flooding,” the City noted.
The forecasted peak may bring minor flooding to low-lying River Valley parks and trails.
Crews are monitoring the situation and will proactively close impacted areas.
Everyone is asked to avoid the River Valley trails for their safety and to protect the trails from any additional damage.
Soft ground and high winds also pose a risk of downed trees. Please report any downed trees in public spaces to Lethbridge 3-1-1.
The City’s Water Treatment Plant continues to deal with murky water. Crews are monitoring conditions and responding, as necessary.
“Our tap water remains safe to drink,” said Jason Drenth, general manager of Water and Wastewater and Electric Utility. “We ask the community and our regional customers to continue voluntary conservation efforts. This protects our equipment and maintains safe treatment standards.”
Conditions are improving slightly, Drenth noted.
“We’re still producing less water than demand, so we’re drawing down our reservoirs. With the drop in demand overnight, we were able to gain a little bit compared to where we started in the evening,” Drenth said Tuesday, during an update from the City.
Drenth also noted the City’s Wastewater Plant is being stressed, as well. “We’re seeing very high flows there right now, but the operations are running 24-7, so they’re able to manage it. They’re having to take some high-flow procedures to accommodate the additional flow.”
On an average day, Drenth explained the City sees about 40 million litres per day. “Last night, we reached just over 100 million litres per day flow. That’s the additional flow just from the rainfall, people’s sumps flowing into the sanitary sewer system, and just the overflow.”
Drenth added the City continues to ask everyone to only use water for essential use, which includes cooking and drinking. “Keeping showers to a minimum, just every little drop helps, until we’re able to produce as much as demand right now.”
“Right now, we’re producing about 10 million litres per day less than what demand is. Demand is right now about 60 million litres per day, and we’re producing about 50,” Drenth said.
With rain levels decreasing, Drenth added, the Wastewater Plant will return to normal operations tomorrow at some point. “The Wastewater Plant is a function of the river, so whenever flood control closes the dams and we stop seeing this influx of silt and sediment in the river, that’s when the Water Treatment Plant will return back to normal operations.”
“We’re starting to see some improvements already. We’re able to keep on top of it and slowly increase production at the Water Treatment Plant.”
(Photo by Stan Ashbee)
