Snow Melt Continues (flood bulletin, March 4-10, 2022)
Watershed Conditions Statement – Flood Outlook
Issued March 04, 2022 at 1:10 pm; Valid until March 10, 2022
The snowpack in the Upper Thames River watershed has been reduced over the past few weeks due to warming temperatures combined with rain. A snow survey completed by Upper Thames River Conservation Authority (UTRCA) staff on Tuesday, March 1, suggests there is still approximately 20-60 mm of snow water equivalent remaining on the landscape. This snow is “ripe,” meaning it has little capacity to hold additional water, and any warming temperatures or rain will initiate the runoff process.
Current forecasts predict temperatures will rise above freezing Saturday afternoon and remain above freezing overnight. A high of 16 degrees Celsius is forecast for Sunday afternoon with 5 mm of rain possible, before a return to below freezing temperatures early Monday morning. The snowpack will deteriorate further due to these conditions, with most of it melting in areas where there is less cover.
While the UTRCA does not expect significant flooding at this time, peak flows are expected to rise above those experienced in the latter half of February. Peaks will develop and move downstream beginning late Sunday night and into Monday.
This Flood Outlook message may be elevated to a Flood Watch on Sunday as forecasts and conditions become more firm. The UTRCA’s flood control reservoirs at Fanshawe, Wildwood, and Pittock Conservation Areas are at seasonal levels and are being operated to reduce any downstream flooding.
Municipal staff are asked to monitor potential drainage problem areas where snow may have covered catch basins. Smaller rural watercourses may have been drifted in by snow which can block flows during a runoff event, backing up water onto adjacent lands and causing localized flooding.
The public is reminded to exercise extreme caution and stay off all frozen water bodies. Any ice cover will be weakened and unstable. Flood control reservoirs will be especially hazardous due to fluctuating water levels. Banks adjacent to rivers and creeks are very slippery and, when combined with cold, fast-moving water, pose a serious hazard. Parents are encouraged to keep children and pets away from all watercourses and off of frozen water bodies.
Contact: Teresa Hollingsworth, Manager, Community and Corporate Services