River Report #9-Rivers Swell With Timely Rains
Streamflows on the South Saskatchewan River at Medicine Hat are rebounding following hitting record lows for June earlier in the month. Streamflows hit a three-year high on Wednesday (above) after hitting a record low for June (below).
The South Saskatchewan River at Medicine Hat hit a three-year streamflow high this week following widespread precipitation across southern Alberta over the weekend.
The timing couldn’t be better as the river came into June with record low streamflows for the month. Wednesday’s early morning peak of the South Saskatchewan at the Hat saw streamflows hit 481 cubic metres per second (m³/s) – the highest since June 17, 2022 when the river swelled to 1020 m³/s.
Conditions on the Red Deer River have also rebounded as it too was facing record low June streamflows. As of Thursday morning, the Red Deer continues to have a streamflow advisory as it hit a monthly high on Wednesday of a little less than 140 m³/s.
The Bow River also continues to have a high streamflow advisory stretching from Cochrane to the forks with the Oldman River.
While the drought-busting rains have significantly improved river health and resulted in ratings putting most southern Alberta water arteries into the normal to above normal range, one exception remains.
The Oldman River continues to be rated below historical averages, according to Alberta Environment’s forecaster’s comments released Wednesday.
While streamflows more than doubled on the Oldman at Lethbridge at its peak on Sunday, the river has fallen from its high of 58 m³/s since then and is sitting just at the bottom half of historical averages.
Upstream of Lethbridge, the Oldman Reservoir has seen gains after storage levels began to fall last week. The Oldman is currently sitting at a little less than 66 per cent capacity.
Alberta Agriculture’s latest crop report released last week prior to the significant rainfall event outlined the issues facing pasture conditions and dryland farming in the southern part of the province. Those conditions highlighted the need for precipitation to improve soil moisture conditions.
The next crop report, out on Friday, is anticipated to outline the impacts of the rains on crops. Irrigated crops are also anticipated to benefit from the precipitation, reducing the amount of water required and slowing down the need for conveyance from reservoirs.
Statistics for the South Saskatchewan River at Medicine Hat for June 26
Upper quartile – 691 m³/s
Lower quartile – 270 m³/s
June 26, 2024 – 147 m³/s
June 26, 2025 – 291 m³/s
Statistic for the Oldman River at Lethbridge for June 26
Upper quartile – 308 m³/s
Lower quartile – 75 m³/s
June 26, 2024 – 18 m³/s
June 26, 2025 – 36 m³/s
Statistics for the Bow River at Calgary for June 26
Upper quartile – 296 m³/s
Lower quartile – 159 m³/s
June 26, 2024 – 162 m³/s
June 26, 2025 – 146 m³/s
*Upper and lower quartile averages are based on data collected between 1911 and 2024.
Oldman Reservoir for June 26 level (metres above sea level)
Upper quartile – 1118.452 m
Lower quartile – 1117.405 m
June 26, 2024 – 1116.668 m
June 26, 2025 – 1110.182 m