Northern Saskatchewan Summer High Water Update – August 14, 2020
Northern Saskatchewan Summer High Water Update – August 14, 2020
Rainfall
Northern Saskatchewan has received extremely high cumulative precipitation since April 1, 2020, resulting in very high flows and lake levels across the Churchill River and Lower Saskatchewan River basins. Much of this rainfall has come in the months of June and July.
Aside from some scattered thunderstorms where some localized higher accumulations have been observed, most of the north received less than 10 mm of rainfall over the past three days.
Flows and Lake Levels:
High river and lake levels can be expected for the remainder of summer and in some cases, such as the mainstem of the Churchill River, into the fall and winter. Many locations saw an increase in flows and levels in response to the rainfall that occurred over the past weekend (August 8-10), but have since stabilized or are declining. The expected peak or observed peak throughout the system is generally slightly lower than previous historical highs. However, flows and levels in the Lower Churchill River, including Reindeer River and Churchill River near Sandy Bay, have exceed previous historical highs.
Below are specific conditions at various locations as well as projected future peak levels.
Ile a la Crosse:
Present elevation: 421.14 m
Due to recent precipitation, levels at Lac Ile a la Crosse have increased to a new peak elevation. With no significant rain in the forecast for the area, levels are expected to drop slightly over the coming week but remain high for some time.
Lac La Ronge:
Current elevation: 364.95 m
Projected peak: 364.96 m on or near August 21, 2020
Recent rainfall had resulted in some increases in inflows near the lake. Inflows are once again receding and are believed to be very close to being equal to outflows. With no significant rainfall forecasted over the next six days, a peak at Lac La Ronge is expected to occur next week.
Sandy Bay
Present Elevation: 9.6 m (2200 m3/s)
Observed peak: 10.14 m (2400 m3/s) on August 4
Water levels at Sandy Bay reached a peak on August 4 and are now down about 0.44 m. Flows and levels are expected to remain relatively steady for the next two weeks.
Meeting Lake
- No new precipitation recorded since August 9, 2020
- Present elevation: 739.40m – August 14, 2020
- Observed peak: 739.48m – July 27, 2020
Cumberland House
Cumberland Lake has peaked and is receding. The lake is now down 1.2 m from the peak observed in late July. Forecasted levels for Cumberland Lake are part of WSA’s 10-Day Saskatchewan River Forecasts which can be found here: https://www.wsask.ca/Lakes-Rivers/Provincial/
Jan, Amisk, and Deschambault Lakes
- Jan Lake peaked in late July, 54 mm above 2017 levels.
- While we do not have any current information for Deschambault or Amisk lakes, with the Sturgeon Weir River at Leaf Rapids appearing to be nearing its peak, Deschambault Lake has likely peaked and a peak at Amisk Lake can be expected prior to the end of the month. Like Jan Lake, peaks that are slightly above 2017 levels are expected at Deschambault and Amisk lakes, unless significant, additional precipitation is observed.
Future Rainfall
Aside from the Lake Athabasca area which is expected to receive upwards of 20 mm of rainfall today into tomorrow, there is minimal precipitation forecasted for the north over the next 5-days. There is currently a system forecasted to bring widespread rainfall to the north beginning on Thursday, August 20, but that is too far out in the forecast to be cause for concern at this time.