SASKATCHEWAN

Water Security Agency
August 10, 2020

Northern Saskatchewan Summer High Water Update – August 10, 2020

Northern Saskatchewan Summer High Water Update – August 10, 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.

Over the weekend, rainfall in the Churchill Basin ranged from 7 mm in the southeastern portion to 84 mm in the Key Lake area. Patuanak area received upwards of 77 mm. The La Ronge area received between 35 to 56 mm and the eastern portion of Reindeer Lake received 35 mm.  Portions of the Lake Athabasca Basin received between 60 to 98 mm of precipitation over the weekend.

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. In most areas flows and water levels are rising as a result of rain received over the weekend. 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: 421.18 m

Due to precipitation received over the weekend, 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, but remain high for some time.

Lac La Ronge:

Current elevation: 364.93 m

Projected peak: 364.95 m on or near August 17, 2020

With the rain received over the weekend, levels have risen steadily and are expected to continue to increase for the next week.  Our current forecast has the lake peaking just shy of the 2011 peak.

Sandy Bay

Present Elevation:  9.8 m (2270 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 0.34 m. Flows and levels are expected to climb slightly over the next week, then remain relatively steady for the next three weeks.  

Meeting Lake

  • With warm and drier conditions, levels at Meeting Lake are still decreasing
  • August 6, 2020 lake level was 739.47 m
  • Outlet spill elevation is 739.23 m
  • Meeting Lake has reached its outlet and is confirmed flowing into outlet channel
  • There is not significant flow moving through outlet currently as it is congested with thick vegetation.
  • Berms around the lake should now be built to WSA recommended standard (739.83-740 m)

Cumberland House

Cumberland Lake has peaked and is receding. 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 Lake, with the Sturgeon Weir River at Leaf Rapids continuing to climb, these lakes are likely not yet at peak.  Like Jan Lake, peaks that are slightly above 2017 levels are expected at these locations unless significant, additional precipitation is observed.


Future Rainfall

Most of the north is expected to receive some rain over the next three days. The area from lake Athabasca southeast down to Reindeer lake is expected to receive 30 to 60 mm over the next 48 hours.  The remainder of the north is only expected to receive between 5 and 20 mm.

For further information:

Patrick Boyle

Water Security Agency

306-631-6997

Patrick.Boyle@wsask.ca