Streamflow Advisory/Warning - Fall & Winter for the Qu'Appelle System
October 21, 2010
Streamflow Advisory/Warning
October 21, 2010
Fall and Winter High Flow Advisory for the Qu’Appelle System
Above normal precipitation during this past summer has left much of the Upper Qu’Appelle River Drainage Basin saturated. Even with a normal snowpack this winter, there is potential for an above normal spring runoff in the basin.
Last Mountain Lake is approximately 0.5 metres above its normal elevation for this time of year. Therefore, the Saskatchewan Watershed Authority will continue to operate the Craven Control Structure on the Qu’Appelle River throughout the fall and winter months to lower the level of the lake, freeing up flood storage for 2011 spring runoff volumes. Depending on the outflow rates that are achieved once an ice cover develops on the Qu’Appelle River, Last Mountain Lake is expected to drop 0.6 m (2.0 ft) from now to the beginning of April 2011. Therefore, it is imperative to bring the Last Mountain Lake down as much as possible prior to spring.
The downstream lakes on the Qu’Appelle River (Pasqua, Echo, Crooked, and Round) are also above their normal operating ranges. As such, their control structures will remain fully open as well to draw the lakes down over the winter months and allow the excess water from Last Mountain Lake to pass through the system. Pasqua and Echo lakes are expected to drop 0.6 m (2.0 ft) from current levels by the beginning of April 2011. Crooked and Round lakes are expected to drop 0.9 m (3.0 ft) over this same period. Mission and Katepwa lakes are expected to rise slightly over this period.
The fall and winter releases may lead to unsafe ice conditions throughout the winter. Areas of concern include areas around the control structures, on connecting river sections, at locations where the lakes narrow, and where the river enters and exits the lakes. Also, the reaches of the river with high currents now will likely have hazardous ice cover. The releases may also create hazards near the banks as the lake ice drops over the winter months, making it difficult to drive onto and off of the ice.
The Saskatchewan Watershed Authority does not mark off potential hazards associated with ice conditions and those that choose to venture out onto the ice do so at their own risk. It is up to the individual to ensure that the ice is safe for the activities planned.
As lakefront cottage owners prepare their properties for the upcoming winter months, it is advised that they take extra precautions with their property located near the lake this season. There is a significant potential for lakeside properties and structures to be damaged by ice during the winter months and spring breakup of the ice. Precautions which should be considered may include removing boats from boathouses and moving docks up to an elevation that is well above the current elevation of the lake.
The Saskatchewan Watershed Authority will monitor the situation and issue updates as new information becomes available. Spring runoff forecasts, with estimated spring peaks for the lakes, will also be issued monthly and posted on our website beginning in March.
For more information, contact:
Doug Johnson
Director, Basin Operations
Saskatchewan Watershed Authority
Moose Jaw
Phone: (306) 694-3959
Cell: (306) 631-0740
