Water Security Agency Reducing Outflow from Lake Diefenbaker
May 6, 2016 – The Water Security Agency (WSA) is advising the public that outflow from Lake Diefenbaker will be reduced from 120 cubic metres per second (m3/s) to 80 m3/s or a drop of roughly 0.1 m on the South Saskatchewan River downstream of the reservoir.
Lake Diefenbaker is roughly 0.5 m above the typically level for this time of year at 552.47 m. WSA is looking to store additional water in Lake Diefenbaker in May, targeting an elevation of 553.3 m for June 1, 2016. By reducing outflow it will reduce the risk of lower than desirable levels at and below the reservoir this summer.
Runoff from the foothills and plains portion of Alberta was earlier than normal and was below normal. This resulted in well below normal inflows to Lake Diefenbaker in April. The snowpack in the alpine headwaters of the South Saskatchewan River Basin was below normal when it peaked in mid-April.
Much of southern Alberta is experiencing agricultural drought conditions and WSA expects irrigation diversions in Alberta to be above normal and earlier in the season which will also reduce some inflows into Lake Diefenbaker.
Above seasonal temperatures at higher elevations of the Rockies is resulting in an early melt of the snowpack. Much of the runoff that typically occurs in June is expected to arrive in May.
In 2015, outflow from Lake Diefenbaker was reduced to 60 m3/s for most of the summer season. This year, Lake Diefenbaker is not expected to fill in 2016 unless a significant rainfall in the Alberta headwaters occurs. Regardless, all water supply demands will be met in 2016, but some modifications or relocation of irrigation intakes may be required to adapt to lower reservoir and river levels.
For more information on stream flows and lake levels visit: www.wsask.ca.
For more information, contact:
Water Security Agency