The following is the latest advisory from the Sask. Watershed Authority:
In response to the major rain event the Saskatchewan Watershed Authority has increased outflows from Rafferty and Boundary Reservoirs to a minimum combined outflow of 300 cubic metres per second (m3/s) at noon Saturday. The Watershed Authority will be closely monitoring inflows and further increases to as much as 400 m3/s (total flow through Estevan area) may be necessary. A flow of 400 m3/s would produce a stage increase of approximately one metre on the river through Estevan and be significantly higher than the peak flow this spring of approximately 211 m3/s.
During the past 24 hours combined inflows to Rafferty and Boundary Dams peaked at approximately 500 m3/s. The dams were used to significantly reduce flooding downstream, but Rafferty Reservoir is rapidly nearing its maximum allowable level requiring that outflows be increased.
Outflow from Rafferty Reservoir is being increased to 200 m3/s and outflow from Boundary to 100 m3/s to produce the combined outflow of 300 m3/s.
Rafferty Reservoir was about 12 centimetres (cm) below the Maximum Allowable Flood Level (MAFL) at 9:00 AM Saturday and rising about 1 centimetre hour. More rain is forecast for the basin.
Inflows to Alameda Reservoir are also being monitored this weekend in the event that increased outflows become necessary to keep the reservoir below MAFL.
The Watershed Authority has notified the City of Estevan, the Village of Roche Percee, the RM of Estevan, and the Ministry of Corrections, Public Safety and Policing of increased outflows and expected increases in water levels.
The Watershed Authority will continue to monitor weather and flow conditions. Updates will be issued as warranted.