Water Supply Update
We received word from the Bureau of Reclamation that Diversions to the St. Mary Canal are being initiated for the season. Construction has concluded on the St Mary’s Siphon, and water is anticipated to be diverted until a scheduled shut down on Aug 15th to accommodate additional construction on the Halls Coulee Siphon. Current reservoir storage at Lake Sherburne is 63,000 ac ft. Conditions may change rapidly; Producers should ensure any temporary fencing placed in or around the Milk River should be removed immediately. If all goes well, flow ramping will occur between today and Sunday with significant flows expected early next week. No additional irrigation is to be permitted in Alberta or Montana, and all diversion water is to support municipal contracts across the highline communities of Montana until spring 2026 diversions are reinitiated.
CURRENT RESERVOIR AND CANAL CONDITIONS
Elevation: 4786.18 feet; Storage: 63,048 acre-feet; River Outlet Works Release: 425 cfs; Inflow: 325 cfs; Canal Diversion: 0 cfs
LAKE SHERBURNE RELEASE AND ST MARY CANAL DIVERSION CHANGES
On Wednesday, June 25, 2025:
Maintain release from Lake Sherburne at 275 cfs
Increase diversion to the St. Mary Canal to 50 cfs
On Thursday, June 26, 2025:
Maintain release from Lake Sherburne at 275 cfs
Increase diversion to the St. Mary Canal to 200 cfs
On Friday, June 27, 2025:
Maintain release from Lake Sherburne at 275 cfs
Increase diversion to the St. Mary Canal to 350 cfs
On Saturday, June 28, 2025:
Maintain release from Lake Sherburne at 275 cfs
Increase diversion to the St. Mary Canal to 500 cfs
On Sunday, June 29, 2025:
Maintain release from Lake Sherburne at 275 cfs
Increase diversion to the St. Mary Canal to 600 cfs
