Diversion Start Date

Releases from Lake Sherburne and diversions to the St. Mary Canal are expected to start for the year on March 25, 2024. As in the past, St. Mary Canal diversions will start near 100 cfs and ramp up as ice is cleared from infrastructure.

It was noted at the February 15th International Joint Commission – Records Meeting: that operational plans are still fluid with the low snowpack conditions; not anticipated to make even average snow water equivalent. Looking to have a startup and run canal at full capacity by April 1st with intent to move as much water as possible by May 1st to Fresno Dam in Montana. It was also noted that there is a modernization of Fresno Dam project underway, adding a filter blanket to the dam face to slow or stop seepage through the face near the spillway. In order to accommodate the work, there will be a reservoir restriction at approximately 30% of full capacity by August 15th. USBR staff noted that conditions are lining up that the diversion will be shut down early this season, possibly by the start of August.

Current conditions are as follows:

The Snowpack in the Upper St Marys has gained since Mid February, and additional significant precipitation is in the forecast for the next week which could improve conditions, but we are still significantly below average with the peek snow load anticipated within the next couple weeks. Sherburne Reservoir is currently 65% full, higher than average for this time of year due to more rain and runoff over the winter months.