March Saskatchewan Runoff Outlook
The Saskatchewan Water Security Agency released its March runoff estimates for the Souris River Basin prior to the recent snowfall that dumped 8-12 inches of snow over a wide area of North Dakota, including the Souris River Basin. However, much less snow fell in southern Saskatchewan as a result of the system, likely too little to have much of an effect on future spring runoff outlooks.
The conclusion of the March outlook was that conditions along the Long Creek, Souris River and Moose Mountain Creek drainages in Saskatchewan were generally dry and lacking in snow cover sufficient enough to produce a significant volume of runoff. Of greater concern, due to conditions present at the time of the report, was that spring snowmelt would be so minimal that a trio of reservoirs impacting the Souris River would not even reach their preferred summer operating levels.
The outlook states that “runoff yields are expected to be well below median values at all forecast points” and that “due to very low projected runoff, flood operations are not in effect and no pre-runoff drawdown is required” at Boundary, Rafferty and Grant Devine reservoirs.
Furthermore, says the outlook, the intent is to store all inflows in the hope or reaching full supply levels. Full supply level does not mean spillway level, but rather summer operating levels. All three reservoirs are currently at drawdown levels specified in the 1989 Agreement between the U.S. and Canada. At this time it does not appear any of the reservoirs will need to release water this spring, other than what is required for downstream interests.
It should be stressed that any changes to the outlook as a result of recent snowfall will be reflected in the next Spring Runoff Outlook scheduled to be released in early April, or sooner if conditions should require significant changes.