Minimal snowmelt forecast
Reservoir gates are closed and below-normal runoff is expected in the Souris River drainage in Canada. That’s the gist of the March outlook issued Tuesday by the Saskatchewan Water Security Agency.
According to the report, “Fall precipitation in 2013 in the Saskatchewan portion of the Souris Basin was well below normal. Meteorological monitoring in the basin indicated cumulative 2014 winter precipitation is generally below normal across the Saskatchewan portion of the Souris River Basin.”
Assuming average spring precipitation, adds the outlook, below-normal runoff is projected as of March 1. The projections mirror an earlier hydrologic outlook for the Souris River in North Dakota issued by the National Weather Service. The conclusion of both reports is that, unless conditions change dramatically, the Souris River will generally remain well below flood stage other than possibly a few perennial problem areas.
While central Saskatchewan received well above to above normal snowfall this past winter, conditions remain much different in the southern portion of the province where the Souris River and Moose Mountain Creek drainages are located. Moose Mountain joins the Souris near Oxbow, Sask.
So little runoff is expected this season that two Saskatchewan impoundments face the possibility of not reaching their customary summer operating levels. Rafferty Reservoir, on the Souris near Estevan, remains slightly below its Feb. 1 flood control elevation. The “best estimate” provided by SWA forecasts the reservoir to fill to 1,842.3 feet, slightly more than two feet below usual summer levels.
Alameda Reservoir is projected to reach 1,842.3 feet, about one and a half feet less than usual. Alameda backs up Moose Mountain Creek above its juncture with the Souris and is currently below its Feb. 1 required maximum operating level in accordance with the International Agreement.
A third Saskatchewan impoundment, Boundary Reservior, is fed by Long Creek. Boundary is expected to reach what is considered normal operating level, a level a mere two feet above the reservoir reading on Tuesday.
In anticipation of the Saskatchewan runoff forecast, releases from Lake Darling Dam above Minot were cut from an estimated 25 cubic feet per second to 5 cfs on Monday. Lake Darling was at 1,595.98 Tuesday. Summer operating level at Lake Darling is considered 1,597 feet.