Snowfall received so far this year across agricultural Saskatchewan points to an "above-normal" spring runoff, according to the February forecast from the province’s Water Security Agency.
The forecast takes into account the below-normal rainfall seen in the last half of 2012, which left most of the agricultural areas in Saskatchewan with relatively dry conditions going into the winter season, the agency said.
However, to date, there has been "above normal" winter precipitation and "well above average" water equivalent in the snowpack so far, the agency added. In its report, the agency estimated water equivalent in the snowpack on Feb. 1 to be "generally 150 to 200 per cent of average for this time of year" and snowpack generally at about 200 per cent of normal in agricultural areas.
"If the precipitation conditions going forward remain the same as their historical averages, there will be an above-average spring runoff this year."
That said, if the above-normal winter precipitation trend continues, 2013 runoff will likely be "well above average," the agency added. Higher runoff would also follow above-normal precipitation just prior to spring runoff, and/or a fast spring melt.
By comparison, following "extremely high" runoff in 2011, Saskatchewan’s 2012 spring runoff from snowmelt was near normal, refilling most water supply reservoirs, the province said. Rainfall in April and May 2012 across the vast majority of Saskatchewan was "well above normal, keeping most reservoirs near full."
Summer rainfall in June, July and August 2012 was below normal for the band along the U.S. border, near normal for the central portion of the province’s agricultural area, and above-normal for the area north of a line extending from Rosetown to Melfort, the province said.
Fall precipitation in 2012 was then "extremely low" for the area south of Saskatoon, near-normal for most areas north of Saskatoon and above-normal in an area northwest of Prince Albert and near Meadow Lake.
"Keep in perspective"
Thus, the province’s ag ministry classifies moisture conditions for much of the area south of Saskatoon as "short." In some areas, particularly in the southwest, topsoil moisture conditions are classified as "very short." The province’s fall moisture map, however, was produced ahead of "significant" late-autumn rainfall in the east-central region.
Recorded snowfall from Nov. 1 to Feb. 1 shows winter precipitation "above average" for most of the agricultural portion of Saskatchewan and "well above normal" in the Moose Jaw, Regina and Yorkton areas.
Thus, as of Feb. 1, the runoff potential is "generally above normal," with "pockets of well above normal" around Moose Jaw, Regina, Yorkton and Saskatoon, the province said.
However, the agency added in its report, "it is important to keep in perspective that there (are) over two months of winter remaining" and assuming average precipitation levels from here out, "the amount of present excess snow becomes relatively less significant."
Prairie winter moisture conditions looking good, Jan. 12, 2013
Reeve slams province for not taking flood threat seriously, Feb. 6, 2013