The Southwest Booster
Well below normal runoff forecast for parts of the Southwest
Projections of well below normal runoff to normal snowmelt runoff are expected in the Southwest according to the Water Security Agency’s 2023 Preliminary Runoff Report.
According to the Water Security Agency’s report released on February 8, the dry conditions experienced across Southern Saskatchewan in the fall will impact this year’s runoff. Overall, the potential exists for below normal to near normal snowmelt for most of southern Saskatchewan based on conditions as of February 1.
“With dry soil moisture conditions at freeze-up, many areas of Saskatchewan are expected to receive below normal snowmelt runoff,” the Executive Summary of the report notes. “The exceptions are the northwest, central and southeast areas of the province, which are expected to receive a near normal runoff response. The area south of the Cypress Hills, including Val Marie and Eastend, currently has an above normal snowpack, leading to expectations of a near normal runoff response there.”
“An area in the Southwest, which includes Maple Creek, is expected to see a runoff response that is well below normal. Periodic warm temperatures in this area have eliminated nearly all the snowpack. This, combined with dry fall soil moisture conditions prior to freeze-up, have increased the probability of minimal snowmelt runoff this spring.”
The preliminary spring runoff outlook points to the impact of dry fall conditions as a factor in this year’s runoff report.
“While much of southern Saskatchewan has a snowpack that is thought to be near to above normal, dry conditions at freeze-up, particularly over areas west of Swift Current and Outlook over to the Alberta Border, are expected to reduce runoff yields. This may result in minimal replenishment of surface water supplies within this area and potentially some shortages later in 2023. At this time, the risk of snowmelt related flooding in the province is low.”
The Water Security Agency highlights that runoff potential is determined based on several factors including the conditions at freeze-up, the snowfall received to date and potential expected further precipitation between now and spring melt.
“The melt rate is expected to have a significant impact on runoff yields, particularly within the Southwest and west central areas of the province. With depleted subsoil moisture, a slow melt will likely result in the bulk of the snowpack recharging the soil column. A rapid melt is likely needed to result in an improvement to surface water supplies. The current snowpack is likely insufficient to satisfy both. Without additional snowfall, surface water supply issues are likely to occur in southwestern Saskatchewan in 2023.”
The specific Southwest forecast in the report is as follows:
“As of February 1, the snowpack across the Southwest region of the province varies greatly. In the Maple Creek area, periodic warm temperatures have eliminated most of the snowpack. South of the Cypress Hills and in the Swift Current Creek Basin, a normal snowpack is present. The snowpack southeast of the Cypress Hills, especially in the Frenchman River Basin, appears to be above normal. Due to warm temperatures in January, the snowpack is hard and dense. Depending on weather conditions during spring runoff, this could result in a more prolonged runoff response.”
An updated runoff outlook report will be issued in early March.