Agency expects below normal runoff

The Water Security Agency (WSA) says all but six of Saskatchewan's reservoirs are expected to be near or entirely full this spring, in anticipation of below average runoff from the west.

As of April, projections show 33 of a total 45 reservoirs are currently full or expected to fill, and six have reached volumes between 70 and 90 per cent of storage capacity.

Six other reservoirs in southwestern Saskatchewan are not expected to fill. Maple Creek, the Harris Reservoir and Mcdougald Reservoir are currently below half capacity. Cypress Hills and Downie Lake are between 50- and 75-per-cent full.

Lake Diefenbaker is currently at approximately three-quarters capacity, one metre higher than this time last year and 1.5 metres higher than in spring 2022.

The update, provided by the WSA on Wednesday, aligns with the most recent runoff report issued in mid-march that predicted persistent dry conditions for the majority of Saskatchewan for a third year in a row.

March's update is improved from February's report, which expected below to well below normal levels of runoff across nearly the entire province.

The WSA now expects well below normal runoff north of Buffalo Narrows, around Moose Jaw and near Maple Creek; below normal throughout most of central and southern zones, including south to Swift Current, Regina and Estevan; and near normal for the North Battleford, Saskatoon and Yorkton areas.

The changes are attributed to warm weather arriving earlier than usual, causing a faster rate of melting in depleted snowpacks, though recent snowstorms have improved conditions. Drier than usual conditions throughout south-central Saskatchewan will be persistent, however, and may cause localized water supply shortages in the southwest this spring.

The WSA engaged a “conservative operating plan” for Lake Diefenbaker over the winter to prepare ahead of projected dry conditions this spring and protect supply needs. A closely managed outflow plan was also implemented last year and in 2022.

“Other major reservoirs are currently at or near full as a result of good water management practices and sound decision making,” reads the update.

The WSA said changes to snowpack conditions and weather patterns over the next few months will be monitored and updates to the spring runoff report will be provided as needed.