Reservoirs below normal capacity

By Lethbridge Herald on September 13, 2024.

Herald photo by Al Beeber A bird perches on a rock in the Oldman River just below the weir on Thursday. Water levels at two major southern Alberta reservoirs are lower than normal for this time of year. The Oldman river has a flow that is normal for this time of year, however.

Two of three major southern Alberta reservoirs have water levels that are lower than normal for this time of year.

The Oldman Reservoir, as of Wednesday, had 65 per cent capacity, down from the normal of 73 to 85 per cent.

The Waterton Reservoir had 57 per cent capacity – it’s normal range is between 53 and 79 per cent.

St. Mary Reservoir had capacity of 52 per cent, within the normal range of 48 to 79 per cent.

Keho Lake near Nobleford was at 89 per cent capacity while the Pine Coulee Reservoir near Stavely was at 58 per cent. Clear Lake near Stavely was at 82 per cent capacity while the Travers Reservoir near Enchant was at 79 per cent.

The latest province-wide updates from the Alberta government show many areas are dealing with drought conditions.

As of Sept. 5, water sharing agreements were active in the Oldman South Saskatchewan River basin and southern tributaries. As of that date, there were 32 water shortage advisories in place for select water management areas across the province.

The most recent report on water sharing agreements from Aug. 29 said storage in most reservoirs is starting to decline because of increased demand.

The Lethbridge Northern Irrigation District’s board on Aug. 20 increased the annual water allocation to 13 inches per irrigation acres from 11 with no further increases planned this year. As of that date, the district’s average water use was 7.2 inches per acre with the year-end water use anticipated to be between 9.5 and 9.75 inches per acre with that allocation increase.

The report says that irrigation demands are decreasing with crops being harvested. Water within irrigation districts is being used for fall pastures and stock watering for winter.

As of Sept. 5 the river monitoring network, which has 450 gauges reporting real-time data, showed that the Oldman River near Lethbridge had a flow of 26.8 cubic metres per second which is within the normal range for this time of year.

The South Saskatchewan River at Medicine Hat had a flow of 110 cubic metres per second which is also within the normal range. The flow of the St. Mary River near the international border is also within normal range but the Waterton River near Waterton Park is below normal with a flow of 4.7 cubic metres per second.