Association of lake manitoba stakeholders

North winds are affecting the gauge readings today, driving up the level of the lake in the south basin: the estimate of the lake level – 811.60 feet — is, therefore suspect and probably too high. Outflow at Fairford continues to fall and it is now 3,637 cfs. The level of Lake St. Martin – 799.57 feet — is up slightly from last week and may be wind affected. This week’s level of Lake Winnipegosis is wind affected at 833.07 feet. The high level of Lake Winnipegosis is keeping flow on the Waterhen River high: it is currently 7,169 cfs. Flow on the Whitefud River is down this week to 28 cfs. Flow on the Assiniboine continues to decline rapidly and is now down to 689 cfs at Holland and 812 cfs at Headingly. The Shellmouth Reservoir is down this week at 1402.92 feet.


The lake level has dropped this summer because of high evaporation and low precipitation: inflow from the Waterhen River remains considerably higher than outflow at Fairford. With cool fall temperatures, the evaporation effect will diminish and the lake will begin to rise again. With an outflow of 2,000 at Fairford, and inflow over 6,000 cfs on the Waterhen, the lake will rise about 2.5” a month in the absence of evaporation.

The theme for this week is down – all lakes and rivers have declining flows and levels. Perhaps most significantly, Lake St. Martin is sitting at 799.70 feet, now comfortably inside its desired operating range (797.00 to 800.00 feet). The last time the level of Lake St. Martin was this low was early 2010. Lake St. Martin has been above its operating range for the best part of a decade. Lake Manitoba is also down this week to 811.36 feet. If that level is accurate, it is the lowest level Lake Manitoba has been since early 2010. We still have a ways to go to reach the low levels seen in 2003, when the lake was just over 810.0 feet.

Lake Winnipegosis is down this week to 832.27 feet, and flow on the Waterhen River is down to 6,357 cfs. Outflow at Fairford is 4,379 cfs and will continue to fall as the lake level falls. The Whitefud River has almost dried up, with flow down to 19 cfs. Flow on the Assiniboine is down to 2,013 cfs at Holland and 2,225 cfs at Headingly. The Shellmouth Reservoir is down this week to to 1402.99 feet.

Strong winds are playing havoc with water levels and river flows, so take this week’s report with more than just a grain of salt. The average gauge reading on Lake Manitoba is currently 811.55 feet. Wind is driving water into the south of Lake Winnipegosis, raising its level (833.76 feet) and flow on the Waterhen River (6851 cfs). Outflow at Fairford is also wind-affected and registering low, at 3,991 cfs. That will rise when the winds subside. The level of Lake St. Martin has reached an historic mark: it is currently 800.00 feet (and is probably below that – the gauge reading is wind-affected). This marks the first time in a very long time that Lake St. Martin has reached the top end of its operating range (800.0 0 feet). I will do a little digging to check the last time that it reached this level and will report back. Flow on the Assiniboine was affected by rain last week and is currently 3,002 cfs at Holland and 2,896 cfs at Headingly. The Shellmouth Reservoir is down this week to to 1403.15 feet.