Posted on: August 10, 2017 | Water Levels
Water Levels Committee:
Water levels throughout the Whiteshell are abnormally low this year, with very little rain since spring break-up. The few lakes with level control structures have been able to retain much of the spring run-off, but the rest are all very near their winter draw down level. Complaints have been received from Caddy Lake, Big Whiteshell Lake, and even from cottagers using the boat access channels on Falcon Lake (which is still within its target range).
Caddy and Betula Lakes: both suffer the same problem with wide – flat top discharge weirs that set a minimum level for the lake, but allow any water above that level, to escape very quickly. We have been asking MI (Manitoba Infrastructure) for several years now, to modify these weirs to reduce the rate of discharge as the level declines (install a higher weir on top of the existing one, with a small tapered section to allow for fall draw down), with no tangible response. Even the preliminary design review has not been done. We continue to raise this issue as a priority in an effort to gain a response. Further inaction will raise this issue to requesting ministerial involvement this fall.
Big Whiteshell Lake: has need of a similar structure, though they do not have an existing weir (setting their minimum level) to work with as yet. Other (long term) modes of relief from chronically low water levels (in Big Whiteshell and the lakes downstream) are being investigated internally by WCA’s Water Levels Committee.
Falcon Lake: still suffers from the lack of a functional level control structure. Water continues to drain from the lake through a rock weir installed to reduce the loss of breeding stock from the resident fish population. This same weir reduced the discharge rate available to relieve the flood last year, but continues to exist.
Progress on the Preliminary Design of the new water level control structure for Falcon Lake has been allowed to fall seriously behind schedule. Review meetings with Hatch (the consultant engaged approximately one year ago, to carry out the hydraulic analysis of the lake, the Falcon River, and water attribution channels, have been delayed. They have been “unable to formulate recommendations” due to unanticipated complexities uncovered during the design development process. Recommendations were expected 6 months ago.
The consultant has confirmed the inadequacy of the River (which flows out of Falcon Lake) to handle the desired discharge flow rate without dredging. Dredging this amount of river bed would be very expensive to carry out, and would require an Environmental Impact Study and approval of those parties affected, before it could be undertaken.
The configuration options put forward by WCA approximately 2 years ago (divert the Falcon Creek (which flows into Falcon Lake) into the Falcon River directly, and use a pumped discharge system to regulate the lake level), remains the most predictable and cost effective option available that we are aware of. This option too, may require an Environmental Impact Assessment be carried out before it could be implemented.
Dredging of the boat access channels: for some reason, SD (Sustainable Development) is delaying a decision to proceed with the maintenance work required, until after the lake level issues have been resolved. They don’t seem to realize that the dredging is a larger and independent issue – that must be resolved regardless of the method of level control selected. It is also the cause of All of the Falcon Lake complaints we’ve received – with many cottagers unable to use their boats because of it.
The bassimetry (underwater topographic survey) of these channels is being gathered by MI this summer. This is a necessary precursor for design of the remedial works and scope of dredging required.
Winnipeg River weekly water levels forecast from Manitoba Hydro are now being posted on the WCA website as well as being distributed by Facebook and Twitter. The cooperation of both LWCB and Manitoba Hydro in reporting on the Winnipeg River lake level data is much appreciated.
We attended the LWCB (Lake of the Woods Control Board) meeting in Kenora on June 15th. Their efforts to prevent changes in the water flow rate during periods of ice formation, and break-up, will reduce damage to shore line infrastructure, and their adoption of a policy to limit weekly changes in the flow rate to 100 m3 /s whenever possible, will reduce the rate of summer level fluctuations. These changes will reduce dock owner’s maintenance costs, and enhance the enjoyment of boaters using the river lakes in the Whiteshell. We delivered thanks on behalf of the Whiteshell cottagers for their cooperation in these matters.
Report by: Alan Roberts
Chair: Water Levels Cmte.