Water level notices

The Water Levels Committee hosted a virtual information session the evening of April 18 to provide an update on basin conditions and forecasts for the rest of spring. 18 participants attended the event online. The Lake of the Woods Secretariat and the National Weather Service- Duluth Office both presented, with the following key takeaways:

-This winter has seen historically high temperatures and a historically low snowpack across the basin. 
-Inflows to both Rainy and Namakan Lakes are in the lower range of normal for this time of year. 
-The very warm winter and below normal snowpack has left a below normal volume of water available for   spring runoff. Most of the snow in the basin has either melted or is in the process of melting. 
-Early spring precipitation has been below normal for this time of year. 
-The drought condition is categorized between abnormally dry and a moderate drought across the basin. 
-Long term forecasts indicate above normal temperatures for spring and equal chances of above and  below normal precipitation (no strong signal in either direction). 

The WLC continues to monitor conditions and is setting water level targets in response to the observed low inflows to the lakes.  The April 30th water level target for Namakan Lake is the 50-100% range of its rule curve and the target for Rainy Lake is the 75-100% of its rule curve, without going below the 100 cms (~3,530 cfs) minimum outflow. Considering the dry conditions summarized above, the Water Levels Committee understands that these water level targets can only be achieved if nature allows and flows into the lakes start increasing.
 

The Water Levels Committee has updated water level targets for the period up to April 30th. Namakan Lake’s target will be the top 50% band of the rule curve. The Rainy Lake water level target will remain between the 75% and 100% band (top quarter) of the rule curve, without going below the 100 cms (~3,530 cfs) minimum outflow.

The Water Levels Committee understands that these targets of stable or rising water levels can only be achieved if nature allows and flows into the lakes start increasing.  If dry conditions persist, these targets may not be achieved within the April 30 period.  The Water Levels Committee will continue to monitor conditions and forecasts, updating targets as needed.

The Water Levels Committee has updated water level targets for the period up to April 15th. Namakan Lake’s target will remain between 339.6 m (1114.17 ft) and the top of the rule curve. The Rainy Lake water level target will remain between the 75% and 100% band of the rule curve, without going below the 100 cms (~3,530 cfs) minimum outflow.

The Water Levels Committee understands that these targets of stable or rising water levels can only be achieved if nature allows and flows into the lakes start increasing.  If dry conditions persist, these targets may not be achieved within the April 15 period.  The Water Levels Committee will continue to monitor conditions and forecasts, updating targets as needed.
 

In accordance with the WLC spring regulation plan, the March 24th target water levels for Rainy Lake will be the top quarter of the rule curve (75-100% band) and Namakan Lake targets will be between lake elevation 339.6 meters and the top of the rule curve (approximately the top third of the rule curve).

The March 24th targets were established based on an evaluation of current basin conditions and concerns over drought, including the following factors:  
•    Conditions are drier than normal. 
•    Below-normal snow water equivalent in the entire basin.  
•    Seasonal forecasts (April through June) indicate warmer than normal temperatures and equal chances of above or below normal precipitation. 
•    Concerns over Rainy River fish spawning and potential low water conditions across the basin.  

The WLC will provide an update to water level targets after March 24th or earlier, based on basin conditions and forecasts.
 

On February 29, the WLC held its virtual Pre-Spring Engagement with a total of 51 participants. The webinar included an overview of basin conditions and spring outlook from the Lake of the Woods Secretariat and the National Weather Service, followed by an opportunity for questions and discussion. Key points from the presentations were as follows:

• Conditions are drier than normal, though precipitation in late December and early February provided some relief.
• Winter temperatures have been warmer than normal. 
• There has been a historically low amount of snowpack and snow water equivalent (SWE) across the basin. 
• There is some uncertainty in frost depth due to fluctuating temperatures, but soil moisture levels are dry to normal. The upper layers of soil in the basin are frozen due to the lack of snowpack that provides insulation. 
• River forecast simulations (going through early-June) are showing lower chances of exceeding flood stage, but hard frost conditions could lead to enhanced runoff if heavy spring rains occur over the basin.  
• Seasonal forecasts (April through June) indicate warmer than normal temperatures and equal chances of above or below normal precipitation. 

The WLC will continue to closely monitor conditions through the remainder of the winter and spring to inform water level targets for Namakan and Rainy Lakes. A list of websites with more information on water levels data is available here: https://www.ijc.org/en/rlwwb/water-level-information#2.

The WLC will host a public meeting at 7:00 p.m. on March 5 in International Falls, MN to provide an overview of regulation in the Rainy-Lake of the Woods Watershed and recap conditions and forecasts discussed during the Pre-Spring Engagement. 

To remain within the rule curves, Rainy Lake outflow has increased the past few weeks. Outflow from Rainy Lake increased to ~200 cms (~7,060 cfs) on January 16th. This increase is temporary and will be reduced to ~160 cms (~5,650 cfs) on January 20th to maintain Rainy Lake levels within the middle band of the rule curves. Increased flow to Rainy River has the potential to increase the amount of slush or water on the ice, which can make the surface more difficult or dangerous to use.

The Water Levels Committee encourages everyone to be extra cautious when near or on the ice, especially when there are fluctuations in temperatures and changes in water flows or levels. Information on ice safety is available on the Minnesota DNR website.

A minor and short duration breach in Rainy Lake’s minimum flow occurred the morning of December 12. Operators were diligent to correct the outflow and no downstream impacts were observed.

Water level targets for Rainy and Namakan Lake continue to be the full range of their respective rule curves.