Outlet Channel

Maintaining an unimpeded flow from Big Marine Lake through Little Carnelian Lake and the outlet pipe to the St. Croix River is a critical responsibility of the Watershed District.  CMSCWD was formed to reduce the threat of flooding in Big Marine and Carnelian Lakes and the solution was the result of many years of study of the causes to these water fluctuations.  Some of the reports that examine the causes of these water fluctuations are:

The range of elevations that the District maintains is a result of negotiations with riparian property owners and the Department of Natural Resources to both protect property and protect wetlands within the watershed.  The only variable in the system is an adjustable weir downstream of the fixed outlet and Turtle Lake.  The current management plan for the weir has evolved over the years and was approved by the Board of Managers on April 12, 2017 after receiving considerable public input. The management plans are available for review here, from the current plan to the original management plan:


Big Marine Lake Outlet Elevations

Yellow designates at or over weir elevation

(Turtle Lake Stop Log status)

  fixed Weir Overflow elevation is 940.8 feet


Upstream of Weir

Downstream of Weir 

04/23/2019 941.19 940.76           (all logs out)
05/02/2019 941.07 940.64          (all logs out)
05/30/2019 941.23 940.98           (all logs out)
06/27/2019 940.97 940.90          (all logs out)
07/17/2019 941.13 941.08           (all logs out)
07/25/2019 941.01 940.94         (all logs out)  
08/19/2019 941.03 941.0            (all logs out)
08/21/2019 941.01 940.98          (all logs out)
9/11/2019 940.97 940.94          (all logs out)
9/20/2019 941.01 940.9             (all logs out)
10/17/2019 941.03 940.76           (all logs out)
2018 Data
2017 Data
2016 Data

Pages 22 through 29 in Section IV of the Management Plan discusses the maintenance activities in further detail.  A history of water elevations of Big Marine Lake is available here.