Wisconsin Valley
Improvement Company
Eau Pleine Dissolved Oxygen Monitoring and Isopleths
The Eau Pleine Reservoir has been studied extensively by WVIC since the 1970’s with a focus on annual depletion of dissolved oxygen along with a host of other water quality parameters.  A system was developed to monitor dissolved oxygen in the reservoir that has been consistently used for decades to aid in operational decisions.  This long-term data set continues to be collected annually and analyzed to provide further insight and understanding of reservoir dynamics.   



Each year during the winter months, dissolved oxygen and temperature profiles are taken at 1 meter intervals from the bottom of the reservoir to the surface at every river mile from the Eau Pleine Dam upstream to mile 18.3 at Balsam Road (Spindler's Bridge).  Using the data collected weekly, staff utilizes computer software to produce an "isopleth" which is a visual depiction of oxygen levels throughout the water column in the original channel of the reservoir.  Isopleths are an example of a tool that can assist WVIC and WDNR staff in decision making pertaining to operating the Eau Pleine aerator system and aid with other resource management efforts.  The isopleths are posted below and shared with a variety of stakeholders and interested parties as a way to keep the general public informed of current conditions and conceptualize oxygen trends on the reservoir throughout the winter season.  
2021 Eau Pleine Dissolved Oxygen Isopleths 
 
    
Eau Pleine Dissolved Oxygen Isopleth 01-25-2021
Eau Pleine Dissolved Oxygen Isopleth 01-21-2021