Northern Plains Ecoregion - National Lakes Assessment Results
Key Results
An estimated 11,110 lakes in the Northern Plains ecoregion are represented in the National Lakes Assessment (NLA). Of these lakes, 47% are natural and 53% are man-made.
The NLA uses trophic state as an important indicator of lake condition and assesses the extent of biological condition and key stressors in the nation’s lakes.
- In the Northern Plains, 40% of lakes are rated as hypereutrophic while 31% are eutrophic, 21% are mesotrophic and 8% are oligotrophic.
- The most widespread stressors assessed are degraded riparian vegetation cover, nitrogen, and phosphorus with 83%, 76% and 73% of lakes in poor condition respectively.
- Cyanobacteria are one-celled photosynthetic organisms that normally occur at low levels. Under eutrophic conditions, cyanobacteria can multiply. Not all cyanobacterial blooms are toxic, but some may release toxins, such as microcystins. For information about risks at specific locations, recreational water users should check with state, tribal or local governments.
![National Lakes Assessment 2012 Sampling in the Northern Plains Ecoregion](/sites/default/files/styles/small/public/2015-12/npl_nd155core_aaron_larsen.jpg?itok=azJBjdpi)
Change from 2012*
- For the Northern Plains, the NLA reports that the percent of lakes in good condition for phosphorus increased by 20 percentage points between 2012 and 2017 and the percent of lakes in good condition based on the lakeshore disturbance indicator increased by 10 percentage points.
- The percent of lakes with atrazine detections decreased by 34 percentage points.
To access more ecoregional specific information, please visit the interactive NLA Dashboard.
* The change analysis is based on information from two points in time – 2012 and 2017.
![Image showing the dashboard results from the NLA Interactive Dashboard](/system/files/styles/large/private/images/2022-06/NPL_2017_Good.png?itok=87IKKcX5)