The LakeBrowser has provided satellite-derived data on lake clarity, an indicator of water quality, for more than 10,000 Minnesota lakes since 2002. An online interactive tool with searchable statewide maps of lake clarity, chlorophyll concentrations, and CDOM levels, it has been updated in ArcGIS Server with improved image and data display, geospatial analyses, and new data created using an automated image processing system that classifies all available Sentinel-2 satellite data. Pixel and lake level maps of lake clarity, chlorophyll, and CDOM can be displayed by seasonal average and since 2017 by month, along with summaries and statistics at state, county, ecoregion, and watershed levels, and land cover maps and statistics for a 1,000-foot buffer area around each lake. It provides daily (when clear imagery is available) and monthly (May–October) average clarity, chlorophyll, and CDOM data. Older data are available for download and more recent data can be accessed through the U of MN GEMS Informatics Exchange.
For more information on remote sensing of satellite monitoring of lake water quality, our methods, and results, see our website, Remote Sensing of Water Resources. The research and development have been conducted by faculty and staff of the Department of Forest Resources – Remote Sensing and Geospatial Analysis Laboratory and associated colleagues in several other departments and colleges in collaboration with the Water Resources Center and Minnesota Supercomputing Institute. ArcGIS hosting and application development have been provided by U-Spatial.
Comments, questions, or suggestions to improve the LakeBrowser are welcome. Please complete the feedback form or email Leif Olmanson (olman002@umn.edu).
Acknowledgments. Our research and development of the LakeBrowser has been supported by the University of Minnesota and state and federal agencies.
Vector and raster data available for download on the Remote Sensing and Geospatial Analysis Laboratory Data List are listed below.
This GIS data set includes water clarity measurements from Landsat imagery, primarily Thematic Mapper and Enhanced Thematic Mapper Plus, for Minnesota lakes larger than eight hectares in surface area. It includes data on more than 10,500 lakes at five-year intervals from 1975–2008. Only 2008 is displayed.
This GIS data set includes water clarity measurements assembled from Landsat imagery, primarily Thematic Mapper and Enhanced Thematic Mapper Plus, for Minnesota lakes and bodies of water.
Recent, lake clarity, chlorophyll and CDOM data are also available and can be accessed for geospatial analysis with other data layers through the GEMS Informatics Exchange.
Who should you contact about concerns and questions you may have about your lake? There are many overlapping agencies at the local, regional, and state levels so who would be the best to contact about your lake may take some research.
The Minnesota Pollution Control Agency (MPCA) is the state lake water quality authority and can be contacted via the MPCA website or by phone at 651-296-6300.
The Minnesota Department of Natural Resources (DNR) is the state authority for water levels and fisheries.
Watershed districts do not cover the entire state but are a good local resource if your lake falls within one. These are special-purpose units of government that work to solve and prevent water-related problems. The boundaries of each district follow those of a natural watershed and consist of land in which all water flows to one outlet. The districts are usually named after that watershed. See What is a watershed district? from the Minnesota Association of Watershed districts for more information.
Another local resource are Soil Water Conservation Districts (SWCDs) which are found throughout the state. SWCDs are local units of government that manage and direct natural resource management programs at the local level. Districts work in both urban and rural settings, with landowners and with other units of government, to carry out a program for the conservation, use, and development of soil, water, and related resources. The Minnesota Association of SWCDs maintains a list of SWCDs websites. To learn more about SWCDs see What is an SWCD?
Lake associations are a great way to find out more about your lake and allows you to get involved with lake-specific projects. Find your lake association on the Minnesota Lakes & Rivers Advocates website.
In addition to data created at the University of Minnesota, the following geospatial datasets were used to summarize water quality by enumeration unit (state, county, ecoregion, watershed) and, for NLCD, to display land cover in Minnesota.
Some of the vector and raster data sources used in this application are available for download from the Remote Sensing and Geospatial Analysis Laboratory Data List and are listed below.
Lake Polygons: 12,193. Note, not all lakes are classified due to clouds, aquatic vegetation or too few pixels.
Land cover is taken from the National Land Cover Database (2016) (NLCD). Note that Lake Superior is excluded from the figures below.
Level 1 Class (General) | % Level 1 Class | Level 2 Class (Detailed) | % Level 2 Class |
---|---|---|---|
Water | Open Water | ||
Developed | Developed, Open Space | ||
Developed, Low Intensity | |||
Developed, Medium Intensity | |||
Developed, High Intensity | |||
Barren | Barren Land (Rock/Sand/Clay) | ||
Forest | Deciduous Forest | ||
Evergreen Forest | |||
Mixed Forest | |||
Shrubland | Shrub/Scrub | ||
Herbaceous | Grassland/ | ||
Planted/ | Pasture/Hay | ||
Cultivated Crops | |||
Wetlands | Woody Wetlands | ||
Emergent Herbaceous Wetlands |
Lake Polygons in County: n/a. Note, not all lakes are classified due to clouds, aquatic vegetation or too few pixels.
Land cover is taken from the National Land Cover Database (2016) (NLCD). Note that Lake Superior is excluded from the figures below.
Level 1 Class (General) | % Level 1 Class | Level 2 Class (Detailed) | % Level 2 Class |
---|---|---|---|
Water | Open Water | ||
Developed | Developed, Open Space | ||
Developed, Low Intensity | |||
Developed, Medium Intensity | |||
Developed, High Intensity | |||
Barren | Barren Land (Rock/Sand/Clay) | ||
Forest | Deciduous Forest | ||
Evergreen Forest | |||
Mixed Forest | |||
Shrubland | Shrub/Scrub | ||
Herbaceous | Grassland/ | ||
Planted/ | Pasture/Hay | ||
Cultivated Crops | |||
Wetlands | Woody Wetlands | ||
Emergent Herbaceous Wetlands |
Lake Polygons in Ecoregion: n/a. Note, not all lakes are classified due to clouds, aquatic vegetation or too few pixels.
Land cover is taken from the National Land Cover Database (2016) (NLCD). Note that Lake Superior is excluded from the figures below.
Level 1 Class (General) | % Level 1 Class | Level 2 Class (Detailed) | % Level 2 Class |
---|---|---|---|
Water | Open Water | ||
Developed | Developed, Open Space | ||
Developed, Low Intensity | |||
Developed, Medium Intensity | |||
Developed, High Intensity | |||
Barren | Barren Land (Rock/Sand/Clay) | ||
Forest | Deciduous Forest | ||
Evergreen Forest | |||
Mixed Forest | |||
Shrubland | Shrub/Scrub | ||
Herbaceous | Grassland/ | ||
Planted/ | Pasture/Hay | ||
Cultivated Crops | |||
Wetlands | Woody Wetlands | ||
Emergent Herbaceous Wetlands |
Lake Polygons in Watershed: n/a. Note, not all lakes are classified due to clouds, aquatic vegetation or too few pixels.
Land cover is taken from the National Land Cover Database (2016) (NLCD). Note that Lake Superior is excluded from the figures below.
Level 1 Class (General) | % Level 1 Class | Level 2 Class (Detailed) | % Level 2 Class |
---|---|---|---|
Water | Open Water | ||
Developed | Developed, Open Space | ||
Developed, Low Intensity | |||
Developed, Medium Intensity | |||
Developed, High Intensity | |||
Barren | Barren Land (Rock/Sand/Clay) | ||
Forest | Deciduous Forest | ||
Evergreen Forest | |||
Mixed Forest | |||
Shrubland | Shrub/Scrub | ||
Herbaceous | Grassland/ | ||
Planted/ | Pasture/Hay | ||
Cultivated Crops | |||
Wetlands | Woody Wetlands | ||
Emergent Herbaceous Wetlands |
The seasonal means for the years 2017–2021 are calculated using values from July 20 through September 20.
Date | Clarity (meters) | Chlorophyll a (µg/L) | CDOM (a440m-1) |
---|
Average summertime (June–September) clarity values calculated from 2018 through 2020 clarity are compared against the values for other lakes throughout the state, as well as county, ecoregion, and watershed (HUC4 and HUC8). Higher percentile values indicate that a lake has greater average clarity than other lakes in the region, e.g. a lake in the 95th percentile in its county has better average clarity than 95% of the lakes in the county. Note that lakes that are not ranked lacked enough measurements to calculate the summertime averages and some lakes may appear as being in the 100th percentile due to rounding.
Unit Level | Unit Name/ID | Percentile |
---|
Chlorophyll a is measured in micrograms per liter (µg/L). The seasonal means for the years 2017—2021 are calculated using values from July 20 through September 20. Learn more about Chlorophyll a.
Colored dissolved organic matter (CDOM) is measured as the light absorption coefficient at 440 nm (a440) and has units of reciprocal meters (m-1). The seasonal means for the years 2017—2021 are calculated using values from July 20 through September 20. Learn more about CDOM
Land cover is calculated for an area within 1000' of the basin (this is considered shoreland) that includes the selected lake feature. Note that the Minnesota LakeBrowser splits some lakes into components. Values are determined using the National Land Cover Database (2016) (NLCD). Additionally, open water within 1000' of the basin is excluded as shorelines change over time. Note that unclassified land cover is common for lakes near the Canadian border as the NLCD does not extend into Canada.
In the image below the lake appears as solid blue and dark lines indicate the shoreland buffer.
Level 1 Class (General) | % Level 1 Class | Level 2 Class (Detailed) | % Level 2 Class |
---|---|---|---|
Developed | Developed, Open Space | ||
Developed, Low Intensity | |||
Developed, Medium Intensity | |||
Developed, High Intensity | |||
Barren | Barren Land (Rock/Sand/Clay) | ||
Forest | Deciduous Forest | ||
Evergreen Forest | |||
Mixed Forest | |||
Shrubland | Shrub/Scrub | ||
Herbaceous | Grassland/ | ||
Planted/ | Pasture/Hay | ||
Cultivated Crops | |||
Wetlands | Woody Wetlands | ||
Emergent Herbaceous Wetlands | |||
Unclassified | Unclassified |