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Volunteer water monitors collect valuable data used by agencies and organizations across the state to protect and manage Minnesota’s waters.

A total of 1,367 volunteers collected data during the most recent monitoring season. The number of lake volunteers has decreased slightly over the past few years, with the number of stream monitoring volunteers remaining fairly stable since 2011.

13221: VMP local site reports
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Local site reports

Reports summarize data gathered at each volunteer monitoring location, compare it to other waterbodies in the local watershed, and highlight changes in clarity over time.

Water clarity data and trends

Water clarity is the primary measurement taken by our volunteers. Water clarity readings for lakes and streams are grouped into ranges, from poor to excellent.

These categories serve as benchmarks for comparing readings across lakes and streams in Minnesota. For the most recent monitoring season, more lakes were in the “Excellent” category than in previous years. The largest percentage of stream sites were in the “Very good” category, similar to previous years. A higher percentage of lakes fall into the “Excellent” category than streams, while more streams were in the “Fair” and “Poor” categories.

One of the uses for water clarity data is to determine water quality trends over time. To analyze water clarity data on a lake or stream, a minimum of eight years and 50 points of data collected between May and September is needed. Water clarity may vary from year to year in response to changes in rainfall amounts, watershed runoff and many other factors. Using datasets with more than eight years of data helps account for these factors.