Local lake grades reflect little change

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The Minnehaha Creek Watershed District (MCWD) has released the 2014 Lake Grades, an annual snapshot of the condition of the lakes and bays within the District. The grade for Lake Hiawatha stayed the same at B-, while the grade for Lake Nokomis went from C+ to B-. The 2014 grade is the first time that Nokomis went out of the “C’s” since the test was established in 2005. In the same period, Hiawatha varied wildly from a D+ in 2007 and 2010, to B- in 05, 11, 13, and 14.

The grades are based on three standard water quality parameters: water clarity,  algae growth, and nutrients. Staff collect data from May to September to calculate the grades, which allow the District to compare and track the health of lakes within its boundaries. Using collected data, District staff average the scores of the three parameters to determine a lake grade, on a curved scale from A to F.  A “C” grade is typical of lakes in the seven-county metropolitan area.

By only measuring water clarity, algae growth, and nutrients, we only have a partial view of a lake’s health.  MCWD is developing a new, more holistic grading system called E-Grade to promote greater understanding of the overall health of lakes, streams and wetlands in the District. MCWD will be phasing in this new system across the District over the next several years and plans to release the first group of these reports in 2017

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