Many area lakes showed significant improvement in water clarity last year, but it was likely due to the dry summer and less runoff the Minnehaha Creek Watershed District said.
Two-thirds of metro area lakes showed improvement on an A-F scale.
Algae growth is what causes lakes to have poor clarity. Algae are largely fed by phosphorus that is carried into lakes by runoff.
In 2007, lawn fertilizer that contains phosphorous was banned in Minnesota.
Metro lakes have been showing improvement over the past decade.
Sources:
http://www.startribune.com/local/west/43494422.html?elr=KArks:DCiUBDia_nDaycUiD3aPc:_Yyc:aUU
http://www.minnehahacreek.org/