Two of Chanhassen’s treasured natural spaces have reached an important water quality milestone.

Lake Riley and Rice Marsh Lake have been removed from the Minnesota Pollution Control Agency’s impaired waters list after years of work by the Riley Purgatory Bluff Creek Watershed District and its partners. The list, required under the federal Clean Water Act, identifies waters that do not meet state water quality standards.

Both lakes had been listed because of excess nutrients, including phosphorus, which can contribute to algae growth and reduced water clarity. Recent monitoring shows both lakes now meet state water quality standards.

Water quality improvements were supported by several projects in the watershed, including stormwater treatment, gully repair, prairie plantings, impervious surface removal, alum treatments and upstream work in the Lake Susan watershed. These efforts helped reduce nutrient loading and improve water clarity over time.

The City of Chanhassen thanks the Riley Purgatory Bluff Creek Watershed District and all project partners for their continued work to protect and improve the lakes, creeks, wetlands and natural spaces that help make Chanhassen a community for life. While this is an important milestone, the work continues through ongoing monitoring, maintenance and water quality improvement efforts to help keep these lakes healthy for years to come.