Keeping It Clean: 175,800 pounds of algae prevented

Storm sewers in city and suburban streets flow directly into lakes and rivers.  Leaves, grass clippings and other organic debris we all often see along curbs and clogging storm drains contain phosphorus, nitrogen and sediment, which are all significant sources of water pollution. These pollutants, especially phosphorus, cause excess algae growth that reduce oxygen in the water, crowd out native plants, kill fish and other organisms and seriously degrade recreational opportunities for citizens.

This organic debris especially tends to pile up along street boulevards in fall when trees are dropping leaves. Its removal is important to helping prevent excess nutrients and algae in our lakes and rivers.  Spring cleaning is important too. Leaves and other debris are not able to break down into frozen ground, so late fall or early spring rains (or snow melts) can move these materials rapidly over land and into waters.

To clean up these pollution sources and to prevent them from getting into lakes and rivers, the Freshwater Society and Friends of the Minnesota Valley developed a community program to help citizens “battle the algae problem” during the months of October and April when nutrient sources are high. The program is called Community Clean-ups for Water Quality.

These clean-ups are local projects that can significantly reduce the phosphorus and other pollutants flowing into lakes and rivers by removing leaves and organic debris from city streets. Any group — scouts, school classes, church committees, service organizations, or a group of neighbors — can participate. Volunteers rake, sweep and bag leaves, dirt and debris in city streets, reducing the amount flowing into lakes and rivers through storm drains.

Carver County had a number of organizations participating in Community Clean-ups for Water Quality this fall.  On Oct. 13, thousands of Girl Scouts of America (GSA) around the state worked to clean up streets as part of the GSA’s Centennial Day of Service.  Their goal is to remove 20,000 pounds of phosphorus, prevent 10 million pounds of algae growth and save $6 million in clean-up costs through a one-day effort.

Girl scouts all over Minnesota and Wisconsin spent the day raking leaves and grass from storm drain surfaces and public areas, distributing door hangers in neighborhoods to raise awareness, and marking storm drains with an “Only Rain Down the Storm Drain” message. For every five bags of leaves removed, that prevents 100 pounds of algae from being formed in lakes and rivers.  They’ll have a lasting impact on water quality in their local neighborhoods. Participating Carver County groups included:
• The West Carver Service Unit of the River Valley Council (Cologne, Norwood Young America and Hamburg). Their efforts focused on NYA where they collected over 459 bags of leaves, distributed over 200 educational door hangers and marked 13 storm drains.
• Watertown Mayer Girl Scouts (pictured above) with a total of 86 volunteers removed leaves from two Watertown Parks and also volunteered time to help six elderly residents rake their lawns. They collected 186 bags of leaves and distributed 150 door hangers
• Waconia Girl Scouts Troop 170 cleaned up 191 bags from the streets of downtown Waconia.

In addition, three classes of students from Waconia High School participated in these clean ups on Oct. 15 and 16, cleaning streets in Waconia’s neighborhoods. In total, the classes removed 43 bags of leaves from streets, preventing 430 lbs of phosphorus from entering into Lake Waconia and Lake Burandt.

In total, the groups removed 879 bags, which will help prevent the growth of 175,800 pounds of algae in our lakes and rivers! Many thanks to all participants and their dedicated efforts towards improving water quality in Carver County! To learn more about the Girl Scouts Centennial Day of Service, visit For Community Clean-ups for Water Quality, visit

Madeline Seveland is the Education Coordinator for the Carver County Water Management Department. Her column is a monthly feature of the Carver County News.