Every year right around now, falling leaves and the final lawn mowing of the year send a tidal wave of organic materials into the storm sewer system. While it may seem as natural as the changing of the seasons, it is a growing threat for our lakes and rivers.

As they reach the watershed, the leaves and grass clippings break down, releasing the chemical remnants of the fertilizers and herbicides into the watershed. Phosphorous from yard waste can cause increased algae growth that, in turn, reduces the oxygen level in the water. With less oxygen, native plants and animals are negatively impacted, as are recreational uses for the water. Working with friends at the Freshwater Society, the Girl Scouts have decided to attack the issue head on by making it the focus of their Centennial Day of Service. On this coming Saturday, nearly 20,000 Girl Scouts, leaders, and community volunteers are already registered to fan out across the state and work on this important issue. The day will include not only collection of leaves and grass clippings that otherwise would have ended up in the storm sewer, but also some groups will be marking storm sewers to remind people to prevent organic materials from being dumped there. And there will be public education going on in communities sharing the message about the importance of keeping potentially harmful waste out of the water. Volunteers are still needed, and you need not be a current or former Girl Scout to join the cause. For more information on the project, or to see how you can help, check out the event's website at: http://www.gsrv100.org/centennial_day_of_service/