As summer comes to an end and days of water fun are over, it’s easy to forget about our lakes. A leaf management study conducted by the U.S. Geological Survey (USGS) suggests that fall is a crucial time of the year to take action.
The leaf management study took place here in Dane County. The study concluded that in the fall, keeping leaf litter off the streets before rainfalls can reduce the amount of phosphorus in city stormwater by 80% compared to no leaf removal. According to USGS Hydrologist Bill Selbig, “In some areas, more than 50% of the annual amount of phosphorus in urban stormwater can come from leaves in the street.” When it rains, stormwater flows through the leaf piles in the streets making a “leaf tea”. This “leaf tea” then travels through storm sewers, making its way to our lakes, rivers, and streams. Too much phosphorus can fuel harmful algae blooms, cause low oxygen levels and green murky waters that can harm the animals living there and make it difficult to enjoy the lakes.
Dane County’s Leaf-Free Streets for Clean Waters program aims to inform neighborhoods about the environmental dangers of leaf-littered streets and encourage clean-up efforts. Large trees that border roads are constantly dropping leaves into the street, where they are left until an incoming rainstorm makes “leaf tea” out of them. This project urges homeowners in areas with heavy tree cover to keep streets leaf-free this fall by properly managing leaves that drop on their property and actively removing street leaves in front of their home before the rain.
In order to protect our waters, we all need to be more vigilant to keep streets leaf-free. You can sign up for the free Leaf-free Streets Rain Alert service that sends email or text reminders when it’s time to remove street leaves.
To learn more or to sign up for Leaf-free Streets Rain Alerts visit: