Autumn leaf cleanup
The timely removal of leaf litter can reduce harmful phosphorus concentrations in stormwater by over 80 percent in Madison, Wisconsin.
Autumn leaf litter contributes a significant amount of phosphorus to urban stormwater, which then runs off into waterways and lakes. Excessive amounts of nutrients like phosphorus and nitrogen can cause eutrophication, or the depletion of oxygen in water, resulting in death of aquatic animals like fish. A USGS-led study found that without removal, leaf litter and other organic debris in the fall contributed 56 percent of the annual total phosphorus load in urban stormwater compared to only 16 percent when streets were cleared of leaves prior to a rain event.