Leaf accumulation on Piper Drive on Madison’s west side, which was an area the Leaf Collection Study covered in 2016.
The USGS Study was conducted from 2012-2018. It looked at how the City and community can improve water quality by changing the leaf collection program, the impacts of collecting leaves regularly, how bagging leaves impacts phosphorus levels in our lakes and how leaf collection impacts spring buds and blossoms and fall leaves.
The results of the study will be important to both
federal and state agencies who regulate the amount of pollutants (phosphorus
and nitrogen) that reach our lakes and streams. In addition, municipalities will
have a better idea of the importance of a sound leaf collection policy.
Four neighborhoods were asked to alter leaf management practices each year of the study to measure the impacts of leaves on water quality.
- Increased leaf removal frequency
- Reduced phosphorus transport
- Current approach: 40 percent fall phosphorus reduction
- Potential for 80 percent fall phosphorus reduction
- Street leaves were most important to focus on
- Leaves only matter when there is rain
- Crews target the heavy canopy areas
- Resident actions were critical to success
- Mulching of leaves in place is a triple win
- Raking leaves from streets before rain is key
- Parking adjustments may speed up removal
The 4-year scientific monitoring study began in fall 2012 thanks to
a generous funding opportunity from the Fund for Lake Michigan and Dane County.
The storm outfalls, where each neighborhood drains to (see maps to right), had monitoring equipment installed by the USGS and a bag was mounted on the end of the pipe to collect leaves and debris, which will be weighed and analyzed off-site. The City checked the status of the bags regularly and switched full bags out with empty ones as needed.
At least 90 residents fell within the boundaries of the different study areas. The City asked them for voluntary participation.
Year 1 (2012) established a statistical relationship between the four different
neighborhoods. The City provided minimal leaf collection in these areas, which means one leaf collection/ sweeping in mid- to late-November.
From 2013-2014, two of the neighborhoods continued
with limited leaf collection to answer the question, ”What if we provided minimal leaf collection?" The other two
neighborhoods received the City's current policy in 2013, then was encouraged to bag leaves with compostable bags the City provided, along with increased street sweeping, in 2014.
In 2015, the City continued to have two control neighborhoods that had one collection in the late fall and an advanced collection strategy in the other two neighborhoods. In 2016, the City switched the control and advanced collection strategy neighborhoods. Data and results in addition to the takeaways above are posted to the USGS website, just click on the neighborhoods below:
S Kenosha Dr (East)
Questions? Contact Greg Fries at (608) 267-1199.