In 2018, Sweet Water formed a Leaf Management Work Group to study the problem of phosphorus entering our waterways from the urban leaf litter that is a result of annual autumn leaf loss. This group hopes to recommend feasible steps to address this problem that will likely follow a model suggested by the Water Quality Improvement Plan Options Paper. These recommendations will help our area attain national and state water quality standards, reduce algae blooms in near-shore Lake Michigan, protect human health, and remove our waterways from the Impaired Waters List.
Although new leaves have only just started to bud on trees in southeastern Wisconsin, Sweet Water’s Leaf Management Work Group (LMWG) is already thinking about when these leaves will mature and fall to the ground in six months. These leaves and their fragments will become urban leaf litter in municipalities around the region. This litter is a top contributor of phosphorus from urban areas to waterways, and 2016 USGS study out of Madison, WI found that it can contribute 60% of the annual P load when left un-collected. This excess of phosphorus leads to issues such as algal blooms and in near-shore Lake Michigan, which in turn leads to decreased dissolved oxygen available to fish and other aquatic species. Blooms have also led to beach closures in the region when they reach levels that are hazardous to human health.
The Leaf Management Work Group intends to address this issue by following a model for convening a municipal learning group suggested by the recently released Water Quality Improvement Plan (WQIP) Options Paper. The fully developed WQIP will create strategies to ensure water quality plans are put into action in an efficient way in the region while also achieving important co-benefits, and the Options Paper contains preliminary suggestions for these strategies. To learn more about the WQIP and to review the Options Paper and summarized version, click here! The LMWG will follow strategy 3 of this paper, entitled Supporting Desired Management Efforts.
Under this strategy, the working group will convene a learning group of municipal representatives from around the basin. Together, these representatives will review their current leaf collection and management practices and try to find solutions to common obstacles through lesson sharing and case studies. The exact format of these sessions will be informed by the knowledge and research of the LMWG and Sweet Water staff. It is anticipated that the sessions will be facilitated by Sweet Water staff, drawing in relevant local and state experts and practitioners to build and share learning. l. This approach will identify cost-effective, efficient, and accessible ways for municipalities to improve their practices based on commonalities between all communities involved as well as the unique situations of different areas .
Municipal interest in this work is expected to be motivated, in part, by phosphorus standards set by recently approved Total Maximum Daily Loads (TMDLs) for the Milwaukee River Basin. A TMDL is the amount of a pollutant a waterbody can receive and still meet water quality standards. The TMDL is expected to focus and increase the interest and resources applied to this problem, as it will provide regulatory leverage to this problem. While most municipalities already have some sort of leaf management practices, past and current practices have been shaped by a number of drivers including neighborhood aesthetics and lawn maintenance concerns. The Leaf Management Learning Group will help municipal officials understand how urban leaf litter affects the water quality of local streams, rivers, and Lake Michigan, and how they might adapt their leaf management practices to protect these waterways, in line with TMDL reduction targets for phosphorus.
If you are interested in joining the Leaf Management Working Group, please contact Kristin Schoenecker at kristin@swwtwater.org. We look forward to continuing this work and sharing our findings and recommendations in coming months--be sure to stay tuned for updates!
