Evaluation of leaf removal as a means to reduce nutrient concentrations and loads in urban stormwater

Science of the Total Environment



While the sources of nutrients to urban stormwater are many, the primary contributor is often organic detritus, especially in areas with dense overhead tree canopy. One way to remove organic detritus before it becomes entrained in runoff is to implement a city-wide leaf collection and street cleaning program. Improving our knowledge of the potential reduction of nutrients to stormwater through removal of leaves and other organic detritus on streets could help tailor more targeted municipal leaf collection programs. This study characterized an upper ideal limit in reductions of total and dissolved forms of phosphorus and nitrogen in stormwater through implementation of a municipal leaf collection and street cleaning program in Madison, WI, USA. Additional measures were taken to remove leaf litter from street surfaces prior to precipitation events.

Loads of total and dissolved phosphorus were reduced by 84 and 83% (p < 0.05), and total and dissolved nitrogen by 74 and 71% (p < 0.05) with an active leaf removal program. Without leaf removal, 56% of the annual total phosphorus yield (winter excluded) was due to leaf litter in the fall compared to 16% with leaf removal. Despite significant reductions in load, total nitrogen showed only minor changes in fall yields without and with leaf removal at 19 and 16%, respectively. The majority of nutrient concentrations were in the dissolved fraction making source control through leaf removal one of the few treatment options available to environmental managers when reducing the amount of dissolved nutrients in stormwater runoff. Subsequently, the efficiency, frequency, and timing of leaf removal and street cleaning are the primary factors to consider when developing a leaf management program.


Study Area

Publication type Article
Publication Subtype Journal Article
Title Evaluation of leaf removal as a means to reduce nutrient concentrations and loads in urban stormwater
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2016.07.003
Volume 571
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) Wisconsin Water Science Center
Description 10 p.
First page 124
Last page 133
Country United States
State Wisconsin
City Madison
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details