Urban stormwater infrastructure:
Water quality, nutrient cycling, and greenhouse gas emissions in road ditches
Wherever there are roads, there are often road ditches to help route storm runoff
away and reduce flooding. While this is good for human safety, this may also quickly route
pollutants toward streams without much opportunity for taking advantage of natural biological
processes that could aid in removing excess nutrients.
This research addresses the role of road ditches in influencing
water quality and nutrient cycling in a suburban watershed located in Tompkins County, NY.
The primary stream is being gaged and periodically sampled for chloride and a suite
of nutrients in two locations. Grassed road ditches between these two locations
are being sampled during storm events for water quality. Additionally, we are
studying nutrient cycling processes that occur in these grassy ditches. With influxes
of nutrient-laden water, there may be microbial processes such as denitrification helping
to remove nitrate. However, some of these microbial processes could also generate
greenhouse gases, such as methane and nitrous oxide, and thus we are also measuring these
Grassed road ditch
Soil gas sampling
Overall, we hope that this research will help us better understand how road ditches influence
downstream water quality in this watershed. It will also show us how microbial processes in the
soil of grassed ditches may aid in taking up excess nutrients in stormwater, as well as whether these processes are
serving as a source of greenhouse gases.
In general, all of this information can help inform future management of stormwater in developed landscapes.
This project is led by PhD student Lauren McPhillips, under the guidance of Professor
Todd Walter and with assistance from undergraduate student Peri Gerson
This work is funded by the NYS Water
Resources Institute and the Cornell Engineering
Learning Initiatives Undergraduate
Research Grant Program
If you have any questions about this
project, please contact Lauren
Last updated June 2014