Effects of Stream Restoration on Nitrogen Removal and Transformation in Urban Watersheds: Lessons from Minebank Run, Baltimore, Maryland
Paul M. Mayer,a Shannon P. Schechter,b* Sujay S. Kaushal,c and Peter M. Groffmand
aResearch Ecologist, US Environmental Protection Agency, National Risk Management Research Laboratory, Ground Water and Ecosystems Restoration Division, Ada, OK
c Assistant Professor, Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD
d Senior Scientist, Cary Institute of Ecosystem Studies, Millbrook, NY
* Corresponding author
Stream restoration is an important green infrastructure tool that may improve water quality and protect watershed function and services. Runoff from impervious surfaces and leakage from sewage infrastructure, septic systems, agricultural ditches, and tile drains creates excess nitrogen (N) in groundwater, surface water, and coastal waters, which is detrimental to human and ecosystem health. Degraded urban streams suffer from altered hydrology and biogeochemistry that can impair a stream’s capacity to process and remove excess N in stream water. This case study of Minebank Run in Baltimore, Maryland, found factors that limit the removal of excess N in degraded streams and identified restoration and management approaches that enhance N removal. We found three stream restoration strategies that can greatly improve N removal capacity: (1) increasing hydrologic residence time, (2) increasing hydrologic connectivity between the stream channel and floodplains, and (3) increasing organic carbon availability to foster denitrification “hot spots.” The findings suggest that combining approaches—such as prioritizing nonpoint N source reductions in watersheds and integrating green infrastructure with stream and floodplain wetland restoration approaches, which reduce peak flow, increase hydrologic residence time, and supply organic matter (e.g., maintaining riparian zones)—will be the most efficient way to enhance N removal and protect ecosystem services in urban streams.
NEW! Runoff Rundown is now monthly! To read the new August 2014 issue CLICK HERE!
Read the June 2014 Watershed Science Bulletin! Click here!
The latest blog from SWEMA and Gene LeManna urges a more balanced approach of green and grey in stormwater treatment.
Need to develop an IDDE program? Read the guidance.
NEW! Two versions of the Watershed Treatment Model (WTM) released to help users estimate benefits from a wide range of stormwater runoff and pollutant removal practices. Download your FREE COPY of the WTM and User's guide.
Onancock parking lot soaks up rain for a cleaner creek. Learn More...
Other Center Websites
- Center receives EPA funding to restore Proctor Creek Watershed in Atlanta
- How to "credit" trees for runoff and pollutant load reduction
- Onancock parking lot soaks up rain for a cleaner creek
- Panelists focus on the changing, more stringent regulations for stormwater management and the new ecological stormwater era
- Center for Watershed Protection Awarded Gold-Level GuideStar Exchange Participant
- Hye Yeong Kwon Graduates from Leadership Maryland- Class of 2013
- The BUBBAs are coming!