Evaluate Sources and Reduction Potential for Nitrogen and Phosphorus in Vegetated and Un-Vegetated Ditches

Ohio has one of the nation's largest roadway systems exceeding 121,000-miles and the Ohio Department of Transportation is responsible for ~16% (i.e., 19,470-miles) of the overall network (ODOT, 2020). In areas where right-of-way is relatively inexpensive, open channels (ditches) parallel to the road are constructed to efficiently drain the roadway and provide safe travel conditions during wet weather. They also provide for pollutant removal through sedimentation, filtration, infiltration, plant uptake, and soil processes (Winston et al. 2012). Finally, they can provide a host of other ecosystem services including carbon sequestration (Bouchard et al. 2013) and habitat (Forman et al., 1998) for species in landscapes that are highly managed (e.g. agriculture). These ditches often outfall into streams and rivers, contributing flow and transporting nutrients and other pollutants to receiving waters. The ability of ditches to function for efficient pollution control is largely dependent on the vegetation (or lack thereof) in the channel. However, most previous research on roadside ditches focuses on systems planted with turfgrass. Few studies have focused on ditches in low-lying areas which may develop (unintended) wetland conditions. These wetland ditches possess vegetation and processes which might remove nutrients more efficiently than standard turfgrass ditches. Further, ditch maintenance in both grassed and wetland ditches often requires highway technicians or contractors to "dip out" accumulated sediments to restore hydraulic capacity resulting in the complete removal of vegetation from the ditch. These denuded ditches can be subject to erosion until stabilizing vegetation takes root. The overarching goal of the proposed study is to gain a better understanding of the extent to which roadside ditches impact watershed hydrology and nutrient processing, storage, and transport. The research team also seeks to develop methods and tools that could inform ditch maintenance decisions with water quality as a consideration. To achieve these goals, the team proposes the following specific objectives: (1) Utilize geospatial data and geographic information systems (GIS): (a) to determine the proportion of watersheds that drain through roadside ditches, and (b) to identify candidate watersheds and sites that span a range of land uses (i.e. forested, agricultural, and residential or developed) for further sampling, (2) Quantify the volume and physical/chemical properties of sediments deposited in ditches throughout the state and across a gradient of land use types to establish sediment and nutrient accumulation rates in ditches, (3) Evaluate a practical and low-cost method to determine if sediments captured in roadside ditches represent an environmental risk for nutrient release, (4) Conduct upstream-downstream water quality sampling in vegetated and unvegetated ditches, and (5) Assess the potential for beneficial reuse of dredged ditch sediments as a soil amendment and fertilizer alternative in agricultural fields.


  • English


  • Status: Active
  • Funding: $100000
  • Contract Numbers:




  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Managing Organizations:

    Ohio Department of Transportation

    Research Program
    1980 West Broad Street
    Columbus, OH  United States  43223
  • Project Managers:

    Lucas, Michelle

  • Performing Organizations:

    The Ohio State University

    2036 Neil Avenue
    Columbus, OH  United States  43210
  • Principal Investigators:

    Witter, Jonathan

  • Start Date: 20230217
  • Expected Completion Date: 20241217
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01872790
  • Record Type: Research project
  • Source Agency: Ohio Department of Transportation
  • Contract Numbers: 38588, 118512, 136692
  • Files: RIP, STATEDOT
  • Created Date: Feb 9 2023 9:13AM