Research Results: Nitrogen and Phosphorus Reduction in Ditches

The overarching goal of the research project was to gain a better understanding of the extent to which roadside ditches impact watershed hydrology and nutrient processing, storage, and transport. The research team was seeking to develop methods and tools that could inform ditch maintenance decisions with water quality as a consideration. To achieve these goals, the research team had the following objectives:
1) Utilize geospatial data and GIS:
a) to determine the proportion of watersheds that drain through roadside ditches
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
5) Assess the potential for beneficial reuse of dredged ditch sediments as a soil amendment and fertilizer alternative in agricultural fields