Runoff from typical urban and suburban landscapes may contain significant levels of nitrogen, phosphorus, and a broad spectrum of various pesticides (mainly herbicides and insecticides) due to excessive application rates of these chemicals and high irrigation requirements of most commonly used landscape plant species. Preliminary water quality data (runoff) from a comparative study of 20 microwatersheds using 4 different levels of maintenance, show reductions in these types of pollutants in runoff for microwatersheds planted to resource efficient plants. Utilization of plants indigenous to an ecoregion (and other resource efficient plants) in landscape design and management allows considerable reduction in inputs from fertilizer, water, and pesticides. This results in lower pollutant concentrations in runoff and is estimated to result in lower total pollutant loadings from such systems. Installation of native or resource efficient plants in new developments (commercial and residential) and replacement of existing landscapes with these plants as older plants die or neighborhoods are updated could provide cities and suburban areas with a cost-effective, low-maintenance, and aesthetically-pleasing pollution control technology. Data from the comparative study should provide municipalities charged with meeting the new requirements of the National Pollutant Elimination Discharge System with a way to compare the pollution prevention effectiveness of resource-efficient landscapes with more traditional structural urban runoff controls.
