Increasing urbanization has resulted in a large proportion of land covered by impervious surfaces (parking lots, building rooftops, etc.), which accumulates debris, sediments and other pollutants. Ultimately, this runoff ends up in local streams, or into the urban drainage system where it mixes with wastewater. The use of green infrastructure such as porous pavements, bioswales, vegetated roofs, etc. filters nutrients and reduces peak flow.

WRI publications

2014 Summer Intern Project: Analysis of New York’s sewage discharge reports

In 2012, New York State enacted the Sewage Pollution Right to Know (SPRtK) Act. The law requires that discharges of untreated and partially treated sewage discharges be reported by publicly owned treatment works and sewer systems within two hours of discovery to DEC and within four hours of discovery to the public and adjoining municipalities. This project analyzed sewage spill reports throughout New York over the period of one year to determine spatial and temporal patterns. Approximately 87% of the reports were recorded in a single county. Weather conditions were listed as the primary reason for the SSO event in a large majority of reports. An analysis of discharge reports by month seemed to confirm this observation – the wetter months of June and October recorded higher than normal number of reports. Aggregation of reports by municipality indicates that villages are more likely to record spills than towns and cities. Low density population, older treatment plants and lower incomes were associated with higher number of reports.

Funded projects

Mary Ann Cunningham, Vassar College: Wetland mitigation of infill development: an evaluation of green infrastructure effectiveness in a near-urban setting [read the report].

The main aim of this project was to study impacts of “green infrastructure” for stormwater management, particularly constructed wetlands and restoration of a riparian corridor, in an urbanized environment. The study focuses on the Fonteynkill, an urbanized tributary of the Hudson River that drains portions of the City of Poughkeepsie and of the Vassar College campus. One of the central questions addressed by this research is how much green infrastructure is needed to reduce impacts of urbanized tributaries on water quality in the Hudson River. Using WRI funding, one year of monitoring was performed before installation of the planned stormwater management wetland. Monitoring has resulted in a better understanding of the various aspects of the hydrological and ecological functions of this urban stream, the extent and geological foundations of its watershed, and its functions as urban riparian habitat.

Katherine Meierdiercks, Siena College: Watershed-scale evaluation of stormwater management practices through geospatial, field, and modeling analyses.


The processes that control flooding in urban watersheds are complex and not well understood. Green Infrastructure (GI) practices such as green roofs, porous pavement, and rain gardens, have been shown to effectively reduce runoff at the lot-scale, but much less is known about their effectiveness at the watershed-scale. These issues will be examined using the Kromma Kill Watershed, a tributary to the Hudson River, as a study area. The objectives of this project include determination of the characteristic response of the Kromma Kill and its subwatersheds through observations of rainfall and runoff, GIS analyses to quantify the geomorphic properties of the Kromma Kill and subwatersheds, and to analyze the impacts of various watershed management strategies using a stormwater model of the Kromma Kill.