Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Tyler Dufault makes this connection here…

The article “Rooftop Agriculture Offers Urban Storm Water Solution” was reported on Thursday August 14, 2012 by the American Society of Civil Engineers magazine.  The article relates to the WRE domain of hydrology, specifically, the quality and management of storm water in urban settings. The article describes how a $6 million dollar grant from the New York City department of environmental protection, will be used to build rooftop agriculture, as well as other green infrastructure, to divert storm water from the city’s sewers. It goes on to explain that the ultimate goal of the plan is to develop infrastructure that will be able to capture the first inch of rainfall on 10 percent of New York City’s impervious surfaces with the prediction that by 2030, approximately 1.5 billion gallons of precipitation will be diverted from sewers, significantly reducing overflows. Through an engineering lens, the article accurately claims that green infrastructure, like green roofs and permeable surfaces, will help with retaining and diverting storm water.  There is a concern about whether or not aging buildings in New York will even be able to support having agriculture and other green infrastructure atop buildings. Because of this serious safety issue, it is required for applicants seeking grant money to first have their building inspected by a professional engineer or licensed architect. As an alternative to rooftop farms, hydroponic greenhouse farms can reduce the load applied to buildings while providing similar absorption and retention benefits. Already in the city there are at least 6 roof top operations with the largest farm residing in Brooklyn. The 40,000 square foot farm was awarded the grant due to its predicted capacity to retain around one million gallons of precipitation. The article mentioned certain issues associated with storm water management but failed to describe the magnitude of the problems associated with sewer overflows and flooding.

The broader social context of this article is that it is a practical implementation of green technology by a major entity. This plan can be a source of motivation and a template for other cities looking to use sustainable techniques to solve engineering problems. In addition to the primary goal of storm water management, roof top farms will also help to mitigate a slew of other poor urban conditions, like noise and air pollution as well as reduce street congestion by providing locally grown food. In an economic context, locally grown food is beneficial to the city by not removing capital from the area.


Figure 1: Brooklyn Grange Farm


Novelli, Lynn (August 14, 2012). “Rooftop Agriculture Offers Urban Storm Water Solution”       American Society of Civil Engineers. Retrieved from,    http://www.asce.org/CEMagazine/ArticleNs.aspx?id=25769810838

“Mayor Bloomberg tours New York’s largest rooftop farm, part of the city’s innovative program to improve water quality.” (August 2, 2012). Retrieved fromhttp://www.nyc.gov/portal/site/nycgov/