The conversation about storm-water run-off in metropolitan areas is becoming an increasingly important issue – especially for major cities such as New York. According to another article, NYC is progressing in the right direction here with an increase in investment in “green” architecture, such as more porous sidewalks and green roofs to collect water instead of investing a higher percentage in “gray” infrastructure. I would be really curious to see if there are any cost and financial data published about the two different approaches. If it is the case that the cost of the gray infrastructure is cheaper in the short-term (that actually might not be the case here with this unique example, given the high costs of underground construction projects, and earth moving equipment vs. less invasive approaches such as green roofs), the city would do well by touting the secondary benefits that come with a greener approach – such as creating more livable spaces, shade, decreasing the heat island effect. The small, distributed nature of these changes would seem harder to quantify, or at least compare with the gray infrastructure, so I would love to see metrics and goals on what makes success here.