for the 100-year event to $21,000 for the 2-year event.106 These avoided damages are highly dependent on physical and economic factors in a given watersheds and need to be estimated using these site-specific conditions.
Conclusion Flooding is a costly phenomenon that affects public and private properties and disrupts economic activity. These events also threaten the public welfare and place an emotional and social burden on impacted communities. Economic impacts due to flooding of all types and magnitudes are significant; however, the severity of impacts varies depending upon the type, frequency and size of the flood event. Although large flood events impacting riverine systems may lead to catastrophic damages and costs, these events occur relatively infrequently. Smaller events are generally more frequent and widespread, so although the damages tend to be smaller in scale, the higher number of events can create a greater overall economic burden on communities. The traditional approach to reducing the impacts of flooding has been to capture, convey, and release runoff with an emphasis placed on large storm events. Green infrastructure approaches that employ infiltration, evapotranspiration, rainfall capture, and other site retention techniques, capture of smaller events in an effort to restore the hydrologic function of an area as well as improve and enhance water quality. Because a significant portion of the flood losses is associated with small, frequent storms, green infrastructure is well-suited to manage these flows, and therefore, provides significant flood loss reductions on an average annual basis The literature illustrates that this type of flood control is cost-effective for small flood events, and also highlights that widespread use of green infrastructure at a watershed scale can also provide measurable flood control benefits for larger, less frequent events. On-the-ground case studies from a variety of locations across the country have also documented the effectiveness of green infrastructure to not only reduce runoff volumes and provide water quality treatment, but also to help address flooding impacts in a cost-effective manner. Add to this the many co-benefits of green infrastructure, which include improved air quality and public health, reduced heat-island effects, greater aesthetic appeal, and an enhanced dimension of flexibility and resiliency. It is clear that green infrastructure is an approach that should be considered when addressing flood impacts for all communities.
Banking on Green: A Look at How Green Infrastructure Can Save Municipalities Money and Provide Economic Benefits Community-wide
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